Trying to avoid dementia? Go fish! That’s the takeaway from a recent study by scientists with the Fatty Acid Research Institute. Researchers say that people with high amounts of the omega-3 fatty acid docosahexaenoic acid (DHA) are 49% less likely to develop Alzheimer’s disease in the future than those with low DHA levels in their blood.

The findings reinforce the importance of eating foods such as tuna, salmon, and walnuts. All are high sources of omega-3 DHA. Alzheimer’s, of course, is the most common form of dementia. This latest study supports past evidence linking the importance of omega-3 DHA to brain health.

“Our study is in line with that of Tan et al., who reported cross-sectional associations with RBC DHA on cognitive performance and brain volume measurements (with higher DHA being associated with beneficial outcomes) in the same cohort as studied here,” explains William S. Harris, PhD, President of FARI, and senior author of the study in a statement.

“Most interestingly, 15 years ago similar findings were reported by Schaefer et al. in the parents of the individuals who were the focus of this present investigation (i.e., the Original Framingham Heart Study cohort). Schaefer et al. reported that participants in the top quartile of plasma phosphatidylcholine DHA experienced a significant, 47% reduction in the risk of developing all-cause dementia compared with those with lower levels,” writes Dr. Harris. “Similar findings a generation apart in a similar genetic pool provide considerable confirmation of this DHA-dementia relationship.”

Turning to omega-3 DHA to fight Alzheimer’s disease

Alzheimer’s disease has no cure. However, the current study suggests omega-3 DHA may have preventative effects, which is especially important for people carrying the ApoE4 gene. Possessing this gene doubles the chances of developing dementia.

The current study recruited 1,490 individuals without dementia who were 65 years or older who had their blood drawn and examined. Researchers looked at DHA levels in the blood and its relationship to Alzheimer’s or people carrying the ApoE4 genetic mutation. They compared the DHA levels of people who later developed Alzheimer’s with how the DHA levels were of people who never had it.

People with high omega-3 DHA levels had a 49% lower chance of having Alzheimer’s. The team estimates that people who maintained high DHA levels will live 4.7 more years without Alzheimer’s.

The impact of preventing Alzheimer’s would not only benefit an individual’s health but also reduce the economic cost of living with the disease. Currently, the cost of treating Alzheimer’s and dementia in the United States is about $355 billion. The researchers estimate living almost 5 years Alzheimer’s-free could save over $500,000.

The study is published in the journal Nutrients.