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

Association between Mediterranean diet and periodontitis among US adults: The mediating roles of obesity indicators

OBJECTIVE

This study aimed to assess the association between the Mediterranean diet (MedDiet) and periodontitis in US adults and to further explore the mediating roles of obesity indicators in this association.

BACKGROUND DATA

The relationship between MedDiet and periodontitis is controversial. And it is unclear whether obesity indicators are potential mediators of this relationship.

METHODS

Using data derived from the National Health and Nutrition Examination Survey (2009-2014). Weighted binary logistic regression and restricted cubic spline were used to assess the association between MedDiet and periodontitis. Weighted ordinal logistic regression was performed to evaluate the relationship between MedDiet and periodontitis severity. The mediating roles of body mass index (BMI) and waist circumference in the relationship between the MedDiet and periodontitis were explored. Association analyses were further performed using mean clinical attachment loss (CAL) or mean periodontal probing depth (PPD) as dependent variables. The false discovery rate method was used to correct the p-values in the regression analyses.

RESULTS

A total of 8290 eligible participants (4159 participants with periodontitis and 4131 without periodontitis) were included. A negative association between the MedDiet adherence score and periodontitis was observed in the binary logistic regression model (adjusted odds ratio = 0.94, 95% confidence interval: 0.90-0.97, p = .001). Restricted cubic spline regression revealed a dose-response relationship between the MedDiet adherence score and periodontitis. BMI and waist circumference significantly mediate this association, with mediation proportions of 9.7% (p = .032) and 9.3% (p = .012), respectively. Multivariable ordinal logistic regression showed that the MedDiet adherence score was negatively associated with the severity of periodontitis (all p < .05). Additionally, the MedDiet adherence score was negatively associated with mean PPD or mean CAL (all p < .05).

CONCLUSIONS

This study suggests a significant negative association between adherence to the MedDiet and periodontitis and a possible mediating role of obesity indicators in this association. Furthermore, studies are still warranted to confirm our findings.

Development and validation of a novel food exchange system for Chinese pregnant women

BACKGROUND

The dietary nutritional status of pregnant women is critical for maintaining the health of both mothers and infants. Food exchange systems have been employed in the nutritional guidance of patients in China, although their application in the dietary guidance of healthy pregnant women is quite limited. This study aimed to develop a novel food exchange system for Chinese pregnant women (NFES-CPW) and evaluate the relative validation of its application.

METHODS

NFES-CPW covers approximately 500 types of food from ten categories and has more elaborate food portion sizes. It established a recommendation index for guiding food selection and used energy, water content, and protein as the exchange basis to balance the supply of energy and important nutrients throughout pregnancy. Furthermore, dietitians used the NFES-CPW and traditional food exchange system to generate new recipes based on the sample recipe. There were 40 derived recipes for each of the two food exchange methods. The food consumption, energy, and key nutrients of each recipe were calculated, and the differences between the two food exchange systems were compared using the Wilcoxon rank sum test or the Chi-square test.

RESULTS

The results revealed that compared to those derived from traditional food exchange system, the NFES-CPW derived recipes had a better dietary structure, as evidenced by the intakes of whole-grain cereals, beans excluding soybeans, potatoes, fruits, fish, shrimp and shellfish, as well as eggs (P < 0.05), which were more conducive to reaching the recommended range of balanced dietary pagoda. After calculating energy and nutrients, although these two food exchange systems have similar effects on the dietary energy and macronutrient intake of pregnant women, the intake of micronutrients in NFES-CPW derived recipes was significantly higher than that from the traditional food exchange system, which was more conducive to meeting the dietary requirements of pregnant women. The outstanding improvement are primarily vitamin A, vitamin B2, folic acid, vitamin B12, vitamin C, calcium, iron, and iodine (P < 0.05). Moreover, when compared to recipes obtained from the traditional food exchange system, the error ranges of energy and most nutrients were significantly reduced after employing the NFES-CPW.

CONCLUSIONS

Therefore, NFES-CPW is an appropriate tool that adheres to Chinese dietary characteristics and can provide suitable dietary guidance to pregnant women.

Machine learning accurately predicts food exchange list and the exchangeable portion

Introduction

Food Exchange Lists (FELs) are a user-friendly tool developed to help individuals aid healthy eating habits and follow a specific diet plan. Given the rapidly increasing number of new products or access to new foods, one of the biggest challenges for FELs is being outdated. Supervised machine learning algorithms could be a tool that facilitates this process and allows for updated FELs-the present study aimed to generate an algorithm to predict food classification and calculate the equivalent portion.

Methods

Data mining techniques were used to generate the algorithm, which consists of processing and analyzing the information to find patterns, trends, or repetitive rules that explain the behavior of the data in a food database after performing this task. It was decided to approach the problem from a vector formulation (through 9 nutrient dimensions) that led to proposals for classifiers such as Spherical K-Means (SKM), and by developing this idea, it was possible to smooth the limits of the classifier with the help of a Multilayer Perceptron (MLP) which were compared with two other algorithms of machine learning, these being Random Forest and XGBoost.

Results

The algorithm proposed in this study could classify and calculate the equivalent portion of a single or a list of foods. The algorithm allows the categorization of more than one thousand foods with a confidence level of 97% at the first three places. Also, the algorithm indicates which foods exceed the limits established in sodium, sugar, and/or fat content and show their equivalents.

Discussion

Accurate and robust FELs could improve implementation and adherence to the recommended diet. Compared with manual categorization and calculation, machine learning approaches have several advantages. Machine learning reduces the time needed for manual food categorization and equivalent portion calculation of many food products. Since it is possible to access food composition databases of various populations, our algorithm could be adapted and applied in other databases, offering an even greater diversity of regional products and foods. In conclusion, machine learning is a promising method for automation in generating FELs. This study provides evidence of a large-scale, accurate real-time processing algorithm that can be useful for designing meal plans tailored to the foods consumed by the population. Our model allowed us not only to distinguish and classify foods within a group or subgroup but also to perform the calculation of an equivalent food. As a neural network, this model could be trained with other food bases and thus improve its predictive capacity. Although the performance of the SKM model was lower compared to other types of classifiers, our model allows selecting an equivalent food not from a group previously classified by machine learning but with a fully interpretable algorithm such as cosine similarity for comparing food.

Effect of anti-inflammatory diets on inflammation markers in adult human populations: a systematic review of randomized controlled trials

CONTEXT

Chronic inflammation, characterized by prolonged elevated inflammation markers, is linked to several chronic conditions. Diet can influence the levels of inflammation markers in the body.

OBJECTIVE

The aim of this systematic review was to assess the effects of anti-inflammatory diets on 14 different inflammation markers in adults.

DATA SOURCES

This systematic review conducted searches using Medline, PubMed, EMCare, Cochrane, and CINAHL, to locate randomized controlled trials (RCTs).

DATA EXTRACTION

Two researchers independently screened 1537 RCTs that measured changes in inflammation markers after prescription of an intervention diet.

DATA ANALYSIS

In total, 20 RCTs were included and assessed qualitatively. The results demonstrated that a Mediterranean diet can bring about statistically significant and clinically meaningful between-group differences in interleukins -1α, -1β, -4, -5, -6, -7, -8, -10, and -18, interferon γ, tumor necrosis factor α, C-reactive protein, and high-sensitivity C-reactive protein, as compared with a control diet.

CONCLUSIONS

There may be a link between diet, inflammation markers, and disease outcomes in various adult populations. However, further research using consistent RCT protocols is required to determine correlations between diet, specific inflammation markers, and clinically relevant outcomes.

Evidence-Based Interventions for Reducing Breast Cancer Disparities: What Works and Where the Gaps Are?

The National Cancer Institute (NCI) has established an online repository of evidence-based cancer control programs (EBCCP) and increasingly calls for the usage of these EBCCPs to reduce the cancer burden. To inventory existing EBCCPs and identify remaining gaps, we summarized NCI's EBCCPs relevant to reducing breast cancer risk with an eye towards interventions that address multiple levels of influence in populations facing breast cancer disparities. For each program, the NCI EBCCP repository provides the following expert panel determined summary metrics: (a) program ratings (1-5 scale, 5 best) of research integrity, intervention impact, and dissemination capability, and (b) RE-AIM framework assessment (0-100%) of program reach, effectiveness, adoption, and implementation. We quantified the number of EBCCPs that met the quality criteria of receiving a score of ≥3 for research integrity, intervention impact, and dissemination capability, and receiving a score of ≥50% for available RE-AIM reach, effectiveness, adoption, and implementation. For breast cancer risk reduction, we assessed the presence and quality of EBCCPs related to physical activity (PA), obesity, alcohol, tobacco control in early life, breastfeeding, and environmental chemical exposures. Our review revealed several major gaps in EBCCPs for reducing the breast cancer burden: (1) there are no EBCCPs for key breast cancer risk factors including alcohol, breastfeeding, and environmental chemical exposures; (2) among the EBCPPs that exist for PA, obesity, and tobacco control in early life, only a small fraction (24%, 17% and 31%, respectively) met all the quality criteria (≥3 EBCCP scores and ≥50% RE-AIM scores) and; (3) of those that met the quality criteria, only two PA interventions, one obesity, and no tobacco control interventions addressed multiple levels of influence and were developed in populations facing breast cancer disparities. Thus, developing, evaluating, and disseminating interventions to address important risk factors and reduce breast cancer disparities are needed.

Development of a Tool for Determining the Equivalence of Nutritional Supplements to Diabetic Food Exchanges

Malnutrition is a prevalent issue in hospitals, nursing homes and the community setting. Nutritional products can be used by dietitians to supplement people’s diet by adding energy, macronutrients and other constituents. The aim of the present work was (i) to create a database of nutritional products with information on their energy and macronutrient content, (ii) to estimate the food exchanges of each product and assist in diet plan development for malnourished persons and (iii) to provide a tool for calculation of food exchanges of newly developed products not included in the database. We searched the web for nutritional supplements, and an electronic database with 461 products was generated with data regarding the contained energy and macronutrients of each entry. The following companies were included: Abbott Nutrition, Nestle Nutrition, Nutricia North America, Nutricia Global, Nutricia Europe & Middle East, Axcan Pharma Inc., Kate Farms, Global Health, High Protein, NutriMedical BV, Hormel Health Labs, Hormel Health Labs/Diamond Crystal Brands, Lyons Magnus, Mead Johnson, Medical Nutrition USA Inc., Medtrition, Nutritional Designs Inc., Nutrisens, Humana (Germany), and Vitaflo USA. The created database facilitates product comparisons and categorization into several groups according to energy and protein content. In addition, a tool was created to determine food exchanges for each supplement per serving and/or food exchanges for newly developed products by simply inserting their macronutrient content. The developed tool can facilitate dietitians in comparing products and incorporating them into diet plans, if needed. Such tools may thus serve clinical practice, may be used in dietary or other smart applications and can familiarize dietitians with the digital epoch.

A New Score for Quantifying Adherence to a Cancer-Preventive Mediterranean Diet

Herein a Mediterranean Cancer Preventive Diet Score (MCAP Score) is proposed to quantify adherence to both traditional Mediterranean fat intakes and the current dietary recommendations for cancer prevention. The scoring uses research-backed cutoff values, unlike other scores that are based on a population-specific median value. The MCAP score awards positive points for seven preventive food categories, including Mediterranean fats (monounsaturated fats, ω-3 fatty acids) associated with reduced adiposity, and negative points for four food categories associated with increased cancer risk, including ultra-processed foods. In a randomized trial of 120 persons at increased risk of colon cancer, the baseline MCAP Score averaged seven of 20 possible points. Counseling for a Healthy Diet or a Mediterranean Diet improved the score to either 11 or 13 points, respectively, and the highest score observed in any individual was 20 points. The MCAP Score was correlated with serum carotenoids and serum ω-3 fatty acids, and improvements in the score were associated with weight loss over six months of study. The MCAP Score is therefore proposed as a new method to assess adherence to a Mediterranean type of diet for cancer prevention using absolute criteria that will facilitate comparisons of dietary intakes across studies.

Effect of polyphenol-rich extra-virgin olive oil on lipid profile and inflammatory biomarkers in patients undergoing coronary angiography: a randomised, controlled, clinical trial

The present study was conducted to compare the effects of high polyphenol extra-virgin olive oil (EVOO) with low polyphenol refined olive oil (ROO) on some cardiovascular risk factors in patients undergoing coronary angiography. In a randomised, controlled, parallel-arm, clinical trial, 40 patients with at least one classic cardiovascular risk factor who referred to coronary angiography were randomly allocated to two groups and receied 25 mL EVOO or ROO daily for 6 weeks. Plasma LDL-cholesterol significantly reduced in EVOO group (-9.52 ± 20.44 vs 8.68 ± 18.77 mg/dL, p = .007 for EVOO and ROO respectively). EVOO resulted in a significant reduction in plasma CRP (-0.40 ± 0.52 vs 0.007 ± 0.42 mg/L, p = .01 for EVOO and ROO respectively) and increased ex-vivo whole blood LPS-stimulated IL-10 production (12.13 ± 33.64 vs -17.47 ± 49.04 pg/mL, p = .035 for EVOO and ROO respectively). Daily consumption of polyphenol-rich EVOO in subjects who have been under medical treatment with risk-reducing agents could additionally improve LDL-C and selected inflammatory markers. Trial Registration Number: NCT03796780.

A Scoping Review of the Operationalization of Fruit and Vegetable Variety

Adequate consumption of fruits and vegetables is critical for healthy growth and development. Less is known about fruit and vegetable variety, with variation in operationalization of variety. This review aims to identify currently available evidence operationalizing fruit and vegetable (FV) variety through a scoping review to summarize, compare, and critically evaluate the operationalization of variety. A secondary aim is to examine the implications of measuring FV variety and outcomes including dietary quality/nutrient intake. PubMed, Medline, PsycINFO were searched using the following criteria: (1) human study participants ages 2 years and above; (2) assessment of fruit variety consumption, vegetable variety consumption, or combined fruit and vegetable variety consumption; and (3) peer-reviewed publication available in the English language. Etiologic, intervention, and determinant studies were eligible to be included, and 47 studies met inclusion criteria. Differences in operationalization of variety were found. Findings included associations of FV variety with aspects of nutrient intake, dietary behaviors, lifestyle behaviors, and health outcomes. There were no studies that assessed conventionally grown produce vs. organic produce, and none of the included studies assessed cultivar. Nonstandard classification of fruit and vegetables, differences in fruit and vegetables grown in other countries, and the restriction to studies published in the English language may have excluded studies examining variety published in languages other than English. Operationalization of variety should be reported to allow one to explore comparability across studies, use national or international guidelines for greater comparability, associate variety with nutrient intake, and change variety behaviors via intervention.

Development of a Sport Food Exchange List for Dietetic Practice in Sport Nutrition

Food exchange lists have been widely used in dietary practice in health and disease situations, but there are still no exchange lists for sports foods. The aim of this study was to apply a previous published methodology to design food exchange lists to the development of a sports food exchange list, with sport products available in Spain. A cross-sectional study of the nutritional composition of sports foods, regarding macronutrients and energy, was carried out. A total of 322 sports foods from 18 companies were selected, taking into account their interest in sports practice and with nutritional data provided by companies. Sports foods were divided into seven groups: sports drinks; sports gels; sports bars; sports confectionery; protein powders; protein bars; and liquid meals. A sports food composition database based on portion size usually consumed by athletes and/or recommended in commercial packaging was created. Within each sports foods group, different subgroups were defined due to differences in the main and/or secondary macronutrient. The definition of each exchange list with the amounts—in grams—of each sports food within each group and subgroup, was done using statistical criteria such as mean, standard deviation, coefficient of variation, and Z value. Final exchange values for energy and macronutrient have been established for each group and subgroup using a methodology to design food exchange lists previously published by the authors. In addition, those products with high Z values that can provide greater variability in dietary planning were included. The usefulness of sport foods lists as well as the use of an exchange system in the dietary practice of sports nutrition is discussed, and examples of how to use them with athletes are presented. This first sport foods exchange list showed in this study, with commercial sports products available in Spain, can be a novel tool for dietetic practice and also can allow sport nutrition professionals to develop another sport food list using the methodology described in this paper. Its management would allow dietitians to adapt dietary plans more precisely to the training and/or competition of the athlete.

Tabla de intercambios de alimentos para uso en pediatría

Introducción. Para el profesional en nutrición, las tablas de intercambios de alimentos (TAI) son una herramienta que permite cuantificar la ingesta de calorías y nutrientes y planear la alimentación de manera práctica.Objetivo. Diseñar una TAI para uso en pediatría que facilite la labor del nutricionista en esta población.Materiales y métodos. Estudio descriptivo transversal. La selección de los alimentos consumidos con mayor frecuencia se realizó de acuerdo con recordatorios de 24 horas y una tabla de composición de alimentos (TCA). Se determinaron los tamaños de intercambio de alimentos teniendo en cuenta las porciones del grupo etario. Después del análisis químico de los alimentos se determinaron las medidas caseras (p. ej. cucharada, cucharadita, taza, etc.) y se diseñó y se validó la TIA.Resultados. Se incluyeron 241 alimentos, los cuales se distribuyeron en 9 grupos y 4 anexos. Se tuvo en cuenta un nutriente principal para cada grupo y la medida casera se definió según las características de cada alimento. Se observó concordancia en la evaluación de consumo entre la TIA para uso en pediatría y la TCA (CCI>0.81).Conclusión. Se desarrolló una TIA para población pediátrica confiable que permitirá evaluar la alimentación y diseñar planes de alimentación en preescolares y escolares de manera práctica.

A Mediterranean diet does not alter plasma trimethylamine N-oxide concentrations in healthy adults at risk for colon cancer

An elevated circulating level of trimethylamine N-oxide (TMAO) has been identified as a risk factor for numerous diseases, including cardiovascular disease (CVD) and colon cancer. TMAO is formed from trimethylamine (TMA)-precursors such as choline via the combined action of the gut microbiota and liver. We conducted a Mediterranean diet intervention that increased intakes of fiber and changed intakes of many other foods containing fat to increase the relative amount of mono-unsaturated fats in the diet. The Mediterranean diet is associated with reduced risks of chronic diseases and might counteract the pro-inflammatory effects of increased TMAO formation. Therefore, the purpose of this study was to determine if the Mediterranean diet would reduce TMAO concentrations. Fasting TMAO concentrations were measured before and after six-months of dietary intervention in 115 healthy people at increased risk for colon cancer. No significant changes in plasma TMAO or in the ratios of TMAO to precursor compounds were found in either the Mediterranean group or the comparison group that followed a Healthy Eating diet. TMAO concentrations exhibited positive correlations with age and markers of metabolic health. TMAO concentrations were not associated with circulating cytokines, but the relative abundance of Akkermansia mucinophilia in colon biopsies was modestly and inversely correlated with baseline TMAO, choline, and betaine serum concentrations. These results suggest that broad dietary pattern intervention over six months may not be sufficient for reducing TMAO concentrations in an otherwise healthy population. Disruption of the conversion of dietary TMA to TMAO should be the focus of future studies.

Colonic Mucosal Bacteria Are Associated with Inter-Individual Variability in Serum Carotenoid Concentrations

BACKGROUND

Relatively high serum carotenoid levels are associated with reduced risks of chronic diseases, but inter-individual variability in serum carotenoid concentrations is modestly explained by diet. The bacterial community in the colon could contribute to the bioaccessibility of carotenoids by completing digestion of plant cells walls and by modulating intestinal permeability.

OBJECTIVE

To evaluate whether colonic bacterial composition is associated with serum and colon carotenoid concentrations.

DESIGN

The study was a randomized dietary intervention trial in healthy individuals who were at increased risk of colon cancer. Colon mucosal biopsy samples were obtained before and after 6 months of intervention without prior preparation of the bowels.

PARTICIPANTS/SETTING

Participants were recruited from Ann Arbor, MI, and nearby areas from July 2007 to November 2010. Biopsy data were available from 88 participants at baseline and 82 participants after 6 months.

METHODS

Study participants were randomized to counseling for either a Mediterranean diet or a Healthy Eating diet for 6 months.

RESULTS

At baseline, bacterial communities in biopsy samples from study participants in the highest vs the lowest tertile of total serum carotenoid levels differed by several parameters. Linear discriminant analysis effect size identified 11 operational taxonomic units that were significantly associated with higher serum carotenoid levels. In linear regression analyses, three of these accounted for an additional 12% of the variance in serum total carotenoid concentrations after including body mass index, smoking, and dietary intakes in the model. These factors together explained 36% of the inter-individual variance in serum total carotenoid concentrations. The bacterial community in the colonic mucosa, however, was resistant to change after dietary intervention with either a Mediterranean diet or Healthy Eating diet, each of which doubled fruit and vegetable intakes.

CONCLUSIONS

The colonic mucosal bacterial community was associated with serum carotenoid concentrations at baseline but was not appreciably changed by dietary intervention.

Food Exchange List and Dietary Management of Non-Communicable Diseases in Cultural Perspective

This review focuses at highlighting the importance of Food Exchange List in cultural perspective, as an effective dietary tool to help individuals' manage their dietary modifications in relation to non communicable diseases whilst specifying measures that can help improve the quality of Food Exchange Lists for combating various non communicable diseases and addressing adherence related issues to specialized diets. A search was done using PubMed & Google Scholar till June 2016. Search terms used were food exchange list AND disease, diet AND non-communicable diseases. We included only studies that discussed Food Exchange List (FEL) in relation to non-communicable diseases; in addition to factors like cultural relevance and adherence. Out of the 837 papers accessed 57 were identified as relevant to the Food Exchange List, out of which 39 papers were focused to the concept and development of the Food Exchange List. Only 18 discussed FEL in relation to non communicable diseases and were thus included in the review. Food exchange list is a user friendly tool for dietary modification due to disease. This tool may help to customize meals for people as it provides information regarding various food items in different groups. This tool is helpful in reducing blood & plasma glucose levels, maintaining lipid profile & effectively combating other diet related diseases & those ailments in which diet plays a significant role in maintenance & prevention from reoccurrences. However, better management and adherence to modified diets for non communicable diseases can be ensured by keeping cultural relevance under consideration before using Food Exchange Lists for such diseases.

Building research in diet and cognition: The BRIDGE randomized controlled trial

Obesity has been linked to cognitive impairment, cognitive decline and dementia. Given that 38.5% of U.S. adults 60years and older are obese and these numbers are rapidly increasing, strategies to decouple obesity from cognitive decline are needed. Innovative lifestyle strategies that may postpone the onset of subclinical symptoms or even arrest the transition to overt dementia in at-risk individuals are critically needed. Poor diet is central to the development of obesity and diet may affect cognition. Adherence to a Mediterranean Diet (MedDiet) is associated with reduced risk of cognitive impairment and dementia. Furthermore, weight loss through caloric restriction improves cognitive function. This paper describes the Building Research in Diet and CoGnition (BRIDGE) study, a randomized trial examining the effect of the MedDiet, with and without weight loss, on cognitive functioning in obese older adults. Obese (BMI≥30 and ≤50kg/m2) older adults (≥55years) (n=180) will be randomized in a 2:2:1 allocation scheme to: Typical Diet Control; MedDiet alone, without weight loss; or MedDiet lifestyle intervention to promote weight loss and weight loss maintenance. Both MedDiet intervention groups will meet for one individual session and 27 group sessions over an 8-month period. Individuals in the control group will not receive instruction on changing lifestyle habits. Outcomes will be assessed at baseline, 8 and 14months. The primary outcome is cognitive functioning; secondary outcomes will include changes in body weight, diet, cardiovascular, metabolic, and inflammatory biomarkers.

Obesity-associated cancer risk: the role of intestinal microbiota in the etiology of the host proinflammatory state

Obesity increases the risks of many cancers. One important mechanism behind this association is the obesity-associated proinflammatory state. Although the composition of the intestinal microbiome undoubtedly can contribute to the proinflammatory state, perhaps the most important aspect of host-microbiome interactions is host exposure to components of intestinal bacteria that stimulate inflammatory reactions. Systemic exposures to intestinal bacteria can be modulated by dietary factors through altering both the composition of the intestinal microbiota and the absorption of bacterial products from the intestinal lumen. In particular, high-fat and high-energy diets have been shown to facilitate absorption of bacterial lipopolysaccharide (LPS) from intestinal bacteria. Biomarkers of bacterial exposures that have been measured in blood include LPS-binding protein, sCD14, fatty acids characteristic of intestinal bacteria, and immunoglobulins specific for bacterial LPS and flagellin. The optimal strategies to reduce these proinflammatory exposures, whether by altering diet composition, avoiding a positive energy balance, or reducing adipose stores, likely differ in each individual. Biomarkers that assess systemic bacterial exposures therefore should be useful to (1) optimize and personalize preventive approaches for individuals and groups with specific characteristics and to (2) gain insight into the possible mechanisms involved with different preventive approaches.

Colonic Saturated Fatty Acid Concentrations and Expression of COX-1, but not Diet, Predict Prostaglandin E2 in Normal Human Colon Tissue

Prostaglandin E2 (PGE2) in the colon is a pro-inflammatory mediator that is associated with increased risk of colon cancer. In this study, expression of genes in the PGE2 pathway were quantified in colon biopsies from a trial of a Mediterranean versus a Healthy Eating diet in 113 individuals at high risk for colon cancer. Colon biopsies were obtained before and after 6 months of intervention. Quantitative, real-time PCR was used to measure mRNA expression of prostaglandin H synthases (PTGS1 and 2), prostaglandin E synthases (PTGES1 and 3), prostaglandin dehydrogenase (HPGD), and PGE2 receptors (PTGER2, PTGER4). The most highly expressed genes were HPGD and PTGS1. In multivariate linear regression models of baseline data, both colon saturated fatty acid concentrations and PTGS1 expression were significant, positive predictors of colon PGE2 concentrations after controlling for nonsteroidal anti-inflammatory drug use, gender, age, and smoking status. The effects of dietary intervention on gene expression were minimal with small increases in expression noted for PTGES3 in both arms and in PTGER4 in the Mediterranean arm. These results indicate that short-term dietary change had little effect on enzymes in the prostaglandin pathway in the colon and other factors, such as differences in fatty acid metabolism, might be more influential.

Markers of systemic exposures to products of intestinal bacteria in a dietary intervention study

PURPOSE

Systemic exposures to intestinal bacteria may play a role in the etiology of the chronic, low-grade inflammation that is associated with western diets. Production of lipopolysaccharide-binding protein (LBP) is one biomarker of increased exposures to intestinal bacteria. This study evaluated whether changes in diet quality could affect serum LBP.

METHODS

This was a randomized, controlled trial of Mediterranean and Healthy Eating diets over 6 months in 120 healthy subjects at increased risk of colon cancer. Blood samples obtained before and after intervention were analyzed for LBP, branched-chain fatty acids characteristic of intestinal bacteria, micronutrients and cytokines. Data were analyzed for changes in LBP over time and for predictors of LBP.

RESULTS

Serum concentrations of branched-chain bacterial fatty acids declined significantly in both diet groups. However, there was no significant change in mean serum LBP concentrations with either diet intervention. In serum, LBP was positively associated with CRP and negatively associated with carotenoids both before and after intervention. After intervention, LBP was predicted positively by both CRP and bacterial fatty acid concentrations in serum, and negatively by serum carotenoids and the ω3/ω6 fatty acid ratio. This model accounted for 30 % of the inter-individual variation in serum LBP after intervention.

CONCLUSIONS

These results indicate that dietary intervention over 6 months was insufficient to alter serum LBP. The relationships with inflammation-related markers, however, indicate that anti-inflammatory strategies other than changes in diet quality, such as weight loss or improved fitness, may have more potential for reducing systemic markers of LPS exposures in well-nourished populations.

Sex Differences in the Effects of Repeated Taste Exposure to the Mediterranean Diet: A 6-month Follow-up Study

PURPOSE

To determine whether an intervention based mainly on exposure to the Mediterranean diet (MedDiet), along with recommendations and tools for encouraging healthy eating, lead to different effects on dietary adherence and body weight management six months post-intervention in Canadian men and women.

METHODS

Thirty-eight males and 32 premenopausal females (all aged 24-53 years) were exposed to the same 4-week experimental MedDiet during which all foods were provided to participants. Participants also received some recommendations and tools to adhere to a healthy way of eating, with no other contact until the 6-month follow-up visit.

RESULTS

Compared with baseline, the Mediterranean score (MedScore) increased at the end of the 6-month follow-up (time effect P = 0.003), with no sex difference (sex-by-time interaction P = 0.97). With regard to MedScore components, sex differences were observed with males reporting changes in more dietary food groups than females. Although the intervention was not focused on body weight management, compared with baseline, BMI decreased during the intervention in both males and females; however, only females maintained the lower BMI 6 months after the intervention.

CONCLUSIONS

Exposure to the MedDiet for a short duration promotes the adherence to this food pattern in both sexes and helps in the management of body weight, especially in females.

Effects of a Mediterranean Diet Intervention on Anti- and Pro-Inflammatory Eicosanoids, Epithelial Proliferation, and Nuclear Morphology in Biopsies of Normal Colon Tissue

This randomized trial evaluated the effects of intervention with either a Healthy Eating or a Mediterranean diet on colon biomarkers in 120 healthy individuals at increased colon cancer risk. The hypothesis was that eicosanoids and markers of proliferation would be favorably affected by the Mediterranean diet. Colon epithelial biopsy tissues and blood samples were obtained at baseline and after 6 mo of intervention. Colonic eicosanoid concentrations were evaluated by HPLC-MS-MS, and measures of epithelial proliferation and nuclear morphology were evaluated by image analysis of biopsy sections. There was little change in proinflammatory eicosanoids and in plasma cytokine concentrations with either dietary intervention. There was, however, a 50% increase in colonic prostaglandin E3 (PGE3), which is formed from eicosapentanoic acid, in the Mediterranean arm. Unlike PGE2, PGE3, was not significantly affected by regular use of non-steroidal anti-inflammatory drugs at baseline, and normal weight subjects had significantly higher colon PGE3 than overweight or obese subjects. Increased proliferation in the colon at baseline, by Ki67 labeling, was associated with morphological features that defined smaller nuclei in the epithelial cells, lower colon leukotriene concentrations and higher plasma cytokine concentrations. Dietary intervention had little effect on measures of epithelial proliferation or of nuclear morphology. The increase in PGE3 with a Mediterranean diet indicates that in normal colon, diet might affect protective pathways to a greater extent than proinflammatory and proliferative pathways. Hence, biomarkers from cancer models might not be relevant in a true prevention setting.

Effects of vitamin E from supplements and diet on colonic α- and γ-tocopherol concentrations in persons at increased colon cancer risk

The available evidence indicates that γ-tocopherol has more potential for colon cancer prevention than α-tocopherol, but little is known about the effects of foods and supplements on tocopherol levels in human colon. This study randomized 120 subjects at increased colon cancer risk to either a Mediterranean or a Healthy Eating diet for 6 mo. Supplement use was reported by 39% of the subjects, and vitamin E intake from supplements was twofold higher than that from foods. Serum α-tocopherol at baseline was positively predicted by dietary intakes of synthetic vitamin E in foods and supplements but not by natural α-tocopherol from foods. For serum γ-tocopherol, dietary γ-tocopherol was not a predictor, but dietary α-tocopherol was a negative predictor. Unlike with serum, the data supported a role for metabolic factors, and not a direct effect of diet, in governing concentrations of both α- and γ-tocopherol in colon. The Mediterranean intervention increased intakes of natural α-tocopherol, which is high in nuts, and decreased intakes of γ-tocopherol, which is low in olive oil. These dietary changes had no significant effects on colon tocopherols. The impact of diet on colon tocopherols therefore appears to be limited.