High- and Low-Fat Dairy Consumption and Long-Term Risk of Dementia

For decades, the nutritional guidelines have been clear: if you want to be healthy, choose the low-fat option. We have swapped cream for skimmed milk and cheddar for cottage cheese, believing we were doing our bodies a favour. However, a major new study published in the journal Neurology suggests that when it comes to long-term brain health, we might have been getting it back to front. The research, conducted by a team at Lund University in Sweden, is one of the most comprehensive of its kind. Instead of looking at a small group for a few months, they tracked over 27,000 people for a staggering 25 years. Their goal was to see if the type of dairy we consume—specifically the fat content—has any impact on the risk of developing dementia later in life. The results challenge the old "fat is bad" dogma. The researchers found that people who consumed high quantities of high-fat cheese (around 50 grams a day) had a significantly lower risk of developing all-cause dementia compared to those who ate very little. Specifically, the risk was reduced by about 13 per cent. Even more surprising was the finding regarding heavy cream. Those who regularly consumed high-fat cream saw a 16 per cent lower risk of dementia compared to those who avoided it. These benefits appeared to extend to specific types of the condition, including vascular dementia, which is caused by reduced blood flow to the brain. Crucially, this benefit did not apply to everything in the dairy aisle. The study found no protective effect from drinking milk—whether full-fat or low-fat—or from eating low-fat cheese and yogurt. The magic seems to be locked specifically within the structure of high-fat fermented cheese and cream. This distinction is vital because it suggests the benefit isn't just about "eating fat." It is likely about the complex matrix of nutrients found in these specific foods, such as certain fatty acids, vitamin K2, or the way the fat interacts with proteins in cheese. The study also revealed a fascinating nuance regarding genetics. The protective effect of high-fat cheese was strongest in people who did not carry the APOE ε4 gene variant—the most common genetic risk factor for Alzheimer’s. This implies that for the vast majority of the population without this specific high-risk gene, a diet richer in traditional, high-fat dairy might offer a layer of neuroprotection. While this is an observational study and cannot prove cause and effect, it adds a significant weight to the argument that our brains, which are largely made of fat, might require high-quality dietary fats to maintain their structure as we age. It certainly suggests that the guilt associated with a good cheese board might be entirely misplaced.