It is generally believed that limiting fat intake is recommended to prevent dementia and other cognitive disorders. However, Swedish researchers have reached the opposite conclusion: consuming high-fat dairy products is associated with a reduced risk of developing these conditions.

Dementia: The Scale of the Problem

Dementia is one of the most serious medical and social challenges of the 21st century. According to the World Health Organization, in 2021 there were 57 million people worldwide diagnosed with dementia, with more than 60% living in low- and middle-income countries. Nearly 10 million new cases of dementia are registered each year. Although effective treatments have already been successfully tested in animals, for ethical reasons, their implementation for humans is unlikely in the near future. Therefore, the main strategy for combating dementia is prevention, in which nutrition plays a key role.

Contradictions in Dietary Recommendations

Dietary advice for dementia prevention is often contradictory, especially when it comes to fats. Dairy products are traditionally divided into "healthy" (low-fat) and "unhealthy" (full-fat) due to their saturated fat content. However, a new study published in the journal Neurology by researchers from Lund University (Sweden) found a link between dairy consumption and the risk of developing dementia.

Study Design

The study involved 27,000 men and women from the Swedish city of Malmö. At the start, each participant underwent a detailed dietary assessment: they kept a food diary, completed an extensive questionnaire, and had interviews with a dietitian. This allowed researchers to accurately determine not only the total dairy intake but also to separately account for different types: cheese, cream, milk of varying fat content, yogurt, and butter.

The participants were then followed for an average of 25 years. Cases of dementia were tracked using Sweden’s national registries, and for periods before 2014, diagnoses were additionally confirmed by neurologists.

Results: High-Fat Dairy and Dementia Risk

The analysis showed that the relationship with dementia risk depended on the type and fat content of dairy products. The strongest protective effect was found for high-fat products. Participants who consumed more than 50 grams of full-fat cheese (over 20% fat) daily had a 13% lower risk of developing dementia and a 29% lower risk of vascular dementia compared to those who rarely ate cheese.

A similar inverse association was found for high-fat cream (over 30% fat): consuming 20 grams or more per day was linked to a 16% reduction in overall dementia risk. Meanwhile, milk (both whole and skimmed), yogurt, butter, and low-fat versions of cheese and cream did not show a statistically significant association with the risk of this neurodegenerative disease.

Genetic Factors and Alzheimer’s Disease

The second important finding concerns Alzheimer’s disease. The protective link between full-fat cheese consumption and reduced risk of Alzheimer’s was observed only in people who did not carry the APOE ε4 gene variant—the strongest known genetic risk factor for this disease. This means that the same dietary factor can have different effects on people depending on their genetic predisposition.