Summary:
This study is a population-based prospective cohort study that investigated whether preparing meals at home is associated with a reduced risk of developing dementia among older adults. Participants were drawn from a large Japanese ageing cohort and followed for six years, with dementia cases identified through national records, which capture individuals with cognitive decline significant enough to require support. A total of 10,978 individuals were included, and over the follow-up period, 1,195 cases of dementia were recorded. At baseline, participants reported how often they cooked meals and their level of cooking skill. Individuals who cooked at least once per week were compared with those who cooked less frequently. To study controlled for differences in demographic, socioeconomic, and health-related characteristics, and analyses were conducted separately for men and women. The risk of death was also accounted for, which is important in older populations where mortality may influence observed dementia incidence. The results indicated that more frequent home cooking was associated with a lower risk of developing dementia in both men and women. Specifically, those who cooked more often had approximately a 23-27% reduced risk compared with those who cooked less frequently. The association was stronger among individuals with lower cooking skills, suggesting that even basic engagement in meal preparation may confer cognitive benefits. These findings may reflect multiple mechanisms, including increased cognitive stimulation, maintenance of daily living skills, improved diet quality, and greater independence. Overall, the study suggests that supporting older adults to engage in home cooking may contribute to dementia prevention. Interventions that promote accessible cooking environments, skill development, and opportunities for routine meal preparation could play a role in maintaining cognitive health and delaying functional decline in ageing populations.
Abstract:
Background People have come to rely on restaurants and takeaway foods, and less on cooking at home. We examined the association between home cooking and dementia incidence, ascertained through administrative long-term care records, and whether the benefits of home cooking differ by cooking skills. Methods Participants in the Japan Gerontological Evaluation Study, a population-based cohort study, were followed for 6 years. The incidence of dementia was ascertained in 10 978 participants through data from the public long-term care insurance system, which captures functionally significant cognitive impairment requiring care. Cooking frequency and skills were assessed in a baseline survey. Participants with high and low frequencies of home cooking were matched in men and women based on demographic, socioeconomic and health-related factors using propensity score matching. Fine-Grey competing risk models were used, with death treated as a competing event. Results During the follow-up, 1195 dementia cases were found. A total of 1347 male and 321 female pairs were matched between high (at least once a week) and low (less than once a week) cooking frequencies. The subdistribution hazard ratio (SHR) for high cooking frequency (vs low cooking frequency) was 0.77 (95% CI 0.61 to 0.98) in men and 0.73 (95% CI 0.54 to 0.98) in women. The benefits of higher cooking frequency were more pronounced in those with low cooking skills (SHR 0.33, 95% CI 0.13 to 0.84). Conclusions Creating an environment where people can cook meals when they are older may be important for the prevention of dementia.
Article Publication Date: 24/03/2026
DOI: 10.1136/jech-2025-225139
