Milk Consumption and Mortality from All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis

A review of dairy food intake for improving health among black geriatrics in the US

The transition to older adulthood is generally marked by progressive declines in body composition, metabolism, cognitive function, and immunity. For socially disadvantaged geriatric populations such as Black Americans, this life stage may also include additional stressors, including dealing with discrimination, poor access to healthcare, and food insecurity. These types of chronic stressors are linked to a higher allostatic load, which is associated with accelerated biological aging, higher rates of adverse health outcomes, and an overall lower quality of life. Of the numerous factors involved in healthy aging, a growing body of research indicates that consuming a higher quality diet that is rich in fruits, vegetables, whole grains, protein foods, and dairy foods, is one of the most potent factors for helping to protect against age-related disease progression. Among the food groups listed above that are recommended by the 2020-2025 Dietary Guidelines for Americans dairy foods are unique in their ability to provide several of the essential nutrients (e.g., high-quality protein, calcium, potassium, vitamin B12, and vitamin D in fortified products) that are most often inadequately consumed by older Black Americans. However, dairy is the most inadequately consumed food group in the US, with older Black adults consuming fewer than half of the 3 daily recommended servings. Therefore, this review examines the current body of evidence exploring the links between dairy intake and age-related disease risk, with a special focus on health and disparities among older Black Americans. Overall, the evidence from most systematic reviews and/or meta-analyses focused on dairy intake and musculoskeletal health suggest that higher dairy intake across the life span, and especially from fermented and fortified products, is associated with better bone and muscle health outcomes in older adults. The evidence on dairy intake and neurocognitive and immune outcomes among older adults holds significant promise for potential benefits, but most of these results are sourced from individual studies or narrative reviews and are not currently corroborated in systematic reviews or meta-analyses. Additionally, most of the research on dairy intake and age-related disease risk has been performed in White populations and can only be extrapolated to Black populations. Nonetheless, older Black populations who do not meet the DGA recommended 3 servings of dairy per day due to lactose intolerance, restrictive dietary patterns, or for other reasons, are likely falling short of several of the nutritional requirements necessary to support healthy aging.

High consumption of dairy products and risk of major adverse coronary events and stroke in a Swedish population

The association between the consumption of dairy products and risk of CVD has been inconsistent. There is a lack of studies in populations with high intakes of dairy products. We aimed to examine the association between intake of dairy products and risk of incident major adverse coronary events and stroke in the Swedish Malmö Diet and Cancer cohort study. We included 26 190 participants without prevalent CVD or diabetes. Dietary habits were obtained from a modified diet history, and endpoint data were extracted from registers. Over an average of 19 years of follow-up, 3633 major adverse coronary events cases and 2643 stroke cases were reported. After adjusting for potential confounders, very high intakes of non-fermented milk (>1000 g/d) compared with low intakes (<200 g/d) were associated with 35 % (95 % CI (8, 69)) higher risk of major adverse coronary events. In contrast, moderate intakes of fermented milk (100-300 g/d) were associated with a lower risk of major adverse coronary events compared with no consumption. Intakes of cheese (only in women) and butter were inversely associated with the risk of major adverse coronary events. We observed no clear associations between any of the dairy products and stroke risk. These results highlight the importance of studying different dairy foods separately. Further studies in populations with high dairy consumption are warranted.

Food Sources of Animal Protein in Relation to Overall and Cause-Specific Mortality-Causal Associations or Confounding? An Analysis of the EPIC-Heidelberg Cohort

While prior prospective iso-caloric substitution studies show a robust association between higher intake of animal protein and risk of mortality, associations observed for mortality risk in relation to major food sources of animal protein have been generally more diverse. We used the EPIC-Heidelberg cohort to examine if confounding, notably, by smoking, adiposity, or alcohol intake, could cause inconsistencies in estimated mortality hazard ratios (HR) related to intake levels of different types of meat and dairy products. Higher intakes of red or processed meats, and lower intakes of milk or cheese, were observed among current heavy smokers, participants with obesity, or heavy alcohol drinkers. Adjusting for age, sex, and total energy intake, risk models showed increased all-cause, cardiovascular, and cancer-related mortality with higher red or processed meat intakes (HR ranging from 1.25 [95% confidence interval = 1.15-1.36] to 1.76 [1.46-2.12] comparing highest to lowest tertiles), but reduced risks for poultry, milk, or cheese (HR ranging from 0.55 [0.43-0.72] to 0.88 [0.81-0.95]). Adjusting further for smoking history, adiposity indices, alcohol consumption, and physical activity levels, the statistical significance of all these observed was erased, except for the association of processed meat intake with cardiovascular mortality (HR = 1.36 [CI = 1.13-1.64]) and cheese intake with cancer mortality (HR = 0.86 [0.76-0.98]), which, however, were substantially attenuated. These findings suggest heavy confounding and provide little support for the hypothesis that animal protein, as a nutrient, is a major determinant of mortality risk.

Dietary Recommendations for Ethiopians on the Basis of Priority Diet-Related Diseases and Causes of Death in Ethiopia: An Umbrella Review

Food-based dietary guidelines (FBDG) need to be evidence-based. As part of the development of Ethiopian FBDG, we conducted an umbrella review to develop dietary recommendations. Protein-energy malnutrition (PEM), deficiencies of vitamin A, zinc, calcium, or folate, cardiovascular diseases (CVD), and type 2 diabetes mellitus (T2DM) were selected as a priority. Systematic reviews were eligible if they investigated the impact of foods, food groups, diet, or dietary patterns on priority diseases. After a search, 1513 articles were identified in PubMed, Scopus, and Google Scholar published from January 2014 to December 2021. The results showed that 19 out of 164 systematic reviews reported the impact of diet on PEM or micronutrient deficiencies. Daily 30-90 g whole-grain consumption reduces risk of CVD and T2DM. Pulses improve protein status, and consuming 50-150 g/d is associated with a reduced incidence of CVD and T2DM. Nuts are a good source of minerals, and consuming 15-35 g/d improves antioxidant status and is inversely associated with CVD risk. A daily intake of 200-300 mL of milk and dairy foods is a good source of calcium and contributes to bone mineral density. Limiting processed meat intake to <50 g/d reduces CVD risk. Fruits and vegetables are good sources of vitamins A and C. CVD and T2DM risks are reduced by consuming 200-300 g of vegetables plus fruits daily. Daily sugar consumption should be below 10% of total energy to lower risk of obesity, CVD, and T2DM. Plant-based fat has favorable nutrient profiles and modest saturated fat content. The association of saturated fatty acids with CVD and T2DM is inconclusive, but intake should be limited because of the low-density lipoprotein cholesterol-raising effect. Plant-based diets lower risk of CVD and T2DM but reduce micronutrient bioavailability. The review concludes with 9 key dietary recommendations proposed to be implemented in the Ethiopian FBDG. This review was registered at PROSPERO (CRD42019125490).

Associations between dairy intake and mortality due to all-cause and cardiovascular disease: the Japan Public Health Center-based prospective study

BACKGROUND

Some studies have investigated the relation between dairy products and mortality, but with inconsistent results.

OBJECTIVE

We examined the association between the consumption of dairy products and the risk of all-cause, cancer-related, and cardiovascular disease (CVD)-related mortality.

METHODS

From the Japan Public Health Center-based Prospective (JPHC) study, 43,117 males and 50,193 females with no history of cancer or CVD finished the food frequency questionnaire (FFQ) and were included in the study. Intake of dairy products was assessed using the FFQ and adjusted for total energy by using the residual method. We used multivariate Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for mortality risk in males and females.

RESULTS

14,211 deaths in males and 9547 deaths in females from all causes were identified during an average follow-up of 19.3 years. For males, total dairy consumption was nonlinearly and significantly associated with lower risk of mortality from all causes [the third quartile, HR = 0.87 (0.83, 0.91), the fourth quartile, HR = 0.89 (0.85, 0.94), P for nonlinearity < 0.001] and CVD [the third quartile, HR = 0.77 (0.70, 0.85), the fourth quartile, HR = 0.78 (0.70, 0.86), P for nonlinearity < 0.001]. Milk and fermented milk intake were inversely associated with all-cause and CVD-related mortality in males. Cheese consumption was inversely associated with CVD-related mortality among males. There was no association between total dairy intake and mortality risk among females.

CONCLUSION

For Japanese people, consumption of dairy products was associated with a decreased risk of mortality from all-cause and cardiovascular diseases among males.

Human health risk surveillance of polychlorinated biphenyls in bovine milk from alluvial plain of Punjab, Pakistan

Punjab is the leading province of Pakistan in the production of bovine milk and its consumption. Rapid industrialization, high energy demand, and the production of waste have increased the risk of polychlorinated biphenyls (PCBs) toxicity in the environment. This research work was designed to assess human dietary exposure of ∑PCBs17 congeners through ingestion of buffalo and cow's milk from eight main districts of Punjab, Pakistan. The average concentrations of ∑DL-PCBs (8.74 ng g^-1 and 14.60 ng g^-1) and ∑I-PCBs (11.54 ng g^-1 and 18.68 ng g^-1) in buffalo and cow milk samples were analyzed, respectively. The PCB-156 was predominantly high congener found in both buffalo (2.84 ng g^-1) and cow milk (2.86 ng g^-1). It was found that the highest PCBs in bovine milk samples were observed in close vicinities of urban and industrial areas. The estimated daily consumptions of DL-PCBs and I-PCBs, from buffalo and cow milk, were below the acceptable daily intake for both adults and children. Moreover, hazard quotients (HQ) of the ∑PCBs17 congener value were less than 1.0 in adults and greater in the case of children reflecting the high chances of cancer. Furthermore, comprehensive monitoring for childhood cancer is recommended to establish the relationship in future studies.

Health effects of milk consumption: phenome-wide Mendelian randomization study

BACKGROUND

We performed phenome-wide Mendelian randomization analysis (MR-PheWAS), two-sample MR analysis, and systemic review to comprehensively explore the health effects of milk consumption in the European population.

METHODS

Rs4988235 located upstream of the LCT gene was used as the instrumental variable for milk consumption. MR-PheWAS analysis was conducted to map the association of genetically predicted milk consumption with 1081 phenotypes in the UK Biobank study (n=339,197). The associations identified in MR-PheWAS were examined by two-sample MR analysis using data from the FinnGen study (n=260,405) and international consortia. A systematic review of MR studies on milk consumption was further performed.

RESULTS

PheWAS and two-sample MR analyses found robust evidence in support of inverse associations of genetically predicted milk consumption with risk of cataract (odds ratio (OR) per 50 g/day increase in milk consumption, 0.89, 95% confidence interval (CI), 0.84-0.94; p=3.81×10^-5), hypercholesterolemia (OR, 0.91, 95% CI 0.86-0.96; p=2.97×10^-4), and anal and rectal polyps (OR, 0.85, 95% CI, 0.77-0.94; p=0.001). An inverse association for type 2 diabetes risk (OR, 0.92, 95% CI, 0.86-0.97; p=0.003) was observed in MR analysis based on genetic data with body mass index adjustment but not in the corresponding data without body mass index adjustment. The systematic review additionally found evidence that genetically predicted milk consumption was inversely associated with asthma, hay fever, multiple sclerosis, colorectal cancer, and Alzheimer's disease, and positively associated with Parkinson's disease, renal cell carcinoma, metabolic syndrome, overweight, and obesity.

CONCLUSIONS

This study suggests several health effects of milk consumption in the European population.

The acute effects of milk intake on calcium homeostasis and cardiovascular outcome: A randomized crossover trial in postmenopausal women

OBJECTIVE

The importance of calcium intake from dairy in regard to cardiovascular health has been investigated in several studies with discrepant results. Hence, we aim to investigate the immediate effects of milk intake on cardiovascular function.

DESIGN

A randomized crossover study with at least 10 days for washout between the two interventions, 500 ml of water with 200 µg of cholecalciferol or 500 ml of semi-skimmed milk containing approximately 600 mg of calcium with 200 µg of cholecalciferol.

PATIENTS

Twenty community-based postmenopausal women aged 60-80 years.

MEASUREMENTS

Parathyroid hormone and ionized calcium were measured at baseline and after 2 and 4 h on each study day. Pulse wave analysis and velocity were measured at baseline and after 4 h on each study day.

RESULTS

Compared to water, milk intake increased ionized calcium levels by 0.02 mmol/L (p = .029) and decreased parathyroid hormone levels by 1.78 pmol/L (p < .001). The two interventions caused no changes as measured 4 h after the intervention in the following indices of cardiovascular health; pulse wave velocity, brachial diastolic or systolic blood pressure, central diastolic or systolic blood pressure, mean arterial pressure, pulse pressure, augmentation pressure, augmentation index, heart rate or pulse transit time.

CONCLUSIONS

Despite significant changes in calcium homeostasis with increased levels of ionized calcium following milk intake, no acute effects seem to occur on measures of cardiovascular health.

Underlying evidence for the health benefits of fermented foods in humans

Fermented foods (FFs) have been a part of our diets for millennia and comprise highly diverse products obtained from plants and animals all over the world. Historically, fermentation has been used to preserve food and render certain raw materials edible. As our food systems evolve towards more sustainability, the health benefits of FFs have been increasingly touted. Fermentation generates new/transformed bioactive compounds that may occur in association with probiotic bacteria. The result can be specific, advantageous functional properties. Yet, when considering the body of human studies on the topic, whether observational or experimental, it is rare to come across findings supporting the above assertion. Certainly, results are lacking to confirm the widespread idea that FFs have general health benefits. There are some exceptions, such as in the case of lactose degradation via fermentation in individuals who are lactose intolerant; the impact of select fermented dairy products on insulin sensitivity; or the benefits of alcohol consumption. However, in other situations, the results fail to categorically indicate whether FFs have neutral, beneficial, or detrimental effects on human health. This review tackles this apparent incongruity by showing why it is complex to test the health effects of FFs and what can be done to improve knowledge in this field.

Dietary sugars and subclinical vascular damage in moderate-to-high cardiovascular risk adults

BACKGROUND AND AIMS

The association between dietary sugars and vascular damage has been scarcely examined out of the context of established cardiovascular disease. We aimed to investigate the association between different types of sugars with subclinical atheromatosis and arteriosclerosis, in individuals free of cardiovascular disease being, however, at moderate-to-high cardiovascular risk.

METHODS AND RESULTS

Two 24-h dietary recalls were conducted to estimate sugars intake. Subclinical atheromatosis was assessed by B-mode ultrasonography and arteriosclerosis (arterial stiffness) via tonometry (carotid-to-femoral pulse wave velocity). Multiple logistic regression analysis was performed to determine the relationship of quartiles of total sugars, monosaccharides and disaccharides with atheromatosis and arteriosclerosis, adjusting for potential confounders [Odds Ratio (95%Confidence Interval)]. In 901 participants (52.4 ± 13.8 years, 45.2% males), total sugars intake was not associated with any type of subclinical vascular damage. Subjects at 4th quartile of lactose intake (15.3 ± 5.5 g/day) had lower probability to present atheromatosis compared to those at 1st quartile (0.00 ± 0.01 g/day) even in the fully adjusted model [0.586 (0.353-0.974)]. Subjects at 3rd quartile of total disaccharides intake and particularly sucrose (15.1 ± 2.2 g/day) had higher probability to present arteriosclerosis compared to those at 1st quartile (3.0 ± 1.9 g/day) even after adjustment for all potential confounders [2.213 (1.110-4.409)].

CONCLUSIONS

Overall, the present data suggest a distinct role of each type of sugars on vascular damage. These observations highlight the need for further studies investigating not only foods rich in sugars, but sugars as separate components of food as they probably contribute via different ways on the development of arterial pathologies.

Dairy Consumption, Lactase Persistence, and Mortality Risk in a Cohort From Southern Sweden

Background: Whether high dairy consumption is related to longevity is still unclear, and additional studies of prospective cohorts with high-quality dietary data from populations with wide consumption ranges are needed.

Objective: To examine the association between dairy consumption and mortality in a Swedish cohort.

Design: Among 26,190 participants (62% females, 45–73 years old) without diabetes and cardiovascular disease from the population-based Malmö Diet and Cancer cohort, 7,156 individuals died during a mean follow-up time of 19 years. Data on intake of dairy (non-fermented milk, fermented milk, cheese, cream and butter) were collected from 7 day food records and food questionnaires. A genetic marker (rs4988235) associated with lactase persistence was detected among 22,234 individuals born in Sweden.

Results: Higher intakes up to 1,000 g/day of non-fermented milk were associated with only marginal higher mortality rates after adjusting for potential confounders. However, intakes above 1,000 g/day (1.5% of the population) were associated with 34% (95% CI: 14, 59%, p-trend=0.002) higher mortality compared to that with < 200 g/day. Fermented milk and cheese intake were inversely associated with mortality. Cream showed a protective association only among men. Butter was not associated with mortality. CT/TT genotype carriers (i.e., individuals with lactase persistence) had a 27% higher reported consumption of non-fermented milk, and non-significant higher mortality risk (HR = 1.08; 95% CI = 0.96, 1.23; p = 0.20) than CC genotype carriers.

Conclusions: Higher mortality rates were mainly observed among participants consuming more than 1,000 g of non-fermented milk per day. In contrast, fermented milk and cheese were associated with lower mortality. Because dairy products differ in composition, it is important to examine them separately in their relation to health and disease. The use of a genetic variant as an objective marker of lactose-containing milk intake should be examined in relation to mortality in a larger population.

Association of dairy intake with all-cause, cancer, and cardiovascular disease mortality in Japanese adults: a 25-year population-based cohort

PURPOSE

The association between dairy intake and mortality remains uncertain, and evidence for the Japanese population is scarce. We aimed to investigate the association between dairy intake and all-cause, cancer, and cardiovascular disease (CVD) mortality in Japanese adults.

METHODS

A total of 34,161 participants (16,565 men and 17,596 women) aged 40-64 years without a history of cancer, myocardial infarction, or stroke at baseline were included in the analysis, using data from the Miyagi Cohort Study initiated in 1990. Milk, yogurt, and cheese intake were obtained using a validated food frequency questionnaire. Total dairy intake was calculated as the sum of milk, yogurt, and cheese intake and then categorized by quartile. The outcomes were all-cause, cancer, and CVD mortality. Cox proportional hazards regression models were used to estimate multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality risks.

RESULTS

During 750,016 person-years of follow-up, the total number of deaths was 6498, including 2552 deaths due to cancer and 1693 deaths due to CVD. There was no association between total dairy intake and all-cause, cancer, and CVD mortality for both men and women. We also examined the associations between subgroup dairy products and mortality. For milk and yogurt intake, our results suggest null associations. However, cheese intake was modestly associated with lower all-cause mortality in women; compared with non-consumers, the multivariable HRs (95%CIs) were 0.89 (0.81-0.98) for 1-2 times/month, 0.88 (0.78-1.00) for 1-2 times/week, and 0.89 (0.74-1.07) for 3 times/week or almost daily (p trend = 0.016).

CONCLUSION

Dairy intake was not associated with mortality in Japanese adults, except for limited evidence showing a modest association between cheese intake and a lower all-cause mortality risk in women.

Decreased risk of all-cause and heart-specific mortality is associated with low-fat or skimmed milk consumption compared with whole milk intake: A cohort study

BACKGROUND&AIMS

It is controversial to preferentially choose low-fat milk or full-fat items. This study aimed to investigate the association of total and cause-specific mortality with 2 g/100 g or ≤ 1 g/100 g low-fat milk consumption compared with whole milk in general population.

METHODS

Overall, 29,283 adults aged ≥20 years from US National Health and Nutrition Examination Survey 1999-2014 were recruited with a median follow-up of 8.3 years. The types of milk consumption at baseline (e.g., whole-fat, 2 g/100 g low-fat, and ≤1 g/100 g low-fat) were reported during in-house interviews. Hazard ratios for the associations between milk types and mortality were assessed with the weighted Cox proportional regression.

RESULTS

During 241,572 person-years of follow-up, 4170 deaths occurred including 730 heart disease-related deaths and 846 cancer deaths. Consumption of milk contained lower fat exhibited an inverse association with total and cardiovascular mortality after multivariable adjustment. Compared with participants consuming whole-fat milk, those consuming 2 g/100 g or ≤1 g/100 g low-fat milk had a 14%-22% decrease in total mortality (p trend ≤0.001). Individuals consuming 2 g/100 g and ≤1 g/100 g low-fat milk had hazard ratios (95%CI) of 0.73 (0.55-0.97) and 0.67 (0.49-0.91) for heart-related mortality (p trend = 0.009). No significant difference was noted between whole-fat and lower-fat milk for mortality due to cancer, Alzheimer's disease, or diabetes mellitus. A similar trend was noted in the stratification and sensitivity analyses.

CONCLUSION

Compared with whole milk, low-fat or skim milk intake was associated with reduced total and heart-related mortality. Low-fat milk may be more conducive than whole milk for promoting cardiovascular health in general adults.

Dairy product consumption reduces cardiovascular mortality: results after 8 year follow-up of ELSA-Brasil

PURPOSE

To investigate whether the consumption of dairy products and their subgroups is associated with the risk of death from cardiovascular disease (CVD) after 8-year follow-up, and verify if dairy products predict changes in high-sensitivity C-reactive protein (hs-CRP) between two follow-up visits of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS

Prospective study with 6671 participants without CVD at baseline. Consumption in grams/day of total dairy, full-fat and low-fat dairy, fermented dairy, and milk was obtained through a food frequency questionnaire and categorized into sex-specific quartiles. Cox regression and linear mixed-effect models were used to estimate associations of dairy products intake with death from CVD and changes in hs-CRP levels, respectively.

RESULTS

After adjustments, individuals in the 3rd and 4th quartiles of total dairy consumption presented, respectively, 62% (HR 0.38; 95% CI 0.15-0.99) and 64% (HR 0.36; 95% CI 0.14-0.94) lower hazards of death from CVD compared to the 1st quartile. Also, participants in the 4th quartile of milk consumption had 66% (HR 0.34; 95% CI 0.14-0.86) lower hazard to die from CVD, but only the 2nd quartile of full-fat dairy consumption indicated a lower hazard to die from CVD (HR 0.30; 95% CI 0.10-0.92). No association was observed between low-fat or fermented dairy products and cardiovascular mortality. Consumption of total dairy and their subgroups did not predict changes in hs-CRP levels after 4-year follow-up.

CONCLUSION

Results suggest beneficial effects of total dairy and milk, but only low-to-moderate full-fat dairy consumption, on the risk of death from CVD. Assuming true effects, public policies should encourage the consumption of dairy products, especially milk.

Biomarkers of dairy fat intake, incident cardiovascular disease, and all-cause mortality: A cohort study, systematic review, and meta-analysis

BACKGROUND

We aimed to investigate the association of serum pentadecanoic acid (15:0), a biomarker of dairy fat intake, with incident cardiovascular disease (CVD) and all-cause mortality in a Swedish cohort study. We also systematically reviewed studies of the association of dairy fat biomarkers (circulating or adipose tissue levels of 15:0, heptadecanoic acid [17:0], and trans-palmitoleic acid [t16:1n-7]) with CVD outcomes or all-cause mortality.

METHODS AND FINDINGS

We measured 15:0 in serum cholesterol esters at baseline in 4,150 Swedish adults (51% female, median age 60.5 years). During a median follow-up of 16.6 years, 578 incident CVD events and 676 deaths were identified using Swedish registers. In multivariable-adjusted models, higher 15:0 was associated with lower incident CVD risk in a linear dose-response manner (hazard ratio 0.75 per interquintile range; 95% confidence interval 0.61, 0.93, P = 0.009) and nonlinearly with all-cause mortality (P for nonlinearity = 0.03), with a nadir of mortality risk around median 15:0. In meta-analyses including our Swedish cohort and 17 cohort, case-cohort, or nested case-control studies, higher 15:0 and 17:0 but not t16:1n-7 were inversely associated with total CVD, with the relative risk of highest versus lowest tertile being 0.88 (0.78, 0.99), 0.86 (0.79, 0.93), and 1.01 (0.91, 1.12), respectively. Dairy fat biomarkers were not associated with all-cause mortality in meta-analyses, although there were ≤3 studies for each biomarker. Study limitations include the inability of the biomarkers to distinguish different types of dairy foods and that most studies in the meta-analyses (including our novel cohort study) only assessed biomarkers at baseline, which may increase the risk of misclassification of exposure levels.

CONCLUSIONS

In a meta-analysis of 18 observational studies including our new cohort study, higher levels of 15:0 and 17:0 were associated with lower CVD risk. Our findings support the need for clinical and experimental studies to elucidate the causality of these relationships and relevant biological mechanisms.

Pasteurized non-fermented cow's milk but not fermented milk is a promoter of mTORC1-driven aging and increased mortality

Recent epidemiological studies in Sweden, a country with traditionally high milk consumption, revealed that the intake of non-fermented pasteurized milk increased all-cause mortality in a dose-dependent manner. In contrast, the majority of epidemiological and clinical studies report beneficial health effects of fermented milk products, especially of yogurt. It is the intention of this review to delineate potential molecular aging mechanisms related to the intake of non-fermented milk versus yogurt on the basis of mechanistic target of rapamycin complex 1 (mTORC1) signaling. Non-fermented pasteurized milk via its high bioavailability of insulinotropic branched-chain amino acids (BCAAs), abundance of lactose (glucosyl-galactose) and bioactive exosomal microRNAs (miRs) enhances mTORC1 signaling, which shortens lifespan and increases all-cause mortality. In contrast, fermentation-associated lactic acid bacteria metabolize BCAAs and degrade galactose and milk exosomes including their mTORC1-activating microRNAs. The Industrial Revolution, with the introduction of pasteurization and refrigeration of milk, restricted the action of beneficial milk-fermenting bacteria, which degrade milk's BCAAs, galactose and bioactive miRs that synergistically activate mTORC1. This unrecognized behavior change in humans after the Neolithic revolution increased aging-related over-activation of mTORC1 signaling in humans, who persistently consume large quantities of non-fermented pasteurized cow's milk, a potential risk factor for aging and all-cause mortality.

Association of food expenditure with life expectancy in the United States, 2001-2014

OBJECTIVES

A healthy diet is associated with reduced risk for premature death; however, data on the association between food expenditure and life expectancy are scarce. The aim of this study was to determine the association of expenditure on food groups with life expectancy in men and women.

METHODS

This study used data from 1548 counties, representing >90% of the population of the United States from 2001 through the end of 2014. Multivariable adjusted Bayesian generalized linear models were used to assess the association of county-level expenditure on nine groups of individual food and combined healthy and unhealthy foods, and a constructed healthy diet score with life expectancy at 40 y of age by sex.

RESULTS

A 1-unit increase in the healthy diet score based on food expenditure was associated with a 0.07 y (95% confidence interval [CI], 0.05-0.10), 0.04 y (95% CI, 0.02-0.07), and 0.06 y (95% CI, 0.04-0.08) increase in county-level life expectancy among men alone, women alone, and men and women combined, respectively. Increasing expenditure on whole grains (estimate of per 1% increase 0.07; 95% CI, 0.03-0.11), fresh fruit and vegetables (0.06; 95% CI, 0.02-0.09), and dairy products (0.05; 95% CI, 0.03-0.07), as well as reducing expenditure on sugar-sweetened beverages (-0.02; 95% CI, -0.04 to -0.01) and processed red meat (-0.05; 95% CI, -0.08 to -0.02) showed a positive association with increased county-level life expectancy.

CONCLUSIONS

These findings may inform a nutritional measure against premature death and stagnation of increase in life expectancy.

Multi-omics analyses reveal relationships among dairy consumption, gut microbiota and cardiometabolic health

BACKGROUND

Little is known about the interplay among dairy intake, gut microbiota and cardiometabolic health in human prospective cohort studies.

METHODS

The present study included 1780 participants from the Guangzhou Nutrition and Health Study. We examined the prospective association between habitual dairy consumption (total dairy, milk, yogurt) and gut microbial composition using linear regression after adjusting for socio-demographic, lifestyle and dietary factors. The cross-sectional association of dairy-associated microbial features with cardiometabolic risk factors was examined with a linear regression model, adjusting for potential confounders. Serum metabolomic profiles were analyzed by partial correlation analysis.

FINDINGS

There was a significant overall difference in gut microbial community structure (β-diversity) comparing the highest with the lowest category for each of total dairy, milk and yogurt (P < 0.05). We observed that dairy-associated microbes and α-diversity indices were inversely associated with blood triglycerides, while positively associated with high-density lipoprotein cholesterol. A follow-up metabolomics analysis revealed the association of targeted serum metabolites with dairy-microbial features and cardiometabolic traits. Specifically, 2-hydroxy-3-methylbutyric acid, 2-hydroxybutyric acid and L-alanine were inversely associated with dairy-microbial score, while positively associated with triglycerides (FDR-corrected P < 0.1).

INTERPRETATION

Dairy consumption is associated with the gut microbial composition and a higher α-diversity, which provides new insights into the understanding of dairy-gut microbiota interactions and their relationship with cardiometabolic health.

FUNDING

This work was supported by the National Natural Science Foundation of China, Zhejiang Ten-thousand Talents Program, Westlake University and the 5010 Program for Clinical Researches of the Sun Yat-sen University.

MILK Symposium review: Foodborne diseases from milk and milk products in developing countries-Review of causes and health and economic implications

Dairy production is rapidly increasing in developing countries and making significant contributions to health, nutrition, environments, and livelihoods, with the potential for still greater contributions. However, dairy products can also contribute to human disease in many ways, with dairyborne disease likely being the most important. Health risks may be from biological, chemical, physical, or allergenic hazards present in milk and other dairy products. Lacking rigorous evidence on the full burden of foodborne and dairyborne disease in developing countries, we compiled information from different sources to improve our estimates. The most credible evidence on dairyborne disease comes from the World Health Organization initiative on the Global Burden of Foodborne Disease. This suggests that dairy products may has been responsible for 20 disability-adjusted life years per 100,000 people in 2010. This corresponds to around 4% of the global foodborne disease burden and 12% of the animal source food disease burden. Most of this burden falls on low- and middle-income countries (LMIC). However, the estimate is conservative. Weaker evidence from historical burden in high-income countries, outbreak reports from LMIC and high-income countries, and quantitative microbial risk assessment suggest that the real burden may be higher. The economic burden in terms of lost human capital is at least US$4 billion/yr in LMIC. Among the most important hazards are Mycobacterium bovis, Campylobacter spp., and non-typhoidal Salmonella enterica. The known burden of chemical hazards is lower but also more uncertain. Important chemical hazards are mycotoxins, dioxins, and heavy metals. Some interventions have been shown to have unintended and unwanted consequences, so formative research and rigorous evaluation should accompany interventions. For example, there are many documented cases in which women's control over livestock is diminished with increasing commercialization. Dairy co-operatives have had mixed success, often incurring governance and institutional challenges. More recently, there has been interest in working with the informal sector. New technologies offer new opportunities for sustainable dairy development.

High vs. low-fat dairy and milk differently affects the risk of all-cause, CVD, and cancer death: A systematic review and dose-response meta-analysis of prospective cohort studies

Considerable controversy exists regarding the association between milk and dairy consumption and mortality risk. The present systematic review and meta-analysis of prospective studies was undertaken to examine the association of high vs. low-fat dairy and milk consumption with mortality. We searched PubMed/Medline, ISI Web of Science, and Scopus databases through February 2020 for prospective cohort studies that reported the association between milk and dairy consumption and mortality risk. High-fat milk consumption was significantly associated with a greater risk of all-cause (Pooled ES: 1.15; 95% CI: 1.09-1.20, I²=24.5%, p = 0.22), CVD (Pooled ES: 1.09; 95% CI: 1.02-1.16, I²=4.5%, p = 0.38) and cancer mortality (Pooled ES: 1.17; 95% CI: 1.08-1.28, I²=30.1%, p = 0.19). However, total dairy consumption was associated with a lower risk of CVD mortality (Pooled ES: 0.93; 95% CI: 0.88-0.98, I²=59.7%, p = 0.001). Dose-response analysis revealed a significant non-linear association of total dairy consumption with all-cause and CVD mortality. Moreover, high-fat milk consumption was significantly associated with risk of cancer mortality in linear and non-linear dose-response analysis. In conclusion, we found high-fat milk consumption was associated with a higher risk of all-cause, CVD, and cancer mortality. However, total dairy consumption was associated with a lower risk of CVD mortality.

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.

In Vitro Protein Digestibility and Fatty Acid Profile of Commercial Plant-Based Milk Alternatives

Plant-based milk alternatives (PBMA) are a new popular food trend among consumers in Europe and North America. The forecast shows that PBMA will double their value by 2023. The objective of this study was to analyze the nutritional value of commercial products in terms of their fatty acid profile and protein digestibility from commercial PBMA. Eight commercially available PBMA were selected for fatty acid analysis, performed with gas chromatography of methylated fatty acids (GC-FAME), and, from these, four commercial products (almond drink, hemp drink, oat drink, and soy drink) were selected for a short-term in vitro protein digestibility (IVPD) analysis. The fatty acid analysis results showed that most of the products predominantly contained oleic acid (C18:1 ω-9) and linoleic acid (C18:2 ω-6). Hemp drink contained the highest omega-6/omega-3 (ω6/ω3) ratio among all tested products (3.43). Oat drink and almond drink were the PBMA with the highest short-term protein digestibility, non-significantly different from cow’s milk, while soy drink showed the lowest value of protein digestibility. In conclusion, PBMA showed a significant variability depending on the plant source, both in terms of fatty acid composition and protein digestibility. These results provide more in-depth nutritional information, for future product development, and for consumer’s choice.

Milk Consumption for the Prevention of Fragility Fractures

Results indicating that a high milk intake is associated with both higher and lower risks of fragility fractures, or that indicate no association, can all be presented in the same meta-analysis, depending on how it is performed. In this narrative review, we discuss the available studies examining milk intake in relation to fragility fractures, highlight potential problems with meta-analyses of such studies, and discuss potential mechanisms and biases underlying the different results. We conclude that studies examining milk and dairy intakes in relation to fragility fracture risk need to study the different milk products separately. Meta-analyses should consider the doses in the individual studies. Additional studies in populations with a large range of intake of fermented milk are warranted.

Intake of Fermented Dairy Products Induces a Less Pro-Inflammatory Postprandial Peripheral Blood Mononuclear Cell Gene Expression Response than Non-Fermented Dairy Products: A Randomized Controlled Cross-Over Trial

SCOPE

It is aimed to investigate how intake of high-fat meals composed of different dairy products with a similar fat content affects postprandial peripheral blood mononuclear cell (PBMC) expression of inflammation-related genes, as well as circulating inflammatory markers and metabolites.

METHODS AND RESULTS

Healthy subjects (n = 47) consume four different high-fat meals composed of either butter, cheese, whipped cream, or sour cream in a randomized controlled cross-over study. Fasting and postprandial PBMC gene expression, plasma metabolites, and circulating inflammatory markers are measured. Using a linear mixed model, it is found that expression of genes related to lymphocyte activation, cytokine signaling, chemokine signaling, and cell adhesion is differentially altered between the four meals. In general, intake of the fermented products cheese and sour cream reduces, while intake of the non-fermented products butter and whipped cream increases, expression of these genes. Plasma amino acid concentrations increase after intake of cheese compared to the other meals, and the amino acid changes correlate with several of the differentially altered genes.

CONCLUSION

Intake of fermented dairy products, especially cheese, induces a less inflammatory postprandial PBMC gene expression response than non-fermented dairy products. These findings may partly explain inconsistent findings in studies on health effects of dairy products.

Association of cardiovascular diseases with milk intake among general Chinese adults

BACKGROUND

The association of milk intake with cardiovascular disease (CVD) and cause-specific mortality remained controversial and evidence among the Chinese population was limited. We aimed to study the relationship between milk intake and CVDs among general Chinese adults.

METHODS

A total of 104,957 participants received questionnaire survey. Results of physical examination such as anthropometric measurements and biochemical tests during 2007 to 2008, demographic data and their information on milk intake were collected through standardized questionnaires. Cox proportional hazard regression models were used to calculate hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) of CVD incidence, cause-specific mortality and all-cause mortality related to milk intake. Restricted cubic splines (RCSs) were applied to examine dose-response associations.

RESULTS

Among the 91,757 participants with a median follow-up period of 5.8 years, we documented 3877 CVD cases and 4091 all-cause deaths. Compared with participants who never consumed milk, the multivariate-adjusted HRs (95% CIs) of CVD incidence for 1 to 150 g/day, 151 to 299 g/day, and ≥300 g/day were 0.94 (0.86-1.03) (P > 0.05), 0.77 (0.66-0.89) (P < 0.05), and 0.59 (0.40-0.89) (P < 0.05), respectively; each 100 g increase of daily milk intake was associated with 11% lower risk of CVD incidence (HR, 0.89; 95% CI: 0.85-0.94; P < 0.001), and 11% lower risk of CVD mortality (HR, 0.89; 95% CI: 0.82-0.97; P = 0.008) after adjustment for age, sex, residential area, geographic region, education level, family history of CVD, smoking, alcohol drinking, physical activity level, body mass index, and healthy diet status (ideal or not). RCS analyses also showed a linear dose-response relationship with CVD (P for overall significance of the curve <0.001; P for non-linearity = 0.979; P for linearity <0.001) and stroke (P for overall significance of the curve = 0.010; P for non-linearity = 0.998; P for linearity = 0.002) incidence, and CVD mortality (P for overall significance of the curve = 0.045; P for non-linearity = 0.768; P for linearity = 0.014) within the current range of daily milk intake.

CONCLUSIONS

Daily milk intake was associated with lower risk of CVD incidence and mortality in a linear inverse relationship. The findings provide new evidence for dietary recommendations in CVD prevention among Chinese adults and people with similar dietary pattern in other countries.

Yogurt consumption in relation to mortality from cardiovascular disease, cancer, and all causes: a prospective investigation in 2 cohorts of US women and men

BACKGROUND

Although a link between regular yogurt consumption and mortality appears plausible, data are sparse and have yielded inconsistent results.

OBJECTIVES

We examined the association between regular yogurt consumption and risk of all-cause and cause-specific mortality among US women and men.

METHODS

A total of 82,348 women in the Nurses' Health Study and 40,278 men in the Health Professionals Follow-Up Study without a history of cardiovascular disease (CVD) and cancer in 1980 (women) or 1986 (men) were followed up until 2012. Yogurt consumption was assessed by updated validated FFQs.

RESULTS

During 3,354,957 person-years of follow-up, 20,831 women and 12,397 men died. Compared with no yogurt consumption, the multivariable-adjusted HRs (95% CIs) of mortality were 0.89 (0.86, 0.93), 0.85 (0.81, 0.89), 0.88 (0.84, 0.91), and 0.91 (0.85, 0.98) for ≤1-3 servings/mo, 1 serving/wk, 2-4 servings/wk, and >4 servings/wk in women (P-trend = 0.34), respectively. For men, the corresponding HRs (95% CIs) were 0.99 (0.94, 1.03), 0.98 (0.91, 1.05), 1.04 (0.98, 1.10), and 1.05 (0.95, 1.16), respectively. We further noted inverse associations for cancer mortality (multivariable-adjusted HR comparing extreme categories: 0.87; 95% CI: 0.78, 0.98; P-trend = 0.04) and CVD mortality (HR: 0.92; 95% CI: 0.79, 1.08; P-trend = 0.41) in women, although the latter was attenuated in the multivariable-adjusted model. Replacement of 1 serving/d of yogurt with 1 serving/d of nuts (women and men) or whole grains (women) was associated with a lower risk of all-cause mortality, whereas replacement of yogurt with red meat, processed meat (women and men), and milk or other dairy foods (women) was associated with a greater mortality.

CONCLUSIONS

In our study, regular yogurt consumption was related to lower mortality risk among women. Given that no clear dose-response relation was apparent, this result must be interpreted with caution.

The Relationship Between Healthy Eating Motivation and Protein Intake in Community-Dwelling Older Adults With Varying Functional Status

In older adults, the relationship between healthy eating motivation (HEM) and protein intake as key component of a healthy diet is poorly understood. Therefore, we investigate the association of HEM with (1) total protein intake and (2) intake of different protein sources in older adults with varying functional status. In this cross-sectional study including 250 adults (≥70 years), we assessed HEM with “The Eating Motivation Survey” and protein intake by 7-day food records. In addition, gender, age, Body Mass Index (BMI), energy intake and functional status were considered. Regression analyses revealed that HEM was neither related to total (β = −0.02; p = 0.723) nor to relative protein intake (β = 0.04; p = 0.370). Notwithstanding this, participants with stronger HEM showed lower intake of protein from meat and meat products (β = −0.14; p = 0.018), higher intake of overall plant-based protein (β = 0.11; p = 0.032), protein from fruit and vegetables (β = 0.20; p = 0.002) and from pulses, nuts an seeds (β = 0.16; p = 0.016). Our findings suggest HEM as a valuable indicator for intake of distinct protein sources. However, since HEM is not related to total protein intake, the importance of sufficient protein consumption should be emphasized by promoting healthy eating, regardless of self-perceived HEM.

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.

Yogurt Intake Reduces All-Cause and Cardiovascular Disease Mortality: A Meta-Analysis of Eight Prospective Cohort Studies

OBJECTIVE

To assess the relationship between yogurt intake and mortality risk from prospective cohort studies.

METHODS

The PubMed, EMBASE, and Web of Science databases were searched for all records related to yogurt intake and mortality risk [all-cause or cardiovascular disease (CVD) or cancer mortality] before October 1, 2018. The Newcastle-Ottawa Quality Scale was used to estimate the quality of all eligible articles. The results of the highest and lowest categories of yogurt intake in each study were collected and the effect size was pooled using a random effects model. The dose-response analysis was calculated using the generalized least squares trend estimation model.

RESULTS

Eight eligible cohort studies were included in this meta-analysis. There were 235,676 participants in the 8 studies, and the number of deaths was 14,831. Compared with the lowest category, the highest category of yogurt intake was not significantly related with all-cause mortality [hazard ratio (HR)=0.93; 95% confidence interval (CI): 0.85, 1.01], CVD mortality (HR=0.92; 95% CI: 0.81, 1.03) and cancer mortality (HR=0.97; 95% CI: 0.83, 1.12). These studies were homogenous, since the homogeneity test showed that I² was 28.7%, 15.1% and 11.8%, respectively. However, yogurt intake ⩾200 g/d was significantly associated with a lower all-cause mortality (HR=0.88; 95% CI: 0.80, 0.96) and CVD mortality (HR=0.87; 95% CI: 0.77, 0.99) in the subgroup analysis. The dose-response analysis showed that yogurt intake of 200 g/d was inversely associated with all-cause mortality (P=0.041, HR=0.95, 95% CI: 0.92, 1.00) and CVD mortality (P=0.009, HR=0.92, 95% CI: 0.86, 0.98), and all of which were linear relationship (P>0.05).

CONCLUSIONS

This review provided the evidence regarding yogurt intake can reduce all-cause and CVD mortality. Although some positive findings were identified, more high-quality cohort studies and randomized controlled trials are warranted on a possible protective effect of yoghurt on health.

Association of supplemental calcium and dairy milk intake with all-cause and cause-specific mortality in the UK Biobank: a prospective cohort study

Excessive Ca intakes have been proposed to associate with vascular calcification and a higher risk of prostate cancer. We investigated the associations of supplemental and dietary Ca intake with mortality using data from 497 828 UK Biobank participants. The average follow-up was 4·2 years and 14 255 participants died, 8297 from cancer, 2959 from CVD and 572 from respiratory disease. The use of Ca supplements and milk consumption were associated with differences in mortality in younger (≤65 years) but not in older participants (>65 years, Pinteraction ≤ 0·04 for all comparisons). Among participants <65 years, there was an inverse association between Ca supplementation (OR 0·91, 95 % CI 0·83, 0·99) and milk consumption (OR 0·93, 95 % CI 0·86, 1·00) with respect to all-cause mortality. In the same age group, milk drinkers had lower odds of cancer mortality (OR 0·89, 95 % CI 0·80, 0·98) but Ca supplement use was associated with increased odds of respiratory mortality (OR 1·69, 95 % CI 1·16, 2·74). All associations in participants aged ≥65 years were null after full adjustment. In sensitivity analyses stratified by hormone replacement therapy, Ca supplement use was associated with decreased odds of cancer mortality in users but increased risk in other women (OR 0·81, 95 % CI 0·69, 0·94 v. OR 1·17, 95 % CI 1·01, 1·35, respectively). To conclude, we saw little evidence for harm with dietary or supplemental Ca. Further studies are required to confirm the proposed interaction with hormone replacement therapy and to exclude reverse causation as a determinant in the association between Ca supplements and increased risk of respiratory diseases.

Meta-Analysis and Meta-Regression Indicate Dynamic Prevalence and Moderators of Foodborne Pathogens in African Indigenous Fermented Milk

As more microbiological data for indigenous fermented milk (IFM) becomes available, concern about their microbial safety becomes eminent. Nonetheless, these data are highly fragmented, and a tool is required to integrate existing data and to provide a basis for data-driven decision making for IFM’s safety. Therefore, meta-analysis and meta-regression were conducted to estimate the prevalence of foodborne pathogens in IFM and to determine factors influencing the estimated values. Using Africa as a case, searches were systematically made for published data and relevant grey literature. Data from 18 studies in 15 countries were analyzed. Staphylococcus aureus (37%), pathogenic Escherichia coli (16%), Listeria monocytogenes (6%), and Salmonella spp. (3%) were the most prevalent pathogens with a pooled prevalence estimate of 12%. Heterogeneity among prevalence estimates was attributed to sampling point and microbial group but could be moderated by publication year, country cluster, and methods for microbial confirmation. The pooled prevalence estimates increased over time as more studies became available, whereby the odds were higher in studies from 2010 onwards than studies before 2010. From the analyses, S. aureus presented the greatest safety concern in African IFM. Future microbiological studies should take into consideration different IFM sampling points and advanced analytical methods to identify pathogens.

Associations of dairy product consumption with mortality in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy cohort

BACKGROUND

The relation of dairy product consumption to health and mortality is controversial.

OBJECTIVES

We investigated associations of consumption of various dairy products with mortality in the Italian cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy study.

METHODS

Dairy product consumption was assessed by validated semiquantitative FFQs. Multivariable Cox models stratified by center, age, and sex and adjusted for confounders estimated associations of milk (total, full fat, and reduced fat), yogurt, cheese, butter, and dairy calcium consumption with mortality for cancer, cardiovascular disease, and all causes. Nonlinearity was tested by restricted cubic spline regression.

RESULTS

After a median follow-up of 14.9 y, 2468 deaths were identified in 45,009 participants: 59% from cancer and 19% from cardiovascular disease. No significant association of consumption of any dairy product with mortality was found in the fully adjusted models. A 25% reduction in risk of all-cause mortality was found for milk intake from 160 to 120 g/d (HR: 0.75; 95% CI: 0.61, 0.91) but not for the highest (>200 g/d) category of intake (HR: 0.95; 95% CI: 0.84, 1.08) compared with nonconsumption. Associations of full-fat and reduced-fat milk consumption with all-cause and cause-specific mortality were similar to those for milk as a whole.

CONCLUSIONS

In this Italian cohort characterized by low to average milk consumption, we found no evidence of a dose-response association between milk consumption and mortality and also no association of consumption of other dairy products investigated with mortality.

Technical position on milk and its derivatives in adult health and disease from the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Gerontología y Geriatría

Milk is a liquid food that possesses an important quantity of highly bioavailable macronutrients. In addition, it is readily accessible, as well as relatively inexpensive. Given that the knowledge of physicians about nutrition and food composition is deficient, in general, many of the dietary interventions recommended in diverse clinical settings lack a scientific basis. The aim of the present review was to produce a technical opinion that serves as a frame of reference to best sustain recommendations for consuming milk and dairy products as daily nutrition in the adult and older adult. The effects of milk and dairy products during the pediatric stage are not addressed in the present work. The Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Gerontología y Geriatría jointly discussed and analyzed topics dealing with the legal designation of milk, the classification and nutritional profile of cow's milk, its nutritional characteristics, its consumption in the adult, intolerance to cow's milk, and associations of milk consumption with digestive tract alterations and other conditions. Finally, certain aspects of milk consumption in the older adult and its relation to overall health are briefly discussed.

Dairy Products: Is There an Impact on Promotion of Prostate Cancer? A Review of the Literature

This review of the literature aims to study potential associations between high consumption of milk and/or dairy products and prostate cancer (PC). Literature is scarce, yet there is a direct relationship between mTORC1 activation and PC; several ingredients in milk/dairy products, when in high concentrations, increase signaling of the mTORC1 pathway. However, there are no studies showing an unequivocal relationship between milk products PC initiation and/or progression. Three different reviews were conducted with articles published in the last 5 years: (M1) PC and intake of dairy products, taking into account the possible mTORC1signaling mechanism; (M2) Intake of milk products and incidence/promotion of PC; (M3) mTORC1 activation signaling pathway, levels of IGF-1 and PC; (M4) mTORC pathway and dairy products. Of the 32 reviews identified, only 21 met the inclusion criteria and were analyzed. There is little scientific evidence that directly link the three factors: incidence/promotion of PC, intake of dairy products and PC, and PC and increased mTORC1 signaling. Persistent hyper-activation of mTORC1 is associated with PC promotion. The activity of exosomal mRNA in cellular communication may lead to different impacts of different types of milk and whether or not mammalian milks will have their own characteristics within each species. Based on this review of the literature, it is possible to establish a relationship between the consumption of milk products and the progression of PC; we also found a possible association with PC initiation, hence it is likely that the intake of dairy products should be reduced or minimized in mens' diet.

Characterization of the in situ pellicle ultrastructure formed under the influence of bovine milk and milk protein isolates

OBJECTIVES

The present study aimed to investigate if bovine milk or milk protein isolates, respectively, alter the ultrastructure of thein situ pellicle and might therefore have an influence on oral health.

METHODS

In situ pellicle samples were formed on bovine enamel slabs exposed in the oral cavity of three subjects for 6, 30, 60 or 120 min. After 3 min of pellicle formation, mouthrinses were performed for 3 min with (non-)homogenized UHT- or fresh milk (0.3% or 3.8% fat), 30% UHT-treated cream or different types of casein- or milk protein isolates containing preparations. The specimens were removed after the exposure times and transmission electron microscopy (TEM) was performed. Native pellicle samples served as controls.

RESULTS

Topical ultrastructural pellicle modifications were detected after mouthrinses with all types of homogenized UHT- or fresh milk and after the application of a 3% native casein micelles containing experimental solution. Atypical globular protein structures, identified as casein micelles, were temporarily adsorbed onto the pellicle. They were closely associated with lipid droplets. Furthermore, the mouthrinses occasionally affected the morphology of salivary bacteria. However, no notable ultrastructural alterations remained after 120 min of pellicle formation.

CONCLUSION

For the first time, bovine milk- and micellar casein-induced pellicle modifications were revealed by TEM. The adsorption of micellar casein is possibly due to its molecular interactions.

CLINICAL SIGNIFICANCE

Bovine milk or micellar caseins provide some potential for the development of preventive strategies against bacterial biofilm formation or erosive processes at the tooth surface.

Milk and Dairy Product Consumption and Risk of Mortality: An Overview of Systematic Reviews and Meta-Analyses

The effect of dairy product consumption on health has received substantial attention in the last decade. However, a number of prospective cohort studies have shown contradictory results, which causes uncertainty about the effects of dairy products on health. We conducted an overview of existing systematic reviews and meta-analyses to examine the association between dairy product consumption and all-cause mortality risk. A literature search was conducted in MEDLINE (via PubMed), EMBASE, the Cochrane Central Database of Systematic Reviews, and the Web of Science databases from their inception to April, 2018. We evaluated the risk of bias of each study included using the AMSTAR 2 tool. The risk ratios (RRs) for each meta-analysis were displayed in a forest plot for dose-response and for high compared with low dairy consumption. The initial search retrieved 2154 articles; a total of 8 meta-analyses were finally included after applying the inclusion and exclusion criteria. The number of included studies in each meta-analysis ranged from 6 to 26 cohort studies, which reported data from 6-28 populations. The sample sizes varied across studies from 24,466 participants reporting 5092 mortality cases to 938,817 participants reporting 126,759 mortality cases. After assessing the risk of bias, 25% of the studies were categorized as acceptable, 25% as good, and 50% as very good. The RRs reported by the meta-analyses ranged from 0.96 to 1.01 per 200 g/d of dairy product consumption (including total, high-fat, low-fat, and fermented dairy products), from 0.99 to 1.01 per 200-244 g/d of milk consumption, and from 0.99 to 1.03 per 10-50 g/d of cheese consumption. The RR per 50 g/d of yogurt consumption was 0.97 (95% CI: 0.85, 1.11). In conclusion, dairy product consumption is not associated with risk of all-cause mortality. This study was registered in PROSPERO as CRD42018091856.

Milk and Dairy Product Consumption and Cardiovascular Diseases: An Overview of Systematic Reviews and Meta-Analyses

Milk and dairy products containing milk fat are major food sources of saturated fatty acids, which have been linked to increased risk of cardiovascular-related clinical outcomes such as cardiovascular disease (CVD), coronary heart disease (CHD), and stroke. Therefore, current recommendations by health authorities advise consumption of low-fat or fat-free milk. Today, these recommendations are seriously questioned by meta-analyses of both prospective cohort studies and randomized controlled trials (RCTs) reporting inconsistent results. The present study includes an overview of systematic reviews and meta-analyses of follow-up studies, an overview of meta-analyses involving RCTs, and an update on meta-analyses of RCTs (2013-2018) aiming to synthesize the evidence regarding the influence of dairy product consumption on the risk of major cardiovascular-related outcomes and how various doses of different dairy products affect the responses, as well as on selected biomarkers of cardiovascular disease risk, i.e., blood pressure and blood lipids. The search strategies for both designs were conducted in the MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science databases from their inception to April 2018. From the 31 full-text articles retrieved for cohort studies, 17 met the eligibility criteria. The pooled risk ratio estimated for the association between the consumption of different dairy products at different dose-responses and cardiovascular outcomes (CVD, CHD, and stroke) showed a statistically significant negative association with RR values <1, or did not find evidence of significant association. The overview of 12 meta-analyses involving RCTs as well as the updated meta-analyses of RCTs did not result in significant changes on risk biomarkers such as systolic and diastolic blood pressure and total cholesterol and LDL cholesterol. Therefore, the present study states that the consumption of total dairy products, with either regular or low fat content, does not adversely affect the risk of CVD.

Genetic determinants of beverage consumption: Implications for nutrition and health

Beverages make important contributions to nutritional intake and their role in health has received much attention. This review focuses on the genetic determinants of common beverage consumption and how research in this field is contributing insight to what and how much we consume and why this genetic knowledge matters from a research and public health perspective. The earliest efforts in gene-beverage behavior mapping involved genetic linkage and candidate gene analysis but these approaches have been largely replaced by genome-wide association studies (GWAS). GWAS have identified biologically plausible loci underlying alcohol and coffee drinking behavior. No GWAS has identified variants specifically associated with consumption of tea, juice, soda, wine, beer, milk or any other common beverage. Thus far, GWAS highlight an important behavior-reward component (as opposed to taste) to beverage consumption which may serve as a potential barrier to dietary interventions. Loci identified have been used in Mendelian randomization and gene×beverage interaction analysis of disease but results have been mixed. This research is necessary as it informs the clinical relevance of SNP-beverage associations and thus genotype-based personalized nutrition, which is gaining interest in the commercial and public health sectors.

Retention of Microbiota Diversity by Lactose-Free Milk in a Mouse Model of Elderly Gut Microbiota

Prebiotics may improve aging-related dysbiosis. Milk is a source of nutrients including oligosaccharides whose prebiotic potential remains largely unexplored. We used a murine model to explore the effect of milk products on high diversity and lower diversity faecal microbiota from healthy and frail elderly subjects, respectively. Mice were treated with antibiotics and subsequently "humanized" with human faecal microbiota. The mice received lactose-free or whole milk, glycomacropeptide, or soy protein (control) supplemented diets for one month. The faecal microbiota was analyzed by 16S rRNA gene amplicon sequencing. Lactose-free milk diet was as efficient as the control diet in retaining faecal microbiota diversity in mice. Both milk diets had a significant effect on the relative abundance of health-relevant taxa (e.g., Ruminococcaceae, Lachnospiraceae). The glycomacropeptide prebiotic activity previously observed in vitro was not replicated in vivo. However, these data indicate the novel prebiotic potential of bovine milk for human nutrition.

Dairy Product Intake and Cardiometabolic Diseases in Northern Sweden: A 33-Year Prospective Cohort Study

Dairy products are important constituents of most diets, and their association with adverse health outcomes remains a focus. We characterized dairy food intake and examined associations with the incidence of type 2 diabetes (T2D), myocardial infarction (MI) or stroke among 108,065 Swedish men and women. Hazard ratios (HRs) and 95% CIs were estimated using the multivariable Cox proportional hazards models in a population characterized by high milk tolerance. During a mean follow-up of 14.2 years, 11,641 first-time events occurred. Non-fermented milk intake decreased, whereas butter intake increased over the period. For high intake of non-fermented milk, the HR (95% CI) for developing T2D and MI was 1.17 (1.03, 1.34) and 1.23 (1.10, 1.37), respectively, in men. A greater intake of butter, fermented milk, and cheese tended to be associated with a reduced risk of T2D and/or MI. Non-consumers and those who chose low-fat variants of the targeted dairy products had increased risk for T2D, MI, or stroke compared to those in the non-case group. Generally, effect-sizes were small. This prospective study found that non-fermented milk was associated with an increased risk for developing T2D and MI and that subjects abstaining from dairy products or choosing low-fat variants were at greater risk. However, the overall cardiometabolic risk of non-fermented milk intake was judged as low, since the effect sizes were small.

Consumption of dairy product and its association with total and cause specific mortality - A population-based cohort study and meta-analysis

BACKGROUND

The intake of dairy products has been thought to be associated with an increased risk of coronary heart diseases (CHD) and total mortality due to its relatively high content of saturated fat. However, reports on this association particularly among US adults are conflicting and controversial. Therefore, we used data from the 1999-2010 National Health and Nutrition Examination Surveys (NHANES) study to examine whether consumption of total dairy and dairy subgroups was associated with total and cause specific (CHD, cerebrovascular and cancer) mortality. Further we carried out a systematic review and meta-analysis of prospective studies to check for consistency with the NHANES findings.

METHODS

In the NHANES cohort vital status through December 31, 2011 was ascertained. Cox proportional hazard regression models were used to relate baseline dairy intake with all-cause and cause-specific mortality. For the systematic review PubMed, SCOPUS, Web of Science and Google Scholar databases were searched (up to December 2017). The DerSimonian-Laird method and generic inverse variance methods were used for quantitative data synthesis.

RESULTS

In the NHANES data set of 24,474 participants, 3520 deaths occurred during follow-up. In multivariate adjusted Cox models, total mortality risk was lower when comparing the top (Q4) with the lower (Q1) quartiles of total dairy (hazard ratio [HR] 0.98, 95% confidence interval [CI]: 0.95-0.99) and cheese (HR: 0.92, 95% CI: 0.87-0.97) consumption. Using a similar model, we have found a negative association between total dairy and milk consumption with risk of cerebrovascular mortality (HR: 0.96, 95% CI: 0.94-0.98, HR: 0.93, 95% CI: 0.91-0.96, respectively), while milk consumption was associated with increased CHD mortality (HR: 1.04, 95% CI: 1.02-1.06). The meta-analysis with 636,726 participants indicated a significant inverse association between fermented dairy products and total mortality (RR: 0.97, 95% CI: 0.96-0.99), while milk consumption was associated with higher CHD mortality (RR: 1.04, 95% CI: 1.01-1.05). These findings were robust in sensitivity analyses.

CONCLUSIONS

Among American adults, higher total dairy consumption was associated with lower total and cerebrovascular mortality, while higher milk consumption was associated with higher risk of CHD. These findings do not support dogmatic public health advice to reduce total dairy fat consumption, although the association between milk consumption and CHD mortality requires further study.

MECHANISMS IN ENDOCRINOLOGY: Estrogens in consumer milk: is there a risk to human reproductive health?

Possible effects of xenoestrogens on human health, in particular on male reproductive health, have attracted considerable attention in recent years. Cow's milk was suggested in numerous publications as one of possible sources of xenoestrogens that could affect human health. Although milk has undoubtedly many beneficial health effects and could even have a role in reducing incidence of some cancers, concerns were raised about presumably high levels of estrogens in cow's milk. In intensive farming, concentrations of estrogens in milk are higher due to long milking periods that today extend long into the pregnancy, when concentrations of estrogens in the cow's body rise. Numerous studies examined potential effects of milk on reproductive health and endocrine-related cancers in both experimental studies with laboratory animals, and in human epidemiological studies. In the present review article, we compiled a review of recently published literature about the content of estrogens in cow's milk and potential health effects, in particular on reproductive system, in humans. Although results of published studies are not unequivocal, it seems that there is stronger evidence suggesting that amounts of estrogens in cow's milk are too low to cause health effects in humans.

Dairy intake revisited - associations between dairy intake and lifestyle related cardio-metabolic risk factors in a high milk consuming population

BACKGROUND

The association between milk and dairy intake and the incidence of cardiometabolic diseases, cancer and mortality has been evaluated in many studies, but these studies have had conflicting results with no clear conclusion on causal or confounding associations. The present study aims to further address this association by cross-sectional and longitudinal evaluation of the associations between exposure to various types of dairy products and metabolic risk markers among inhabitants in northern Sweden while taking other lifestyle factors into account.

METHODS

Respondents in the Västerbotten Intervention Programme with complete and plausible diet data between 1991 and 2016 were included, yielding 124,934 observations from 90,512 unique subjects. For longitudinal analysis, 27,682 participants with a visit 8-12 years after the first visit were identified. All participants completed a validated Food Frequency Questionnaire. Metabolic risk markers, including body mass index (BMI), blood pressure, serum (S) cholesterol and triglycerides, and blood glucose, were measured. Participants were categorized into quintiles by intake of dairy products, and risk (odds ratios, OR) of undesirable levels of metabolic risk markers was assessed in multivariable logistic regression analyses. In longitudinal analyses, intake quintiles were related to desirable levels of metabolic risk markers at both visits or deterioration at follow-up using Cox regression analyses.

RESULTS

The OR of being classified with an undesirable BMI decreased with increasing quintiles of total dairy, cheese and butter intake but increased with increasing non-fermented milk intake. The OR of being classified with an undesirable S-cholesterol level increased with increasing intake of total dairy, butter and high fat (3%) non-fermented milk, whereas an undesirable S-triglyceride level was inversely associated with cheese and butter intake in women. In longitudinal analyses, increasing butter intake was associated with deterioration of S-cholesterol and blood glucose levels, whereas increasing cheese intake was associated with a lower risk of deterioration of S-triglycerides.

CONCLUSIONS

Confounding factors likely contribute to the demonstrated association between dairy intake and mortality, and other medical conditions and analyses should be stratified by dairy type.

Association of sodium intake and major cardiovascular outcomes: a dose-response meta-analysis of prospective cohort studies

Background

The association of sodium intake with the risk of cardiovascular morbidity and mortality is inconsistent. Thus, the present meta-analysis was conducted to summarize the strength of association between sodium intake and cardiovascular morbidity and mortality.

Methods

PubMed, Embase, and the Cochrane Library were searched systematically to identify the relevant studies up to October 2017. The effect estimates for 100 mmol/day increase in sodium intake were calculated using 95% confidence intervals (CIs) of cardiac death, total mortality, stroke, or stroke mortality for low (< 3 g/d), moderate (3–5 g/d), or heavy (> 5 g/d) sodium intake, and minimal sodium intake comparison.

Results

A total of 16 prospective cohort studies reported data on 205,575 individuals. The results suggested that an increase in sodium intake by 100 mmol/d demonstrated little or no effect on the risk of cardiac death (P = 0.718) and total mortality (P = 0.720). However, the risk of stroke incidence (P = 0.029) and stroke mortality (P = 0.007) was increased significantly by 100 mmol/day increment of sodium intake. Furthermore, low sodium intake was associated with an increased risk of cardiac death (P = 0.003), while moderate (P < 0.001) or heavy (P = 0.001) sodium intake was associated with an increased risk of stroke mortality.

Conclusions

These findings suggested that sodium intake by 100 mmol/d increment was associated with an increased risk of stroke incidence and stroke mortality. Furthermore, low sodium intake was related to an increased cardiac death risk, while moderate or heavy sodium intake was related to an increased risk of stroke mortality.