Elevated levels of HDL-C, often hailed as the “good cholesterol,” have been linked to an increased risk of Alzheimer’s disease. A recent study featured in the Journal of Clinical Endocrinology & Metabolism provides insights into this connection. According to a research team led by an epidemiologist from the University of Pittsburgh School of Public Health, once women undergo menopause, the focus shifts from the quantity to the quality of the cholesterol carried by HDL particles in their blood, which tends to deteriorate over time.
HDL particles differ in size, makeup, and functionality. The researchers assessed these characteristics in the blood samples of 503 women participating in the Study of Women’s Health Across the Nation (SWAN) HDL ancillary study. Their findings revealed that, as time progresses, the quantity of larger HDL particles in the women’s systems increased, yet these larger particles were less effective than the smaller ones.
The team consistently evaluated the cognitive abilities of the participants from 2000 to 2016, drawing comparisons between these cognitive changes and the shifts in HDL particles, their composition, and functionality as the women aged.
“Our study demonstrated that even in midlife, women with a higher proportion of smaller HDL particles and those whose phospholipid-rich particles increased during menopause tend to show better episodic memory as they age,” stated Samar R. El Khoudary, Ph.D., M.P.H., a professor of epidemiology at Pitt Public Health. She emphasized that memory loss is often the initial sign of Alzheimer’s disease.
El Khoudary’s earlier research has indicated that lifestyle factors — such as those highlighted in the American Heart Association’s (AHA) Life’s Essential 8 — can enhance the quality of HDL particles by increasing the presence of phospholipid-rich varieties in the bloodstream.
“This offers a glimmer of hope in the evolving understanding of brain health and the ‘not-so-good-after-all’ cholesterol,” commented El Khoudary. “While higher HDL-C levels may not offer protective benefits with aging, there are proactive measures one can take starting in your 40s. The same modifiable risk factors promoted by the AHA — including regular physical activity, maintaining a healthy weight, and quitting smoking — could also safeguard your brain health.”
Meiyuzhen Qi, Ph.D., a postdoctoral researcher in the Department of Epidemiology at Pitt Public Health, is the lead author of this study, with contributions from scientists at various prestigious institutions including the University of Pennsylvania Perelman School of Medicine, Rush University Medical Center, UCLA David Geffen School of Medicine, Albert Einstein College of Medicine, University of Michigan School of Public Health, and the University of Massachusetts Medical School.
