A recent study suggests that drinking non-fermented milk might increase the risk of heart disease in women.
The research, published in BMC Medicine, looked at the relationship between milk intake and heart conditions like ischemic heart disease (IHD) and heart attacks, known medically as acute myocardial infarction (MI).
The study’s findings indicate that replacing non-fermented milk with fermented milk products, like yogurt or kefir, could help women reduce their chances of these serious heart issues.
Heart disease remains one of the top causes of death worldwide. Ischemic heart disease, in particular, is common and deadly. While milk is a staple in many diets globally, researchers are still exploring how different types of milk products affect heart health.
Fermented milk, produced when lactic acid bacteria process milk, is widely available in foods like yogurt and kefir.
On the other hand, non-fermented milk includes traditional, fresh milk that hasn’t gone through this bacterial transformation. Both types of milk are popular, especially in Scandinavian countries where this study took place.
In general, health guidelines, like those from the British Dietetic Association, recommend about three servings of dairy each day. This could be three 200-milliliter glasses of semi-skimmed milk, around 90 grams of cheddar cheese, or about 450 grams of low-fat yogurt.
While dairy is encouraged for its benefits like bone health, this study indicates that the type of dairy—fermented versus non-fermented—might make a difference when it comes to heart health.
The study was led by Karl Michaëlsson and his research team, who analyzed data from two Swedish population studies. In total, the researchers tracked 59,998 women with an average age of 54 and 40,777 men with an average age of 60.
All participants were free of heart disease and cancer at the start of the study in 1987. Over the course of 33 years, ending in 2021, the researchers followed these participants and recorded 17,896 cases of ischemic heart disease, including 10,714 heart attacks.
To better understand how milk intake related to heart health, participants shared details about their daily consumption of both fermented and non-fermented milk.
The researchers also took into account other factors, such as alcohol consumption, smoking habits, and pre-existing health conditions like diabetes, to get a clearer picture of each participant’s overall health and lifestyle.
In women, drinking more than 300 milliliters of non-fermented milk daily was linked to a higher risk of developing IHD. For example, women who drank 400 milliliters of non-fermented milk each day had a 5% greater risk of IHD compared to women who drank less.
This risk continued to rise with increased intake: a daily intake of 600 milliliters raised the risk by 12%, and drinking 800 milliliters increased it by 21%.
A similar pattern was observed for the risk of heart attacks in women. Interestingly, this link between non-fermented milk and higher heart disease risk was not found in men.
The study also showed that women who replaced 200 milliliters of non-fermented milk with the same amount of fermented milk each day could lower their heart disease risk. This switch seemed to reduce the risk of IHD by about 5% and the risk of heart attack by around 4%.
The researchers believe that non-fermented milk may affect certain proteins in the body, such as angiotensin-converting enzyme 2 (ACE2) and fibroblast growth factor 21 (FGF21), which play roles in blood pressure regulation and heart health.
However, they caution that since this is an observational study, it cannot prove that non-fermented milk directly causes heart disease. The study was conducted with participants mostly from Scandinavian countries, so the findings might not apply to people in other parts of the world.
In summary, the study suggests that for women, switching from non-fermented milk to fermented milk might be a simple change with potential heart health benefits.
However, more research is needed to confirm these findings across different populations and to understand the underlying reasons for this possible link between milk type and heart disease.
If you care about heart health, please read studies about how eating eggs can help reduce heart disease risk, and Vitamin K2 could help reduce heart disease risk.
For more information about heart health, please see recent studies about how to remove plaques that cause heart attacks, and results showing a new way to prevent heart attacks, strokes.
The research findings can be found in BMC Medicine.
