Researchers determined that the risk of Alzheimer’s disease in the highest red blood cell DHA quintile was 49% lower compared to the lowest quintile.
A newly published study2 found that higher levels of omega-3 DHA in the blood was associated with a lower risk of developing Alzheimer’s Disease. The study was led by Aleix Sala-Vila, PhD, an associate scientist at the Fatty Acid Research Institute (FARI). In the prospective observational study conducted within the Framingham Offspring Cohort that included 1490 dementia-free participants aged 65 and under, researchers examined the association between red blood cell DHA and the incidence of Alzheimer’s Disease. During follow-up (median of 7.2 years), 131 cases of Alzheimer’s Disease were documented. Researchers determined that the risk of Alzheimer’s disease in the highest red blood cell DHA quintile was 49% lower compared to the lowest quintile. They predicted that an increase in red blood cell DHA from the lowest quintile to the highest may provide an estimated 4.7 additional years of life free of Alzheimer’s Disease.
The association between higher levels of red blood cell DHA and lower risk of Alzheimer’s Disease also reached borderline statistical significance among carriers of the APOLIPOPROTEIN E (APOE)-ε4 allele. APOE-ε4 allele carriership is the strongest genetic risk factor of Alzheimer’s Disease.
"Our study is in line with that of Tan et al.2 who reported cross-sectional associations with [red blood cell] DHA on cognitive performance and brain volume measurements (with higher DHA being associated with beneficial outcomes) in the same cohort as studied here," said William S. Harris, PhD, president of FARI and senior author on this recent study, in a press release.
"Most interestingly, 15 years ago similar findings were reported by Schaefer et al.3 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," Harris continued. "Similar findings a generation apart in a similar genetic pool provide considerable confirmation of this DHA-dementia relationship."