Is milk or yogurt better for heart health? A new study offers insights that may help you decide. Researchers have found that non-fermented milk intake could raise heart disease risk in women while switching to a fermented alternative like yogurt might reduce the risk.
A recent study investigated the impact of non-fermented and fermented milk on the risk of developing ischemic heart disease (IHD) and acute myocardial infarction (MI) in a population of around 60,000 women and more than 40,000 men from two Swedish studies.
Ischemic heart disease is a condition that occurs when the blood supply to the heart is restricted due to a blood clot or constriction of the blood vessels. Myocardial infarction, or heart attack, is a life-threatening complication that happens when the blood supply is completely blocked.
The participants in the study did not have heart disease or cancer at the start of the study. They also did not smoke or consume alcohol. The researchers recorded the number of servings of fermented and non-fermented milk each participant consumed daily.
During the 33 years of follow-up, 17,896 people developed IHD, including 10,714 cases of MI. Analysis revealed that daily intake of more than 1.25 cups (300 milliliters) of milk was linked to an increased risk of heart disease, including both IHD and MI. Specifically, IHD risk rose by 5% at 400 milliliters, 12% at 600 milliliters, and 21% at 800 milliliters. A similar pattern was found in women for the risk of acute MI. The heart disease risks prevailed regardless of the milk's fat content. However, in men, no increased risk of heart disease was associated with milk consumption.
Interestingly, when women substituted their 200 ml of daily milk intake with the fermented option, there was a 5% decreased risk of IHD and a 4% decreased risk of MI.
Researchers attribute milk's increased risk of heart disease to its effect on two cardiometabolic proteins: angiotensin-converting enzyme 2 (ACE2) and fibroblast growth factor 21 (FGF21), which play key roles in regulating blood pressure and blood flow.
"Our complementary analyses of potential protein pathways underlying the observed association showed that non-fermented milk intake was associated in different directions with circulating levels of ACE2 and FGF21 in women—two essential cardiometabolic proteins, also related to IHD in women in our study," the researchers wrote in the study published in BMC Medicine.
However, researchers caution that the findings may not be generalizable, as the participants were solely Scandinavians. Also, since it is an observational study, it cannot directly establish a causal relationship between women's non-fermented milk intake and IHD.
