Home cooking, cooking skills and dementia requiring long-term care: a population-based cohort study in Japan

Since my medical team completely failed at recovering my left hand, cutting anything is a recipe for danger. I am currently getting meals from Home Chef with very limited cutting needed. That will allow me to live independently for decades to come.

Is that considered cooking at home?

 Home cooking, cooking skills and dementia requiring long-term care: a population-based cohort study in Japan

1. http://orcid.org/0000-0001-5533-2844Yukako Tani1,
2. http://orcid.org/0000-0002-1074-3954Takeo Fujiwara1,
3. Katsunori Kondo2

1. Department of Public Health, Institute of Science Tokyo, Tokyo, Japan
2. Center for Preventive Medical Sciences, Chiba University, Chiba, Japan

1. Correspondence to Dr Yukako Tani; tani.hlth@tmd.ac.jp

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.

Data availability statement

Data are available upon reasonable request. The data that support the findings of this study are available from JAGES Agency but restrictions apply to the availability of these data, which were used under licence for the current study, and so are not publicly available. Data are however available from the corresponding author upon reasonable request and with permission of JAGES Agency (dataadmin.ml@jages.net).

https://doi.org/10.1136/jech-2025-225139