Research from the University of Southern California Examines Link Between Sex Hormones and Aging

The University of Southern California has conducted multiple studies that investigated how differences in sex hormones affect the aging process in men and women. The projects were led by Bérénice Benayoun, Teal Eich, and Christian Pike; faculty members of the University of Southern California’s Leonard Davis School of Gerontolgy.

Dr. Benayoun, assistant professor of gerontology, biological sciences, biochemistry, and molecular medicine, examined how pathogen-like molecules affected geriatric male and female mice by injecting them with macrophages, a type of immune cell. The results found differences between the sexes.

“The male macrophages, we give them ‘pathogens,’ they eat them up normally, they do everything normally,” says Dr. Benayoun. “But the female macrophages — oof. Let’s just say it’s kind of sad. They’re about 30 percent less good at taking up and clearing pathogens.”

An experiment from Dr. Eich, assistant professor of gerontology and psychology, studied the relationship between the memories of older people, both men and women, and their level of GABA, a neurotransmitter in the hippocampus. After conducting a small pilot study, Dr. Eich found that women with less GABA had difficulties recalling memories, whereas men in the study generally had stable GABA levels. Dr. Eich is currently investigating this phenomena further, with a particular interest in how menopause relates to memory function.

In his study, Dr. Pike, professor of gerontology and assistance dean of research, injected APOE4, a human gene connected to an increased risk of Alzheimer’s disease, into a group of mice and examined the effects of the injected mice compared to another group who were not injected. The results found vast differences in the two groups, and within the set of mice who were injected with APOE4, the female mice had even worse symptoms than the males.

The School of Gerontoloy plans to further their research in this area through a number of future studies, including a joint study from Dr. Benayoun and Dr. Pike that will examine how certain drugs found to increase mice lifespan will affect mice injected with APOE4.

“Finding a female-specific effect vindicates the fact that we do need to study both men and women,” Dr. Benayoun says, “and that we’re probably making a lot of wrong assumptions about the state of things by just looking at males.”