Dudley Lamming, PhD

Sexual dimorphism in response to longevity interventions

Aging researchers are often asked why women live longer than men. While it is true that men are more likely than women to have hazardous occupations and to engage in violent behavior, these factors alone cannot fully account for the difference in lifespan between the sexes. Many other species, including laboratory mice, also have a difference between male and female lifespan even when the animals are kept under tightly controlled conditions. This suggests that fundamental, biological differences between males and females lead to the observed differences in lifespan.

Research over the past several decades has identified a variety of drug treatments and gene mutations that can extend lifespan in animals such as mice. These often show differential efficacy between the two sexes. For example, long-term treatment with a drug called rapamycin extends the lifespan of mice, but has a greater effect in females than males.

Dr. Lamming’s previous work has indicated that a gene called Rictor, which plays an important role in the function of the liver, may be responsible for the differential effects of rapamycin in males and females. Dr. Lamming will now test whether sex hormones such as estrogen and testosterone control what Rictor does in the liver, and whether this hormonal control is important in regulating lifespan. Understanding why treatments such as rapamycin are more effective in females than in males will facilitate the development of treatments that are equally effective in both sexes.