Higher blood levels of omega-3 fatty acids are associated with a significantly lower risk of developing early-onset dementia, according to a large-scale analysis of more than 217,000 adults from the UK Biobank. The study was published in the journal Clinical Nutrition.

The study followed adults aged 40-64 for an average of 8.3 years and identified 325 cases of early-onset dementia, defined as diagnosis before age 65. Researchers found that individuals with higher plasma omega-3 levels had substantially reduced risk of developing early-onset dementia compared with those who had the lowest levels.

Participants in the highest omega-3 quintiles experienced a 35-40 percent lower risk even after adjusting for genetic risk, lifestyle factors and cardiometabolic health variables, researchers said.

“This is the first large-scale study to show that objectively measured omega-3 status is linked to lower risk of dementia diagnosed before age 65,” said Aleix Sala‑Vila, PhD, lead author of the study. “Most prior research has focused on older populations. Our findings strongly suggest that omega-3 intake earlier in midlife may play a meaningful role in brain health decades before dementia typically appears.”

Notably, the protective association was observed not only for DHA—the most abundant omega-3 fatty acid in the brain—but was even stronger for non-DHA omega-3 fatty acids, highlighting the potential importance of considering the full spectrum of omega-3s rather than focusing on DHA alone, researchers said.

“These results reinforce the value of using blood biomarkers rather than self-reported diet when studying nutrition and brain health,” said Nathan L. Tintle, PhD, co-author of the study. “Because omega-3 levels can be safely and effectively increased through diet and supplementation, this represents a plausible, low-cost strategy that could help reduce the burden of early-onset dementia.”

For more information, visit www.omegaquant.com.