Drinking large amounts of non-fermented milk may increase the risk of heart disease in women, according to new research published in BMC Medicine. The study suggests that replacing non-fermented milk with fermented dairy products, such as yogurt or kefir, could lower this risk.
Understanding the Risks of Heart Disease
Ischemic heart disease (IHD) is one of the leading causes of death worldwide. It occurs when blood flow to the heart is reduced, often due to narrowed or blocked arteries. Acute myocardial infarction (MI), commonly known as a heart attack, is a serious form of IHD.
Although milk is a common part of many diets, there has been ongoing debate about whether dairy products influence heart disease risk. Fermented milk products contain beneficial lactic acid bacteria and are known for their potential health benefits, while non-fermented milk, such as regular cow’s milk, lacks this fermentation process.
The Study: How Milk Consumption Affects Heart Disease Risk
Researchers from Sweden analyzed two large health studies that tracked participants for 33 years, from 1987 to 2021. The study included:
- 59,998 women (average age 54)
- 40,777 men (average age 60)
- 17,896 cases of ischemic heart disease, including 10,714 heart attacks
The participants provided details on their daily consumption of both fermented and non-fermented milk. Researchers also accounted for lifestyle factors such as smoking, alcohol intake, and pre-existing conditions like diabetes.
Key Findings
- Higher Non-Fermented Milk Intake Linked to Increased Heart Disease Risk in Women
- Women who drank more than 300 milliliters per day (about 1.5 glasses) of non-fermented milk had a higher risk of heart disease.
- The risk increased with higher milk consumption:
- 400 mL/day → 5% higher risk of IHD
- 600 mL/day → 12% higher risk of IHD
- 800 mL/day → 21% higher risk of IHD
- A similar pattern was observed for the risk of heart attacks (MI) in women.
- No Increased Risk Found in Men
Unlike women, men who consumed higher amounts of non-fermented milk did not show a significant increase in heart disease risk.
- Switching to Fermented Milk May Lower Risk
- Women who replaced 200 milliliters (about one glass) of non-fermented milk with fermented milk saw a:
- 5% decrease in the risk of heart disease (IHD)
- 4% decrease in the risk of heart attacks (MI)
Why Might Non-Fermented Milk Increase Heart Disease Risk?
Researchers suggest that non-fermented milk may affect levels of certain proteins involved in heart health, such as:
- Angiotensin-converting enzyme 2 (ACE2) – plays a role in regulating blood pressure.
- Fibroblast growth factor 21 (FGF21) – helps control metabolism and blood vessel function.
However, more research is needed to fully understand these connections.
Study Limitations
While these findings are significant, the researchers caution that:
- The study was observational, meaning it cannot prove cause and effect—it only shows an association.
- Most participants were Scandinavian, so results may not apply to people from other backgrounds.
What This Means for Women’s Health
This study suggests that drinking large amounts of non-fermented milk could increase heart disease risk for women, while switching to fermented dairy products like yogurt or kefir may have protective benefits.
Takeaways for Women:
Limit intake of non-fermented milk—especially if consuming more than 300 mL per day.
Consider switching to fermented dairy products such as yogurt or kefir.
Maintain a balanced diet rich in heart-healthy foods like fruits, vegetables, and whole grains.
Consult a doctor or nutritionist if you have concerns about dairy intake and heart health.
While more research is needed to confirm these findings, this study adds valuable insights into how different types of dairy may affect heart disease risk, especially in women.
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.
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