A fat called trans-palmitoleic acid was once thought to protect against diabetes, but when scientists accounted for other similar fats in dairy, the link disappeared — meaning the earlier belief was probably wrong.

A specific type of fat found naturally in dairy products is linked to a much lower risk of developing type 2 diabetes, even though people don’t eat much of it.

A specific type of fat found in milk and cheese is linked to a much lower chance of getting type 2 diabetes, possibly because it helps the body use insulin better.

People with more of a specific fat found in dairy products like butter and cheese in their blood have a lower chance of getting type 2 diabetes, even after accounting for how much dairy they eat.

Not all trans fats are the same — some dairy fats lower diabetes risk, one dairy fat raises it, and artificial trans fats don’t seem to matter at all. What matters most is the exact molecular shape, not whether it’s natural or artificial.

A different type of fat found in dairy called c9t11-CLA is linked to a higher chance of getting type 2 diabetes, which is surprising because other dairy fats are usually thought to be harmless or even helpful.