Women are disproportionately affected by Alzheimer’s disease—making up nearly two-thirds of the 7.2 million Americans living with the condition. Now, new research suggests omega-3 fatty acids—long tied to better brain health—may offer women a unique form of protection.
For the study, researchers analyzed blood lipid levels in more than 800 people. Women with Alzheimer’s—unlike men with the disease—had lower levels of unsaturated fats that carry omega-3s in the bloodstream, the team reported in August in the journal Alzheimer’s & Dementia.
Omega-3s are a type of polyunsaturated fat that helps build and strengthen brain cells. Because the body doesn’t naturally produce them, you need to get them through supplements or foods like fatty coldwater fish.
According to Cristina Legido-Quigley, PhD, the study’s lead author and a reader in the Institute of Pharmaceutical Science at King’s College London, the findings not only mean that omega-3s may play a unique role in Alzheimer’s progression, but also highlight broader sex-based differences in how the disease develops.
“This suggests we need sex-specific approaches to understanding, diagnosing, and potentially treating Alzheimer’s disease,” she told Health.
The new study was inspired by recent research showing that up to 45% of dementia cases may be preventable—with 7% linked to high LDL cholesterol (the “bad” kind).
That finding underscored how important it is to understand the role of lipid metabolism—or how the body manages fats—in brain health, Legido-Quigley noted.
To explore this connection, she and her colleagues analyzed blood samples from 841 people, screening for 700 different lipids. The participants were enrolled in ANMerge, a European study to better understand biomarkers for Alzheimer’s. Of the group, 306 had Alzheimer’s, while 165 had mild cognitive impairment.
The team found that saturated—or “unhealthy”—lipids were highest in women living with Alzheimer’s disease, while unsaturated lipids that carry omega-3s were lowest in this group.
Notably, men with and without Alzheimer’s showed no significant differences in lipid molecule composition, suggesting that lipids may affect women in a unique way.
“This study fills a critical gap by showing that lipid associations with Alzheimer’s disease were exclusively found in women,” Legido-Quigley said. There were “32 significant lipid changes in women,” she pointed out, but “zero in men.”
The new research was “well designed” and “builds on the evidence of lipids associated with Alzheimer’s disease in women,” Timothy Chang, MD, PhD, an assistant professor of neurology at Mary S. Easton Center for Alzheimer’s Research and Care at UCLA Chang Lab, told Health.
It’s important to note that while the study indicates that omega-3s may play a role in Alzheimer’s development in women, it doesn’t prove causation. The findings may also not be fully applicable to the broader public, given that all study participants were older European adults.
Moving forward, Legido-Quigley said she hopes to design clinical trials that involve younger women and measure “these lipids at baseline.” Future research could also explore why omega-3s appear to be more protective for women—something that’s currently unclear.
While it’s too soon to recommend that women eat more omega-3s specifically to reduce Alzheimer’s risk, she added, doing so could still be beneficial for overall health. In general, experts suggest getting omega-3s through food rather than supplements. Good sources include:
