Oily fish is known for its health benefits, primarily due to its rich content of omega-3 fatty acids, which are essential for a balanced diet. For those who do not consume oily fish regularly, fish oil supplements are often recommended. These supplements are believed to offer various health advantages, including supporting heart health, preserving eye function, aiding fetal development, and enhancing memory and mental well-being. However, the effectiveness of fish oil supplements is debated, and they may pose health risks for some individuals.
A recent small-scale study has explored the potential benefits of fish oil supplements for older adults carrying the APOEε4 gene, which is associated with an increased risk of Alzheimer’s disease. Published in JAMA Network Open, the research observed that fish oil seemed to reduce nerve cell degeneration in those with the APOEε4 gene but showed no significant benefits for those without this genetic marker.
Dr. Steve Allder, a consultant neurologist at Re:Cognition Health, commented on the study’s findings, noting that while the results are promising, more extensive research is needed to fully understand the implications. He highlighted the importance of personalized nutrition based on genetic predispositions and emphasized the need to explore other lifestyle and dietary factors for maintaining brain health in older adults.
The Alzheimer’s Association identifies several risk factors for developing Alzheimer’s, including age, smoking, poor diet, lack of exercise, and genetic factors. Among these, the APOEε4 allele is a well-known genetic risk factor, particularly when inherited from both parents.
The study involved 102 participants aged 75 and older, all with low levels of omega-3 fatty acids but otherwise healthy, with no signs of dementia at the start. Half of the participants received 1.65 grams of omega-3 daily through fish oil capsules, while the other half were given placebo capsules containing soybean oil. The treatment and placebo capsules were identical in appearance and taste.
Over the three-year trial, researchers monitored the participants’ white matter lesions using MRI scans and assessed cognitive function. While the overall results showed no significant difference between the fish oil and placebo groups, individuals with the APOEε4 gene who took fish oil experienced less nerve cell damage compared to those with the gene who received the placebo.
Dr. Allder explained that carriers of the APOEε4 gene might respond differently to omega-3 fatty acids due to increased brain inflammation and oxidative stress associated with the gene. Omega-3 fatty acids could potentially mitigate these effects, leading to observed reductions in neuronal damage.
The study’s authors suggest that fish oil supplements could be beneficial for older adults with the APOEε4 gene but caution against recommending them for everyone. They stress the need for further research to confirm these findings and refine guidelines for preventive treatments.
Senior co-author Lynne Shinto, a professor of neurology at OHSU School of Medicine, noted that while fish oil did not show a statistically significant difference compared to placebo in the study, it might still be worth considering under medical guidance. Both Dr. Allder and Molly Rapozo, a registered dietitian nutritionist, recommend consulting healthcare providers before starting fish oil supplements and suggest increasing omega-3 intake through dietary sources like cold-water fish.
The study’s authors and experts agree on the need for larger, more diverse studies to validate these results and investigate the long-term effects and optimal dosages of omega-3 supplements. They also suggest that higher doses of omega-3s might offer more pronounced benefits, based on evidence from other conditions related to chronic inflammation.
