You remember the ad. It asked if you've "got milk?" and said that "milk does a body good."
So, does it? New research suggests it might.
In the study, people who consumed more dairy fat actually had a lower risk of cardiovascular disease than those who drank or ate less dairy, CNN reported.
"Increasing evidence suggests that the health impact of dairy foods may be more dependent on the type — such as cheese, yogurt, milk and butter — rather than the fat content, which has raised doubts if avoidance of dairy fats overall is beneficial for cardiovascular health," said lead author Kathy Trieu, a researcher from the George Institute for Global Health in Sydney, Australia.
"Our study suggests that cutting down on dairy fat or avoiding dairy altogether might not be the best choice for heart health," Trieu told CNN.
To study the issue, her team looked to Sweden, measuring the blood levels of a fatty acid mostly found in dairy food. The country is known to be among the world's highest consumers and producers of dairy products.
The investigators continued to follow just over 4,000 participants, whose blood was analyzed for an average of 16 years.
The researchers adjusted for known cardiovascular disease risk factors and looked at how many in the group had had heart attacks, strokes and other circulatory illnesses, and how many had died during those intervening years. Those whose blood contained the highest levels of the fatty acid had the lowest risk of cardiovascular disease and no increased risk of death from all causes, the study found.
The researchers didn't stop at Sweden. They confirmed their findings by combining the results with 17 other studies that included 43,000 people from the United States, the United Kingdom and Denmark, CNN reported.
"While the findings may be partly influenced by factors other than dairy fat, our study does not suggest any harm of dairy fat, per se," said Matti Marklund, a senior researcher at the George Institute and joint senior author of the paper.
"We found those with the highest levels actually had the lowest risk of CVD [cardiovascular disease]. These relationships are highly interesting, but we need further studies to better understand the full health impact of dairy fats and dairy foods," Marklund added.
The results should not be interpreted to mean that full-fat dairy products cut the risk of cardiovascular disease, Alice Lichtenstein, director and senior scientist at Tufts University's Cardiovascular Nutrition Research Laboratory in Boston, told CNN.
The study showed that the group with the highest biomarker of dairy intake also had a significantly lower BMI, were more physically active, had a lower smoking rate, lower rates of type 2 diabetes and cardiovascular disease, a higher level of education, higher intakes of vegetables, fruit and fish, and lower intake of processed meat. All of these factors are associated with a lower risk of cardiovascular disease.
"They were controlled for in the statistical analyses, however, residual confounding cannot be ruled out. The data reported are for associations, however, associations cannot establish causality," Lichtenstein explained.
What researchers do know is that dairy, especially when it's fermented, had been associated with heart benefits.
Trieu said, "It is important to remember that although dairy foods can be rich in saturated fat, they are also rich in many other nutrients and can be a part of a healthy diet. However, other fats like those found in seafood, nuts and non-tropical vegetable oils can have greater health benefits than dairy fats."
Brian Power, a lecturer at the department of health and nutritional sciences at Ireland's Institute of Technology Sligo, said the study should prompt scientists to "rethink what we think we know about food and disease."
"Dairy products do not need to be avoided," Power, who was not involved in the study, told CNN. "This is largely lost in its translation when communicating what we know about healthy eating."
The research was published Sept. 21 in the journal PLOS Medicine.