A prospective cohort study by Swedish researchers found that drinking more than 1.5 glasses of milk per day increased the risk of coronary heart disease and myocardial infarction in women. On average, drinking two glasses of milk increased the risk by five percent, while drinking four glasses increased it by 21 percent. Men were not at increased risk of heart disease due to milk consumption. The article was published in the journal BMC Medicine.
It is well known that a healthy diet is important for the prevention of cardiovascular disease. However, there is uncertainty regarding the effect of dairy products on the risk of coronary heart disease (CHD). Various studies have shown that whole milk and fermented milk products may have different effects on cardiovascular health. Furthermore, consumption patterns of various dairy products have changed significantly over the past half-century: on average, in many countries, whole milk consumption has decreased, while consumption of fermented milk products has increased.
To shed light on this issue, a research team led by Karl Michaëlsson of Uppsala University used data from two large population-based Swedish longitudinal cohorts of women and men to assess the risk of coronary heart disease and myocardial infarction associated with the consumption of whole milk and fermented milk products. The total study sample included 100,775 people.
The average milk consumption was 240 milliliters per day for women and 290 milliliters per day for men. About nine percent of women and 15 percent of men reported consuming more than 600 milliliters of milk per day. Compared to the low-consumption group, women and men with high whole milk consumption averaged higher calorie intake, more red meat, a slightly higher body mass index, lower educational levels, and lower alcohol consumption.
After adjusting for various covariates, whole milk consumption was positively associated with a higher risk of CHD in women only (p = 0.01). Higher milk consumption was associated with a higher risk when consuming more than 300 milliliters of milk per day. Compared with 100 milliliters of milk per day, 400 milliliters (two glasses per day) increased the risk of CHD by five percent, 600 milliliters (three glasses) by 12 percent, and 800 milliliters (four glasses per day) by 21 percent, regardless of milk fat content. Similar patterns were found for myocardial infarction. In men, increased whole milk consumption was not associated with an increased risk of CHD.
Although age-adjusted models suggested a reduced risk of coronary heart disease or myocardial infarction with fermented milk product consumption, no association was found in either women or men after multivariable adjustment. However, an analysis of substituting 200 milliliters of whole milk per day with fermented milk products showed that the risk of coronary heart disease decreased by five percent in women and three percent in men. Of the 276 cardiometabolic proteins analyzed, two were consistently associated with whole milk consumption: angiotensin-converting enzyme 2 and fibroblast growth factor 21. Angiotensin-converting enzyme 2 levels in women increased with increasing milk consumption, while fibroblast growth factor 21 concentrations decreased.
According to scientists, there is a direct link between consuming more than 300 milliliters of whole milk of any fat content and an increased risk of coronary heart disease in women. This link is apparently mediated by two compounds: angiotensin-converting enzyme 2 and fibroblast growth factor 21. These data may be important in developing preventative diets for patients at high risk for cardiovascular disease.
We previously reported that plant-based milk contains little phosphorus, magnesium, zinc, and selenium compared to cow's milk.
