Milk has long been treated as a simple symbol of health: calcium, protein, strong bones, and an easy daily habit. But recent research has made the conversation more complicated, especially when it comes to the difference between full-fat milk and low-fat milk. A large Norwegian study followed 73,860 people over roughly three decades and found that whole milk consumption was associated with higher cardiovascular and all-cause mortality, while low-fat milk was not linked to the same increase.

That does not mean one glass of full-fat milk is dangerous, or that every person must avoid it completely. Nutrition is rarely that simple. But the findings do suggest that the type of milk people drink may matter over the long term, especially for those already watching cholesterol, saturated fat, weight, or heart disease risk. Here are ten key points that explain what the study found and why it matters.