- Higher dairy intake was linked to lower risks of heart attack and hemorrhagic stroke.
- Dairy intake was associated with a higher risk of ischemic heart disease in this study
- People who ate more dairy tended to have lower BMI and blood pressure.
Cardiometabolic diseases, a group of conditions that includes diabetes, heart disease and stroke, are a major health concern worldwide. While we know that factors like high blood pressure and obesity are linked to an increased risk of these diseases, scientists are still exploring how our dietary habits contribute. One area of particular interest is dairy consumption. For years, research has produced mixed results, with some studies suggesting benefits and others finding no effect.
Most of this research has focused on Western populations, where dairy intake is relatively high. This leaves a significant knowledge gap for other groups. To bridge this gap, a large-scale study was conducted in China, where dairy consumption is traditionally low but on the rise, to explore potential links between consumption and health outcomes. These results were published in the Journal of Nutrition.
How Was This Study Conducted?
To investigate the link between dairy and health, researchers turned to the China Kadoorie Biobank, a massive prospective study. They analyzed data from more than 460,000 Chinese adults aged 30 to 79 who had no history of major diseases like cancer, heart disease or diabetes at the start.
Participants were recruited from 10 diverse regions across China between 2004 and 2008. Using a detailed questionnaire, researchers collected information about their lifestyle, medical history and how often they consumed 12 major food groups, including dairy products. At the beginning of the study, a striking 70% of participants reported rarely or never consuming dairy, while just under 11% consumed it four or more times a week.
Over an average follow-up period of nearly 12 years, the researchers tracked who developed cardiometabolic diseases by linking to national health insurance and disease registries. This long-term approach allowed them to see how initial dairy habits correlated with future health outcomes.
What Did the Study Find?
After adjusting for various factors like age, smoking, income, physical activity and body mass index (BMI), the study revealed several key associations.
First, higher dairy intake was associated with a lower risk for several serious events:
- Acute myocardial infarction (heart attack): 12% lower risk.
- Intracerebral hemorrhage, a type of stroke caused by bleeding in the brain: 31% lower risk.
- Cardiovascular death: 18% lower risk.
But the results weren’t all positive. Results also suggest that those who consumed at least four servings of dairy every week had an 11% higher risk of ischemic heart disease, compared to those who never or rarely consumed dairy.
When it comes to dairy’s link to diabetes, before adjusting for BMI, results suggest that higher dairy intake was linked to a lower risk of diabetes. But after accounting for BMI, this association disappeared, suggesting that dairy’s effect on diabetes risk might be closely tied to its influence on body weight. Indeed, the study found that people who consumed more dairy tended to have a lower BMI and lower blood pressure.
Limitations
First, the dietary information was self-reported and collected through a frequency questionnaire, which can be less precise than detailed food diaries. This method didn’t allow for a thorough analysis of total energy intake.
Second, the study could not reliably distinguish between different types of dairy products, such as milk, yogurt or cheese. The health effects of these products may vary, and lumping them together might mask more specific relationships. Third, the study included only Chinese participants, which may limit how well these findings apply to other populations with different genetic backgrounds or dietary habits.
Finally, while the researchers adjusted for many potential confounding factors, it is impossible to rule out all of them. This means the study shows associations, but it cannot definitively prove that dairy consumption causes these outcomes.
How Does This Apply to Real Life?
For people in China and other countries where dairy intake is generally low, these results point to potential benefits in including more dairy in the diet. The study found that higher dairy consumption was linked with a lower risk of several serious outcomes, including heart attack, hemorrhagic stroke and cardiovascular death. These protective associations suggest that moderate intake of dairy products may play a positive role in supporting heart and vascular health, especially by influencing factors like blood pressure and certain blood biomarkers. Of course, the elevated ischemic heart disease risk cannot be understated and is worth keeping on the radar.
While the relationship with ischemic heart disease was more complex, the overall findings add to a growing body of evidence that dairy foods, when consumed as part of a balanced diet, can be part of a healthy lifestyle for many people.
Our Expert Take
This large-scale study of Chinese adults published in the Journal of Nutrition provides a nuanced look at how dairy consumption relates to cardiometabolic health. It reveals that higher intake was linked to a lower risk of heart attack, hemorrhagic stroke, and cardiovascular death, while being associated with a greater risk of ischemic heart disease.
Of course, differences in individual health profiles, types of dairy products, and regional habits still matter, and more research is needed to fully understand these connections. Nevertheless, this study adds to the growing evidence that enjoying dairy may be a positive element for cardiometabolic health when incorporated thoughtfully.
