High-Fat Dairy Consumption Linked to Decreased Risk of Dementia

A 25-year study showed that a higher intake of high-fat cheese or dairy is associated with a lower risk of all-cause dementia. Researchers from Sweden found that this association differed depending on whether someone carried the APOE ε4 gene.¹

“For decades, the debate over high-fat versus low-fat diets has shaped health advice, sometimes even categorizing cheese as an unhealthy food to limit," said Emily Sonestedt, PhD, senior study author, senior lecturer, and associate professor of nutrition at Lund University in Sweden. "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."²

How Does the APOE ε4 Gene Affect Alzheimer Disease Risk?

Alzheimer disease (AD) is a progressive neurodegenerative condition marked by the buildup of beta-amyloid plaques and abnormal tau protein in the brain, leading to gradual declines in memory, language, thinking, and mood regulation. A key genetic risk factor for AD is the apolipoprotein E (APOE) gene, which plays a role in transporting cholesterol and other fats in the bloodstream. APOE exists in several forms, or alleles—most commonly ε2, ε3, and ε4.^1,3

The ε4 variant is associated with a higher risk of developing AD and, in some populations, an earlier age of onset. An estimated 15% to 25% of people carry 1 copy of APOE ε4, while about 2% to 5% carry 2 copies.³

Could Dairy Choices Affect Long-Term Brain Health?

The relationship between dairy intake and dementia risk remains unclear, particularly when considering differences in fat content across dairy products. Evidence suggests cheese may offer some protection against cognitive decline, while associations for cream, milk, and yogurt are less consistent, and findings vary across populations and studies; genetic factors like APOE ε4 may influence these relationships, though prior research has not shown clear interactions.¹

To address this gap, researchers analyzed long-term data from the Malmö Diet and Cancer cohort in Sweden to examine whether high-fat and low-fat dairy consumption were associated with the risk of developing dementia, including AD and vascular dementia (VaD).¹

The prospective study included 27,670 community-dwelling adults with a mean baseline age of 58 years, 61% of whom were women. Dietary intake was assessed between 1991 and 1996 using a detailed diet history method that combined a 7-day food diary, a food frequency questionnaire, and an in-person dietary interview.¹

Dementia diagnoses were identified using the Swedish National Patient Register through December 31, 2020, with earlier cases undergoing additional validation. Over a median follow-up of 25 years, 3208 participants developed dementia.¹

Can Dairy Intake Influence Dementia Risk?

The data showed that higher consumption of certain high-fat dairy products was associated with a lower risk of dementia. Participants consuming at least 50 g per day of high-fat cheese (>20% fat) had a reduced risk of all-cause dementia and VaD compared with those consuming less than 15 g per day.¹

Among individuals who did not carry the APOE ε4 allele, high-fat cheese intake was also inversely associated with AD risk, suggesting a modifying effect of genetic risk. Similarly, consuming at least 20 g per day of high-fat cream (>30% fat) was associated with a 16% lower risk of all-cause dementia, with inverse associations also observed for AD and VaD. In contrast, no significant associations were found for low-fat cheese, low-fat cream, milk, fermented milk, or butter, regardless of fat content.¹

“Our research suggests that people who ate more high-fat cheese had a slightly lower risk of developing dementia later in life,” Sonestedt told CNN. “This does not prove that cheese prevents dementia, but it does challenge the idea that all high-fat dairy is bad for the brain.”

REFERENCES

1. Du Y, Borné Y, Samuelsson J, et al. High- and low-fat dairy consumption and long-term risk of dementia. Neurology. December 17, 2025. Doi:10.1212/WNL.0000000000214343

2. Starr M. Cheese linked to lower dementia risk in 25-year study. ScienceAlert. December 18, 2025. Accessed December 23, 2025. https://www.sciencealert.com/cheese-linked-to-lower-dementia-risk-in-25-year-study

3. Alzheimer's disease genetics fact sheet. National Institute on Aging. March 1, 2023. Accessed December 23, 2025. https://www.nia.nih.gov/health/alzheimers-causes-and-risk-factors/alzheimers-disease-genetics-fact-sheet