A decades-long study has finally revealed how healthy full-fat and low-fat milk are, with researchers concluding that one is safer for your heart.
Experts analysed three decades of health data and found the fat level of milk influenced a person’s risk of dying of heart disease.
The 2025 study published in the The American Journal of Clinical Nutrition used data from three cardiovascular health screenings conducted between 1974 and 1988.
Researchers in Norway tracked the data of 73,860 individuals, with an average age of 41, over 33 years and recorded 26,393 deaths, including 8,590 from cardiovascular disease.
They found those who drank full-fat milk had a higher mortality risk in than those who drank low-fat milk.
Researchers were able to make this comparison due to a unique historical context. In the 1970s, most people in Norway drank whole milk, but by the 1980s more people drank low-fat milk. This meant researchers were able to investigate the long-term health consequences of drinking both of these milk types.
Those who drank the most milk in the study had a 22 per cent increased risk of all-cause mortality and a 12 per cent increased risk of death from cardiovascular disease in comparison to those who drank the least.
But further analysis revealed whole milk in particular was driving this increased risk of death.
When researchers compared full-fat and low-fat milk and adjusted for how much they drank, they found consuming low-fat milk was associated with a 11 per cent lower mortality risk and a 7 per cent lower risk of cardiovascular disease than consuming whole milk.
The findings remained consistent even after excluding early deaths or participants with pre-existing conditions.
However, low-fat milk drinkers tended to be females, have higher education and not smoke, in comparison to whole fat milk drinkers who frequently reported being current smokers.
Study authors concluded: “Associations between milk intake and cardiovascular disease and all-cause mortality varied by type of milk, with positive associations found for whole milk and a modestly inverse association with ischemic heart disease and all-cause mortality was found for low-fat milk when compared with whole milk.”
The results are in line with current NHS health advice. Most of the fat in milk and dairy foods is saturated fat which when eating in large amounts can contribute to weight gain, the NHS explains. A diet high in saturated fat can also lead to raised levels of cholesterol in the blood, increasing the risk of having a heart attack or a stroke.
