Quality of good cholesterol linked to Alzheimer’s risk in women: Study

A recent study has shed light on an intriguing connection between good cholesterol (HDL-C) and the risk of developing Alzheimer’s disease, especially in women. Conducted by researchers at the University of Pittsburgh, the study, published in the Journal of Clinical Endocrinology and Metabolism, emphasizes that after women reach menopause, the quality of HDL-C, rather than its overall level, plays a significant role in cognitive health.

The study delves into how different HDL-C particles impact memory and the onset of Alzheimer’s disease. It challenges the longstanding belief that higher levels of HDL-C—commonly referred to as “good cholesterol”—are always protective. Instead, it reveals that it’s the composition and function of these particles that determine their efficacy in safeguarding cognitive function.

Cholesterol and cognitive health

According to the research, during the transition to menopause, there is an increase in the number of larger HDL particles in women’s bodies. Unfortunately, these larger particles do not function as effectively as their smaller counterparts. The study highlights that smaller HDL particles, which are rich in phospholipids, are more beneficial in supporting episodic memory—one of the first cognitive functions to decline in Alzheimer’s disease.

Dr. Samar R. El Khoudary, a professor of epidemiology at Pitt Public Health and the study’s lead author, explained the findings: “We were able to show that as early as midlife, women who have more of the smaller-sized HDL particles and those whose concentrations of phospholipids increased over the menopause transition are more likely to experience better episodic memory later in life.” This indicates that the type of HDL particles circulating in a woman’s blood could influence her risk of developing memory-related conditions such as Alzheimer’s.

The study’s findings

The research team analyzed data collected from participants between 2000 and 2016, tracking their cognitive function as they aged. These assessments were then compared to changes in the size, composition, and function of HDL particles in the participants’ blood. The study revealed that while larger HDL particles became more prevalent after menopause, they did not perform as effectively in promoting brain health.

One of the study’s key takeaways is that higher levels of HDL-C may not be as protective for older women as previously thought. Instead, having more small, phospholipid-rich HDL particles can offer better protection against cognitive decline. The researchers believe that understanding this distinction between particle size and quality is crucial for developing better prevention strategies for Alzheimer’s disease.

Implications for prevention

While the findings may seem concerning, the research also offers hope. Dr. El Khoudary pointed out that there are health behaviors women can adopt to improve the quality of their HDL particles, potentially reducing the risk of cognitive decline. “The good news in this developing picture of brain health and cholesterol is that there are things you can do, even as early as your 40s, to improve the quality of HDL particles,” she said.

These behaviors include regular exercise, maintaining a healthy diet, and possibly medical interventions aimed at improving the quality of HDL particles rather than merely increasing their quantity.

The research team had previously demonstrated that lifestyle changes, such as a healthy diet and physical activity, can boost the presence of phospholipid-rich HDL particles in the bloodstream. These small particles have been shown to play a vital role in maintaining cognitive function and protecting the brain from the harmful effects of aging.

This study marks an important step in understanding the complex relationship between cholesterol and brain health. While high levels of good cholesterol have long been considered beneficial, the findings suggest that quality is just as important, if not more so, than quantity—particularly for postmenopausal women. The research offers new insights into potential preventive measures that could help women protect their cognitive function as they age.