Is dairy fat protective or harmful when it comes to diabetes risk? A new study evaluates international data.
Recent studies have been suggesting that the consumption of dairy products may have various health benefits.
For instance, one study covered on Medical News Today last month argued that full-fat dairy could help maintain cardiovascular health.
Still, not everyone agrees with these findings, and some countries — including the United Kingdom and the United States — have proposed dietary guidelines that encourage people to choose low-fat or fat-free dairy products.
Now, an international research team led by scientists from the University of Cambridge in the United Kingdom, and from Tufts University in Medford, MA, has conducted a pooled analysis of various prospective cohort studies, looking at the relationship between dairy fat consumption and the risk of type 2 diabetes.
The researchers analyzed the data collected from 16 prospective cohorts from 12 countries, including the U.S. and Australia, which amounted to 63,682 participants in total. Their findings appear in the journal PLOS Medicine.
In explaining why they chose to conduct this analysis, the authors write that the "effects of dairy fat on type 2 diabetes are not well established."
"While dairy fat contains palmitic acid that could increase risk of [type 2 diabetes], it also contains several other types of fatty acids and further reflects specific foods, such as cheese or yogurt, that could reduce risk," they note.
Dairy fat levels and diabetes risk
The investigators studied the participants' biomarkers of dairy fat consumption, considering how these correlated with the risk of type 2 diabetes.
None of the participants had diabetes at baseline, though 15,158 individuals developed this metabolic condition over the study follow-up period, which lasted more than 20 years.
By analyzing the data derived from all of the 16 studies, the researchers found links between people with higher concentrations of dairy fat biomarkers in their system and a lower risk of type 2 diabetes.
Moreover, the scientists acknowledge that factors other than a person's levels of dairy consumption could influence the levels of the biomarkers considered in this study.
Compared with participants with the lowest concentrations of dairy fat biomarkers, those with the highest levels had an approximately 30 percent decreased risk of developing type 2 diabetes, the study authors note.
"Our results provide the most comprehensive global evidence to date about dairy fat biomarkers and their relationship with lower risk of type 2 diabetes," says lead researcher Dr. Fumiaki Imamura.
"We're aware that our biomarker work has limitations and requires further research on underlying mechanisms, but at the very least, the available evidence about dairy fat does not indicate any increased risk for the development of type 2 diabetes," he adds.
"We hope that our findings and existing evidence about dairy fat will help inform future dietary recommendations for the prevention of lifestyle-related diseases."
Dr. Fumiaki Imamura
'A need to re-examine' dairy benefits
Senior study author Prof. Dariush Mozaffarian also believes that the current findings may call for a revision of dietary guidelines that encourage people to avoid full-fat dairy.
"While dairy foods are recommended as part of a healthy diet, the U.S. and international guidelines generally recommend low-fat or non-fat dairy due to concerns about adverse effects of higher calories or saturated fat," says Prof. Mozaffarian.
"Our findings, measuring biomarkers of fatty acids consumed in dairy fat, suggest a need to re-examine the potential metabolic benefits of dairy fat or foods rich in dairy fat, such as cheese," the senior author advises.
This topic warrants further research. However, any future studies will need to take some of the limitations faced by the current analysis into consideration.
The researchers explain that their results do not distinguish between different types of dairy products, though it is important to note that the consumption of different foods, such as milk versus cheese, may have a different impact on metabolic risk.
Finally, the current analysis focused mostly on white populations, which means that the findings may not apply to different cohorts. For this reason, future studies should aim to include more diverse populations.