Sex-based differences in Alzheimer’s risk revealed through omega-3 analysis

Omega-3 fatty acids may help protect women against Alzheimer’s disease, potentially more than men, according to new research. A recent UK study uncovered a noticeable loss of unsaturated fats, such as those that contain omega fatty acids, in the blood of women with Alzheimer’s disease compared to healthy women.

Conversely, it found “no significant difference” in the same lipid molecule composition in men with Alzheimer’s disease compared to healthy men, which suggests that those lipids have a different role in the disease according to sex.

The study authors at King’s College London and Queen Mary University London say their paper is the first to reveal the important role lipids could have in Alzheimer’s risk between the sexes.

“Women are disproportionately impacted by Alzheimer’s Disease and are more often diagnosed with the disease than men after the age of 80,” says senior author Dr. Cristina Legido-Quigley.

“One of the most surprising things we saw when looking at the different sexes was that there was no difference in these lipids in healthy and cognitively impaired men, but for women, this picture was completely different. The study reveals that Alzheimer’s lipid biology is different between the sexes, opening new avenues for research.”

Unhealthy fats high among Alzheimer’s patients

The study analyzed lipids in the blood of 841 participants who either had Alzheimer’s disease, mild cognitive impairment, or were cognitively healthy controls.

Scientists used mass spectrometry to analyze 700 individual lipids in the blood.

The study found a steep increase in lipids with saturation — the “unhealthy lipids” — in women with Alzheimer’s compared to the healthy group. Additionally, the report authors note that lipids with attached omega fatty acids decreased the most in the Alzheimer’s group.

While the scientists believe there is a statistical indication that there is a causal link between Alzheimer’s Disease and fatty acids, they state that a clinical trial is necessary to confirm it. 

“Our study suggests that women should make sure they are getting omega fatty acids in their diet through fatty fish or via supplements. However, we need clinical trials to determine if shifting the lipid composition can influence the biological trajectory of Alzheimer’s disease,” adds Legido-Quigley.

Higher impact on women

Dr. Asger Wretlind, the study’s first author, stresses that scientists have known for some time that more women than men are diagnosed with Alzheimer’s disease.

“Although this still warrants further research, we were able to detect biological differences in lipids between the sexes in a large cohort and show the importance of lipids containing omegas in the blood, which has not been done before,” she notes.

“The results are very striking, and now we are looking at how early in life this change occurs in women.”

According to Dr. Julia Dudley, head of Research at Alzheimer’s Research UK, two in three UK residents living with dementia are women.

“This could be linked to living longer or other risk factors like social isolation, education, or hormonal changes from menopause being at play.”

She adds that further work is needed to understand the mechanisms and if lifestyle changes could play a role. “Future research should also be carried out in a more ethnically diverse population to see if the same effect is seen,” she concludes.

The research was supported by funding from LundbeckFonden and Alzheimer’s Research UK. Its findings are published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

Earlier this year, a US study by Case Western Reserve University flagged intensifying global omega-3 deficiencies, largely attributed to environmental factors such as rising ocean temperatures, overfishing, and pollution. The analysis warned 85% of the world’s population has not been getting enough omega-3s simply through their diets.

Nutrition Insight recently explored the latest formulation innovations and market trends around omega-3s with dsm-firmenich, Gelita, GC Rieber VivoMega, Epax, and Aker BioMarine.