A prospective cohort study by Swedish scientists has shown that drinking more than 1.5 glasses of milk per day increases the risk of coronary heart disease and myocardial infarction in women. On average, drinking two glasses of milk increased the risk by five percent, and 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 known that a healthy diet is important for the prevention of cardiovascular diseases. However, there is uncertainty in understanding 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. In addition, consumption patterns of various dairy products have changed significantly over the past half century: on average, in many countries, the consumption of whole milk has decreased, while the consumption of fermented milk products has increased.
To shed light on this issue, a research team led by Karl Michaëlsson from 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 when consuming whole milk and fermented milk products. The total study sample included 100,775 people.
Average milk consumption was 240 millilitres per day for women and 290 millilitres per day for men. About nine per cent of women and 15 per cent of men reported consuming more than 600 millilitres of milk per day. Compared with the low-consumption group, women and men with high whole milk consumption on average consumed more calories, more red meat, had a slightly higher body mass index, lower education 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). At a daily intake of more than 300 milliliters of milk, higher intake was associated with a higher risk. 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, higher whole milk consumption was not associated with an increased risk of CHD.
Although age-adjusted models suggested a reduced risk of CHD or MI with fermented milk consumption, no association was found in either women or men after multivariable adjustment. However, an analysis of replacing 200 milliliters of whole milk per day with fermented milk showed that the risk of CHD was reduced 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 increased with milk consumption in women, while fibroblast growth factor 21 levels decreased.
According to scientists, there is a direct link between the consumption of more than 300 milliliters of whole milk of any fat content and an increased risk of coronary heart disease in women. Apparently, this link is mediated by two compounds - angiotensin-converting enzyme 2 and fibroblast growth factor 21. These data may be important in developing preventive diets for patients from high-risk groups for cardiovascular disease.
We previously reported that plant milk contains little phosphorus, magnesium, zinc and selenium compared to cow's milk.
