Is there an incidence of dairy foods on diabetes and mortality? 3 new investigations

Three new investigations have been recently published in the American Journal of Clinical Nutrition. These studies present interesting data about dairy consumption, dairy fat and risk of type 2 diabetes and about dairy intake and mortality. We wrote for you a quick sneak peek, gather here the highlights of this very interesting supplement.

Changes in dairy product consumption and risk of type 2 diabetes

This analysis is based on three large US prospective cohorts (34 224 men in the Health Professionals Follow-Up Study, 76 531 women in the Nurses’ Health Study and 81 597 women in the Nurses’ Health Study II). It evaluates the association of long-term changes in dairy product consumption with subsequent risk of Type 2 diabetes (T2D) among adults.

According to the analysis, increasing yogurt consumption (by >0.5 serving/day) over a 4-year period is associated with an 11% lower risk of T2D, whereas increasing cheese consumption (>0.5 serving/day) is associated with a 9% higher risk compared with maintaining stable intakes. This work suggests that substituting yogurt or reduced-fat milk for cheese may be associated with a 16% or 12% lower risk of T2D, respectively.

We wrote a whole post about this article that you can read here.

Reference: Drouin-Chartier J.P. et al. Changes in dairy product consumption and risk of type 2 diabetes: results from 3 large prospective cohorts of US men and women; Am J Clin Nutr 2019;110:1201–1212.

Dairy fat intake and risk of type 2 diabetes in 3 cohorts of US men and women

As the previous research, this study is built on the three US cohorts (41 808 men in the Health Professionals Follow-Up study, 65 929 women in the Nurses’ Health Study and 89, 565 women in the NHS II. This time, the analysis is focusing on the association between dairy fat intake and risk of T2D, in comparison with carbohydrates from whole or refined grains. It shows that dairy fat is not associated with risk of T2D (compared with calories from carbohydrates). Replacing dairy fat with carbohydrates from whole grains was associated with lower risk of T2D. Replacement with other animal fats or refined carbohydrates was associated with higher risk.

Reference: Ardisson Korat A.V. et al. Dairy fat intake and risk of type 2 diabetes in 3 cohorts of US men and women; Am J Clin Nutr 2019;110:1192–1200.

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

This work investigates associations of consumption of various dairy products with mortality (cancer, cardiovascular diseases…) in the Italian cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). The Italian cohort is characterized by low average milk consumption. This study shows no significant association of consumption of any dairy product with mortality. Milk intake from 160-120 g/day is related to a 25% reduction in risk of all-cause mortality. However, there is no significant difference between the highest (>200 g/day) intake and non-consumption.

Reference: Pala V. et al. Associations of dairy product consumption with mortality in the European Prospective Investigation into Cancer and Nutrition (EPIC)–Italy cohort; Am J Clin Nutr 2019; 110:1220–1230.

As a summary, what can be learned about dairy foods, dairy fat, diabetes, and mortality?

Dairy products are a major component of many diets, contributing ∼10% of calories in the United States ⁽¹⁾. However, data on the health effects of dairy products remain uncertain or controversial. Dietary guidelines remain based on considerations about nutrients (calcium, vit. D, fat) rather than evidences on how milk, cheese or yogurt may relate to clinical endpoints. These 3 new publications bring therefore an interesting new contribution and report on dairy products, dairy fat, diabetes and death.

The new results by Ardisson Korat et al. about dairy fat consumption and T2D risks provide little support for metabolic harms of dairy fat. They suggest potential benefits among younger adults, women, and as a replacement for other animal fats or refined carbohydrates from grain.

Drouin-Chartier et al. shows that changes in low-fat milk, whole milk, and cream were not significantly associated with diabetes, whereas decreases in yogurt or increases in some types of cheese were each associated with higher risk.

Finally, Pala et al. shows that moderate milk intake was associated with ∼25% lower mortality, largely owing to ∼50% lower cardiovascular mortality.

All these findings continue to build the case for possible benefits of some dairy products consumption. The studies highlight this complexity and need for additional long-term prospective studies, interventional trials, and mechanistic investigations of dairy foods and health.

Reference: Mozaffarian D. Dairy foods, dairy fat, diabetes, and death: what can be learned from 3 large new investigations? Am J Clin Nutr 2019; 110:1053–1054.

⁽¹⁾ National Research Council (US) Committee on Technological Options to Improve the Nutritional Attributes of Animal Products. Current trends in consumption of animal products. Washington (DC): National Academies Press 1988; p.18–44.