Thinking about what you eat and drink is one place to start if you’re looking to lower your cholesterol. According to a new study that included close to two million people, regular consumption of milk is not associated with an increase in cholesterol.

Researchers have looked at whether certain types of milk affect cardiovascular health before, but studies investigating general milk consumption’s role on blood cholesterol levels have been limited.

To find answers to that question, the researchers behind the latest study evaluated data from large meta-analyses that included health outcomes. 

Genetics Determine How Your Body Reacts to Milk

Elina Hyppönen, a professor in Nutritional and Genetic Epidemiology at the University of South Australia and an investigator on the study, tells Verywell that the study’s findings “suggest that milk can be a part of a balanced heart-healthy diet.”

Dairy milk is a complex food, and its role in heart health depends on several variables. For the new study, the researchers used genetic factors to determine whether there could be a potential link between a person’s milk intake and their cholesterol levels. 

Some people have a hard time digesting lactose, the sugar naturally found in milk. The body relies on an enzyme called lactase to break the sugar down. Certain genetic factors can affect how well the body digests milk.

People who are lactose intolerant may have digestive symptoms when they consume dairy products, which may lead them to drink less milk. By looking at specific genetic factors like this one, the researchers were able to figure out whether people were more or less likely to drink milk.

Results

The study’s findings, which were published in the International Journal of Obesity, show that people with the genetic factors needed to break down lactase had lower levels of both HDL (“good”) and LDL (“bad”) cholesterol compared to people who did not have milk-digesting genes.

The researchers proposed that people who are able to digest milk well are more likely to drink milk than people who do not digest it as well. In fact, the odds of consuming milk were higher among people who had the gene for breaking down lactose than people who did not have the gene.

Researchers then made a connection between milk intake and cholesterol levels: The people with the gene for digesting lactose drank more milk and had lower cholesterol levels than people who did not have the gene and, presumably, drank less milk.

Limitations

Although the study was large, it was not an intervention trial. Therefore, a definitive causal relationship between milk intake and cholesterol levels cannot be assumed.

People who had the lactose-digesting gene also had a slightly higher body mass index (BMI) than people who did not have the gene. People who drank more milk had a 14% lower risk of developing coronary heart disease (CHD) than people who drank less milk. No direct link between milk intake and type 2 diabetes was found.

More research is needed, but if you’re looking to make evidence-backed changes to your diet, past studies have also highlighted milk’s heart-health benefits. A study published in the American Journal of Clinical Nutrition indicated that certain dairy fats, including whole milk, might be protective against stroke and heart disease.

Lainey Younkin, MS, RD, LDN, a Boston-based registered dietitian at Lainey Younkin Nutrition, tells Verywell that milk can be a healthful addition to your diet because it “contains essential nutrients like vitamin D, vitamin A, protein, calcium, B vitamins, including vitamin B12, and minerals like magnesium and selenium.”

Younkin adds that drinking milk can fill key nutrient gaps—especially magnesium and calcium, which may play a role in heart health.

Including Milk in a Heart-Healthy Diet

Milk has unique nutritional components that no other food can match. The researchers think that some of these factors might be why milk can have heart-health benefits.

The calcium and lactose found in milk may enhance calcium absorption—a factor that has been shown to lower cholesterol levels. Milk drinkers may consume less fat overall compared to people who cannot break down the lactose sugar. Higher fat dairy products like butter and cheese typically contain less lactose; therefore, people who cannot break down the sugar may consume more of these higher-calorie foods. The sugars found in milk can be fermented in the gut, which can lower cholesterol formation rates.