New Delhi: Higher levels of good cholesterol (HDL-C) have been shown to correlate with heightened risk for Alzheimer’s disease and, a new study has revealed that it depends on the quality, rather than quantity, of the total cholesterol carried by HDL particles circulating in a woman’s blood. 

The study, published in the Journal of Clinical Endocrinology and Metabolism, explained that once women reach the menopause transition, it’s a matter of the quality, rather than quantity.

The researchers from University of Pittsburgh in the US found that, over time, the number of larger HDL particles in the women’s bodies increased. These larger particles, unfortunately, did not function as well as their smaller counterparts.

“We were able to show that as early as midlife, women who have more of the smaller-sized particles and those whose particles’ concentrations of phospholipids increased over the menopause transition are more likely to experience better episodic memory later in life,” said Samar R. El Khoudary, professor of epidemiology at Pitt Public Health.

The loss of working memory is the first sign of Alzheimer’s disease. HDL particles vary in their size, composition and level of functioning.

During the study, the researchers conducted repeated assessments of participants’ cognitive function from 2000 to 2016 and compared these data to changes in the women’s HDL particles, composition and function as they aged.

The research team has previously shown that health behaviours work to improve the quality of HDL particles, for example by adding more of the phospholipid-rich particles in the bloodstream.

“That’s the good news in this developing picture of brain health and the ‘not-so-good-after-all’ cholesterol,” said El Khoudary.

Even though higher levels of HDL-C may not be protective as you get older and there are things you can do that might help, even as early as your 40s, the researchers advised.