Almost two thirds of Americans living with Alzheimer’s disease are women. For decades, scientists have struggled to explain this striking imbalance, often attributing it to age, hormones, or genetics. Now, a new study has revealed a different clue: the fats circulating in women’s blood.
Researchers from King’s College London, led by Dr. Cristina Legido-Quigley, found that women with Alzheimer’s have lower levels of unsaturated lipids, including those rich in omega fatty acids, and higher levels of saturated ones. This distinct pattern did not appear in men. The findings mark a turning point in how scientists understand sex-specific risk in neurodegenerative disease.
What the study on women and Alzheimer’s found
The team analyzed blood samples from adults who were cognitively healthy, had mild cognitive impairment, or were diagnosed with Alzheimer’s. Using lipidomics, a detailed scan of fat molecules, they measured 268 individual lipids and compared the results by sex.
In women with Alzheimer’s, highly unsaturated lipids were consistently lower, while saturated and monounsaturated phospholipids were higher. Unsaturated lipids are key for brain cell membranes and synapses. They keep cells flexible, support signaling, and help transport nutrients. A shortage of these fats can disrupt communication between neurons and make the brain more vulnerable to injury and inflammation.
These lipid shifts also tracked with worse cognitive test scores and higher levels of proteins linked to brain stress, such as neurofilament light chain. Men with Alzheimer’s, however, did not show the same lipid pattern when compared to healthy peers. This points to a biological difference tied to sex rather than age alone.
The results highlight the relevance of sex-specific analysis in brain research. Without separating the data by men and women, the lipid changes would have been invisible.
Why lipids matter and what comes next
Lipids are more than stored energy. They form cell membranes, carry signals, and regulate inflammation. Phospholipids, for example, control what enters and exits cells, while triglycerides transport fatty acids through the blood. When their balance shifts, brain health can suffer.
For women, lower levels of unsaturated lipids, particularly those carrying omega fatty acids, appear connected to both memory decline and markers of brain damage. This suggests that diet or metabolism of fats may play a larger role in Alzheimer’s risk for women. Dr. Legido-Quigley noted that “there’s an indication that having less of these compounds could be causal in Alzheimer’s, but we need a clinical trial to confirm that”.
Future research will test whether increasing intake of omega-rich foods, like salmon or mackerel, or taking supplements can improve lipid profiles and potentially slow disease progression. Trials will also need to include diverse populations, since most current data are from European participants, and genetics is part of the puzzle.
The study doesn’t prove cause and effect, but it provides a strong lead. It also underscores the need for more personalized approaches to prevention and treatment. Understanding how Alzheimer’s affects women differently could open the door to earlier detection, tailored nutrition advice, and more effective therapies.
For now, the takeaway is that in women with Alzheimer’s, healthy unsaturated fats are consistently lower, and addressing that shortage may one day change how we approach the disease.