Dairy Research Bulletin – June 2019

Check out the latest and greatest milk and dairy science! The Dairy Research Bulletin delivers a brief synopsis of the most current Human, Animal, and Environmental dairy research that is going on in the World, and also that which is of special interest to California dairy producers and consumers alike.

If you would like to peruse the most pertinent dairy research from months past, then visit the Dairy Research Bulletin Archive

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Selected Articles on Social Responsibility, Environmental Management, and Sustainability

Needs assessment for cooperative extension dairy programs in California. Martins JPN, Karle BM, Heguy JM. J Dairy Sci. 2019 Jun 6. pii: S0022-0302(19)30487-4.

  • In 2001, there were 2,157 dairies in California with an average of 721 cows per dairy, compared with 1,331 dairies in 2017, with an average of 1,304 cows per dairy. With these changes, fewer individuals are directly involved with on-farm management, and dairy producer participation in cooperative extension dairy educational programs has decreased.
  • The present study aimed to identify dairy producer needs and how best to direct and deliver cooperative extension programming.
  • In March 2017, the research mailed a needs assessment survey to grade A dairy producers in California (n = 1,080). The response rate was 15.4% (n = 166) and herd size averaged 1,405 milking cows (range 83-5,500).
  • The top 5 concerns/obstacles indicated were milk price, labor availability/quality, environmental issues/regulations, labor costs, and water .
  • The 5 highest priority research topics were herd health, environmental issues, reproduction, milk quality, and water quality.
  • The 5 highest priority educational topics were herd health, milk quality, reproduction, environmental issues, and calf and heifer management.
  • As far as cooperative extension information delivery method, most respondents indicated preference for newsletter or magazine articles (81%), half-day/short meetings (47%), and on-farm training/meetings (39%). Webinars and 2- or 3-d destination meetings were the least preferable methods (27 and 9%, respectively).

Management factors associated with bovine respiratory disease in preweaned calves on California dairies: The BRD 100 study. Maier GU, Love WJ, Karle BM, Dubrovsky SA, Williams DR, Champagne JD, Anderson RJ, Rowe JD, Lehenbauer TW, Van Eenennaam AL, Aly SS. J Dairy Sci. 2019 Jun 12. pii: S0022-0302(19)30511-9.

  • Bovine respiratory disease complex is one of the most common causes of death in dairy calves and poses a significant welfare and economic burden on the industry. In 2010, respiratory disease in dairy heifers was reported as the cause in 22.5% of deaths before and 46.5% of deaths after weaning. In addition, 18.1% of preweaning heifers on dairy heifer-raising operations were reportedly affected by pneumonia, making it the second most common calf illness after diarrhea
  • The objective of this cross-sectional study was to determine how management practices on California dairies may be associated with bovine respiratory disease in preweaned calves.
  • A convenience sample of 100 dairies throughout California, providing a study population of 4,636 calves, were visited between May 2014 and April 2016. During each farm visit, in-person interviews with the herd manager or calf caretaker were conducted to collect information about herd demographics, maternity pen, colostrum and calf management, herd vaccinations, and dust abatement.
  • Overall survey-adjusted bovine respiratory disease prevalence in the study herds was 6.91%. Housing factors positively associated with bovine respiratory disease were metal hutches compared with wood hutches, calf-to-calf contact in calves >75 d of age, feeding Holstein calves <2.84 L of milk or replacer per day, and lagoon water used for flushing manure under hutches compared with no flush.
  • Providing extra shade over hutches, feeding calves at least 90% saleable milk or pasteurized milk, and feeding >5.68 L of milk or replacer per day to Jersey calves were negatively associated with bovine respiratory disease.
  • This study identified management practices on California dairies that may contribute to differences in bovine respiratory disease prevalence, which will be incorporated into a risk-assessment tool to control and prevent bovine respiratory disease in preweaned dairy calves.

Production-related contaminants (pesticides, antibiotics and hormones) in organic and conventionally produced milk samples sold in the USA. Welsh JA, Braun H, Brown N, Um C, Ehret K, Figueroa J, Boyd Barr D. Public Health Nutr. 2019 Jun 26:1-9.

  • Consumption of cow’s milk, which is associated with diet and health benefits, has decreased in the USA. The simultaneous increase in demand for more costly organic milk suggests consumer concern about exposure to production-related contaminants may be contributing to this decline.
  • The researchers sought to determine if contaminant levels differ by the production method used. Half-gallon containers of organic and conventional milk (four each) were collected by volunteers in each of nine US regions and shipped on ice for analysis.
  • Pesticide, antibiotic and hormone (bovine growth hormone (bGH), bGH-associated insulin-like growth factor 1 (IGF-1)) residues were measured using liquid or gas chromatography coupled to mass or tandem mass spectrometry. Levels were compared against established federal limits and by production method.
  • Current-use pesticides and antibiotics were detected in several conventional but not in organic samples. Among the conventional samples, residue levels exceeded federal limits for sulfamethazine (37%) and sulfathiazole (26%). Median bGH and IGF-1 concentrations in conventional milk were 20 and 3 times greater than in organic samples, respectively.
  • Current-use antibiotics and pesticides were undetectable in organic but prevalent in conventionally produced milk samples, with multiple samples exceeding federal limits.
  • Higher bGH and IGF-1 levels in conventional milk suggest the presence of synthetic growth hormone. Further research is needed to understand the impact of these differences, if any, on consumers.

Bedding and bedding management practices are associated with mesophilic and thermophilic spore levels in bulk tank raw milk. Murphy SI, Kent D, Martin NH, Evanowski RL, Patel K, Godden SM, Wiedmann M. J Dairy Sci. 2019 Jun 12. pii: S0022-0302(19)30522-3.

  • Mesophilic and thermophilic spore-forming bacteria represent a challenge to the dairy industry, as these bacteria are capable of surviving adverse conditions associated with processing and sanitation and eventually spoil dairy products.
  • The dairy farm environment, including soil, manure, silage, and bedding, has been implicated as a source for spores in raw milk. High levels of spores have previously been isolated from bedding, and different bedding materials have been associated with spore levels in bulk tank raw milk; however, the effect of different bedding types, bedding management practices, and bedding spore levels on the variance of spore levels in bulk tank raw milk has not been investigated.
  • To this end, farm and bedding management surveys were administered and unused bedding, used bedding, and bulk tank raw milk samples were collected from dairy farms (1 or 2 times per farm) across the United States over 1 year; the final data set included 182 dairy farms in 18 states.
  • Bedding suspensions and bulk tank raw milk were spore pasteurized (80°C for 12 min), and mesophilic and thermophilic spores were enumerated. The analyses showed that bedding material had a direct influence on levels of spores in unused and used bedding as well as an indirect association with spore levels in bulk tank raw milk through used bedding spore levels.
  • Specific bedding and farm management practices as well as cow hygiene in the housing area were associated with mesophilic and thermophilic spore levels in unused bedding, used bedding, and bulk tank raw milk. Notably, levels of spores in used bedding were positively related to those in unused bedding and used bedding spore levels were positively related to those in bulk tank raw milk.
  • The results of this study increase the understanding of the levels and ecology of mesophilic and thermophilic spores in raw milk, emphasize the possible role of bedding as a source of spores on-farm, and present opportunities for dairy producers to reduce spore levels in bulk tank raw milk.

Estimating the impact of clinical mastitis in dairy cows on greenhouse gas emissions using a dynamic stochastic simulation model: a case study. Mostert PF, Bokkers EAM, de Boer IJM, van Middelaar CE. Animal. 2019 Jun 18:1-9.

  • The dairy sector is an important contributor to GHG emissions. The increasing attention for global warming is likely to contribute to the introduction of policies or other incentives to reduce greenhouse gas (GHG) emissions related to livestock production, including dairy.
  • Clinical mastitis, an intramammary infection, results in reduced milk production and fertility, increases culling and mortality of cows and, therefore, has a negative impact on the efficiency (output/input) of milk production. This may increase GHG emissions per unit of product.
  • This study’s objective was to estimate the impact of clinical mastitis in dairy cows on GHG emissions of milk production for the Dutch situation.
  • Using life cycle assessment, emissions of GHGs were estimated from cradle to farm gate for processes along the milk production chain that are affected by clinical mastitis. Processes included were feed production, enteric fermentation, and manure management. Emissions of GHGs were expressed as kg CO2 equivalents per ton of fat-and-protein-corrected milk (kg CO2e/t FPCM).
  • Emissions of cows with clinical mastitis increased on average by 6.2% (57.5 kg CO2e/t FPCM) compared with cows without clinical mastitis. This increase was caused by removal (39%), discarded milk (38%), reduced milk production (17%) and prolonged CI (6%).
  • The GHG emissions increased by 48 kg CO2e/t FPCM for cows with one case of clinical mastitis, by 69 kg CO2e/t FPCM for cows with two cases of clinical mastitis and by 92 kg CO2e/t FPCM for cows with three cases of clinical mastitis compared with cows without clinical mastitis.
  • Preventing clinical mastitis can be an effective strategy for farmers to reduce GHG emissions and can contribute to sustainable development of the dairy sector, because this also can improve the income of farmers and the welfare of cows.

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Selected Articles on Sustainable Nutrition

Vegan vs Paleo: Carbon Footprints and Diet Quality of 5 Popular Eating Patterns as Reported by US Consumers. Alleyway K, Willits-Smith A, Aranda R, Heller M, Rose D. Curr Dev Nutr. 2019 Jun 13;3(Suppl 1). pii: nzz047.P03-007-19.

  • The food system contributes substantially to current environmental problems, which has prompted researchers to evaluate both environmental as well as nutritional impacts of dietary choices. However, there has been no research on the impacts of popular diets as consumed in the US.
  • This study estimated the carbon footprint and diet quality of popular diets as selected by a nationally representative sample of US consumers. The 2005-2010 National Health and Nutrition Examination Survey (NHANES) 24-hour recall data were used to categorize individual adult diets (N = 16,800) into one of six mutually exclusive dietary patterns: vegan, vegetarian (can include dairy), pescatarian, paleolithic (no grains, legumes or dairy), and ketogenic (low in carbohydrate, moderate in protein, high in fat). All other diets were classified into an omnivore pattern.
  • Average daily greenhouse gas emissions (GHGE) in carbon dioxide equivalents per 1000 kilocalories (kg CO2-eq 1000 kcal-1) were calculated by matching our previously developed database of Food Impacts on the Environment for Linking to Diets (dataFIELD) to NHANES individual diet data. Diet quality was determined using the Healthy Eating Index 2010 (HEI).
  • The most frequent 1-day diet patterns were omnivore (87%), pescatarian (7%), and vegetarian (6%). The lowest carbon footprint diets were vegan (mean = 1.0 kg CO2-eq 1000 kcal-1), vegetarian (1.1), and pescatarian (1.9), and the highest footprints were omnivore (2.3), paleo (2.8) and keto (4.2).
  • These average carbon footprints for the vegan, vegetarian, and pescatarian patterns were significantly lower than that of the omnivore pattern, and the keto pattern was significantly higher. 
  • These data support the growing body of research identifying the environmental benefits of plant-based diet patterns and identify the environmental cost of other popular diet patterns in the US.

Country-Specific Sustainable Diets Using Optimization Algorithm. Chaudhary A, Krishna V. Environ Sci Technol. 2019 Jun 11.

  • Current diets of most nations either do not meet the nutrition recommendations or transgress environmental planetary boundaries or both. Transitioning toward sustainable diets that are nutritionally adequate and low in environmental impact is key in achieving the United Nations’ Sustainable Development Goals. However, designing region-specific sustainable diets that are culturally acceptable is a formidable challenge.
  • Recent studies have suggested that optimization algorithms offer a potential solution to the above challenge, but the evidence is mostly based on case studies from high-income nations using widely varying constraints and algorithms.
  • Here, the researchers employ nonlinear optimization modeling with a consistent study design to identify diets for 152 countries that meet four cultural acceptability constraints, five food-related per capita environmental planetary boundaries (carbon emissions, water, land, nitrogen, and phosphorus use), and the daily recommended levels for 29 nutrients.
  • The results show that a considerable departure from current dietary behavior is required for all countries. The required changes in intake amounts of 221 food items are highly country-specific but in general point toward a need to reduce the intake of meat, dairy, rice, and sugar and an increase in fruits, vegetables, pulses, nuts, and other grains.
  • The constraints for fiber, vitamin B12, vitamin E, and saturated fats and the planetary boundaries for carbon emissions and nitrogen application were the most difficult to meet, suggesting the need to pay special attention to them. The analysis demonstrates that nonlinear optimization is a powerful tool to design diets achieving multiple objectives.

Healthy diet: a step toward a sustainable diet by reducing water footprint. Sobhani SR, Rezazadeh A, Omidvar N, Eini-Zinab H. J Sci Food Agric. 2019 Jun;99(8):3769-3775.

  • Water shortage is one of the most important crises facing humanity in the 21st century, as it affects general welfare, public health, and ecosystems.
  • This paper aims to assess different scenarios that reduce water use by following healthy diet recommendations.
  • In this study, a food frequency questionnaire was used to assess the usual food intake of a sample of 723 individuals, aged 20-64 years, from Urmia, Iran. In order to calculate water use for production of food items, the water footprint method was applied. A linear programming technique was used to find a healthy diet with low blue water footprint in three scenarios.
  • The results showed that a healthy diet with greater proportion of energy from fruit and dairy instead of a diet with high proportion of energy from ‘meat-fish-poultry-eggs’ and ‘bread-cereal-rice-pasta’ can supply all Recommended Dietary Allowances while reducing water use.

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Selected Articles on Dairy Intake and Human Health

Dairy foods and health: an umbrella review of observational studies. Godos J, Tieri M, Ghelfi F, Titta L, Marventano S, Lafranconi A, Gambera A, Alonzo E, Sciacca S, Buscemi S, Ray S, Del Rio D, Galvano F, Grosso G.

  • Evidence on consumption of dairy foods and human health is contradictory.
  • This study aimed to summarize the level of evidence of dairy consumption on various health outcomes.
  • A systematic search for meta-analyses was performed: study design, dose-response relationship, heterogeneity and agreement of results over time, and identification of potential confounding factors were considered to assess the level of evidence.
  • Convincing and probable evidence of decreased risk of colorectal cancer, hypertension and cardiovascular disease, elevated blood pressure and fatal stroke, respectively, was found for total dairy consumption
  • Possible decreased risk of breast cancer, metabolic syndrome, stroke and type-2 diabetes was found. Increased risk of prostate cancer and Parkinson’s disease was found.
  • Similar, yet not entirely consistent evidence for individual dairy products was reported. Among potential confounding factors, geographical localization and fat content of dairy have been detected.

Association between dairy intake and the risk of contracting type 2 diabetes and cardiovascular diseases: a systematic review and meta-analysis with subgroup analysis of men versus women. Mishali M, Prizant-Passal S, Avrech T, Shoenfeld Y. Nutr Rev. 2019 Jun 1;77(6):417-429.

  • The association between dairy product intake and the risk of developing type 2 diabetes (T2D) or cardiovascular disease (CVD) has been investigated in several studies, but little attention was given to the role of sex as a moderator of these associations. (In this article, the term “sex” is used to denote the biologically-based differences between males and females.).
  • This meta-analysis examines whether dairy consumption has different effects on T2D and CVD in men and women.
  • The PubMed database and previous reviews were searched for cohort studies published between 2006 and 2016. Reported risk ratios (RRs) for T2D/CVD with high versus low dairy intake were extracted.
  • The present meta-analysis of 201 studies found that T2D (n = 16 studies) and CVD (n = 13 studies) are inversely associated with dairy intake. Subgroup analysis for sex showed that the association between dairy intake and T2D and between dairy intake and CVD are significant in women but not in men.
  • There is an inverse association between high dairy intake and the risk of developing T2D and CVD in women.

High-Protein Diet Containing Dairy Products is Associated with Low Body Mass Index and Glucose Concentrations: A Cross-Sectional Study. Giglio BM, Duarte VIR, Galvão AF, Marini ACB, Schincaglia RM, Mota JF, Souza LB, Pimentel GD. Nutrients. 2019 Jun 20;11(6). pii: E1384.

  • Despite the fact that overeating is related to obesity and type 2 diabetes, it is suggested that protein intake above the recommended dietary intake (>1.2 g/kg/day) reduces body weight. The probable mechanisms involved would be the increase of thermogenesis and satiety, which contribute to energy balance.
  • The aim was to evaluate whether the ingestion of a high protein diet containing dairy protein is associated with anthropometric indicators of adiposity and blood glucose.
  • A cross-sectional study was conducted with 418 volunteers of 20-89 years of age who performed leisure physical activity. The researchers assessed dietary intake, body mass index (BMI), waist circumference (WC), triceps skinfold thickness (TSFT), random blood glucose as well as sociodemographic and behavioral variables.
  • The consumption of a high-protein diet (1.8 g/kg/day) was found in 37.8% of individuals, which showed lower BMI, WC, TSFT and blood glucose concentrations compared to those with a low-protein diet (0.6 g/kg/day).
  • Dairy products consumption was inversely associated with BMI and with blood glucose. Cheese consumption was inversely associated with blood glucose. Two portions of cheeses/day reduced the risk of having high blood glucose levels by approximately 80%.
  • A high-protein diet containing dairy food, in particular two servings of cheese, was associated with low BMI and random glucose concentration.

Total Fermented Dairy Food Intake Is Inversely Associated with Cardiovascular Disease Risk in Women. Buziau AM, Soedamah-Muthu SS, Geleijnse JM, Mishra GD. J Nutr. 2019 Jun 13. pii: nxz128.

  • The relation between fermented dairy consumption and type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) in an Australian population remains to be established.
  • This study aimed to investigate the association between fermented dairy consumption and T2DM and CVD risk.
  • The Australian Longitudinal Study on Women’s Health included Australian women (aged 45-50 years) who were followed for 15 years of study.
  • Of the 7,633 who were free of diabetes at baseline, women in the highest yogurt intake group had 19% lower odds of developing T2DM than those in the lowest intake group.
  • Of the 7,679 women free of CVD at baseline, high intake of yogurt and total fermented dairy was associated with 16% lower CVD risk compared to those in the lowest intake group. No associations were found with other dairy groups.
  • The findings from this population-based study of Australian women suggest an inverse association between total fermented dairy intake and CVD risk, which may partly be accounted for by other dietary components.

Milk polar lipids reduce lipid cardiovascular risk factors in overweight postmenopausal women: towards a gut sphingomyelin-cholesterol interplay. Vors C, Joumard-Cubizolles L, Lecomte M, et al. Gut. 2019 Jun 12. pii: gutjnl-2018-318155.

  • Nutritional strategies can play a major role in the management of cardiovascular disease. Interest has recently grown on the potential health benefits of milk polar lipids, which have been shown to improve several lipid cardiovascular risk factors, potentially through mechanisms that decrease cholesterol absorption and/or and by increasing conversion of cholesterol to coprostanol.
  • The aim of this study was to investigate whether milk polar lipids impact human intestinal lipid absorption, metabolism, microbiota and associated markers of cardiometabolic health.
  • A double-blind, randomized controlled 4-week study involving 58 postmenopausal women was used to assess the chronic effects of milk polar lipids consumption (0, 3 or 5 g-PL/day) on lipid metabolism and gut microbiota.
  • Over 4 weeks, milk polar lipids significantly reduced fasting and postprandial plasma concentrations of cholesterol and surrogate lipid markers of cardiovascular disease risk.
  • Acute ingestion of milk polar lipids by ileostomy patients shows that milk polar lipids decreased cholesterol absorption and increased cholesterol-ileal efflux, which can be explained by the observed co-excretion with milk sphingomyelin in the gut.
  • The present data demonstrate for the first time in humans that milk polar lipids can improve the cardiometabolic health by decreasing several lipid cardiovascular markers, notably through a reduced intestinal cholesterol absorption involving specific interactions in the gut, without disturbing the major bacterial phyla of gut microbiota.

Yogurt improves insulin resistance and liver fat in obese women with nonalcoholic fatty liver disease and metabolic syndrome: a randomized controlled trial. Chen Y, Feng R, Yang X, Dai J, Huang M, Ji X, Li Y, Okekunle AP, Gao G, Onwuka JU, Pang X, Wang C, Li C, Li Y, Sun C. Am J Clin Nutr. 2019 Jun 1;109(6):1611-1619.

  • Higher yogurt intake has been shown to have beneficial effects healthy populations, but its effects on insulin resistance, nonalcoholic fatty liver disease, and metabolic syndrome are unclear.
  • The aim of this study was to investigate the effects of yogurt on insulin resistance and secondary endpoints including liver fat, gut microbiota, and serum biomarkers of inflammation and oxidative stress in obese women with nonalcoholic fatty liver disease and metabolic syndrome.
  • One hundred obese women aged 36-66 years with both nonalcoholic fatty liver disease and metabolic syndrome were randomly assigned to consume 220 grams/day of either conventional yogurt or milk for 24 weeks.
  • Compared with milk, yogurt significantly decreased insulin resistance, fasting insulin, 2-h insulin, 2-h area under the curve for insulin, alanine aminotransferase, intrahepatic lipi, and hepatic fat fraction.
  • Yogurt also decreased serum lipids, and biomarkers of inflammation and oxidative stress, and altered gut microbiota composition. Further analysis showed that yogurt may improve insulin resistance by reducing serum lipids, inflammation, and oxidative stress.
  • Yogurt performed better than milk at ameliorating insulin resistance and liver fat in obese Chinese women with nonalcoholic fatty liver disease and metabolic syndrome, possibly by improving lipid metabolism, reducing inflammation, oxidative stress, and changing the gut microbiota composition.

Intake of milk and other dairy products and the risk of bladder cancer: a pooled analysis of 13 cohort studies. Acham M, Wesselius A, van Osch FHM, Yu EY, van den Brandt PA, White E, Adami HO, Weiderpass E, Brinkman M, Giles GG, Milne RL, Zeegers MP. Eur J Clin Nutr. 2019 Jun 17.

  • Inconsistent associations between milk and other dairy product consumption and bladder cancer have been reported.
  • This research aimed to investigate possible associations with bladder cancer risk for total and individual dairy products by bringing together the world’s data on this topic.
  • Thirteen cohort studies, included in the BLadder cancer Epidemiology and Nutritional Determinants (BLEND) study, provided data for 3590 bladder cancer cases and 593,637 non-cases. Associations between milk and other dairy product consumption and bladder cancer risk were investigated.
  • Overall, higher total dairy product consumption was not associated with bladder cancer risk compared with lower intake, and likewise no association was observed for either liquid milk, processed milk, cream, cheese or ice cream.
  • However, an inverse association was observed for moderate and high yogurt consumption and bladder cancer risk when compared with non-consumers.
  • In summary, the researchers found no evidence of association between either total or individual dairy products and bladder cancer risk, but suggestive evidence that consumption of yogurt may be associated with a decreased risk.

Dairy Product Consumption and Prostate Cancer Risk in the US. Preble I, Zhang Z, Kopp R, Garzotto M, Bobe G, Shannon J, Takata Y. Curr Dev Nutr. 2019 Jun 13;3(Suppl 1). pii: nzz030.P05-034-19.

  • Milk and dairy product consumption has been associated with an increase in prostate cancer risk; however, discrepancies have been observed in the literature.
  • This study prospectively investigated the association between dairy product intake and prostate cancer risk among 49,472 men in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) cohort.
  • Over the average follow-up period of 11 years, total dairy product consumption was not statistically significantly associated with risk of any prostate cancer or stratified by disease severity. The hazard ratio comparing the highest with the lowest quartiles of total dairy product intake was 1.05 for overall prostate cancer risk and ranged from 1.00, for risk of prostate cancer with high-Gleason score, to 1.24, for risk of late-stage prostate cancer.
  • The only statistically significant finding in our stratified analyses was a positive association between high-fat dairy product intake and late-stage prostate cancer risk (hazard ratio = 1.37). However, associations with high-fat dairy intake did not differ by stage, suggesting a chance finding for the positive association with late-stage prostate cancer.
  • These preliminary findings do not support the previously-reported harmful impact of dairy product consumption on prostate cancer risk among US men. The observed association of high-fat dairy intake with late-stage prostate cancer needs to be confirmed in other studies.

Dairy, soy, and calcium consumption and risk of cognitive impairment: the Singapore Chinese Health Study. Talaei M, Feng L, Yuan JM, Pan A, Koh WP. Eur J Nutr. 2019 Jun 3.

  • Consistent findings from observational studies have shown associations between nutritional factors and cognition in the elderly. While, the link between milk intake and cognitive disorders has been assessed in some epidemiological studies, the results are inconsistent.
  • The aim of this study was to investigate if consumption of dairy and soy food intake, and their components of calcium and isoflavones (in soy), is related to cognitive impairment in elderly.
  • The researchers used baseline data on lifestyle and habitual diet of 16,948 participants, and data on their cognitive function.
  • Higher dairy intake was shown to have an inverse relationship with cognitive impairment compared to the lowest dairy intake.
  • Similar results were found for dairy calcium intake. However, there was no statistically significant association for intake of soy, isoflavones, or non-dairy calcium with risk of cognitive impairment.
  • Dairy intake at midlife could have a protective association against cognitive impairment that may not be attributed to its calcium content alone, while soy or isoflavone intake was not associated with the cognition of elderly in our study.

Dairy consumption and risk of functional disability in an elderly Japanese population: the Hisayama Study. Yoshida D, Ohara T, Hata J, Shibata M, Hirakawa Y, Honda T, Uchida K, Takasugi S, Kitazono T, Kiyohara Y, Ninomiya T. Am J Clin Nutr. 2019 Jun 1;109(6):1664-1671

  • Little is known about the association between dairy intake and risk of functional disability in the elderly.
  • The researchers examined the influence of dairy intake on the development of declining functional capacity and activities of daily living in a prospective cohort study of an elderly population.
  • A total of 859 community-dwelling Japanese residents, aged ≥65 years without functional disability, were followed up for 7 years.
  • The relative risk of impaired functional capacity decreased significantly with increasing dairy intake levels. Regarding the three subscales of functional capacity, the inverse association between dairy intake and risk for impairment of intellectual activity and social role remained significant, but such an association was not observed for instrumental activities of daily living.
  • The risk of activities of daily living disability also decreased weakly but significantly with elevating dairy intake. A similar association was seen for severity of functional disability. However, the magnitude of these associations was attenuated after further adjustment for protein intake.
  • These findings suggest that higher dairy intake is associated with a lower risk of functional disability and its progression in the elderly, probably via an increase in protein intake.