Implementation of a 4-y, high-fiber, high-fruit-and-vegetable, low-fat dietary intervention: results of dietary changes in the Polyp Prevention Trial

Processed meat, red meat, white meat, and digestive tract cancers: A two-sample Mendelian randomization study

Background

Previous observational studies suggested inconsistent insights on the associations between meat intake and the risk of digestive tract cancers (DCTs). The causal effect of meat intake on DCTs is unclear.

Methods

Two-sample Mendelian randomization (MR) was performed based on genome-wide association studies (GWAS) summary data from UK Biobank and FinnGen to evaluate the causal effect of meat intake [processed meat, red meat (pork, beef, and lamb), and white meat (poultry)] on DCTs (esophageal, stomach, liver, biliary tract, pancreatic, and colorectal cancers). The causal effects were estimated using a primary analysis that employed inverse-variance weighting (IVW) and complementary analysis that utilized MR-Egger weighted by the median. A sensitivity analysis was conducted using the Cochran Q statistic, a funnel plot, the MR-Egger intercept, and a leave-one-out approach. MR-PRESSO and Radial MR were performed to identify and remove outliers. To demonstrate direct causal effects, multivariable MR (MVMR) was applied. In addition, risk factors were introduced to explore potential mediators of the relationship between exposure and outcome.

Results

The results of the univariable MR analysis indicated that genetically proxied processed meat intake was associated with an increased risk of colorectal cancer [IVW: odds ratio (OR) = 2.12, 95% confidence interval (CI) 1.07-4.19; P = 0.031]. The causal effect is consistent in MVMR (OR = 3.85, 95% CI 1.14-13.04; P = 0.030) after controlling for the influence of other types of exposure. The body mass index and total cholesterol did not mediate the causal effects described above. There was no evidence to support the causal effects of processed meat intake on other cancers, except for colorectal cancer. Similarly, there is no causal association between red meat, white meat intake, and DCTs.

Conclusions

Our study reported that processed meat intake increases the risk of colorectal cancer rather than other DCTs. No causal relationship was observed between red and white meat intake and DCTs.

Circulating Bile Acids and Adenoma Recurrence in the Context of Adherence to a High-Fiber, High-Fruit and Vegetable, and Low-Fat Dietary Intervention

INTRODUCTION

Diet may affect bile acid (BA) metabolism and signaling. In turn, BA concentrations may be associated with cancer risk. We investigated (i) associations of BA concentrations with adenoma recurrence and (ii) the effect of a high-fiber, high-fruit and vegetable, and low-fat dietary intervention on serum BA concentrations.

METHODS

The Polyp Prevention Trial is a 4-year randomized, controlled trial that investigated the effect of a high-fiber, high-fruit and vegetable, and low-fat diet on colorectal adenoma recurrence. Among 170 participants who reported adhering to the intervention and 198 comparable control arm participants, we measured 15 BAs in baseline, year 2, and year 3 serum using targeted, quantitative liquid chromatography-tandem mass spectrometry. We estimated associations of BAs with adenoma recurrence using multivariable logistic regression and the effect of the dietary intervention on BA concentrations using repeated-measures linear mixed-effects models. In a subset (N = 65), we investigated associations of BAs with 16S rRNA gene sequenced rectal tissue microbiome characteristics.

RESULTS

Baseline total BA concentrations were positively associated with adenoma recurrence (odds ratio Q3 vs Q1 = 2.17; 95% confidence interval = 1.19-4.04; Ptrend = 0.03). Although we found no effect of the dietary intervention on BA concentrations, pretrial dietary fiber intake was inversely associated with total baseline BAs (Spearman = -0.15; PFDR = 0.02). BA concentrations were associated with potential colorectal neoplasm-related microbiome features (lower alpha diversity and higher Bacteroides abundance).

DISCUSSION

Baseline circulating BAs were positively associated with adenoma recurrence. Although the dietary intervention did not modify BA concentrations, long-term fiber intake may be associated with lower concentrations of BAs that are associated with higher risk of adenoma recurrence.

Processed Meat Consumption and the Risk of Cancer: A Critical Evaluation of the Constraints of Current Evidence from Epidemiological Studies

Based on a large volume of observational scientific studies and many summary papers, a high consumption of meat and processed meat products has been suggested to have a harmful effect on human health. These results have led guideline panels worldwide to recommend to the general population a reduced consumption of processed meat and meat products, with the overarching aim of lowering disease risk, especially of cancer. We revisited and updated the evidence base, evaluating the methodological quality and the certainty of estimates in the published systematic reviews and meta-analyses that examined the association between processed meat consumption and the risk of cancer at different sites across the body, as well as the overall risk of cancer mortality. We further explored if discrepancies in study designs and risks of bias could explain the heterogeneity observed in meta-analyses. In summary, there are severe methodological limitations to the majority of the previously published systematic reviews and meta-analyses that examined the consumption of processed meat and the risk of cancer. Many lacked the proper assessment of the methodological quality of the primary studies they included, or the literature searches did not fulfill the methodological standards needed in order to be systematic and transparent. The primary studies included in the reviews had a potential risk for the misclassification of exposure, a serious risk of bias due to confounding, a moderate to serious risk of bias due to missing data, and/or a moderate to serious risk of selection of the reported results. All these factors may have potentially led to the overestimation of the risk related to processed meat intake across all cancer outcomes. Thus, with the aim of lowering the risk of cancer, the recommendation to reduce the consumption of processed meat and meat products in the general population seems to be based on evidence that is not methodologically strong.

Maternal Serum Antioxidants in Mid Pregnancy and Risk of Preterm Delivery and Small for Gestational Age Birth: Results from a Prospective Pregnancy Cohort

Background: Preterm delivery (PTD) and poor fetal growth are major contributors to neonatal mortality and morbidity that can extend from birth onward. Although overt maternal nutrient deficiencies are associated with adverse pregnancy outcomes, such deficiencies are rare in developed countries. However, some evidence suggests that even within the normal range, higher levels of antioxidant nutrients are protective against adverse pregnancy outcomes. Materials and Methods: Using data from the prospective Pregnancy Outcomes and Community Health (POUCH) Study (n = 301 preterm; n = 246 term), we examined associations between maternal blood levels of selected antioxidants and pregnancy outcomes. Serum collected at 16-27 weeks' gestation was analyzed for carotenoids, retinol, and α- and γ-tocopherol. Using weighted polytomous regression, these nutrient concentrations were assessed in relation to (1) PTD (<37 weeks gestation) overall and grouped as spontaneous or medically indicated; and (2) small for gestational age (SGA) defined as birthweight-for-gestational age <10th percentile of a national reference population. Results: Women with total serum carotenoids in the upper quartile (Q4) had significantly lower odds of medically indicated PTD compared with women in the lower quartiles (Q1-Q3) even after adjustment for maternal characteristics (aOR = 0.4; 95% CI: 0.2-0.9). Odds ratios for SGA were consistently ≤0.5 among women with any of the serum nutrients in Q4 as compared with Q1-Q3, but final models did not reach statistical significance. Conclusion: Results support the possibility that high maternal serum antioxidants and/or the larger dietary or lifestyle pattern they represent may play a protective role in preventing adverse pregnancy outcomes.

Composition of Amino Acids in Foodstuffs for Humans and Animals

Amino acids (AAs) are the building blocks of proteins that have both structural and metabolic functions in humans and other animals. In mammals, birds, fish, and crustaceans, proteinogenic AAs are alanine, arginine, asparagine, aspartate, cysteine, glutamate, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. All animals can synthesize de novo alanine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and serine, whereas most mammals (including humans and pigs) can synthesize de novo arginine. Results of extensive research over the past three decades have shown that humans and other animals have dietary requirements for AAs that are synthesizable de novo in animal cells. Recent advances in analytical methods have allowed us to determine all proteinogenic AAs in foods consumed by humans, livestock, poultry, fish, and crustaceans. Both plant- and animal-sourced foods contain high amounts of glutamate, glutamine, aspartate, asparagine, and branched-chain AAs. Cysteine, glycine, lysine, methionine, proline, threonine, and tryptophan generally occur in low amounts in plant products but are enriched in animal products. In addition, taurine and creatine (essential for the integrity and function of tissues) are absent from plants but are abundant in meat and present in all animal-sourced foods. A combination of plant- and animal products is desirable for the healthy diets of humans and omnivorous animals. Furthermore, animal-sourced feedstuffs can be included in the diets of farm and companion animals to cost-effectively improve their growth performance, feed efficiency, and productivity, while helping to sustain the global animal agriculture (including aquaculture).

Recruitment and retention of mothers of preschoolers and school-aged children in a social media-delivered healthy eating intervention: lessons learned from a randomized controlled trial

BACKGROUND

Social media represent cost-effective platforms to advance the dissemination and uptake of health research to improve population health. However, there is limited evidence available to support researchers overcome methodological challenges related to recruitment and retention of participants in studies using social media for delivering behavior change interventions. This study aims to describe the recruitment and the retention strategies used in a randomized controlled trial (RCT) that evaluated a blog-delivered healthy eating intervention among mothers of preschoolers and school-aged children.

METHODS

Eighty-four adult mothers of children aged between two and 12 years old living in Quebec City, Quebec, Canada, were recruited between October 2015 and February 2017 using traditional methods (e.g. institutional email lists, flyers, newspapers, and word of mouth) and Facebook advertisements. Retention rates were calculated at the end of the 6-month intervention and at a 12-month follow-up assessment. Sociodemographic characteristics, Internet use behaviors and retention rates of mothers recruited through traditional methods and Facebook were compared using Wilcoxon-Mann-Whitney tests and Fisher exact tests.

RESULTS

Of the 196 mothers who responded to the recruitment call, 87 (44.4%) were eligible and 84 (42.9%) were randomized to the trial, representing a recruitment success of 76.4% (84/110) from the planned sample size target. Among those, a minority (3.6%) were recruited using Facebook. Those mothers presented similar sociodemographic characteristics to those recruited using traditional methods. Retention rates were 73.8% and 66.7% at 6 and 12 months, respectively, with similar rates between mothers recruited using Facebook and traditional methods. Various challenges associated with population retention were highlighted with lack of time being mothers' main reason for withdrawing from the study.

CONCLUSIONS

The methodological challenges experienced during the conduct of the blog-delivered healthy eating intervention allowed to draw upon several lessons regarding the recruitment process and the retention of mothers of preschoolers and school-aged children to inform future social media-delivered research. Recommendations for future research include exploring mothers' perceptions and preferences to tailor social media recruitment, ensure that interventions are delivered to them using social media platforms that are already integrated into their routine, and are providing remote outcome assessments to increase participant retention.

TRIAL REGISTRATION

Clinical Trial Protocol NCT03156803 . Registered on 17 May 2017, retrospectively registered.

Long-term effects of a healthy eating blog in mothers and children

In the context of low consumption of vegetables and fruits and milk and alternatives among Canadian mothers and children, novel strategies are needed to improve maternal and child nutrition. This study evaluated the long‐term effects of an evidence‐informed healthy eating blog on dietary intakes and food‐related behaviours of mothers and their child. The study presents a secondary outcome analysis of a randomised controlled trial in which 84 mothers (mean age of 37.6 ± 6.7 years) of 2‐ to 12‐year‐old children living in Quebec City, Canada, were randomly assigned to a dietary intervention delivered through a healthy eating blog written by a registered dietitian (RD; n = 42) or a control group (n = 42) during a period of 6 months. Dietary intakes, maternal eating behaviours, food parenting practices, and body weight were measured at baseline, 3 months, at the end of the intervention (6 months), and 6‐month post‐intervention (12 months). Differences between groups were assessed with mixed linear models. Globally, this study found no evidence of long‐term differences in mean dietary intakes in mothers exposed to the blog and their children as well as other food‐related outcomes and body weight compared with the control condition. Potential predictors of adherence to dietary recommendations in mothers and children (e.g., involvement of children in household food activities) were identified. In conclusion, a healthy eating blog written by an RD did not result in evidence of any long‐term differences in dietary intakes and food‐related behaviours in mothers and their children compared with the control condition.

Effectiveness of information technology-enabled 'SMART Eating' health promotion intervention: A cluster randomized controlled trial

BACKGROUND

Unhealthy dietary behaviour-high intake of fat, sugar, and salt, and low intake of fruits and vegetables-is a major risk factor for chronic diseases. There is a lack of evidence-based interventions to promote healthy dietary intake among Indian populations. Therefore, we tested the effectiveness of an information technology-enabled 'SMART Eating' intervention to reduce the intake of fat, sugar and salt, and to increase the intake of fruits and vegetables.

METHODS

In Chandigarh, a North Indian city, a cluster randomized controlled trial was implemented in twelve geographical clusters, based on the type of housing (i.e., LIG: Low-income group; MIG; Middle-income group, and HIG: High-income group-a proxy for socio-economic status). Computer-generated randomization was used to allocate clusters to intervention and comparison arms after pairing on the basis of socioeconomic status and geographical distance between clusters. The sample size was 366 families per arm (N = 732). One adult per family was randomly selected as an index case to measure the change in the outcomes. For behaviour change, a multi-channel communication approach was used, which included information technology-short message service (SMS), email, social networking app and 'SMART Eating' website, and interpersonal communication along with distribution of a 'SMART Eating' kit-kitchen calendar, dining table mat, and measuring spoons. The intervention was implemented at the family level over a period of six months. The comparison group received pamphlets on nutrition education. Outcome measurements were made at 0 and 6 months post-intervention at the individual level. Primary outcomes were changes in mean dietary intakes of fat, sugar, salt, and fruit and vegetables. Secondary outcomes included changes in body mass index (BMI), blood pressure, haemoglobin, fasting plasma glucose (FPG), and serum lipids. Mixed-effects linear regression models were used to determine the net change in the outcomes in the intervention group relative to the comparison group.

RESULTS

Participants' mean age was 53 years, a majority were women (76%), most were married (90%) and 51% had completed a college degree. All families had mobile phones, and more than 90% of these families had access to Internet through mobile phones. The intervention group had significant net mean changes of -12.5 g/day (p<0.001), -11.4 g/day (p<0.001), -0.5 g/day (p<0.001), and +71.6 g/day (p<0.001) in the intake of fat, sugar, salt, and fruit and vegetables, respectively. Similarly, significant net changes occurred for secondary outcomes: BMI -0.25 kg/m2, diastolic blood pressure -2.77 mm Hg, FPG -5.7 mg/dl, and triglycerides -24.2mg/dl. The intervention had no effect on haemoglobin, systolic blood pressure, low-density lipoprotein cholesterol, or high-density lipoprotein cholesterol.

CONCLUSION

The IT-enabled 'SMART Eating' intervention was found to be effective in reducing fat, sugar, and salt intake, and increasing fruit and vegetable consumption among urban adults from diverse socio-economic backgrounds.

TRIAL REGISTRATION

Clinical Trial Registry of India CTRI/2016/11/007457.

Dietary quality differences between women with and without weight loss in nutritional treatment

BACKGROUND & AIMS

The obesity nutritional treatment is structured to weight loss and diet is considered an important indicator of treatment effectiveness. The purpose of this study is to compare the diet quality among women who lost weight to women who maintained or gained weight during the nutritional treatment.

METHODS

This is a retrospective study that included 66 obese women in nutritional treatment for weight loss, over six months, divided in tercile according to their weight loss. The diet quality was evaluated by score, which was obtained with a food frequency questionnaire.

RESULTS

The diet quality comparison was made among the group with weight loss (GL; n = 22) and the group that maintained or gained weight during the nutritional treatment (GG; n = 22) showed that both groups had improvement in their diet quality scores from pre-treatment to post-treatment. Nevertheless, the GG had higher sugar consumption than the GL in the pre-treatment (p = 0.02) and in the post-treatment (p 0.01) periods. In the post-treatment, GL increased their scores for leafy vegetables (0.013), fruit (0.004), sweets (p 0.03), and soft drinks (p 0.02). GL improved their scores for fried food (p 0.01) and sweets (p 0.008).

CONCLUSION

This indicates that in the weight loss treatment special attention should be given to the incentive to the fruit and leafy vegetables consumption and, to reduce the consumption of sweets.

Comparative effectiveness trial comparing MyPlate to calorie counting for mostly low-income Latino primary care patients of a federally qualified community health center: study design, baseline characteristics

BACKGROUND

Primary care-based behavior change obesity treatment has long featured the Calorie restriction (CC), portion control approach. By contrast, the MyPlate-based obesity treatment approach encourages eating more high-satiety/high-satiation foods and requires no calorie-counting. This report describes study methods of a comparative effectiveness trial of CC versus MyPlate. It also describes baseline findings involving demographic characteristics and their associations with primary outcome measures and covariates, including satiety/satiation, dietary quality and acculturation.

METHODS

A comparative effectiveness trial was designed to compare the CC approach (n = 130) versus a MyPlate-based approach (n = 131) to treating patient overweight. Intervenors were trained community health workers. The 11 intervention sessions included two in-home health education sessions, two group education sessions, and seven telephone coaching sessions. Questionnaire and anthropometric assessments occurred at baseline, 6- and 12 months; food frequency questionnaires were administered at baseline and 12 months. Participants were overweight adult primary care patients of a federally qualified health center in Long Beach, California. Two measures of satiety/satiation and one measure of post-meal hunger comprised the primary outcome measures. Secondary outcomes included weight, waist circumference, blood pressure, dietary quality, sugary beverage intake, water intake, fruit and vegetable fiber intake, mental health and health-related quality of life. Covariates included age, gender, nativity status (U.S.-born, not U.S.-born), race/ethnicity, education, and acculturation.

ANALYSIS

Baseline characteristics were compared using chi square tests. Associations between covariates and outcome measures were evaluated using multiple regression and logistic regression.

RESULTS

Two thousand eighty-six adult patients were screened, yielding 261 enrollees who were 86% Latino, 8% African American, 4% White and 2% Other. Women predominated (95%). Mean age was 42 years. Most (82%) were foreign-born; 74% chose the Spanish language option. Mean BMI was 33.3 kg/m2; mean weight was 82 kg; mean waist circumference was 102 cm. Mean blood pressure was 122/77 mm. Study arms on key baseline measures did not differ except on dietary quality and sugary beverage intake. Nativity status was significantly associated with dietary quality.

CONCLUSIONS

The two treatment arms were well-balanced demographically at baseline. Nativity status is inversely related to dietary quality.

TRIAL REGISTRATION

NCT02514889 , posted on 8/4/2015.

Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease

BACKGROUND

The Seven Countries study in the 1960s showed that populations in the Mediterranean region experienced lower coronary heart disease (CHD) mortality probably as a result of different dietary patterns. Later observational studies have confirmed the benefits of adherence to a Mediterranean dietary pattern on cardiovascular disease (CVD) risk factors but clinical trial evidence is more limited.

OBJECTIVES

To determine the effectiveness of a Mediterranean-style diet for the primary and secondary prevention of CVD.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 9); MEDLINE (Ovid, 1946 to 25 September 2018); Embase (Ovid, 1980 to 2018 week 39); Web of Science Core Collection (Thomson Reuters, 1900 to 26 September 2018); DARE Issue 2 of 4, 2015 (Cochrane Library); HTA Issue 4 of 4, 2016 (Cochrane Library); NHS EED Issue 2 of 4, 2015 (Cochrane Library). We searched trial registers and applied no language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) in healthy adults and adults at high risk of CVD (primary prevention) and those with established CVD (secondary prevention). Both of the following key components were required to reach our definition of a Mediterranean-style diet: high monounsaturated/saturated fat ratio (use of olive oil as main cooking ingredient and/or consumption of other traditional foods high in monounsaturated fats such as tree nuts) and a high intake of plant-based foods, including fruits, vegetables and legumes. Additional components included: low to moderate red wine consumption; high consumption of whole grains and cereals; low consumption of meat and meat products and increased consumption of fish; moderate consumption of milk and dairy products. The intervention could be dietary advice, provision of relevant foods, or both. The comparison group received either no intervention, minimal intervention, usual care or another dietary intervention. Outcomes included clinical events and CVD risk factors. We included only studies with follow-up periods of three months or more defined as the intervention period plus post intervention follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data and assessed risk of bias. We conducted four main comparisons:1. Mediterranean dietary intervention versus no intervention or minimal intervention for primary prevention;2. Mediterranean dietary intervention versus another dietary intervention for primary prevention;3. Mediterranean dietary intervention versus usual care for secondary prevention;4. Mediterranean dietary intervention versus another dietary intervention for secondary prevention.

MAIN RESULTS

In this substantive review update, 30 RCTs (49 papers) (12,461 participants randomised) and seven ongoing trials met our inclusion criteria. The majority of trials contributed to primary prevention: comparisons 1 (nine trials) and 2 (13 trials). Secondary prevention trials were included for comparison 3 (two trials) and comparison 4 (four trials plus an additional two trials that were excluded from the main analyses due to published concerns regarding the reliability of the data).Two trials reported on adverse events where these were absent or minor (low- to moderate-quality evidence). No trials reported on costs or health-related quality of life.Primary preventionThe included studies for comparison 1 did not report on clinical endpoints (CVD mortality, total mortality or non-fatal endpoints such as myocardial infarction or stroke). The PREDIMED trial (included in comparison 2) was retracted and re-analysed following concerns regarding randomisation at two of 11 sites. Low-quality evidence shows little or no effect of the PREDIMED (7747 randomised) intervention (advice to follow a Mediterranean diet plus supplemental extra-virgin olive oil or tree nuts) compared to a low-fat diet on CVD mortality (hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.50 to 1.32) or total mortality (HR 1.0, 95% CI 0.81 to 1.24) over 4.8 years. There was, however, a reduction in the number of strokes with the PREDIMED intervention (HR 0.60, 95% CI 0.45 to 0.80), a decrease from 24/1000 to 14/1000 (95% CI 11 to 19), moderate-quality evidence). For CVD risk factors for comparison 1 there was low-quality evidence for a possible small reduction in total cholesterol (-0.16 mmol/L, 95% CI -0.32 to 0.00) and moderate-quality evidence for a reduction in systolic (-2.99 mmHg (95% CI -3.45 to -2.53) and diastolic blood pressure (-2.0 mmHg, 95% CI -2.29 to -1.71), with low or very low-quality evidence of little or no effect on LDL or HDL cholesterol or triglycerides. For comparison 2 there was moderate-quality evidence of a possible small reduction in LDL cholesterol (-0.15 mmol/L, 95% CI -0.27 to -0.02) and triglycerides (-0.09 mmol/L, 95% CI -0.16 to -0.01) with moderate or low-quality evidence of little or no effect on total or HDL cholesterol or blood pressure.Secondary preventionFor secondary prevention, the Lyon Diet Heart Study (comparison 3) examined the effect of advice to follow a Mediterranean diet and supplemental canola margarine compared to usual care in 605 CHD patients over 46 months and there was low-quality evidence of a reduction in adjusted estimates for CVD mortality (HR 0.35, 95% CI 0.15 to 0.82) and total mortality (HR 0.44, 95% CI 0.21 to 0.92) with the intervention. Only one small trial (101 participants) provided unadjusted estimates for composite clinical endpoints for comparison 4 (very low-quality evidence of uncertain effect). For comparison 3 there was low-quality evidence of little or no effect of a Mediterranean-style diet on lipid levels and very low-quality evidence for blood pressure. Similarly, for comparison 4 where only two trials contributed to the analyses there was low or very low-quality evidence of little or no effect of the intervention on lipid levels or blood pressure.

AUTHORS' CONCLUSIONS

Despite the relatively large number of studies included in this review, there is still some uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and CVD risk factors for both primary and secondary prevention. The quality of evidence for the modest benefits on CVD risk factors in primary prevention is low or moderate, with a small number of studies reporting minimal harms. There is a paucity of evidence for secondary prevention. The ongoing studies may provide more certainty in the future.

Protocol for a cluster randomised controlled trial on information technology-enabled nutrition intervention among urban adults in Chandigarh (India): SMART eating trial

Nutrition is an important determinant of health. At present, nutrition programs in India mainly emphasize improving maternal and child nutrition. Adult nutrition has not received due attention, though diseases like hypertension and diabetes are largely preventable through changes in dietary and physical activity behaviour. Little is known about the best approaches to improve dietary behaviours, especially the role of modern information technology (IT) in health education. We describe the protocol of the SMART Eating (Small, Measurable and Achievable dietary changes by Reducing fat, sugar and salt consumption and Trying different fruits and vegetables) health promotion intervention. A Cluster Randomised Controlled Trial will evaluate the effect of an IT-enabled intervention on nutrition behaviour among urban adults of Chandigarh, India. Formative research using a qualitative exploratory approach was undertaken to inform the intervention. The IT-enabled intervention programme includes website development, Short Message Service (SMS), e-mail reminders and interactive help by mobile and landline phones. The IT-enabled intervention will be compared to the traditional nutrition education program of distributing pamphlets in the control group. The primary outcome will be the percentage of study participants meeting the dietary intake guidelines of the National Institute of Nutrition, Hyderabad, India and the change in intake of fat, sugar, salt, fruit and vegetables after the intervention. The difference in differences method will be used to determine the net change in dietary intakes resulting from the interventions. Measurements will be made at baseline and at 6 months post-intervention, using a food frequency questionnaire. The formative research led to the development of a comprehensive intervention, focusing on five dietary components and using multi-channel communication approach including the use of IT to target urban North Indians from diverse socio-economic backgrounds. The Cluster Randomised Controlled Trial design is suitable for evaluating the effectiveness of this IT-enabled intervention for dietary behaviour change.

Effectiveness of Dietetic Consultations in Primary Health Care: A Systematic Review of Randomized Controlled Trials

BACKGROUND

A dietetic consultation is a structured process aimed at supporting individual patients to modify their dietary behaviors to improve health outcomes. The body of evidence on the effectiveness of nutrition care provided by dietitians in primary health care settings has not previously been synthesized. This information is important to inform the role of dietitians in primary health care service delivery.

OBJECTIVE

The aim of this systematic review was to evaluate the evidence of the effectiveness of individual consultations provided exclusively by dietitians in primary care to support adult patients to modify dietary intake and improve health outcomes.

STUDY DESIGN

ProQuest Family Health, Scopus, PubMed Central, Medline, the Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases were searched for English language systematic reviews or randomized controlled trials published before October 2016. The key terms used identified the provision of nutrition care exclusively by a dietitian in a primary health care setting aimed at supporting adult patients to modify dietary behaviors and/or improve biomarkers of health. Interventions delivered to patients aged younger than 18 years, in hospital, via telephone only, in a group or lecture setting, or by a multidisciplinary team were excluded. The methodologic quality of each study was appraised using the Cochrane Risk of Bias tool and the body of evidence was assessed using the Academy of Nutrition and Dietetics Evidence Analysis Manual.

MAIN OUTCOME MEASURES

Outcomes included the effectiveness of dietetic interventions in terms of anthropometry, clinical indicators, and dietary intake. A statistically significant between-group difference was used to indicate intervention effectiveness (P<0.05).

RESULTS

Twenty-six randomized controlled studies met eligibility criteria, representing 5,500 adults receiving dietetic consultations in a primary care setting. Eighteen of 26 included studies showed statistically significant differences in dietary, anthropometric, or clinical indicators between intervention and comparator groups. When focusing specifically on each study's stated aim, significant improvements favoring the intervention compared with control were found for the following management areas: glycemic control (four out of four studies), dietary change (four out of four studies), anthropometry (four out of seven studies), cholesterol (two out of eight studies), triglycerides (one out of five), and blood pressure (zero out of three) studies.

CONCLUSIONS

Dietetic consultations for adults in primary care settings appear to be effective for improvement in diet quality, diabetes outcomes (including blood glucose and glycated haemoglobin values), and weight loss outcomes (eg, changes in weight and waist circumference) and to limit gestational weight gain (Grade II: Fair evidence). Research evaluated in this review does not provide consistent support for the effectiveness of direct dietetic counseling alone in achieving outcomes relating to plasma lipid levels and blood pressure (Grade III: Limited evidence). Therefore, to more effectively control these cardiovascular disease risk factors, future research might explore novel nutrition counseling approaches as well as dietitians functioning as part of multidisciplinary teams.

Correlation between Oxidative Stress, Nutrition, and Cancer Initiation

Inadequate or excessive nutrient consumption leads to oxidative stress, which may disrupt oxidative homeostasis, activate a cascade of molecular pathways, and alter the metabolic status of various tissues. Several foods and consumption patterns have been associated with various cancers and approximately 30-35% of the cancer cases are correlated with overnutrition or malnutrition. However, several contradictory studies are available regarding the association between diet and cancer risk, which remains to be elucidated. Concurrently, oxidative stress is a crucial factor for cancer progression and therapy. Nutritional oxidative stress may be induced by an imbalance between antioxidant defense and pro-oxidant load due to inadequate or excess nutrient supply. Oxidative stress is a physiological state where high levels of reactive oxygen species (ROS) and free radicals are generated. Several signaling pathways associated with carcinogenesis can additionally control ROS generation and regulate ROS downstream mechanisms, which could have potential implications in anticancer research. Cancer initiation may be modulated by the nutrition-mediated elevation in ROS levels, which can stimulate cancer initiation by triggering DNA mutations, damage, and pro-oncogenic signaling. Therefore, in this review, we have provided an overview of the relationship between nutrition, oxidative stress, and cancer initiation, and evaluated the impact of nutrient-mediated regulation of antioxidant capability against cancer therapy.

Development of an Evidence-Informed Blog to Promote Healthy Eating Among Mothers: Use of the Intervention Mapping Protocol

BACKGROUND

Low adherence to dietary guidelines and a concurrent rise of obesity-related chronic diseases emphasize the need for effective interventions to promote healthy eating. There is growing recognition that behavior change interventions should draw on theories of behavior change. Online interventions grounded in theory lead to increased effectiveness for health behavior change; however, few theory-driven social media-based health promotion interventions have been described in the literature.

OBJECTIVE

The objective of this study was to describe the application of the Intervention Mapping (IM) protocol to develop an evidence-informed blog to promote healthy eating among French-Canadian mothers of preschool and school-aged children.

METHODS

The following six steps of the IM protocol were performed. In Step 1, a preliminary needs assessment included a literature search on theoretical domains predicting Vegetables and Fruits intakes and Milk and Alternatives intakes in adults (ie, knowledge, beliefs about capabilities, beliefs about consequences, intention/goals) and a qualitative study including focus groups to identify female Internet users' perceptions of their use of healthy eating blogs. In Step 2, two behavioral outcomes were selected (ie, increase daily intakes of Vegetables and Fruits and Milk and Alternatives of mothers to reach Canadian dietary recommendations) and subsequently divided into six performance objectives inspired by national and international dietary recommendations such as planning for healthy meals. A matrix of change objectives was then created by crossing performance objectives with theoretical domains predicting Vegetables and Fruits intakes and Milk and Alternatives intakes in adults. Step 3 consisted of selecting theory-based intervention methods (eg, modeling and goal setting) and translating them into practical applications for the context of a dietary intervention delivered through a blog. A 6-month intervention was developed in Step 4 in which we aimed to address one performance objective per month in weekly blog publications written by a registered dietitian. For Step 5, we sought to include engagement-promoting methods (eg, peer and counselor support) to promote mothers' use of the blog and adherence to the intervention. Finally in Step 6, a randomized controlled trial has been launched to evaluate the effects of the blog on dietary behaviors of French-Canadian mothers.

RESULTS

The intervention study is expected to be completed in March 2018.

CONCLUSIONS

An intervention mapping protocol allowed for effective decision making in the development of a novel knowledge translation tool to increase adherence to dietary recommendations among mothers of preschool and school-aged children.

Dietary fibre for the prevention of recurrent colorectal adenomas and carcinomas

BACKGROUND

This is an update of the Cochrane review published in 2002.Colorectal cancer (CRC) is a major cause of morbidity and mortality in industrialised countries. Experimental evidence has supported the hypothesis that dietary fibre may protect against the development of CRC, although epidemiologic data have been inconclusive.

OBJECTIVES

To assess the effect of dietary fibre on the recurrence of colorectal adenomatous polyps in people with a known history of adenomatous polyps and on the incidence of CRC compared to placebo. Further, to identify the reported incidence of adverse effects, such as abdominal pain or diarrhoea, that resulted from the fibre intervention.

SEARCH METHODS

We identified randomised controlled trials (RCTs) from Cochrane Colorectal Cancer's Specialised Register, CENTRAL, MEDLINE and Embase (search date, 4 April 2016). We also searched ClinicalTrials.gov and WHO International Trials Registry Platform on October 2016.

SELECTION CRITERIA

We included RCTs or quasi-RCTs. The population were those having a history of adenomatous polyps, but no previous history of CRC, and repeated visualisation of the colon/rectum after at least two-years' follow-up. Dietary fibre was the intervention. The primary outcomes were the number of participants with: 1. at least one adenoma, 2. more than one adenoma, 3. at least one adenoma greater than or equal to 1 cm, or 4. a new diagnosis of CRC. The secondary outcome was the number of adverse events.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data, assessed trial quality and resolved discrepancies by consensus. We used risk ratios (RR) and risk difference (RD) with 95% confidence intervals (CI) to measure the effect. If statistical significance was reached, we reported the number needed to treat for an additional beneficial outcome (NNTB) or harmful outcome (NNTH). We combined the study data using the fixed-effect model if it was clinically, methodologically, and statistically reasonable.

MAIN RESULTS

We included seven studies, of which five studies with 4798 participants provided data for analyses in this review. The mean ages of the participants ranged from 56 to 66 years. All participants had a history of adenomas, which had been removed to achieve a polyp-free colon at baseline. The interventions were wheat bran fibre, ispaghula husk, or a comprehensive dietary intervention with high fibre whole food sources alone or in combination. The comparators were low-fibre (2 to 3 g per day), placebo, or a regular diet. The combined data showed no statistically significant difference between the intervention and control groups for the number of participants with at least one adenoma (5 RCTs, n = 3641, RR 1.04, 95% CI 0.95 to 1.13, low-quality evidence), more than one adenoma (2 RCTs, n = 2542, RR 1.06, 95% CI 0.94 to 1.20, low-quality evidence), or at least one adenoma 1 cm or greater (4 RCTs, n = 3224, RR 0.99, 95% CI 0.82 to 1.20, low-quality evidence) at three to four years. The results on the number of participants diagnosed with colorectal cancer favoured the control group over the dietary fibre group (2 RCTS, n = 2794, RR 2.70, 95% CI 1.07 to 6.85, low-quality evidence). After 8 years of comprehensive dietary intervention, no statistically significant difference was found in the number of participants with at least one recurrent adenoma (1 RCT, n = 1905, RR 0.97, 95% CI 0.78 to 1.20), or with more than one adenoma (1 RCT, n = 1905, RR 0.89, 95% CI 0.64 to 1.24). More participants given ispaghula husk group had at least one recurrent adenoma than the control group (1 RCT, n = 376, RR 1.45, 95% CI 1.01 to 2.08). Other analyses by types of fibre intervention were not statistically significant. The overall dropout rate was over 16% in these trials with no reasons given for these losses. Sensitivity analysis incorporating these missing data shows that none of the results can be considered as robust; when the large numbers of participants lost to follow-up were assumed to have had an event or not, the results changed sufficiently to alter the conclusions that we would draw. Therefore, the reliability of the findings may have been compromised by these missing data (attrition bias) and should be interpreted with caution.

AUTHORS' CONCLUSIONS

There is a lack of evidence from existing RCTs to suggest that increased dietary fibre intake will reduce the recurrence of adenomatous polyps in those with a history of adenomatous polyps within a two to eight year period. However, these results may be unreliable and should be interpreted cautiously, not only because of the high rate of loss to follow-up, but also because adenomatous polyp is a surrogate outcome for the unobserved true endpoint CRC. Longer-term trials with higher dietary fibre levels are needed to enable confident conclusion.

Dietary protein intake and human health

A protein consists of amino acids (AA) linked by peptide bonds. Dietary protein is hydrolyzed by proteases and peptidases to generate AA, dipeptides, and tripeptides in the lumen of the gastrointestinal tract. These digestion products are utilized by bacteria in the small intestine or absorbed into enterocytes. AA that are not degraded by the small intestine enter the portal vein for protein synthesis in skeletal muscle and other tissues. AA are also used for cell-specific production of low-molecular-weight metabolites with enormous physiological importance. Thus, protein undernutrition results in stunting, anemia, physical weakness, edema, vascular dysfunction, and impaired immunity. Based on short-term nitrogen balance studies, the Recommended Dietary Allowance of protein for a healthy adult with minimal physical activity is currently 0.8 g protein per kg body weight (BW) per day. To meet the functional needs such as promoting skeletal-muscle protein accretion and physical strength, dietary intake of 1.0, 1.3, and 1.6 g protein per kg BW per day is recommended for individuals with minimal, moderate, and intense physical activity, respectively. Long-term consumption of protein at 2 g per kg BW per day is safe for healthy adults, and the tolerable upper limit is 3.5 g per kg BW per day for well-adapted subjects. Chronic high protein intake (>2 g per kg BW per day for adults) may result in digestive, renal, and vascular abnormalities and should be avoided. The quantity and quality of protein are the determinants of its nutritional values. Therefore, adequate consumption of high-quality proteins from animal products (e.g., lean meat and milk) is essential for optimal growth, development, and health of humans.

Determinants of Forward Stage Transition from Precontemplation and Contemplation for Fruit Consumption

Purpose.

To examine associations between decisional balance, self-efficacy, fruit intake, and stage of change transition from precontemplation and contemplation with cross-sectional and longitudinal methods.

Design.

A longitudinal cohort study with the use of electronic questionnaires was conducted. Three measurements were analyzed cross-sectionally, and the two intervals between the measurements were analyzed longitudinally.

Setting.

A random sample of 1500 individuals from an existing Dutch Internet panel resulted in a cohort of 735 individuals. Of the cohort, 648 (response rate 88%), 592 (response rate 81%), and 570 (response rate 78%) respondents completed questionnaires at the start of the present study (T1), 53 days after T1 (T2), and 106 days after T1 (T3), respectively.

Subjects.

Mean age was 37.5 years, 51% were women, and 57% ate less than the recommended intake of 250 g of fruit per day.

Measures.

Questionnaires included items measuring stage of change, factors favoring (pros) or working against (cons) behavior change, and self-efficacy. A food frequency questionnaire was used to assess fruit intake.

Results.

Logistic regression analyses showed that pros, fruit intake, and self-efficacy predicted forward stage transition from precontemplation. Self-efficacy predicted forward stage transition from contemplation. Cons did not predict stage transitions. Results from longitudinal analyses were similar to cross-sectional results, except for self-efficacy: no differences between early stages in self-efficacy were found, whereas self-efficacy predicted these early stage transitions.

Conclusions.

Within the limitations posed by the sampling frame, results provided support for the Transtheoretical Model, although determinants might not always be stage specific.

Enhancing adherence in trials promoting change in diet and physical activity in individuals with a diagnosis of colorectal adenoma; a systematic review of behavioural intervention approaches

BACKGROUND

Little is known about colorectal adenoma patients' ability to adhere to behavioural interventions promoting a change in diet and physical activity. This review aimed to examine health behaviour intervention programmes promoting change in diet and/or physical activity in adenoma patients and characterise interventions to which this patient group are most likely to adhere.

METHODS

Searches of eight databases were restricted to English language publications 2000-2014. Reference lists of relevant articles were also reviewed. All randomised controlled trials (RCTs) of diet and physical activity interventions in colorectal adenoma patients were included. Eligibility and quality were assessed and data were extracted by two reviewers. Data extraction comprised type, intensity, provider, mode and location of delivery of the intervention and data to enable calculation of four adherence outcomes. Data were subject to narrative analysis.

RESULTS

Five RCTs with a total of 1932 participants met the inclusion criteria. Adherence to the goals of the intervention ranged from 18 to 86 % for diet and 13 to 47 % for physical activity. Diet interventions achieving ≥ 50 % adherence to the goals of the intervention were clinic based, grounded in cognitive theory, delivered one to one and encouraged social support.

CONCLUSIONS

The findings of this review indicate that behavioural interventions can encourage colorectal adenoma patients to improve their diet. This review was not however able to clearly characterise effective interventions promoting increased physical activity in this patient group. Further research is required to establish effective interventions to promote adherence to physical activity in this population.

Higher Intake of Fruit, but Not Vegetables or Fiber, at Baseline Is Associated with Lower Risk of Becoming Overweight or Obese in Middle-Aged and Older Women of Normal BMI at Baseline

BACKGROUND

Fruit, vegetable, and dietary fiber intake have been associated with lower risk of cardiovascular disease (CVD); however, little is known about their role in obesity prevention.

OBJECTIVE

Our goal was to investigate whether intake of fruits, vegetables, and dietary fiber is associated with weight change and the risk of becoming overweight and obese.

METHODS

We studied 18,146 women aged ≥45 y from the Women's Health Study free of CVD and cancer with an initial body mass index (BMI) of 18.5 to <25 kg/m². Fruit, vegetable, and dietary fiber intakes were assessed at baseline through a 131-item food-frequency questionnaire, along with obesity-related risk factors. Women self-reported body weight on annual questionnaires.

RESULTS

During a mean follow-up of 15.9 y, 8125 women became overweight or obese (BMI ≥25 kg/m²). Intakes of total fruits and vegetables, fruits, and dietary fiber were not associated with the longitudinal changes in body weight, whereas higher vegetable intake was associated with greater weight gain (P-trend: 0.02). In multivariable analyses, controlling for total energy intake and physical activity along with other lifestyle, clinical, and dietary factors, women in the highest vs. lowest quintile of fruit intake had an HR of 0.87 (95% CI: 0.80, 0.94; P-trend: 0.01) of becoming overweight or obese. No association was observed for vegetable or dietary fiber intake. The association between fruit intake and risk of becoming overweight or obese was modified by baseline BMI (P-interaction: <0.0001) where the strongest inverse association was observed among women with a BMI <23 kg/m² (HR: 0.82; 95% CI: 0.71, 0.94).

CONCLUSION

Our results suggest that greater baseline intake of fruit, but not vegetables or fiber, by middle-aged and older women with a normal BMI at baseline is associated with lower risk of becoming overweight or obese.

Identification and monitoring of metabolite markers of dry bean consumption in parallel human and mouse studies

SCOPE

Aim of the study was to identify and monitor metabolite markers of dry bean consumption in parallel human and mouse studies that each had shown chemopreventive effects of dry bean consumption on colorectal neoplasia risk.

METHODS AND RESULTS

Using LC/mass spectroscopy ± ESI and GC/mass spectroscopy, serum metabolites of dry beans were measured in 46 men before and after a 4-week dry bean enriched diet (250 g/day) and 12 mice that received a standardized diet containing either 0 or 10% navy bean ethanol extract for 6 weeks; we also investigated fecal metabolites in the mice. The serum metabolites identified in these controlled feeding studies were then investigated in 212 polyp-free participants from the Polyp Prevention Trial who self-reported either increased (≥+31 g/day from baseline), high dry bean intake of ≥42 g/day in year 3 or low, unchanged dry bean consumption of <8 g/day; serum was analyzed from baseline and year 3. Serum pipecolic acid and S-methyl cysteine were elevated after dry bean consumption in human and mouse studies and reflected dry bean consumption in the Polyp Prevention Trial.

CONCLUSION

Serum levels of pipecolic acid and S-methyl cysteine are useful biomarkers of dry bean consumption.

Comparison of two theory-based, fully automated telephone interventions designed to maintain dietary change in healthy adults: study protocol of a three-arm randomized controlled trial

Background

Health behavior change interventions have focused on obtaining short-term intervention effects; few studies have evaluated mid-term and long-term outcomes, and even fewer have evaluated interventions that are designed to maintain and enhance initial intervention effects. Moreover, behavior theory has not been developed for maintenance or applied to maintenance intervention design to the degree that it has for behavior change initiation.

Objective

The objective of this paper is to describe a study that compared two theory-based interventions (social cognitive theory [SCT] vs goal systems theory [GST]) designed to maintain previously achieved improvements in fruit and vegetable (F&V) consumption.

Methods

The interventions used tailored, interactive conversations delivered by a fully automated telephony system (Telephone-Linked Care [TLC]) over a 6-month period. TLC maintenance intervention based on SCT used a skills-based approach to build self-efficacy. It assessed confidence in and barriers to eating F&V, provided feedback on how to overcome barriers, plan ahead, and set goals. The TLC maintenance intervention based on GST used a cognitive-based approach. Conversations trained participants in goal management to help them integrate their newly acquired dietary behavior into their hierarchical system of goals. Content included goal facilitation, conflict, shielding, and redundancy, and reflection on personal goals and priorities. To evaluate and compare the two approaches, a sample of adults whose F&V consumption was below public health goal levels were recruited from a large urban area to participate in a fully automated telephony intervention (TLC-EAT) for 3-6 months. Participants who increase their daily intake of F&V by ≥1 serving/day will be eligible for the three-arm randomized controlled trial. A sample of 405 participants will be randomized to one of three arms: (1) an assessment-only control, (2) TLC-SCT, and (3) TLC-GST. The maintenance interventions are 6 months. All 405 participants who qualify for the trial will complete surveys administered by blinded interviewers at baseline (randomization), 6, 12, 18, and 24 months.

Results

Data analysis is not yet complete, but we hypothesize that (1) TLC-GST > TLC-SCT > control at all follow-up time points for F&V consumption, and (2) intervention effects will be mediated by the theoretical constructs (eg, self-efficacy, goal pursuit, conflict, shielding, and facilitation).

Conclusions

This study used a novel study design to initiate and then promote the maintenance of dietary behavior change through the use of an evidence-based fully automated telephony intervention. After the first 6 months (the acquisition phase), we will examine whether two telephony interventions built using different underlying behavioral theories were more successful than an assessment-only control group in helping participants maintain their newly acquired health behavior change.

Trial Registration

Clinicaltrials.gov NCT00148525; http://clinicaltrials.gov/ct2/show/NCT00148525 (Archived by Webcite at http://www.webcitation.org/6TiRriJOs).

Association of behaviour change techniques with effectiveness of dietary interventions among adults of retirement age: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

There is a need for development of more effective interventions to achieve healthy eating, enhance healthy ageing, and to reduce the risk of age-related diseases. The aim of this study was to identify the behaviour change techniques (BCTs) used in complex dietary behaviour change interventions and to explore the association between BCTs utilised and intervention effectiveness.

METHODS

We undertook a secondary analysis of data from a previous systematic review with meta-analysis of the effectiveness of dietary interventions among people of retirement age. BCTs were identified using the reliable CALO-RE taxonomy in studies reporting fruit and vegetable (F and V) consumption as outcomes. The mean difference in F and V intake between active and control arms was compared between studies in which the BCTs were identified versus those not using the BCTs. Random-effects meta-regression models were used to assess the association of interventions BCTs with F and V intakes.

RESULTS

Twenty-eight of the 40 BCTs listed in the CALO-RE taxonomy were identified in the 22 papers reviewed. Studies using the techniques 'barrier identification/problem solving' (93 g, 95% confidence interval (CI) 48 to 137 greater F and V intake), 'plan social support/social change' (78 g, 95%CI 24 to 132 greater F and V intake), 'goal setting (outcome)' (55 g 95%CI 7 to 103 greater F and V intake), 'use of follow-up prompts' (66 g, 95%CI 10 to 123 greater F and V intake) and 'provide feedback on performance' (39 g, 95%CI -2 to 81 greater F and V intake) were associated with greater effects of interventions on F and V consumption compared with studies not using these BCTs. The number of BCTs per study ranged from 2 to 16 (median = 6). Meta-regression showed that one additional BCT led to 8.3 g (95%CI 0.006 to 16.6 g) increase in F and V intake.

CONCLUSIONS

Overall, this study has identified BCTs associated with effectiveness suggesting that these might be active ingredients of dietary interventions which will be effective in increasing F and V intake in older adults. For interventions targeting those in the peri-retirement age group, 'barrier identification/problem solving' and 'plan for social support/social change' may be particularly useful in increasing the effectiveness of dietary interventions.

Effectiveness of dietary interventions among adults of retirement age: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Retirement from work involves significant lifestyle changes and may represent an opportunity to promote healthier eating patterns in later life. However, the effectiveness of dietary interventions during this period has not been evaluated.

METHODS

We undertook a systematic review of dietary interventions among adults of retirement transition age (54 to 70 years). Twelve electronic databases were searched for randomized controlled trials evaluating the promotion of a healthy dietary pattern, or its constituent food groups, with three or more months of follow-up and reporting intake of specific food groups. Random-effects models were used to determine the pooled effect sizes. Subgroup analysis and meta-regression were used to assess sources of heterogeneity.

RESULTS

Out of 9,048 publications identified, 68 publications reporting 24 studies fulfilled inclusion criteria. Twenty-two studies, characterized by predominantly overweight and obese participants, were included in the meta-analysis. Overall, interventions increased fruit and vegetable (F&V) intake by 87.5 g/day (P <0.00001), with similar results in the short-to-medium (that is, 4 to 12 months; 85.6 g/day) and long-term (that is, 13 to 58 months; 87.0 g/day) and for body mass index (BMI) stratification. Interventions produced slightly higher intakes of fruit (mean 54.0 g/day) than of vegetables (mean 44.6 g/day), and significant increases in fish (7 g/day, P = 0.03) and decreases in meat intake (9 g/day, P <0.00001).

CONCLUSIONS

Increases in F&V intakes were positively associated with the number of participant intervention contacts. Dietary interventions delivered during the retirement transition are therefore effective, sustainable in the longer term and likely to be of public health significance.

Fit and Strong! Plus: design of a comparative effectiveness evaluation of a weight management program for older adults with osteoarthritis

Osteoarthritis (OA) is the most common chronic condition and principal cause of disability among older adults. The current obesity epidemic has contributed to this high prevalence rate. Fortunately both OA symptoms and obesity can be ameliorated through lifestyle modifications. Physical activity (PA) combined with weight management improves physical function among obese persons with knee OA but evidence-based interventions that combine PA and weight management are limited for this population. This paper describes a comparative effectiveness trial testing an evidence-based PA program for adults with lower extremity (LE) OA, Fit and Strong!, against an enhanced version that also addresses weight management based on the evidence-based Obesity Reduction Black Intervention Trial (ORBIT). Adult participants (n=400) with LE OA, age 60+, overweight/obese, and not meeting PA requirements of ≥ 150 min per week, are randomized to one of the two programs. Both 8-week interventions meet 3 times per week and include 60 min of strength, flexibility, and aerobic exercise instruction followed by 30 min of education/group discussion. The Fit and Strong! education sessions focus on using PA to manage OA; whereas Fit and Strong! Plus addresses PA and weight loss management strategies. Maintenance of behavior change is reinforced in both groups during months 3-24 through telephone calls and mailed newsletters. Outcomes are assessed at baseline, and 2, 6, 12, 18, and 24 months. Primary outcomes are dietary change at 2 months followed by weight loss at 6 months that is maintained at 24 months. Secondary outcomes assess PA, physical performance, and anxiety/depression.

Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies

Resonance Raman spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes.

Development of exchange lists for Mediterranean and Healthy Eating diets: implementation in an intervention trial

BACKGROUND

There has been little research published on the adaptation of diabetic exchange list diet approaches for the design of intervention diets in health research despite their clinical utility. The exchange list approach can provide clear and precise guidance on multiple dietary changes simultaneously. The present study aimed to develop exchange list diets for Mediterranean and Healthy Eating, and to evaluate adherence, dietary intakes and markers of health risks with each counselling approach in 120 subjects at increased risk for developing colon cancer.

METHODS

A randomised clinical trial was implemented in the USA involving telephone counselling. The Mediterranean diet had 10 dietary goals targeting increases in mono-unsaturated fats, n-3 fats, whole grains and the amount and variety of fruits and vegetables. The Healthy Eating diet had five dietary goals that were based on the US Healthy People 2010 recommendations.

RESULTS

Dietary compliance was similar in both diet arms, with 82-88% of goals being met at 6 months, although subjects took more time to achieve the Mediterranean goals than the Healthy Eating goals. The relatively modest fruit and vegetable goals in the Healthy Eating arm were exceeded, resulting in fruit and vegetable intakes of approximately eight servings per day in each arm after 6 months. A significant (P < 0.05) weight loss and a decrease in serum C-reactive protein concentrations were observed in the overweight/obese subgroup of subjects in the Mediterranean arm in the absence of weight loss goals.

CONCLUSIONS

Counselling for the Mediterranean diet may be useful for both improving diet quality and for achieving a modest weight loss in overweight or obese individuals.

Implementing a farmers' market incentive program: perspectives on the New York City Health Bucks Program

INTRODUCTION

One strategy for lowering the prevalence of obesity is to increase access to and affordability of fruits and vegetables through farmers' markets. However, little has been documented in the literature on the implementation of such efforts. To address this gap, the Division of Nutrition, Physical Activity, and Obesity (DNPAO) sponsored an evaluation of the New York City Health Bucks program, a farmers' market coupon incentive program intended to increase access to fresh fruits and vegetables in underserved neighborhoods while supporting local farmers.

METHODS

We conducted a process evaluation of Health Bucks program implementation. We interviewed 6 farmer/vendors, 3 market managers, and 4 program administrators, and collected data on site at 86 farmers' markets, including surveys of 81 managers and 141 farmer/vendors on their perspectives on promotion and redemption of the incentive coupons; knowledge and attitudes regarding the program; experiences with markets and products; and facilitators and barriers to program participation.

RESULTS

Results indicate that respondents view Health Bucks as a positive program model. Farmers' market incentive coupon programs like Health Bucks are one strategy to address the problem of obesity and were associated with higher fruit and vegetable access and purchases in low-income communities.

CONCLUSIONS

This evaluation identified some areas for improving implementation of the Health Bucks program. Farmers' market incentive programs like Health Bucks may be one avenue to increase access to and affordability of fruits and vegetables among low-income persons. Further research is needed to assess the potential effects of these programs on access and health outcomes.

'Mediterranean' dietary pattern for the primary prevention of cardiovascular disease

BACKGROUND

The Seven Countries study in the 1960s showed that populations in the Mediterranean region experienced lower cardiovascular disease (CVD) mortality probably as a result of different dietary patterns. Later observational studies have confirmed the benefits of adherence to a Mediterranean dietary pattern on CVD risk factors. Clinical trial evidence is limited, and is mostly in secondary prevention.

OBJECTIVES

To determine the effectiveness of a Mediterranean dietary pattern for the primary prevention of CVD.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 9 of 12, September 2012); MEDLINE (Ovid, 1946 to October week 1 2012); EMBASE (Ovid, 1980 to 2012 week 41); ISI Web of Science (1970 to 16 October 2012); Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment Database and Health Economics Evaluations Database (Issue 3 of 12, September 2012). We searched trial registers and reference lists of reviews and applied no language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials in healthy adults and adults at high risk of CVD. A Mediterranean dietary pattern was defined as comprising at least two of the following components: (1) high monounsaturated/saturated fat ratio, (2) low to moderate red wine consumption, (3) high consumption of legumes, (4) high consumption of grains and cereals, (5) high consumption of fruits and vegetables, (6) low consumption of meat and meat products and increased consumption of fish, and (7) moderate consumption of milk and dairy products. The comparison group received either no intervention or minimal intervention. Outcomes included clinical events and CVD risk factors.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and contacted chief investigators to request additional relevant information.

MAIN RESULTS

We included 11 trials (15 papers) (52,044 participants randomised). Trials were heterogeneous in the participants recruited, in the number of dietary components and follow-up periods. Seven trials described the intervention as a Mediterranean diet. Clinical events were reported in only one trial (Women's Health Initiative 48,835 postmenopausal women, intervention not described as a Mediterranean diet but increased fruit and vegetable and cereal intake) where no statistically significant effects of the intervention were seen on fatal and non-fatal endpoints at eight years. Small reductions in total cholesterol (-0.16 mmol/L, 95% confidence interval (CI) -0.26 to -0.06; random-effects model) and low-density lipoprotein (LDL) cholesterol (-0.07 mmol/L, 95% CI -0.13 to -0.01) were seen with the intervention. Subgroup analyses revealed statistically significant greater reductions in total cholesterol in those trials describing the intervention as a Mediterranean diet (-0.23 mmol/L, 95% CI -0.27 to -0.2) compared with control (-0.06 mmol/L, 95% CI -0.13 to 0.01). Heterogeneity precluded meta-analyses for other outcomes. Reductions in blood pressure were seen in three of five trials reporting this outcome. None of the trials reported adverse events.

AUTHORS' CONCLUSIONS

The limited evidence to date suggests some favourable effects on cardiovascular risk factors. More comprehensive interventions describing themselves as the Mediterranean diet may produce more beneficial effects on lipid levels than those interventions with fewer dietary components. More trials are needed to examine the impact of heterogeneity of both participants and the intervention on outcomes.

Effects of fruit and vegetable, consumed in solid vs beverage forms, on acute and chronic appetitive responses in lean and obese adults

BACKGROUND

The effects of fruits and vegetables in solid vs beverage forms on human appetite and food intake, acutely and chronically, are unclear.

METHODS

This 21-week, randomized, crossover study assessed appetitive ratings following the inclusion of fruits and vegetables, in solid and beverage form, into the habitual diet of healthy lean (n=15) and overweight/obese (n=19) adults with low customary consumption. The primary acute outcomes were satiation (amount of challenge meal consumed), satiety (latency of subsequent eating event) and dietary compensation after a 400 kcal fruit preload. Ratings of appetite were also obtained before and after 8 weeks of required increased fruit and vegetable consumption (20% estimated energy requirement).

RESULTS

Acutely, overweight/obese participants reported smaller reductions of hunger after consuming the fruit preload in beverage compared with solid form (preload × form × body mass index effects, P=0.03). Participants also consumed significantly less of a challenge meal (in both gram and energy) after the ingestion of the solid fruit preload (P<0.005). However, the subsequent meal latency was not significantly different between the solid and the beverage fruit preloads. Total daily energy intake was significantly higher when the obese participants consumed the beverage fruit preload compared with the solid (P<0.001). Daily energy intake was markedly, but not significantly, higher among the lean with the beverage vs solid food form. Hunger and fullness ratings remained stable when participants consumed fruits and vegetables in solid or beverage form for 8 weeks each.

CONCLUSION

Acute post-ingestive appetitive responses were weaker following consumption of fruits in beverage vs solid food forms. Consumption of beverage or solid fruit and vegetable food loads for 8 weeks did not chronically alter appetitive responses.

Baseline transtheoretical and dietary behavioral predictors of dietary fat moderation over 12 and 24 months

Longitudinal predictors of dietary behavior change are important and in need of study. This secondary data analysis combined primary data across three randomized trials to examine transtheoretical model (TTM) and specific dietary predictors of successful dietary change at 12 and 24 months separately in treatment and control groups (N = 4178). The treatment group received three TTM-tailored print interventions over 12 months between 1995 and 2000. Chi-square and MANOVA analyses were used to examine baseline predictors of dietary outcome at 12 and 24 months. Last, a multivariable logistic regression was conducted with all baseline variables included. Across all analyses in both treatment and control groups, the most robust predictors of successful change were for TTM-tailored treatment group, preparation stage of change, and increased use of dietary behavior variables such as moderating fat intake, substitution of lower fat foods, and increasing intake of healthful foods. These results provide strong evidence for treatment, stage and behavioral dietary severity effects predicting dietary behavior change over time, and for targeting these variables with the strongest relationships to outcome in interventions, such as TTM-tailored dietary interventions.

Relationships between serum and colon concentrations of carotenoids and fatty acids in randomized dietary intervention trial

Little is known about the effect of preventive diets on colonic nutrient concentrations. This study randomized 120 persons at increased risk of colon cancer to a Mediterranean versus a Healthy Eating diet for six months. The former targeted increases in whole grains, fruits, vegetables, monounsaturated, and n3 fats. The Healthy Eating diet was based on Healthy People 2010 recommendations. At baseline, dietary fat and carotenoid intakes were poorly associated (Spearman ρ < 0.4) with serum and colon concentrations. Strong associations were observed between serum and colon measurements of β-cryptoxanthin (ρ = 0.58; P < 0.001), α-carotene (ρ = 0.48; P < 0.001), and β-carotene (ρ = 0.45; P < 0.001). After six months, the Healthy Eating intervention increased serum lutein, β-, and α-carotene significantly (P < 0.05). In the Mediterranean arm, the significant increases were in serum lutein, β-cryptoxanthin, β-carotene, monounsaturated, and n3 fats. A significant group-by-time interaction (P = 0.03) was obtained for monounsaturated fats. Colonic increases in carotenoids and n3 fats were significant only in Healthy Eating arm, whereas the group-by-time interaction was significant for β-carotene (P = 0.02) and α-carotene (P = 0.03). Changes in colon concentrations were not significantly associated with reported dietary changes. Changes in colon and serum concentrations were strongly associated for β-cryptoxanthin (ρ = 0.56; P < 0.001) and α-carotene (ρ = 0.40; P < 0.001). The associations between colonic and serum concentrations suggest the potential use of using serum concentration as a target in dietary interventions aimed at reducing colon cancer risk.

Dietary advice for reducing cardiovascular risk

BACKGROUND

Changes in population diet are likely to reduce cardiovascular disease and cancer, but the effect of dietary advice is uncertain. This review is an update of a previous review published in 2007.

OBJECTIVES

To assess the effects of providing dietary advice to achieve sustained dietary changes or improved cardiovascular risk profile among healthy adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, the Database of Abstracts of Reviews of Effects (DARE) and the HTA database on The Cochrane Library (Issue 4, 2010). We searched MEDLINE (Ovid) (1950 to week 2 October 2010) and EMBASE (Ovid) (1980 to Week 42 2010). Additional searches were done on CAB Health (1972 to December 1999), CVRCT registry (2000), CCT (2000) and SIGLE (1980 to 2000). Dissertation abstracts and reference lists of articles were checked and researchers were contacted.

SELECTION CRITERIA

Randomised studies with no more than 20% loss to follow-up, lasting at least three months and involving healthy adults comparing dietary advice with no advice or minimal advice. Trials involving children, trials to reduce weight or those involving supplementation were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Forty-four trials with 52 intervention arms (comparisons) comparing dietary advice with no advice were included in the review; 18,175 participants or clusters were randomised. Twenty-nine of the 44 included trials were conducted in the USA. Dietary advice reduced total serum cholesterol by 0.15 mmol/L (95% CI 0.06 to 0.23) and LDL cholesterol by 0.16 mmol/L (95% CI 0.08 to 0.24) after 3 to 24 months. Mean HDL cholesterol levels and triglyceride levels were unchanged. Dietary advice reduced blood pressure by 2.61 mm Hg systolic (95% CI 1.31 to 3.91) and 1.45 mm Hg diastolic (95% CI 0.68 to 2.22) and 24-hour urinary sodium excretion by 40.9 mmol (95% CI 25.3 to 56.5) after 3 to 36 months but there was heterogeneity between trials for the latter outcome. Three trials reported plasma antioxidants, where small increases were seen in lutein and β-cryptoxanthin, but there was heterogeneity in the trial effects. Self-reported dietary intake may be subject to reporting bias, and there was significant heterogeneity in all the following analyses. Compared to no advice, dietary advice increased fruit and vegetable intake by 1.18 servings/day (95% CI 0.65 to 1.71). Dietary fibre intake increased with advice by 6.5 g/day (95% CI 2.2 to 10.82), while total dietary fat as a percentage of total energy intake fell by 4.48% (95% CI 2.47 to 6.48) with dietary advice, and saturated fat intake fell by 2.39% (95% CI 1.4 to 3.37).Two trials analysed incident cardiovascular disease (CVD) events (TOHP I/II). Follow-up was 77% complete at 10 to 15 years after the end of the intervention period and estimates of event rates lacked precision but suggested that sodium restriction advice probably led to a reduction in cardiovascular events (combined fatal plus non-fatal events) plus revascularisation (TOHP I hazards ratio (HR) 0.59, 95% CI 0.33 to 1.08; TOHP II HR 0.81, 95% CI 0.59 to 1.12).

AUTHORS' CONCLUSIONS

Dietary advice appears to be effective in bringing about modest beneficial changes in diet and cardiovascular risk factors over approximately 12 months, but longer-term effects are not known.

Diet adherence dynamics and physiological responses to a tomato product whole-food intervention in African-American men

Tomatoes may have beneficial effects on prostate health. Efficacy trials would require long-term adherence to high levels of tomato product (TP) consumption. Therefore, factors that affect adherence in men most at risk and whether increased consumption of TP negatively affects diet and health are important concerns. Cancer-free African–American (AA) men (n 36) with mean serum prostate-specific antigen of 7.4 SD 5.6) ng/ml were randomised to consume one serving of TP/d or a control diet for 3 months. Mean intervention group lycopene intake rose to 464%, with negligible control group increase. Plasma lycopene levels rose by 53 and 40% in the intervention group in months 1 and 3, respectively (P < 0.0001), with no control group change. The intervention group’s barriers to adherence score was inversely associated with both dietary (r -0.49, P = 0.02) and plasma lycopene concentration (r -0.37, P = 0.02). Their TP disadvantage score negatively correlated with the 3-month plasma lycopene concentrations (r -0.37, P = 0.008) and their weekly incentives and impediments were remarkably stable, ‘concern for prostate health’ being the most consistent over time. ‘Liking tomatoes’ and ‘study participation’ decreased in citation frequency at weeks 6 and 9, respectively. No major shifts occurred in dietary cholesterol or saturated fat, with no adverse effects on gastrointestinal complaints, serum total cholesterol, body weight or blood pressure. Lower socio-economic status AA men at higher prostate cancer risk can successfully achieve a whole food intervention goal with a corresponding rise in plasma lycopene concentrations, with no adverse effects on self-selected diet quality or health parameters.

Beverage vs. solid fruits and vegetables: effects on energy intake and body weight

Beverage consumption has been implicated in weight gain, but questions remain about the veracity of the association, whether the relationship is causal and what property of beverages is responsible. It was hypothesized that food form is the most salient attribute. Thus, a randomized controlled trial of food form was conducted. Energy-matched beverage or solid forms of fruits and vegetables were provided to 34, lean or overweight/obese adults for two 8-week periods with a 3-week washout interspersed. Dietary compensation was incomplete (beverage 53%; solid 78%) and body weight increased after the beverage (1.95 ± 0.33 kg) (77% fat mass) and solid (1.36 ± 0.30 kg) (85% fat mass) treatments (both P < 0.0005). Differences between food forms were not significant. The lean group had the highest dietary compensation (119%) and no significant weight change (0.84 ± 0.53 kg) after consuming the solid fruits and vegetables whereas the overweight/obese group had lower compensation and significant weight gain during the solid arm (46%, 1.77 ± 0.32 kg, P < 0.0001). In contrast, incomplete dietary compensation and weight gain occurred in both the lean (43%, 1.61 ± 0.44 kg, P = 0.003) and overweight/obese (61%, 2.22 ± 0.47 kg, P < 0.0005) groups during the beverage arm. Secondary analyses revealed the obese group gained more weight than the lean and overweight groups during the beverage intervention (P = 0.024). These data demonstrate energy consumed as beverages may be especially problematic for weight gain. They also indicate that advice to increase fruit and vegetable consumption should emphasize total energy intake because the additional energy contributed may promote weight gain, especially among overweight and obese individuals.

Daily self-monitoring of body weight, step count, fruit/vegetable intake, and water consumption: a feasible and effective long-term weight loss maintenance approach

Maintenance of weight loss remains a challenge for most individuals. Thus, practical and effective weight-loss maintenance (WTLM) strategies are needed. A two-group 12-month WTLM intervention trial was conducted from June 2007 to February 2010 to determine the feasibility and effectiveness of a WTLM intervention for older adults using daily self-monitoring of body weight, step count, fruit/vegetable (F/V) intake, and water consumption. Forty weight-reduced individuals (mean weight lost=6.7±0.6 kg; body mass index [calculated as kg/m²] 29.2±1.1), age 63±1 years, who had previously participated in a 12-week randomized controlled weight-loss intervention trial, were instructed to record daily body weight, step count, and F/V intake (WEV [defined as weight, exercise, and F/V]). Experimental group (WEV+) participants were also instructed to consume 16 fl oz of water before each main meal (ie, three times daily), and to record daily water intake. Outcome measures included weight change, diet/physical activity behaviors, theoretical constructs related to health behaviors, and other clinical measures. Statistical analyses included growth curve analyses and repeated measures analysis of variance. Over 12 months, there was a linear decrease in weight (β=-0.32, P<0.001) and a quadratic trend (β=0.02, P<0.01) over time, but no group difference (β=-0.23, P=0.08). Analysis of the 365 days of self-reported body weight for each participant determined that weight loss was greater over the study period in the WEV+ group than in the WEV group, corresponding to weight changes of -0.67 kg and 1.00 kg, respectively, and an 87% greater weight loss (β=-0.01, P<0.01). Overall compliance to daily tracking was 76%±5%. Daily self-monitoring of weight, physical activity, and F/V consumption is a feasible and effective approach for maintaining weight loss for 12 months, and daily self-monitoring of increased water consumption may provide additional WTLM benefits.

Dietary lignan and proanthocyanidin consumption and colorectal adenoma recurrence in the Polyp Prevention Trial

Lignans and proanthocyanidins are plant polyphenols that have shown protective properties against colorectal neoplasms in some human studies. Using logistic regression, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) to prospectively evaluate the association between lignan and proanthocyanidin intake, estimated from databases linked to a food frequency questionnaire, and adenoma recurrence in 1,859 participants of the Polyp Prevention Trial. Overall, individual or total lignans or proanthocyanidins were not associated with colorectal adenoma recurrence. However, in sex-specific analyses, total lignan intake was positively associated with any adenoma recurrence in women (highest vs. lowest lignan intake quartile OR = 2.07, 95% CI: 1.22-3.52, p trend = 0.004) but not in men (p interaction = 0.04). To conclude, dietary lignan and proanthocyanidin consumption were not generally related to colorectal adenoma recurrence; however, high lignan intake may increase the risk of adenoma recurrence in women.

Fruit and vegetable consumption and prospective weight change in participants of the European Prospective Investigation into Cancer and Nutrition-Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home, and Obesity study

BACKGROUND

Fruit and vegetable consumption might prevent weight gain through their low energy density and high dietary fiber content.

OBJECTIVE

We assessed the association between the baseline consumption of fruit and vegetables and weight change in participants from 10 European countries participating in the European Prospective Investigation into Cancer and Nutrition study.

DESIGN

Diet was assessed at baseline in 373,803 participants by using country-specific validated questionnaires. Weight was measured at baseline and self-reported at follow-up in most centers. Associations between baseline fruit and vegetable intakes (per 100 g/d) and weight change (g/y) after a mean follow-up of 5 y were assessed by using linear mixed-models, with age, sex, total energy intake, and other potential confounders controlled for.

RESULTS

After exclusion of subjects with chronic diseases at baseline and subjects who were likely to misreport energy intakes, baseline fruit and vegetable intakes were not associated with weight change overall. However, baseline fruit and vegetable intakes were inversely associated with weight change in men and women who quit smoking during follow-up. We observed weak positive associations between vegetable intake and weight change in women who were overweight, were former smokers, or had high prudent dietary pattern scores and weak inverse associations between fruit intake and weight change in women who were >50 y of age, were of normal weight, were never smokers, or had low prudent dietary pattern scores.

CONCLUSIONS

In this large study, higher baseline fruit and vegetable intakes, while maintaining total energy intakes constant, did not substantially influence midterm weight change overall but could help to reduce risk of weight gain in persons who stop smoking. The interactions observed in women deserve additional attention.

Serum macrophage inhibitory cytokine-1 (MIC-1/GDF15): a potential screening tool for the prevention of colon cancer?

BACKGROUND

Macrophage inhibitory cytokine-1 (MIC-1/GDF15) mediates nonsteroidal anti-inflammatory drug (NSAID) protection from colonic polyps in mice and is linked to the development of colorectal carcinoma in humans. Therefore, changes in serum MIC-1/GDF15 levels could predict the presence of premalignant colonic polyposis and assist in population screening strategies.

METHODS

Serum MIC-1/GDF15 levels were measured in subjects in the Polyp Prevention Trial, in which NSAID use and colon cancer risk factors were defined. Subjects had an initial adenoma removed, a repeat colonoscopy removing previously unidentified polyps, and serum MIC-1/GDF15 estimation. Three years later recurrent adenomas were identified and serum MIC-1/GDF15 levels reestimated. The relationship between serum MIC-1/GDF15 levels and adenoma presence or recurrence was examined.

RESULTS

Serum MIC-1/GDF15 levels differed by adenoma status and were significantly related to colon cancer risk factors. In addition, mean serum MIC-1/GDF15 levels rose with increasing numbers of adenomas present and high-risk adenoma recurrence. NSAID users had higher serum MIC-1/GDF15 concentrations, which were related to protection from adenoma recurrence. Furthermore, adjusted serum MIC-1/GDF15 levels at final follow-up were related to adenoma recurrence (highest quartile MIC-1/GDF15; OR = 14.7, 95% CI: 3.0-73).

CONCLUSIONS

These data suggest that MIC-1/GDF15 mediates at least some of the protection afforded by NSAIDs against human colonic polyposis. Furthermore, serum MIC-1/GDF15 levels vary with the development of adnenomatous colonic polyps.

IMPACT

Serum MIC-1/GDF15 determination may hold promise as the first serum screening test to assist the detection of premalignant adenomatous colonic polyposis.

Improvement of meal composition by vegetable variety

Objective

Our physical environment influences our daily food choices unconsciously. Strategic changes in the food environment might therefore be potential measures to influence consumers’ food selection towards better nutrition, without affecting the consumers’ freedom of choice. The present study aimed to examine whether increased vegetable variety enhances healthy food choices and improves meal composition.

Design

A randomised experiment.

Setting

Participants were instructed to serve themselves a lunch from a buffet of food replicas. Individuals were randomly assigned to one of three food combinations: condition A – cooked carrots, pasta and chicken; condition B – cooked green garden beans, pasta and chicken; condition AB – carrot sticks, green garden beans, pasta and chicken. Two one-vegetable conditions were compared with one two-vegetable condition. Data from Zurich, Switzerland, were analysed using one-way ANOVA.

Subjects

Ninety-eight students (fifty-three men; mean age 22·8 (sd 2·2) years, minimum = 19 years, maximum = 29 years).

Results

Participants who could choose from two vegetables derived significantly more energy (141 kJ) from vegetables compared with participants in the one-vegetable condition (104 and 84 kJ, respectively). Furthermore, in the two-vegetable condition, the relative energy of the meal derived from vegetables (10·9 %) increased significantly compared with the one-vegetable condition (8 % and 6·1 %, respectively). The total energy content of the meal (mean 1472 (sd 468) kJ) was not affected by the experimental manipulation.

Conclusions

Having a choice of vegetables increases a person's tendency to choose vegetables and leads to the selection of a more balanced meal. Serving an assortment of vegetables as side dishes might be a simple and effective strategy to improve food selection.

Do interleukin polymorphisms play a role in the prevention of colorectal adenoma recurrence by dietary flavonols?

Chemopreventive dietary compounds, such as flavonols, may inhibit colorectal carcinogenesis partly by altering cytokine expression and attenuating inflammation. Single nucleotide polymorphisms (SNPs) in the promoter regions of genes encoding cytokines may influence flavonol-induced changes in cytokine expression and consequently cancer risk. Using logistic regression, we estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between SNPs of interleukin (IL)-1β, 6, 8, and 10 alone or combined with flavonol intake or serum IL concentration changes, and adenoma recurrence in 808 participants from the intervention arm of the Polyp Prevention Trial, a 4-year intervention study evaluating the effectiveness of a low-fat, high-fiber, high-fruit and vegetable diet on adenoma recurrence. Overall, SNPs in genes encoding IL-1β, 6, 8, and 10 were not associated with their corresponding serum concentrations or adenoma recurrence. However, individuals homozygous for IL-10 -592 C (OR=2.23, 95% CI: 1.07-4.66, P(interaction)=0.03) orIL-10 -819 C (OR=2.18, 95% CI: 1.05-4.51, P(interaction)=0.05) had an elevated risk of high-risk adenoma recurrence when their serum IL-10 concentrations increased during the trial. In addition, IL-6 -174 GG in combination with above median flavonol intake (OR=0.14, 95% CI: 0.03-0.66) or with decreased IL-6 concentrations (OR=0.14, 95% CI: 0.03-0.65) reduced the risk of advanced adenoma recurrence, although the interaction term was not statistically significant. In conclusion, our results suggest that IL SNPs, in combination with a flavonol-rich diet or decreased serum IL, may lower the risk of adenoma recurrence.

Linking obesity to colorectal cancer: application of nutrigenomics

Diet is one of the most affective environmental factors in cancer development. Due to complicated nature of the diet, it has been very difficult to provide clear explanations for the role of dietary components in carcinogenesis. However, as high-throughput omics techniques became available, researchers are now able to analyze large sets of gene transcripts, proteins, and metabolites to identify molecules involved in disease development. Bioinformatics uses these data to perform network analyses and suggest possible interactions between metabolic processes and environmental factors. Obesity is known as one of the most closely related risk factors of colorectal cancer (CRC). Metabolic disturbances due to a positive energy balance may trigger and accelerate CRC development. In this review, we have summarized reports on genes, proteins and metabolites that are related to either obesity or CRC, and suggested candidate molecules linking obesity and CRC based on currently available literature. Possible application of bioinformatics for a large scale network analysis in studying cause-effect relationship between dietary components and CRC are suggested.