Alcohol consumption from midlife and risk of disabling dementia in a large population-based cohort study in Japan

In a study published in the International Journal of Geriatric Psychiatry, researchers in Japan explore the association between alcohol consumption and dementia in the Japanese population using repeated alcohol assessments.
Participants in the Japan Public Health Center-based Prospective Study (JPHC Study) since 1990 and who were alive in 2006 were followed from 2006 until 2016 for dementia ascertainment. Disabling dementia was identified through long-term care insurance records. Alcohol consumption was assessed at the 5-year questionnaire survey (1995–1999) and drinking patterns were assessed on repeated follow-up (2000–2003). Using light consumption (<75 g ethanol/week, hereinafter “g”) as reference, the researchers estimated hazard ratios adjusting for various lifestyle factors and medical history.
Among 42,870 participants aged 54–84 years, 4802 cases of disabling dementia were newly diagnosed. Average years from alcohol assessment until dementia incidence was 14.9 years. Non-drinkers and regular drinkers with ≥450 g at 5 years had adjusted HRs (95% CI) of 1.29 (1.12–1.47) and 1.34 (1.12–1.60). Patterns of long-term abstinence, former drinking, and regular heavy weekly consumption of ≥450 g showed increased adjusted HRs of 1.61 (1.28–2.03), 2.54 (1.93–3.35), and 1.96 (1.49–2.59), respectively.
In the Japanese population, non-drinking and regular weekly consumption of ≥450 g from midlife were associated with high risk of disabling dementia compared with light drinking (<75 g ethanol/week).
Source: Shimizu Y, Sawada N, Ihira H, Abe SK, Inoue M, Yasuda N, Yamagishi K, Iwasaki M, Tsugane S. Alcohol consumption from midlife and risk of disabling dementia in a large population-based cohort study in Japan. Int J Geriatr Psychiatry. 2023 Mar;38(3):e5896