This Amount (and Type) of Fish Oil May Protect Against Alzheimer's.

White matter, composed largely of myelinated nerve fibers, facilitates communication between different brain regions. Damage to white matter, observed (i.e., lesions) via MRI, is associated with cognitive decline and increased dementia risk. Plasma concentrations of omega-3 fatty acids in epidemiological research is associated with a reduced burden of white matter lesions (WML)

An RCT published in Neurology (PMID: 39088212) this August looked at the effects of omega-3 supplementation on white matter lesions (size of which can be indicative of neurodegenerative diseases like Alzheimer’s) in adults aged 75 and over.

This study examined whether supplementing with omega-3 fatty acids daily (from 2014-2019) could slow the progression of WML in older adults with low baseline omega-3 levels.

Findings:

• Fish Oil Benefits: reduction in WML progression not statistically significant across the entire cohort. However, participants with the APOE ε4 allele (genetic marker linked to a higher risk of Alzheimer’s) experienced a significant decrease in neuronal integrity breakdown when supplemented with omega-3s.
• EPA for the win? - Plasma levels of the omega 3 fatty acid EPA in this case and past research had the largest association with less white matter lesions (EPA is more abundant in microglia vs. DHA)
• Fish Oil Dosage: The study used 1.65 grams of omega-3 per day, containing 975 mg of EPA and 675 mg of DHA (EPA dominant).
• Fish Oil Side Effects: supplementation at this dosage was well-tolerated, with no significant difference in adverse events between the omega-3 and placebo groups, making it a viable option for long-term use in older adults.

For those concerned about cognitive health, especially if there’s a genetic predisposition to Alzheimer’s, maintaining an adequate intake of omega-3s through diet or supplementation is generally recommended. The fish oil benefits for men and women likely extend beyond cardiovascular health, offering potential protection against the neurodegenerative changes associated with aging especially those at high risk for something like Alzheimer’s disease.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2821809?resultClick=3