A 3,000-participant study found that people who included dairy fat in their diet had a lower risk of diabetes. One theory for the link is that people who skip or limit dairy might compensate by eating more refined, low-fiber carbohydrates, which can increase diabetes risk.
A study that followed more than 200,000 people over several decades looked at the relationship between dairy fat intake and heart disease.
It found no increase in heart disease risk among people who ate dairy fat, although the risk was lowered when calories from dairy fat were replaced with calories from plant-based fats or whole grains -- 24% when they were replaced by polyunsaturated fats and 28% when replaced with whole grains. On the other hand, the risk went up by 6% if those calories went instead to foods with other types of saturated fat, like red meat.
A third piece of research reviewed nine studies that looked specifically at butter, another source of saturated fat, and its role in heart disease, diabetes and all causes of death. The analysis found that while plant-based fats are healthier, small amounts of butter aren't likely to hurt you.
What might you do with all this information? The familiar bottom line is moderation. While it's still healthier to cook with olive oil, for instance, you can indulge in a pat of butter on your hot whole-grain cereal or an ounce of cheese on whole-grain bread or, perhaps best of all, a serving of full-fat yogurt and a cup of berries.