Drinking milk regularly may be linked to lower risk of heart disease, study suggests

• Regularly drinking milk could reduce the risk of heart disease, according to new research.
• A study on 2 million people found that habitual milk drinkers had more body fat, but lower cholesterol.
• It's not clear how this works; we might metabolize milk differently than other fat sources, research suggests.

Drinking milk could be good for your heart, evidence suggests.

People who regularly drank milk had lower cholesterol levels and were less likely to develop heart disease, according to a study published May 24 in the International Journal of Obesity.

Researchers from the University of Reading, University of South Australia, and University of Auckland looked at data from nearly two million adults in the UK.

The researchers used genetics to help identify habitual milk drinkers - they found that people with a genetic variation that helps digest lactose were more likely to drink milk. Combined with surveys about milk consumption, the researchers used this information to assess how drinking milk might be linked to health outcomes, such as risk of disease.

They found that milk drinkers tend to have a higher body mass index, but lower levels of both good and bad cholesterol, and 14% lower risk of developing cardiovascular disease.

Milk's high fat content may be digested differently, based on an 'unknown milk factor'

Previous research suggests that saturated fat may be linked to a higher risk of heart disease. But milk, which is high in saturated fat, doesn't appear to be linked to health risks in the same way that other fatty foods, such as red meat, are.

These findings suggest that a heart-healthy diet can include milk, according to Vimal Karani, lead author of the study and professor of nutrigenetics at the University of Reading.

"The study certainly shows that milk consumption is not a significant issue for cardiovascular disease risk even though there was a small rise in [body mass index] and body fat among milk drinkers," Karani said in a press release. "What we do note in the study is that it remains unclear whether it is the fat content in dairy products that is contributing to the lower cholesterol levels or it is due to an unknown 'milk factor.'"

One explanation might be that the high calcium and lactose content of milk could change how fats are metabolized in the body, the researchers suggested. It could also be that milk drinking affects bacteria that live in the gut, altering how cholesterol is processed. More research is needed to better understand how exactly milk plays a role in disease risk.

For now, experts say that milk and dairy products can be part of a healthy diet, since they also include important nutrients like protein and calcium.