Share on PinterestWomen with Alzheimer’s disease have lower levels of healthy fats, study finds. Image credit: Alina Rudya/Bell Collective/Getty Images
- Researchers based in the United Kingdom recently published a study that analyzed lipid levels in men and women with and without Alzheimer’s disease or mild cognitive impairment.
- Women with the disease had fewer healthy fats and more unhealthy fats.
- Men with Alzheimer’s did not have a difference in lipid levels compared to men without Alzheimer’s.
- This led the researchers to believe that increasing omega-3 intake could provide protective benefits to women.
- While omega-3 is available as a supplement, it is found in foods such as salmon, flax seed, and edamame.
Alzheimer’s disease is a brain disorder that impacts memory and thinking skills. The disease is progressive and can cause complications that can lead to death.
Alzheimer’s affects more than 7 million people in the United States, and the Alzheimer’s Association projects this number will almost double by 2050.
Women receive an Alzheimer’s diagnosis more often than men, and researchers are curious about why this happens.
Scientists in the United Kingdom have recently conducted a study evaluating lipid (fat) biomarkers in men and women to see if there were any differences that could explain the disparity.
The study findings appear in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Lipids’ role in the brain
Lipids are essential to the composition of the cell membrane. They are especially important in the brain because they support nerve function and electrical impulse transmission.
Some types of lipids include cholesterol, triglycerides, and fatty acids. While some lipids, like unsaturated fats, are beneficial, others, like saturated and trans fats, can cause LDL or “bad” cholesterol to go up.
The researchers analyzed samples from 841 participants from the AddNeuroMed cohort and the Dementia Case Register to determine lipid levels. The participant pool included:
- 306 people with Alzheimer’s disease
- 165 with mild cognitive impairment
- 370 cognitively healthy people.
The study included 491 women and 350 men. The researchers did not include any participants who had other psychiatric or neurological disorders.
To determine lipid levels, the scientists tested plasma using a process called lipidomics to measure hundreds of lipids and chose to focus on 268 lipids that passed quality control.
They next compared the results to determine if there were any differences associated with Alzheimer’s and biological sex.
Lipid changes found in women with Alzheimer’s
Women displayed the greatest differences when compared with healthy individuals.
Women with Alzheimer’s had significantly lower levels of highly unsaturated lipids, especially those containing omega-3 fatty acids like DHA and EPA. These women also had higher levels of unhealthy lipids.
The researchers did not find the same pattern in men with Alzheimer’s when comparing them to men in the control group.
Overall, the scientists found 32 lipids that were significantly associated with Alzheimer’s in women, and none were significantly linked in men.
When reviewing cognitive test scores, the researchers found that the changes in unhealthy lipids were linked to worse cognitive test scores in women with Alzheimer’s but not in men with the disease.
According to the study authors, this may be due to changes in enzymes that process healthy fats or from disruptions to pathways that help maintain brain cells. A group of fats called plasmalogens helps reduce inflammation and protect the brain but in women with Alzheimer’s, their levels appear disrupted.
Overall, the study demonstrates the importance of not taking a “one-size-fits-all” approach to researching Alzheimer’s in women and men.
While the authors note the importance of incorporating more omega-3s in the diet, they said further studies and clinical trials are needed to confirm whether dietary changes can influence Alzheimer’s disease.
Why Alzheimer’s may impact women more
Allison B. Reiss, MD, an associate professor of medicine at NYU Grossman Long Island School of Medicine and a member of the Alzheimer’s Foundation of America’s (AFA) Medical, Scientific and Memory Screening Advisory Board, spoke with Medical News Today about the study.
“The differences between male and female metabolism in relation to [Alzheimer’s disease] risk are explored here, and the sexes are not lumped together,” said Reiss, who was not involved in this research. “This makes sense because we know that both [Alzheimer’s disease] risk and lipid metabolism differ in men and women and that lipid metabolism is influenced by sex hormones.”
When asked whether incorporating omega-3s could reduce Alzheimer’s risk, Reiss said, “it is possible, but not proven.”
“Healthy, balanced, and nutritious diets incorporate omega-3s. A diet where we ‘eat the rainbow’ of many fruits and vegetables will have benefits that cannot be achieved by concentrating on trying to jam into your system a specific type of chemical compound.“
– Allison B. Reiss, MD
Timothy Ciesielski, MD, a research scientist in the Department of Population and Quantitative Health Sciences at Case Western Reserve’s School of Medicine, also spoke with MNT about the study findings.
According to Ciesielski, who likewise not involved in the research, this study “provides more evidence that lipid physiology contributes to Alzheimer’s development, and that the impact of lipids on Alzheimer’s development may differ between males and females.”
Ciesielski explained that women process polyunsaturated fats faster and often have higher levels, partly because omega-3s are needed for fetal brain development during pregnancy. He said this may leave women more vulnerable to omega-3 depletion, which could possibly increase Alzheimer’s risk.
Additionally, Ciesielski said the study demonstrates that “we should stratify by sex whenever possible in future research.”
