Researchers followed over 1,200 adults in China for about 6 years to understand how dairy products affect heart health. They discovered that people with higher levels of special fatty acids from dairy in their blood were less likely to develop plaque buildup in their neck arteries—a sign of heart disease risk. The study suggests that dairy’s benefits might work through changes in gut bacteria that help protect blood vessels. This finding could lead to new ways to prevent heart disease by targeting gut health, though more research is needed to confirm these results in different populations.

The Quick Take

  • What they studied: Whether special fatty acids found in dairy products protect against plaque buildup in arteries, and whether gut bacteria play a role in this protection
  • Who participated: 1,211 adults in China with an average age of 59 years, followed for about 6 years. Researchers also looked at a younger population to confirm their findings
  • Key finding: People with the highest levels of dairy-related fatty acids in their blood were 37% less likely to develop artery plaque compared to those with the lowest levels
  • What it means for you: Eating dairy products may help protect your heart and arteries, possibly by improving your gut bacteria. However, this study was done in a Chinese population, so results may differ for other groups. Talk to your doctor about your individual heart health needs

The Research Details

This was a long-term follow-up study where researchers tracked the same group of people over time. At the beginning, they measured special fatty acids (called odd-chain saturated fatty acids) in participants’ blood—these are natural markers that show how much dairy someone eats. They also analyzed the bacteria living in participants’ guts using genetic testing. Over 6 years, researchers checked who developed plaque in their neck arteries, which is a sign of heart disease risk.

To understand how dairy might work its magic, the researchers also studied a younger group of people to see if the same gut bacteria changes happened in different age groups. This two-step approach helped them understand not just that dairy seemed protective, but possibly how it worked.

Instead of just asking people what they eat (which can be unreliable), researchers measured actual dairy markers in the blood—like taking a test to see what you’ve actually consumed. This is much more accurate. By also studying gut bacteria, they could explore the actual biological pathway explaining why dairy might help, rather than just showing a connection

This study has several strengths: it followed real people over years rather than just observing them once, it used objective blood tests instead of relying on memory, and it examined the biological mechanisms involved. However, the study was done only in China, so results might not apply equally to all populations. The study shows association (connection) but cannot prove that dairy directly causes the protection—other lifestyle factors could be involved

What the Results Show

The main finding was clear: people with the highest levels of dairy-related fatty acids in their blood had significantly lower risk of developing artery plaque. Specifically, those in the top quarter had about 37% lower risk compared to those in the bottom quarter.

The researchers also found that these dairy fatty acids were strongly connected to the diversity and types of bacteria in people’s guts. People with higher dairy markers had more diverse gut bacteria communities, which is generally considered healthy. The study identified 36 different types of bacteria that were associated with these dairy markers.

One particular type of bacteria called Christensenellaceae R-7 group stood out. This bacteria was more common in people with higher dairy intake, and importantly, people who had more of this bacteria were less likely to have artery plaque. This suggests this specific bacteria might be part of the protective mechanism.

Finally, researchers identified 13 different compounds produced by gut bacteria that were linked to both the dairy markers and the protective bacteria. These compounds, including deoxycholic acid and lithocholic acid, may be the actual messengers that carry the protective signal from dairy through your gut bacteria to your arteries.

The study found that the relationship between dairy intake and gut bacteria was consistent across different age groups, suggesting this mechanism works similarly whether you’re younger or older. The diversity of gut bacteria (having many different types) was particularly important—people with more diverse bacteria had better protection. The specific bacterial compounds identified suggest that the benefit isn’t just about eating dairy, but about how your body processes it through your gut bacteria

Previous research has suggested that dairy products have mixed effects on heart health—some studies showed benefits while others showed concerns, particularly about saturated fat content. This study helps explain why: the type of saturated fat in dairy (odd-chain fatty acids) appears to be protective, possibly because of how it influences gut bacteria. This aligns with growing research showing that gut bacteria play a major role in heart health, and it suggests that not all saturated fats affect the body the same way

The study was conducted only in a Chinese population, so results may not apply equally to people of other ethnic backgrounds or living in different regions. The study shows association but cannot prove cause-and-effect—people who eat more dairy might also have other healthy habits. The researchers adjusted for many factors, but some unmeasured lifestyle differences could still explain the results. Additionally, the study measured dairy intake indirectly through blood markers rather than directly tracking what people ate

The Bottom Line

Based on this research, consuming dairy products appears to be associated with better heart artery health, possibly through beneficial changes in gut bacteria. This supports general dietary guidelines that include moderate dairy consumption. However, this is one study in one population, so it should be considered alongside other nutrition research. People concerned about heart health should discuss dairy intake with their doctor, as individual needs vary based on allergies, intolerances, and other health conditions

This research is most relevant to adults concerned about heart disease prevention, particularly those with family history of heart disease or existing risk factors. People interested in gut health and how diet affects bacteria should find this interesting. However, people with dairy allergies or lactose intolerance should not feel pressured to consume dairy—other foods can provide similar benefits. Those taking medications that affect gut bacteria should discuss dairy intake with their healthcare provider

Changes in gut bacteria can happen relatively quickly (weeks to months) when diet changes, but the protective effects on artery health likely take much longer to develop. In this study, benefits were measured over 6 years. You shouldn’t expect to feel immediate changes, but consistent dairy consumption over months and years may contribute to better long-term heart health

Want to Apply This Research?

  • Track daily dairy consumption (servings of milk, yogurt, cheese) and note any digestive changes. Users could log: type of dairy, amount, and any symptoms. Over time, this creates a personal record of dairy intake patterns
  • If not currently consuming dairy, gradually introduce one serving daily (like a cup of yogurt or milk) and track how you feel. If already consuming dairy, note the types you eat most—the study suggests all dairy sources provide the beneficial fatty acids. Users could set a goal of consistent daily dairy intake and monitor adherence
  • Monthly check-ins on dairy consumption consistency, quarterly notes on digestive health and energy levels, and annual discussions with healthcare provider about heart health markers (like blood pressure or cholesterol). Users could also track general wellness indicators that might correlate with improved gut health

This research suggests an association between dairy consumption and reduced artery plaque risk, but does not prove dairy directly prevents heart disease. Individual results vary based on genetics, overall diet, lifestyle, and health conditions. People with dairy allergies, lactose intolerance, or specific health conditions should consult their healthcare provider before making dietary changes. This study was conducted in a Chinese population and may not apply equally to all groups. Always discuss significant dietary changes with your doctor, especially if you have existing heart disease, high cholesterol, or take medications affecting digestion. This information is for educational purposes and should not replace professional medical advice