Three daily servings of reduced-fat milk: an evidence-based recommendation?

Comprehensive analysis of phospholipid in milk and their biological roles as nutrients and biomarkers

Phospholipids (PL) have garnered significant attention due to their physiological activities. Milk and other dairy products are important dietary sources for humans and have been extensively used to analyze the presence of PL by various analytical techniques. In this paper, the analysis techniques of PL were reviewed with the eight trigrams of phospholipidomics and a comprehensive fingerprint of 1295 PLs covering 8 subclasses in milk and other dairy products, especially. Technology is the primary productive force. Based on phospholipidomics technology, we further review the relationship between the composition of PL and factors that may be involved in processing and experimental operation, and emphasized the significance of the biological role played by PL in dietary supplements and biomarkers (production, processing and clinical research), and providing the future research directions.

Dairy product consumption and incident prediabetes in the Australian Diabetes, Obesity and Lifestyle Study with 12 years follow up

BACKGROUND

Investigating modifiable risk factors of early stages of the development of type 2 diabetes is essential for effective prevention. Some studies show protective associations between dairy and prediabetes, yet associations are heterogenous by type and fat content of dairy foods.

OBJECTIVE

To examine the relationship between the consumption of dairy, including different types of dairy products and the risk of prediabetes.

METHODS

The study included 4,891 participants with normal glucose tolerance (aged 49.0±12.3 years, 57% female) of the Australian Diabetes, Obesity and Lifestyle (AusDiab) study, a longitudinal population-based study. Dairy intake was measured at baseline using a food frequency questionnaire. Prediabetes at 5-year and 12-year follow-up was defined according to WHO criteria as fasting plasma glucose levels of 110-125 mg/dl or 2-hour plasma glucose levels of 140-199 mg/dl. Associations were analyzed using Poisson regression, adjusted for social demographics, lifestyle behaviors, family history of diabetes, and food group intake.

RESULTS

765 (15.6%) incident cases of prediabetes were observed. The mean intake of dairy foods was 2.4±1.2 servings/day, mostly consisting of low-fat milk (0.70±0.78) and high-fat milk (0.47±0.72). A higher intake of high-fat dairy (RR_servings/day, 0.92, 95%CI 0.85-1.00), high-fat milk (0.89, 0.80-0.99), and total cheese (0.74, 0.56-0.96)was associated with lower prediabetes risk. Low-fat milk intake was associated non-linearly with prediabetes risk. Low-fat dairy foods, total milk, yogurt, low-fat cheese, and ice cream were not associated with prediabetes risk.

CONCLUSION

In this large Australian cohort, protective associations were found for high-fat dairy types, while neutral associations were seen for low-fat dairy. Studies with more detail on sugar content of types of dairy foods and products eaten with dairy foods (e.g., cereals or jam), as well as studies into potential causal mechanisms of the health effects of dairy intake are required.

Association of dairy consumption patterns with the incidence of type 2 diabetes: Findings from Alberta's Tomorrow Project

BACKGROUND AND AIMS

We aimed to extract dairy consumption patterns of men and women from a population-based cohort and then assess the association of each consumption pattern with incident T2D risk.

METHODS AND RESULTS

This prospective study was conducted within the framework of Alberta's Tomorrow Project (ATP), in which 8615 men and 15,016 women provided information on dietary intake by completing a food-frequency questionnaire at baseline, and then were followed up over time to determine the incidence of T2D via questionnaires. Principal Component Analysis (PCA) was used to extract dairy consumption patterns (DCPs). The association between each extracted pattern and T2D incidence was estimated using multivariable logistic regression models.The incidence of T2D among men and women was 3.8 and 3.2%, respectively, and the mean duration of follow-up was 5.2 years. Three major DCPs were identified. After controlling for potential confounders, the OR for risk of T2D in men in the highest compared with those in the lowest quartile of the DCP3 (whole milk, regular cheese, and non-fat milk as a beverage and in cereal) was 0.64 (95%CI: 0.47 to 0.88, P-trend=0.001), whereas it was not significant for women. DCP1 and DCP2 were not associated with incident T2D in men or women.

CONCLUSION

Adherence to a DCP characterized by higher consumption of whole milk, regular cheese, and non-fat milk was associated with decreased risk of incident T2D only in men. Our results support current evidence that a combination of different dairy products, regardless of their fat content, might be favorable for health maintenance, at least in men.

Early nutritional influences of cardiovascular health

INTRODUCTION

Increasing evidence shows that nutritional choices during children's formative years, including prenatally, impacts the development of adult onset cardiovascular diseases (CVDs), such as hypertension, myocardial infarction, or stroke.

AREAS COVERED

This literature review aims to synthesize the current body of evidence on nutritional factors, from conception through adolescence, which may influence a person's risk factors for future development of CVD.

EXPERT OPINION

Given the escalating healthcare costs associated with CVD, it is imperative that medical professionals and scientists remain steadfast in prioritizing and promoting early CVD prevention, even within the first few years of life. Though not the only contributing risk factor, diet is a modifiable risk factor and has been shown to have a profound impact on the reduction of cardiovascular morbidity and mortality in adult literature. Nutritional choices should be targeted on multiple levels: prenatally with the mother, individually with the patient, in conjunction with their family unit, and also within the broader community wherein they reside. Healthcare providers can play a key advocacy role for local and national food environment policy changes.

Whole-fat dairy products do not adversely affect adiposity or cardiometabolic risk factors in children in the Milky Way Study: a double-blind randomized controlled pilot study

BACKGROUND

Limited evidence supports the common public health guideline that children >2 y of age should consume dairy with reduced fat content.

OBJECTIVES

We aimed to investigate the effects of whole-fat compared with reduced-fat dairy intake on measures of adiposity and biomarkers of cardiometabolic risk in healthy 4- to 6-y-old children.

METHODS

The Milky Way Study enrolled 49 children (mean ± SD age: 5.2 ± 0.9 y; 47% girls) who were habitual consumers of whole-fat dairy, then randomly assigned them in a double-blind fashion to remain on whole-fat dairy or switch their dairy consumption to reduced-fat products for 3 mo. Primary endpoints included measures of adiposity, body composition, blood pressure, fasting serum lipids, blood glucose, glycated hemoglobin (HbA1c), and C-reactive protein (CRP) and were assessed at baseline and study end. Pre- and postintervention results were compared using linear mixed models, adjusted for growth, age, and sex.

RESULTS

Dairy fat intake was reduced by an adjusted (mean ± SEM) 12.9 ± 4.1 g/d in the reduced-fat compared with the whole-fat dairy group (95% CI: -21.2, -4.6 g/d; P = 0.003), whereas dietary energy intakes remained similar (P = 0.936). We found no significant differential changes between dairy groups in any measure of adiposity, body composition, blood pressure, or fasting serum lipids, glucose, HbA1c, and CRP.

CONCLUSIONS

Our results suggest that although changing from whole-fat to reduced-fat dairy products does reduce dairy fat intake, it does not result in changes to markers of adiposity or cardiometabolic disease risk in healthy children.This trial was registered at www.anzctr.org.au as ACTRN12616001642471.

Impact of low-fat and full-fat dairy foods on fasting lipid profile and blood pressure: exploratory endpoints of a randomized controlled trial

BACKGROUND

Dietary guidelines traditionally recommend low-fat dairy because dairy's high saturated fat content is thought to promote cardiovascular disease (CVD). However, emerging evidence indicates that dairy fat may not negatively impact CVD risk factors when consumed in foods with a complex matrix.

OBJECTIVE

The aim was to compare the effects of diets limited in dairy or rich in either low-fat or full-fat dairy on CVD risk factors.

METHODS

In this randomized controlled trial, 72 participants with metabolic syndrome completed a 4-wk run-in period, limiting their dairy intake to ≤3 servings/wk of nonfat milk. Participants were then randomly assigned to 1 of 3 diets, either continuing the limited-dairy diet or switching to a diet containing 3.3 servings/d of either low-fat or full-fat milk, yogurt, and cheese for 12 wk. Exploratory outcome measures included changes in the fasting lipid profile and blood pressure.

RESULTS

In the per-protocol analysis (n = 66), there was no intervention effect on fasting serum total, LDL, and HDL cholesterol; triglycerides; free fatty acids; or cholesterol content in 38 isolated plasma lipoprotein fractions (P > 0.1 for all variables in repeated-measures ANOVA). There was also no intervention effect on diastolic blood pressure, but a significant intervention effect for systolic blood pressure (P = 0.048), with a trend for a decrease in the low-fat dairy diet (-1.6 ± 8.6 mm Hg) compared with the limited-dairy diet (+2.5 ± 8.2 mm Hg) in post hoc testing. Intent-to-treat results were consistent for all endpoints, with the exception that systolic blood pressure became nonsignificant (P = 0.08).

CONCLUSIONS

In men and women with metabolic syndrome, a diet rich in full-fat dairy had no effects on fasting lipid profile or blood pressure compared with diets limited in dairy or rich in low-fat dairy. Therefore, dairy fat, when consumed as part of complex whole foods, does not adversely impact these classic CVD risk factors. This trial was registered at clinicaltrials.gov as NCT02663544.

The potential nutrition-, physical- and health-related benefits of cow's milk for primary-school-aged children

Cow's milk is a naturally nutrient-dense foodstuff. A significant source of many essential nutrients, its inclusion as a component of a healthy balanced diet has been long recommended. Beyond milk's nutritional value, an increasing body of evidence illustrates cow's milk may confer numerous benefits related to health. Evidence from adult populations suggests that cow's milk may have a role in overall dietary quality, appetite control, hydration and cognitive function. Although evidence is limited compared with the adult literature, these benefits may be echoed in recent paediatric studies. This article, therefore, reviews the scientific literature to provide an evidence-based evaluation of the associated health benefits of cow's milk consumption in primary-school-aged children (4-11 years). We focus on seven key areas related to nutrition and health comprising nutritional status, hydration, dental and bone health, physical stature, cognitive function, and appetite control. The evidence consistently demonstrates cow's milk (plain and flavoured) improves nutritional status in primary-school-aged children. With some confidence, cow's milk also appears beneficial for hydration, dental and bone health and beneficial to neutral concerning physical stature and appetite. Due to conflicting studies, reaching a conclusion has proven difficult concerning cow's milk and cognitive function; therefore, a level of caution should be exercised when interpreting these results. All areas, however, would benefit from further robust investigation, especially in free-living school settings, to verify conclusions. Nonetheless, when the nutritional-, physical- and health-related impact of cow's milk avoidance is considered, the evidence highlights the importance of increasing cow's milk consumption.

Is milk and dairy intake a preventive factor for elderly cognition (dementia and Alzheimer's)? A quality review of cohort surveys

Milk and dairy (M&D) is a longstanding human food with widespread use. Many studies showed the preventive capacity of M&D in several human health disorders, but its utility in others is under discussion. Aging has been associated to elderly cognitive decline including dementia-Alzheimer syndrome (Dem-AD). The absence of a therapy to impede or postpone Dem-AD determines the need for its prevention, including nutritional factors. To evaluate the preventive capacity of M&D consumption in elderly Dem-AD we performed a systematic review in the main biomedical databases and information resources, but we present this study as a narrative review to discuss better the complexity of this subject. The elderly Dem-AD has a long pre-symptomatic period and the M&D intake has a widespread use. These determinants and the quality flaws of published studies impeach us to answer whether M&D consumption is preventive for Dem-AD. Moreover, two long Japanese cohorts suggest that M&D intake could prevent Dem-AD. Prospective cohorts beginning in midlife (or early life) could answer this question in the future.

Whole-Fat or Reduced-Fat Dairy Product Intake, Adiposity, and Cardiometabolic Health in Children: A Systematic Review

Dietary guidelines commonly recommend that children aged >2 y consume reduced-fat dairy products rather than regular- or whole-fat dairy. In adults, most studies have not found the consumption of whole-fat dairy products to be associated with increased cardiometabolic or adiposity risk. Associations in children could differ due to growth and development. We systematically reviewed the literature in indexed, peer-reviewed journals to summarize pediatric studies (children aged from 2 to 18 y) assessing associations between whole- and reduced-fat dairy intake and measures of adiposity as well as biomarkers of cardiometabolic disease risk, including the serum lipid profile, blood pressure, low-grade chronic inflammation, oxidative stress, and measures of glucose homeostasis. For the purposes of this review, a "whole-fat" dairy product was defined as a product with the natural fat content, whereas a "reduced-fat" dairy product was defined as a product with some or all of the fat removed (including "low-fat" and "skim" versions). A total of 29 journal articles met our criteria for inclusion. The majority were conducted in the United States and were prospective or cross-sectional observational studies, with only 1 randomized controlled trial. Studies were consistent in reporting that whole-fat dairy products were not associated with increased measures of weight gain or adiposity. Most evidence indicated that consumption of whole-fat dairy was not associated with increased cardiometabolic risk, although a change from whole-fat to reduced-fat dairy improved outcomes for some risk factors in 1 study. Taken as a whole, the limited literature in this field is not consistent with dietary guidelines recommending that children consume preferably reduced-fat dairy products. High-quality randomized controlled trials in children that directly compare the effects of whole-fat compared with reduced-fat dairy intake on measures of adiposity or biomarkers of cardiometabolic disease risk are needed to provide better quality evidence in this area.

Science dialogue mapping of knowledge and knowledge gaps related to the effects of dairy intake on human cardiovascular health and disease

Dairy has been described as everything from a superfood to a poison; yet, arguments, assumptions, and data justifying these labels are not always clear. We used an issue-based information system, "dialogue mapping™," to summarize scientific points of a live panel discussion on the putative effects of dairy on cardiovascular diseases (CVD) from a day-long session among experts in nutrition and CVD. Dialogue mapping captures relations among ideas to explicitly, logically, and visually connect issues/questions, ideas, pro/con arguments, and agreements, even if discussed at different times. Experts discussed two propositions: for CVD risk, consumption of full-fat dairy products 1) should be minimized, in part because of their saturated fat content, or 2) need not be minimized, despite their saturated fat content. The panel discussed the dairy-CVD relation through blood lipids, diabetes, obesity, energy balance, blood pressure, dairy bioactives, biobehavioral components, and other putative causal pathways. Associations and effects reported in the literature have varied by fat content of dairy elements considered, study design, intake methods, and biomarker versus disease outcomes. Two conceptual topics emerged from the discussion: 1) individual variability: whether recommendations should be targeted only to those at high CVD risk; 2) quality of evidence: whether data on dairy-CVD relations are strong enough for reliable conclusions-positive, negative, or null. Future procedural improvements for science dialog mapping include using singular rather than competing propositions for discussion.

Cow milk does not affect adiposity in growing piglets as a model for children

The effect of milk consumption on childhood obesity is unclear and a direct demonstration of an association is needed. In the present study, we used piglets as a model for prepubertal children to determine the effect of milk on adipose tissue. Two studies were conducted: study 1 with 5-wk-old male piglets (n = 8) and study 2 with 8- to 9-wk-old male piglets (n = 12). The piglets were fed a normal growing diet and randomly assigned to receive daily either 750 mL of whole cow milk or an isocaloric maltodextrin solution (control). For approximately 12 wk, body weight, feed intake, and subcutaneous back fat thickness were determined ultrasonographically and recorded. At euthanasia, back and neck fat thicknesses were measured and samples of back fat were collected for adipose histology. In study 1, but not study 2, piglets receiving milk grew more and ate more compared with control. In study 1, both back fat and neck fat thickness were greater in the milk-fed piglets and they had a higher frequency of small adipocytes and a lower frequency of intermediate and large adipocytes compared with controls. In study 2, control pigs had a significantly greater frequency of intermediate adipocytes but the milk-fed piglets tended to have a higher frequency of the largest adipocytes. In conclusion, milk has no apparent causal or consistent effect on adipose tissue in growing piglets.

Dairy product consumption and development of cancer: an overview of reviews

OBJECTIVES

To provide a comprehensive systematic overview of current evidence from pooled analyses/meta-analyses and systematic reviews (PMASRs) pertaining to dairy consumption and incident cancer and/or all-cause or cancer-specific mortality.

DESIGN

Overview of reviews.

SETTING

Community setting.

PARTICIPANTS

The unit of analysis is PMASRs. A total of 42 PMASRs was included in this overview of reviews.

INTERVENTIONS/EXPOSURES

Any dairy product consumption (eg, milk, yogurt, etc).

PRIMARY AND SECONDARY OUTCOMES MEASURES

Primary outcome measure is development of any type of cancer. Secondary outcome measures are all-cause mortality and cancer-specific mortality.

RESULTS

From 9693 citations identified, we included 42 PMASRs (52 study reports) published between 1991 and 2017. Thirty-one (74%) of these was pooled analyses/meta analyses, and only 11 (26%) were systematic reviews and meta-analyses. There was a wide variability in the type of study designs included within the other PMASRs, thus contributing to variable and, in instances, divergent estimates of cancer risk for several cancer subtypes. For example, only one systematic review and meta-analysis exclusively included prospective study designs. Most PMASRs were of low to moderate quality based on the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) scores. The median AMSTAR score was 5 (IQR 2-7). Our overview identified conflicting evidence from PMASRs on association between dairy consumption and incident cancers or mortality. Heterogeneity in summary estimates reflected the inclusion of variable study designs and overall low methodological quality of individual PMASRs.

CONCLUSIONS

The association between dairy consumption and cancer risk has been explored in PMASRs with a variety of study designs and of low to moderate quality. To fully characterise valid associations between dairy consumption and risk of cancer and/or mortality rigorously conducted, PMASRs including only high-quality prospective study designs are required.

TRIAL REGISTRATION NUMBER

CRD42017078463.

Health and nutritional aspects of sustainable diet strategies and their association with environmental impacts: a global modelling analysis with country-level detail

BACKGROUND

Sustainable diets are intended to address the increasing health and environmental concerns related to food production and consumption. Although many candidates for sustainable diets have emerged, a consistent and joint environmental and health analysis of these diets has not been done at a regional level. Using an integrated health and environmental modelling framework for more than 150 countries, we examined three different approaches to sustainable diets motivated by environmental, food security, and public health objectives.

METHODS

In this global modelling analysis, we combined analyses of nutrient levels, diet-related and weight-related chronic disease mortality, and environmental impacts for more than 150 countries in three sets of diet scenarios. The first set, based on environmental objectives, replaced 25-100% of animal-source foods with plant-based foods. The second set, based on food security objectives, reduced levels of underweight, overweight, and obesity by 25-100%. The third set, based on public health objectives, consisted of four energy-balanced dietary patterns: flexitarian, pescatarian, vegetarian, and vegan. In the nutrient analysis, we calculated nutrient intake and changes in adequacy based on international recommendations and a global dataset of nutrient content and supply. In the health analysis, we estimated changes in mortality using a comparative risk assessment with nine diet and weight-related risk factors. In the environmental analysis, we combined country-specific and food group-specific footprints for greenhouse gas emissions, cropland use, freshwater use, nitrogen application, and phosphorus application to analyse the relationship between the health and environmental impacts of dietary change.

FINDINGS

Following environmental objectives by replacing animal-source foods with plant-based ones was particularly effective in high-income countries for improving nutrient levels, lowering premature mortality (reduction of up to 12% [95% CI 10-13] with complete replacement), and reducing some environmental impacts, in particular greenhouse gas emissions (reductions of up to 84%). However, it also increased freshwater use (increases of up to 16%) and had little effectiveness in countries with low or moderate consumption of animal-source foods. Following food-security objectives by reducing underweight and overweight led to similar reductions in premature mortality (reduction of up to 10% [95% CI 9-11]), and moderately improved nutrient levels. However, it led to only small reductions in environmental impacts at the global level (all impacts changed by <15%), with reduced impacts in high-income and middle-income countries, and increased resource use in low-income countries. Following public health objectives by adopting energy-balanced, low-meat dietary patterns that are in line with available evidence on healthy eating led to an adequate nutrient supply for most nutrients, and large reductions in premature mortality (reduction of 19% [95% CI 18-20] for the flexitarian diet to 22% [18-24] for the vegan diet). It also markedly reduced environmental impacts globally (reducing greenhouse gas emissions by 54-87%, nitrogen application by 23-25%, phosphorus application by 18-21%, cropland use by 8-11%, and freshwater use by 2-11%) and in most regions, except for some environmental domains (cropland use, freshwater use, and phosphorus application) in low-income countries.

INTERPRETATION

Approaches for sustainable diets are context specific and can result in concurrent reductions in environmental and health impacts globally and in most regions, particularly in high-income and middle-income countries, but they can also increase resource use in low-income countries when diets diversify. A public health strategy focused on improving energy balance and dietary changes towards predominantly plant-based diets that are in line with evidence on healthy eating is a suitable approach for sustainable diets. Updating national dietary guidelines to reflect the latest evidence on healthy eating can by itself be important for improving health and reducing environmental impacts and can complement broader and more explicit criteria of sustainability.

FUNDING

Wellcome Trust, EAT, CGIAR, and British Heart Foundation.

Association between excess weight and beverage portion size consumed in Brazil

OBJECTIVE To describe the beverage portion size consumed and to evaluate their association with excess weight in Brazil. METHODS We used data from the National Dietary Survey, which included individuals with two days of food record aged over 20 years (n = 24,527 individuals). The beverages were categorized into six groups: soft drink, 100% fruit juice, fruit drink, alcoholic beverage, milk, and coffee or tea. We estimated the average portion consumed for each group and we evaluated, using linear regression, the association between portion size per group and the variables of age, sex, income, and nutritional status. We tested the association between portion size and excess weight using Poisson regression, adjusted for age, sex, income, and total energy intake. RESULTS The most frequently consumed beverages in Brazil were coffee and tea, followed by 100% fruit juices, soft drinks, and milk. Alcoholic beverages presented the highest average in the portion size consumed, followed by soft drinks, 100% fruit juice, fruit drink, and milk. Portion size showed positive association with excess weight only in the soft drink (PR = 1.19, 95%CI 1.10-1.27) and alcoholic beverage groups (PR = 1.20, 95%CI, 1.11-1.29), regardless of age, sex, income, and total energy intake. CONCLUSIONS Alcoholic beverages and soft drinks presented the highest averages in portion size and positive association with excess weight. Public health interventions should address the issue of portion sizes offered to consumers by discouraging the consumption of large portions, especially sweetened and low nutritional beverages.

Can Latino food trucks (loncheras) serve healthy meals? A feasibility study

OBJECTIVE

To conduct a pilot study to assess the feasibility of modifying food truck meals to meet the My Plate guidelines as well as the acceptability of healthier meals among consumers.

DESIGN

We recruited the owners of Latino food trucks (loncheras) in 2013-2014 and offered an incentive for participation, assistance with marketing and training by a bilingual dietitian. We surveyed customers and we audited purchases to estimate sales of the modified meals.

SETTING

City of Los Angeles, CA, USA.

SUBJECTS

Owners or operators of Latino food trucks (loncheras) and their customers.

RESULTS

We enrolled twenty-two lonchera owners and eleven completed the intervention, offering more than fifty new menu items meeting meal guidelines. Sales of the meals comprised 2 % of audited orders. Customers rated the meals highly; 97 % said they would recommend and buy them again and 75 % of participants who completed the intervention intended to continue offering the healthier meals. However, adherence to guidelines drifted after several months of operation and participant burden was cited as a reason for dropout among three of eleven lonchera owners who dropped out.

CONCLUSIONS

Lonchera owners/operators who participated reported minimal difficulty in modifying menu items. Given the difficulty in enrolment, expanding this programme and ensuring adherence would likely need to be accomplished through regulatory requirements, monitoring and feedback, similar to the methods used to achieve compliance with sanitary standards. A companion marketing campaign would be helpful to increase consumer demand.

Daily milk consumption and all-cause mortality, coronary heart disease and stroke: a systematic review and meta-analysis of observational cohort studies

BACKGROUND

Observational studies and meta-analyses relating milk consumption by adults to all-cause mortality, coronary heart disease and stroke have obtained contradictory results. Some studies found a protective effect of milk consumption, whilst other found an increased risk.

METHODS

We performed a systematic literature search until June 2015 on prospective studies that looked at milk consumption, all-cause mortality, coronary heart disease and stroke. Random-effect meta-analyses were performed with dose-response.

RESULTS

Twenty-one studies involving 19 cohorts were included in this meta-analysis, 11 on all-cause mortality, 9 on coronary heart disease, and 10 on stroke. Milk intake ranged from 0 to 850 mL/d. The summary relative risk (SRR) for 200 mL/d milk consumption was 1.01 (95% CI: 0.96-1.06) for all-cause mortality, 1.01 (95% CI: 0.98-1.05) for fatal and non fatal coronary heart disease, and 0.91 (95% CI: 0.82-1.02) for fatal and non fatal stroke. Stratified analyses by age, Body Mass Index, total energy intake and physical acitivity did not alter the SRR estimates. The possibility of publication bias was found for all cause mortality and for stroke, indicating a gap in data that could have suggested a higher risk of these conditions with increased milk consumption.

CONCLUSIONS

We found no evidence for a decreased or increased risk of all-cause mortality, coronary heart disease, and stroke associated with adult milk consumption. However, the possibility cannot be dismissed that risks associated with milk consumption could be underestimated because of publication bias.

Yogurt consumption and abdominal obesity reversion in the PREDIMED study

BACKGROUND AND AIMS

Evidence on the association yogurt consumption and obesity is not conclusive. The aim of this study was to prospectively evaluate the association between yogurt consumption, reversion of abdominal obesity status and waist circumference change in elderly.

METHODS AND RESULTS

4545 individuals at high cardiovascular risk were prospectively followed. Total, whole-fat and low-fat yogurt consumption were assessed using food frequency questionnaires. Generalized estimating equations were used to analyze the association between yogurt consumption and waist circumference change (measured at baseline and yearly during the follow-up). Logistic regression models were used to evaluate the odds ratios (ORs) and 95% CIs of the reversion rate of abdominal obesity for each quintile of yogurt consumption compared with the lowest quintile. After multivariable adjustment, the average yearly waist circumference change in the quintiles of whole-fat yogurt consumption was: Q1: 0.00, Q2: 0.00 (-0.23 to 0.23), Q3: -0.15 (-0.42 to 0.13), Q4: 0.10 (-0.21 to 0.42), and Q5: -0.23 (-0.46 to -0.00) cm; p for trend = 0.05. The ORs for the reversion of abdominal obesity for whole-fat yogurt consumption were Q1: 1.00, Q2: 1.40 (1.04-1.90), Q3: 1.33 (0.94-1.89), Q4: 1.21 (0.83-1.77), and Q5: 1.43 (1.06-1.93); p for trend = 0.26.

CONCLUSION

Total yogurt consumption was not significantly associated with reversion of abdominal obesity status and a lower waist circumference. However, consumption of whole-fat yogurt was associated with changes in waist circumference and higher probability for reversion of abdominal obesity. Therefore, it seems that whole-fat yogurt has more beneficial effects in management of abdominal obesity in elderly population at high cardiovascular risk.

Regular Fat and Reduced Fat Dairy Products Show Similar Associations with Markers of Adolescent Cardiometabolic Health

Reduced fat dairy products are generally recommended for adults and children over the age of two years. However, emerging evidence suggests that dairy fat may not have detrimental health effects. We aimed to investigate prospective associations between consumption of regular versus reduced fat dairy products and cardiometabolic risk factors from early to late adolescence. In the West Australian Raine Study, dairy intake was assessed using semi-quantitative food frequency questionnaires in 860 adolescents at 14 and 17-year follow-ups; 582 of these also had blood biochemistry at both points. Using generalized estimating equations, we examined associations with cardiometabolic risk factors. Models incorporated reduced fat and regular fat dairy together (in serves/day) and were adjusted for a range of factors including overall dietary pattern. In boys, there was a mean reduction in diastolic blood pressure of 0.66 mmHg (95% CI 0.23-1.09) per serve of reduced fat dairy and an independent, additional reduction of 0.47 mmHg (95% CI 0.04-0.90) per serve of regular fat dairy. Each additional serve of reduced fat dairy was associated with a 2% reduction in HDL-cholesterol (95% CI 0.97-0.995) and a 2% increase in total: HDL-cholesterol ratio (95% CI 1.002-1.03); these associations were not observed with regular fat products. In girls, there were no significant independent associations observed in fully adjusted models. Although regular fat dairy was associated with a slightly better cholesterol profile in boys, overall, intakes of both regular fat and reduced fat dairy products were associated with similar cardiometabolic associations in adolescents.

‘It’s just so much waste.’ A qualitative investigation of food waste in a universal free School Breakfast Program

Objective

To understand stakeholders’ perspectives on food waste in a universal free School Breakfast Program implementing a Breakfast in the Classroom model.

Design

Semi-structured focus groups and interviews were conducted with school district stakeholders. Inductive methods were used to code resulting transcripts, from which themes were identified. The analysis provides a thematic analysis of stakeholders’ perspectives on food waste in the School Breakfast Program.

Setting

Ten elementary schools in a large urban school district implementing a universal free Breakfast in the Classroom model of the US national School Breakfast Program.

Subjects

Elementary-school students (n85), parents (n86), teachers (n44), cafeteria managers (n10) and school principals (n10).

Results

Stakeholders perceived food waste as a problem and expressed concern regarding the amount of food wasted. Explanations reported for food waste included food-related (palatability and accessibility), child-related (taste preferences and satiation) and programme-related (duration, food service policies, and coordination) factors. Milk and fruit were perceived as foods particularly susceptible to waste. Several food waste mitigation strategies were identified by participants: saving food for later, actively encouraging children’s consumption, assisting children with foods during mealtime, increasing staff support, serving smaller portion sizes, and composting and donating uneaten food.

Conclusions

Stakeholders recognized food waste as a problem, reported myriad contributing factors, and have considered and employed multiple and diverse mitigation strategies. Changes to the menu and/or implementation logistics, as well as efforts to use leftover food productively, may be possible strategies of reducing waste and improving the School Breakfast Program’s economic, environmental and nutritional impact.

The effects of changing dairy intake on trans and saturated fatty acid levels- results from a randomized controlled study

Background

Dairy food is an important natural source of saturated and trans fatty acids in the human diet. This study evaluates the effect of dietary advice to change dairy food intake on plasma fatty acid levels known to be present in milk in healthy volunteers.

Methods

Twenty one samples of whole fat dairy milk were analyzed for fatty acids levels. Changes in levels of plasma phospholipid levels were evaluated in 180 healthy volunteers randomized to increase, not change or reduce dairy intake for one month. Fatty acids were measured by gas chromatography–mass spectrometry and levels are normalized to d-4 alanine.

Results

The long chain fatty acids palmitic (13.4%), stearic (16.7%) and myristic (18.9%) acid were most common saturated fats in milk. Four trans fatty acids constituted 3.7% of the total milk fat content. Increased dairy food intake by 3.0 (± 1.2) serves/ day for 1 month was associated with small increases in plasma levels of myristic (+0.05, 95% confidence level-0.08 to 0.13, p = 0.07), pentadecanoic (+0.014, 95% confidence level -0.016 to 0.048, p = 0.02) and margaric acid (+0.02, -0.03 to 0.05, p = 0.03). There was no significant change in plasma levels of 4 saturated, 4 trans and 10 unsaturated fatty acids. Decreasing dairy food intake by 2.5 (± 1.2) serves per day was not associated with change in levels of any plasma fatty acid levels.

Conclusion

Dietary advice to change dairy food has a minor effect on plasma fatty acid levels.

Trial registration

ACTRN12612000574842.

Calcium intake and colorectal cancer risk: dose-response meta-analysis of prospective observational studies

Mechanistic and epidemiologic studies provide considerable evidence for a protective association between calcium intake and incident colorectal cancer (CRC). While the relationship has not been substantiated by short-duration randomized controlled trials (RCTs) of CRC, trials do show a benefit on adenomas, a precursor to CRC. To address some of this inconsistency, we conducted dose-response meta-analyses by sources of calcium intake, based on prospective observational studies published up to December 2013 identified from PubMed, Embase, and BIOSIS. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model. For total calcium intake, each 300 mg/day increase was associated with an approximately 8% reduced risk of CRC (summary RR = 0.92, 95% CI = 0.89-0.95, I(2)  = 47%, 15 studies with 12,305 cases, intake = 250-1,900 mg/day, follow-up = 3.3-16 years). While the risk decreased less steeply in higher range of total calcium intake (P(non-linearity)  = 0.04), the degree of curvature was mild and statistical significance of non-linearity was sensitive to one study. For supplementary calcium, each 300 mg/day increase was associated with an approximately 9% reduced risk of CRC (summary RR = 0.91, 95% CI = 0.86-0.98, I(2)  = 67%, six studies with 8,839 cases, intake = 0-1,150 mg/day, follow-up = 5-10 years). The test for non-linearity was not statistically significant (P(non-linearity)  = 0.11). In conclusion, both dietary and supplementary calcium intake may continue to decrease CRC risk beyond 1,000 mg/day. Calcium supplements and non-dairy products fortified with calcium may serve as additional targets in the prevention of CRC. RCTs of calcium supplements with at least 10 years of follow-up are warranted to confirm a benefit of calcium supplements on CRC risk.

Organic production enhances milk nutritional quality by shifting fatty acid composition: a United States-wide, 18-month study

Over the last century, intakes of omega-6 (ω-6) fatty acids in Western diets have dramatically increased, while omega-3 (ω-3) intakes have fallen. Resulting ω-6/ω-3 intake ratios have risen to nutritionally undesirable levels, generally 10 to 15, compared to a possible optimal ratio near 2.3. We report results of the first large-scale, nationwide study of fatty acids in U.S. organic and conventional milk. Averaged over 12 months, organic milk contained 25% less ω-6 fatty acids and 62% more ω-3 fatty acids than conventional milk, yielding a 2.5-fold higher ω-6/ω-3 ratio in conventional compared to organic milk (5.77 vs. 2.28). All individual ω-3 fatty acid concentrations were higher in organic milk—α-linolenic acid (by 60%), eicosapentaenoic acid (32%), and docosapentaenoic acid (19%)—as was the concentration of conjugated linoleic acid (18%). We report mostly moderate regional and seasonal variability in milk fatty acid profiles. Hypothetical diets of adult women were modeled to assess milk fatty-acid-driven differences in overall dietary ω-6/ω-3 ratios. Diets varied according to three choices: high instead of moderate dairy consumption; organic vs. conventional dairy products; and reduced vs. typical consumption of ω-6 fatty acids. The three choices together would decrease the ω-6/ω-3 ratio among adult women by ∼80% of the total decrease needed to reach a target ratio of 2.3, with relative impact “switch to low ω-6 foods” > “switch to organic dairy products” ≈ “increase consumption of conventional dairy products.” Based on recommended servings of dairy products and seafoods, dairy products supply far more α-linolenic acid than seafoods, about one-third as much eicosapentaenoic acid, and slightly more docosapentaenoic acid, but negligible docosahexaenoic acid. We conclude that consumers have viable options to reduce average ω-6/ω-3 intake ratios, thereby reducing or eliminating probable risk factors for a wide range of developmental and chronic health problems.

Effects of high and low fat dairy food on cardio-metabolic risk factors: a meta-analysis of randomized studies

IMPORTANCE

Clear guidelines on the health effects of dairy food are important given the high prevalence of obesity, cardiovascular disease and diabetes, and increasing global consumption of dairy food.

OBJECTIVE

To evaluate the effects of increased dairy food on cardio metabolic risk factors.

DATA SOURCES

Searches were performed until April 2013 using MEDLINE, Science Direct, Google,Embase, the Cochrane Central Register of Controlled Trials, reference lists of articles, and proceedings of major meetings.

STUDY SELECTION

Randomized controlled studies with healthy adults randomized to increased dairy food for more than one month without additional interventions.

DATA EXTRACTION AND SYNTHESIS

A standard list was used to extract descriptive, methodological and key variables from all eligible studies. If data was not included in the published report corresponding authors were contacted.

RESULTS

20 studies with 1677 participants with a median duration of dietary change of 26 (IQR 10-39) weeks and mean increase in dairy food intake of 3.6 (SD 0.92) serves/day were included. Increased dairy food intake was associated with a modest weight gain (+0.59, 95% confidence interval 0.34 to 0.84kg, p<0.0001) but no significant change in waist circumference (0.35 , -0.75 to 1.45 cm); insulin resistance (HOMA –IR -0.94 , -1.93 to 0.05 units); fasting glucose (0.87, -0.27 to 2.01 mg/dl); LDL-cholesterol (1.36 ,-2.38 to 5.09 mg/dl); HDL-cholesterol (0.45, -2.13 to 3.04 mg/dl); systolic (-0.13, -1.73 to 1.98 mmHg) and diastolic blood pressure (0.13, -1.73 to 1.98 mmHg) or C-reactive protein (-0.08, -0.63 to 0.48 mg/L). Results were similar for studies with low-fat and whole-fat dairy interventions.

LIMITATIONS

Most clinical trials were small and of modest quality. .

CONCLUSION

Increasing whole fat and low fat dairy food consumption increases weight but has minor effects on other cardio-metabolic risk factors.

TRIAL REGISTRATION ACTRN

Australian New Zealand Clinical Trials Registry ACTRN12613000401752, http://www.anzctr.org.au.

ETHICS APPROVAL NUMBER

NTX/10/11/115.