Can cheese help prevent dementia? Japanese researchers say it might

By Priyanjana Pramanik, MSc.Reviewed by Susha Cheriyedath, M.Sc.Oct 27 2025

A large Japanese cohort study reveals that even modest weekly cheese consumption may help preserve cognitive health, offering fresh insight into how simple dietary habits could support an aging brain.

Study: Cheese Consumption and Incidence of Dementia in Community-Dwelling Older Japanese Adults: The JAGES 2019–2022 Cohort Study. Image Credit: Jiri Hera / Shutterstock

In a recent study published in the journal Nutrients, researchers investigated whether older adults who consume cheese at least once each week are less likely to develop dementia.

Their findings, based on a Japanese population aged 65 and over, suggest that weekly cheese consumers may be at a lower risk of dementia than non-consumers, although residual confounding cannot be completely ruled out despite adjustment for multiple socioeconomic and health variables.

Background

Dementia is a growing global health concern. It is projected to affect over 150 million people by 2050. Japan, one of the world’s most rapidly aging societies, faces a steep rise. Researchers expect the number of cases in Japan to increase from 4.4 million older adults with dementia in 2022 to 5.8 million by 2040.

This increasing burden strains both healthcare systems and the families of those facing cognitive decline. Despite advances in medicine, curative treatments remain limited, and current prevention strategies targeting modifiable lifestyle factors have become essential. Of these, diet has emerged as a potential protective factor, with a growing body of evidence suggesting that certain foods may influence brain health.

Cheese, in particular, contains bioactive compounds such as vitamin K₂, peptides, and probiotics. These may support neuroprotection through anti-inflammatory and metabolic mechanisms. However, epidemiological findings about the link between dairy consumption and cognitive decline are inconsistent across studies.

To address these gaps, the authors of this study focused on Japanese older adults, a group with relatively low dairy intake. Using an observational cohort design, they aimed to determine whether habitual cheese consumption is associated with reduced dementia risk. Their goal was also to provide real-world epidemiological evidence relevant to public health in aging societies.

About the Study

The authors conducted a longitudinal cohort study using data from the Japan Gerontological Evaluation Study (JAGES) 2019 survey, linked to long-term care insurance (LTCI) records from 2022. The study included community-dwelling adults aged 65 or older who had not previously been certified for LTCI benefits.

Of 26,408 survey respondents, 10,180 met the eligibility criteria after excluding participants with missing or incomplete data. Propensity score matching (PSM) was used to control for potential confounding by age, sex, education, income, health status, instrumental activities of daily living (IADL), and memory complaints.

After 1:1 nearest-neighbor matching, 7,914 participants were included, of whom 3,957 were cheese consumers and 3,957 non-consumers. Cheese consumption was defined as eating cheese at least once per week. Dementia incidence was determined from new LTCI certifications indicating dementia during the three-year follow-up period.

The primary analysis used a Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia, comparing consumers and non-consumers. Covariate balance was confirmed using standardized mean differences. Follow-up continued until dementia diagnosis, death, out-migration, or the end of the fiscal year 2022.

Key Findings

Most cheese consumers (72.1%) reported eating cheese one or two times per week, and processed cheese was the predominant type (82.7%). Over three years, dementia developed in 134 consumers (3.4%) and 176 non-consumers (4.5%), corresponding to an absolute risk reduction of 1.06 percentage points (approximately 10.6 fewer cases per 1,000 individuals).

Kaplan–Meier survival curves showed a significantly lower cumulative incidence of dementia among consumers. In the Cox proportional hazards analysis, cheese consumption was associated with a 24% reduced risk of dementia. When further adjusted for dietary habits, such as fruit, vegetable, and meat or fish intake, the association remained significant though slightly weaker, at 21%.

Restricted mean survival time analysis showed an average difference of about 7.7 days in dementia-free survival, favoring cheese consumers. These findings suggest that even modest cheese consumption, at least once a week, is associated with a lower incidence of dementia in older adults during a short-term follow-up.

Conclusions

The study found that older adults who consumed cheese at least weekly had a 21–24% lower hazard of dementia over 3 years, consistent with prior evidence suggesting that fermented dairy products have protective effects on cognitive health.

Cheese’s nutrient profile, rich in probiotics, peptides, antioxidants, and vitamin K₂, may promote vascular and neural health, though most participants consumed processed cheese, which may have lower levels of these bioactive compounds.

The absolute reduction in dementia cases was modest but potentially meaningful at a population level, especially in Japan, where cheese intake is low.

The strengths of this analysis include the large, population-based cohort and rigorous control for confounding through propensity score matching. However, dietary data were collected only once, portion sizes and genotypes were unmeasured, and dementia diagnoses were based on administrative records, limiting precision and generalizability.

The authors also disclosed that the study was partly funded by Meiji Co., Ltd., a Japanese dairy manufacturer. However, the funder had no role in the execution, analysis, or interpretation of the data or the writing of the manuscript.

Overall, habitual cheese intake may support cognitive health, but future studies should clarify optimal intake levels, cheese types, and biological mechanisms.