Dietary docosahexaenoic acid and docosapentaenoic acid ameliorate amyloid-beta and tau pathology via a mechanism involving presenilin 1 levels.
Level 5 - mechanism / opinion, no new human data
Preclinical animal model study (3xTg-AD mice) without human data.
PubMed 17442823 · doi:10.1523/JNEUROSCI.0055-07.2007
What was done
Transgenic 3xTg-AD mice were fed diets supplemented with docosahexaenoic acid (DHA, an n-3 polyunsaturated fatty acid) alone or in combination with n-6 fatty acids (arachidonic acid or docosapentaenoic acid [DPAn-6]) over a 12-month period. Investigators assessed intraneuronal accumulation of amyloid-beta and tau, steady-state levels of presenilin 1, amyloid precursor protein processing via alpha- and beta-secretases, early-stage phospho-tau epitopes, and phosphorylated c-Jun N-terminal kinase.
What was found
The abstract reports no numerical values, effect sizes, or confidence intervals. It reports that DHA supplementation reduced intraneuronal accumulation of both amyloid-beta and tau. Combining DHA with arachidonic acid or DPAn-6 reduced DHA efficacy over 12 months. The reduction in soluble amyloid-beta was accompanied by decreased steady-state levels of presenilin 1, without altered alpha- or beta-secretase processing. Inclusion of DPAn-6 reduced early-stage phospho-tau epitopes, which correlated with decreased phosphorylated c-Jun N-terminal kinase.
Why it matters
This study provides an animal-model mechanism linking dietary polyunsaturated fatty acids to reductions in amyloid-beta and tau pathology via modulation of presenilin 1 and tau kinase pathways.
Limits
The study was conducted in a transgenic mouse model, limiting direct translation to human Alzheimer disease. The abstract omits sample sizes, specific dietary dosages, exact quantitative effect sizes, and behavioral or cognitive outcomes.
Cited by
- supports In mice, omega-3 deficiency makes cell membranes too stiff, impairing glucose transporters into the brain and leading to the accumulation of tau tangles.