Recent studies highlight the potential role of omega-3 fatty acids in protecting brain health, especially among older adults. These essential fats, found in fatty fish like salmon, offer benefits for heart health, inflammation, and brain function. Now, two studies suggest they may also benefit individuals at higher risk for cognitive decline, such as carriers of the ε4 allele of the apolipoprotein E gene (APOE4). APOE4 carriers have a significantly higher risk of developing late-onset Alzheimer’s disease, though the disease is not guaranteed and lifestyle factors also influence risk.
What are omega-3 fatty acids?
Omega-3 fatty acids are healthy fats crucial for our bodies. The three main types are:
- ALA (alpha-linolenic acid): Found in plant oils like flaxseed and walnuts.
- EPA (eicosapentaenoic acid): Found in fatty fish and supports heart and brain health.
- DHA (docosahexaenoic acid): A key component of brain cell membranes, DHA is also found in seafood and is particularly important for cognitive function.
Doctors recommend eating omega-3-rich fish twice weekly or taking supplements to maintain optimal levels.
The APOE4 gene, DHA, and protecting brain health
People with the APOE4 gene variant may experience disrupted brain cholesterol transport and increased amyloid plaque buildup. This results in a higher risk of Alzheimer’s disease.
The brains of APOE4 carriers have unique needs. They require more DHA, a type of omega-3 fatty acid, to function normally. DHA helps maintain neuronal membranes, reduces inflammation, and supports nerve communication.
Studies suggest that supplementing with DHA may compensate for DHA deficiencies common in APOE4 carriers. DHA supplementation could support brain function, slow cognitive decline, and protect brain health.
Key findings from the PUFA clinical trial
A study led by Lynne Shinto, N.D., M.P.H. explored the effects of omega-3 polyunsaturated fatty acids (PUFAs) on brain health in older adults. The study was conducted at Oregon Health & Science University in Portland and published in Neurology on August 1, 2024.
The study was a quadruple-blinded, placebo-controlled, randomized clinical trial of 102 participants. Participants were adults aged 75 years and older without dementia but with sub-optimal plasma PUFA levels and white matter lesions (damage to the brain’s white matter) indicating possible increased risk for cognitive decline. They received either 1.65 grams per day of omega-3 PUFAs (975 mg of EPA and 650 mg of DHA) or a soybean oil placebo matched for taste, smell, and appearance for three years. Participants were demographically and geographically homogeneous, which may limit the generalizability of the findings to other populations.
The main study finding was that different combinations of EPA and DHA were effective for different groups. The researchers found that an EPA-dominant omega-3 supplement may provide some benefit in APOE4 carriers who don’t have dementia or white matter lesions, and a DHA-dominant omega-3 supplement may benefit noncarriers of APOE4 with mild-to-moderate Alzheimer’s disease.
Key findings from the PreventE4 clinical trial
The PreventE4 clinical trial, led by Hussein Yassine, MD, examined DHA’s impact on brain health. The study was conducted at the Keck School of Medicine at the University of Southern California in Los Angeles and reported at the Clinical Trials on Alzheimer’s Disease annual meeting in Madrid on October 31, 2024.
The study was a double-blind, single-center trial of cognitively unimpaired individuals with at least one vascular dementia risk factor and limited seafood consumption. By design, half the study population had at least one APOE4 allele. The mean age of participants was 66 years, and 59% were women. Participants were randomized to DHA supplements of 2 grams per day or placebo for 2 years. All participants received a vitamin B complex supplement. 225 people completed the trial. The trial ended recently, and data analyses are ongoing.
Findings showed that high-dose DHA supplementation improved brain DHA levels in APOE4 carriers, and higher DHA levels were linked to better cognitive test scores.
These results highlight the importance of DHA in supporting brain function before dementia symptoms appear.
Important Considerations
- Dosage Matters: The right dosage varies for each individual. Experts recommend consulting a healthcare provider before starting omega-3 supplements.
- Timing is Key: Benefits are greater when omega-3 supplementation starts early, before noticeable cognitive decline.
- Personalized Treatment: Genetic testing can help determine if omega-3 supplements might benefit you.
Conclusion
Omega-3 fatty acids, particularly DHA, show potential in protecting brain health, especially for APOE4 carriers. Adding omega-3-rich foods like salmon, mackerel, and walnuts to your diet may support brain function as you age. If you’re concerned about cognitive health, consult your doctor to discuss omega-3 supplements and genetic testing.
These new studies add to previous evidence that omega-3 fatty acids preserve brain health. The Parsemus Foundation provided early support for a study on the impact of testosterone or fish oil (DHA) versus placebo on the onset of amyloid plaque associated with Alzheimer’s disease in men with memory complaints.
While the results of these latest studies are promising, more studies are needed to confirm the findings and refine treatment strategies. Large-scale clinical trials will help determine the best doses and forms of omega-3 supplements for individuals at risk.
By understanding the unique needs of our brains, we can take proactive steps to maintain cognitive health and enjoy a better quality of life as we age.
To learn more about strategies to prevent dementia and Alzheimer’s disease, check out our Alzheimer’s Disease Prevention pages. Also see our blog posts on the topic.
