What the study asks
Can a simple dietary habit—consuming cheese at least once a week—influence the risk of developing dementia in older adults? A large Japanese cohort study published in Nutrients investigates this possibility, offering real-world evidence on how everyday food choices might impact cognitive health.
Study design and population
Researchers used data from the Japan Gerontological Evaluation Study (JAGES) 2019 survey, linked to long-term care insurance records through 2022. The study focused on community-dwelling adults aged 65 and older who were not yet certified for long-term care benefits. After applying eligibility criteria and addressing data completeness, 7,914 participants were analyzed using a rigorous matching approach to minimize bias.
Key methodology included 1:1 propensity score matching to balance factors such as age, sex, education, income, health status, instrumental activities of daily living (IADL), and memory complaints. Cheese consumption was defined as eating cheese at least once per week, and dementia incidence was tracked via new LTCI certifications during a three-year follow-up.
What constitutes cheese consumption in this study
Most cheese consumers reported modest intake, with 72.1% eating cheese one or two times weekly. Processed cheese dominated (82.7%), reflecting common dietary patterns in Japan where dairy consumption tends to be moderate.
Key findings
During the three-year period, dementia developed in 134 cheese consumers (3.4%) and 176 non-consumers (4.5%). This translated to an absolute risk reduction of about 1.06 percentage points, or roughly 10.6 fewer dementia cases per 1,000 individuals among weekly cheese eaters.
In statistical terms, cheese consumption was associated with a 24% lower hazard of dementia in the primary model. Even after adjusting for broader dietary factors such as fruit, vegetable, and meat/fish intake, the association remained significant but slightly attenuated to about a 21% reduced risk.
Restricted mean survival time analyses indicated an average dementia-free survival advantage of around 7.7 days for cheese consumers over the 3-year span, suggesting a tangible though modest short-term benefit at the population level.
Biological plausibility and nutrients
The study notes that cheese contains bioactive compounds—including vitamin K2, certain peptides, and probiotics—that may support vascular and neural health. Fermented dairy products have been linked in prior research to protective effects on cognitive function, possibly through anti-inflammatory and metabolic pathways. However, most participants in this study consumed processed cheese, which may have lower levels of some of these beneficial compounds.
Interpreting the results
While the findings point toward a potential protective association between weekly cheese intake and dementia risk, several caveats apply. Residual confounding cannot be entirely ruled out in observational research, even with sophisticated matching. Dietary data were collected at a single time point, limiting insight into long-term eating patterns. Dementia diagnoses relied on administrative LTCI records, which may not capture all cases or differentiate dementia subtypes in detail.
Nevertheless, the study contributes to a growing body of evidence suggesting that simple dietary habits, such as modest weekly cheese consumption, could play a role in cognitive health—particularly for aging populations where dairy intake tends to be low.
Public health implications
Japan’s aging society stands to gain from clearer guidance on modifiable factors that support brain health. The observed absolute reduction in dementia cases, while modest on an individual level, could have meaningful population-level effects given Japan’s scale of older adults. These results may inform dietary recommendations and encourage further research into the optimal type and amount of cheese, including the roles of fermentation and processing.
What’s next in research
Experts would benefit from longitudinal studies capturing changes in cheese intake over time, distinguishing cheese types (fermented vs. processed), and integrating biomarkers to clarify biological mechanisms. Randomized trials, though challenging for dietary patterns, could help establish causality and identify which populations stand to gain the most from cheese consumption as part of a brain-healthy diet.
Bottom line
For older adults, integrating cheese into a balanced diet—at least weekly—may be associated with a lower short-term risk of dementia. While not a guaranteed shield, this simple habit aligns with broader dietary patterns aimed at promoting vascular and neural health, warranting further investigation into how dairy products can fit into effective dementia prevention strategies.
