Swedish study links high-fat dairy to lower dementia risk, researchers say

A Swedish study suggests that eating high-fat dairy products may be linked to a lower risk of dementia among middle-aged adults. Researchers followed more than 27,000 participants for about 25 years, tracking diet and cognitive health. Over the follow-up period, 3,207 people developed dementia.

The analysis found that regular intake of high-fat dairy was associated with lower dementia risk. Those who consumed about 50 grams of cheese daily saw a 13% lower risk, compared with those who ate less than 15 grams per day. Those who ate around 1.5 tablespoons of high-fat cream daily had a 16% lower risk. The cheeses involved include varieties with more than 20% fat, such as cheddar, parmesan, stilton and brie. In the study, participants kept food diaries, and researchers tracked outcomes over 25 years. After accounting for other factors, the study also found a 29% lower risk of vascular dementia for high-fat cheese eaters, and a reduced chance of Alzheimer’s disease among those who did not carry the APOE e4 gene variant. Full-fat cream appeared to have a similar protective effect. There was no observed association between dementia risk and low-fat cheese, low-fat cream, milk, butter or fermented dairy products.

The researchers published their findings in Neurology, noting that some high-fat dairy products may be linked to cognitive outcomes, though they cautioned that further studies are needed to confirm causality and to understand potential mechanisms. The authors also emphasized that the observed associations do not prove that cheese or cream prevent dementia.

Professor Emily Sonestedt, an expert in nutrition and public health at Lund University and a co-author of the study, said: "For decades, the debate over high-fat versus low-fat diets has shaped health advice, sometimes categorising cheese as an unhealthy food to limit. Our study found that some high-fat dairy products may actually lower the risk of dementia, challenging some long-held assumptions about fat and brain health."

Outside experts who were not involved in the research urged caution about drawing conclusions from observational data. Professor Naveed Sattar, a cardiometabolic medicine expert at the University of Glasgow, noted that the study is observational rather than randomized and highlighted potential confounding. "I do not believe there is a causal link here," he said, adding that higher education levels were more common among those who consumed more high-fat cheese and cream, which could reflect other healthy characteristics rather than the dairy itself. He stressed that well-established risk-reduction measures—such as controlling blood pressure, maintaining a healthy weight, and preventing heart disease or stroke—should remain the focus.

Professor Tara Spires-Jones, Director of the Centre for Discovery Brain Sciences at the University of Edinburgh, said it is likely that diet and other lifestyle factors changed over the 25-year study period. She noted that robust evidence across the field supports healthy eating, physical activity, and cognitive engagement as ways to bolster brain resilience, but there is not strong evidence that any single food protects against dementia.

Dementia now affects about one in 11 people over 65 in the United Kingdom and claims about 76,000 lives each year, making it the country’s biggest killer. The condition also imposes a heavy economic cost, with the Alzheimer’s Society estimating around £42 billion a year for care and related expenses, a figure expected to rise by 2040. The Daily Mail’s Defeating Dementia campaign, run with Alzheimer’s Society, seeks to raise awareness, promote earlier diagnosis, and support research and care, amid growing calls for prevention-focused public health strategies. Researchers say that around 45% of all dementia cases may be preventable or subject to delayed onset through lifestyle changes.

NHS guidance already cautions that cheese should be consumed in moderation due to saturated fat and salt. The health service typically recommends about 30 grams of cheese per day, as part of an overall balanced diet and healthy lifestyle that includes weight maintenance, moderate alcohol use, and blood pressure control. While the new findings add to the discussion on dairy fats, experts say people should not rely on any single food to prevent dementia. More research is needed to confirm the links and understand potential mechanisms.