Riboflavin intake and dementia risk in Japanese adults
What it found
In 4,171 Japanese adults followed for about 15 years, those who took in more riboflavin from food were less likely to develop disabling dementia.
The same pattern was seen for vitamin B6 and folate.
What they found
Studies in people
Riboflavin and dementia
People with the highest riboflavin intake from food had about half the rate of disabling dementia compared with those with the lowest intake. The link got stronger as intake rose.
Vitamin B6 and dementia
Higher vitamin B6 intake was also linked to fewer cases of disabling dementia. The difference between the highest and lowest intake groups was smaller than for riboflavin.
Folate and dementia
Folate showed a similar pattern, with fewer cases of disabling dementia in the highest intake group than in the lowest.
Other findings
How the study was done
Food intake was estimated from one 24-hour diet recall. Disabling dementia meant needing care under Japan's national long-term care insurance.
What the authors conclude
“Our findings suggest that dietary intake of B vitamins, especially riboflavin, vitamin B 6 , and folate, is associated with a reduced risk of disabling dementia in Japanese individuals.”
Also in their conclusions
- They suggest that dietary intake of B vitamins, especially riboflavin, vitamin B6, and folate, is associated with a reduced risk of disabling dementia in Japanese individuals.
How it was done
Low intake of B vitamins may raise the risk of dementia, but evidence for riboflavin in particular is still sparse.
They followed 4,171 Japanese people aged 40 to 69 for a median of 15.4 years. Food intake of B vitamins was estimated from a single 24-hour diet recall, and cases of disabling dementia were identified through Japan's long-term care insurance system.
What it can’t tell you
- We summarised it from the abstract only.
- This kind of study follows people over time and can show a link, not that riboflavin causes the lower dementia risk.
- Food intake was estimated from a single 24-hour diet recall, which may not reflect long-term eating habits.
- The findings are from Japanese adults aged 40 to 69 and may not apply to other groups.
Who paid
- Conflicts
- Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: The institutional review boards of the Osaka Institute of Public Health (No. 2409-02), Kindai University (No. R04-255), Osaka University (No. 14285-13), and University of Tsukuba (No. 2047-1) approved the study procedure. This study conformed to the principles of the Declaration of Helsinki. Informed consent was obtained from community leaders. Based on the nature of the study as a secondary use of data initially obtained for public health practice on cardiovascular disease prevention within the local community, individual consent was not required for the analysis. In compliance with relevant guidelines and regulations, the participants were retrospectively allowed to opt out of the analysis. If participants did not decline participation in this study, their consent for data usage was assumed.
- Authors work at
- University of Tsukuba, Japan; National University of Singapore, Singapore; Juntendo University, Japan
The paper
- Title
- Dietary intake of folate, vitamin B6, vitamin B12, and riboflavin and the risk of incident dementia
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Kishida R, Yamagishi K, Maruyama K, et al (2025). Dietary intake of folate, vitamin B6, vitamin B12, and riboflavin and the risk of incident dementia. European journal of clinical nutrition. doi:10.1038/s41430-025-01663-5PubMed 40999064DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error