A large-scale study from the UK Biobank has found that higher blood levels of omega-3 fatty acids are associated with a reduced risk of early-onset dementia (EOD) diagnosed before age 65. The research analyzed data from 217,122 participants aged 40-64 who were free of dementia at baseline. Over a mean follow-up period of 8.3 years, 325 cases of incident EOD were identified.

Researchers examined three omega-3 exposures: total omega-3, DHA, and non-DHA omega-3. Participants in the highest quintiles of total omega-3 showed a 38-40% lower risk of EOD compared to those in the lowest quintile. The inverse relationship remained statistically significant even after adjusting for sex, age, APOE-ε4 allele load, and other lifestyle factors. Non-DHA omega-3 also showed protective associations, with participants in the highest quintile experiencing significantly lower risk.

This study is particularly significant because most previous research on omega-3 and dementia has focused on late-onset cases in people over 65. The findings suggest that maintaining adequate omega-3 intake earlier in life may help slow the development of early-onset dementia. No interaction was found between omega-3 levels and APOE-ε4 allele load, indicating the protective effect appears consistent regardless of genetic risk factors.

Quick Fact: The study tracked 217,122 participants over a mean follow-up period of 8.3 years.