MedicalResearch.com Interview with:
Morgan Elyse Levine, PhD
Department of Human Genetics
University of California, Los Angeles
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: From an evolutionary perspective, aging and reproduction are two processes that are linked. For instance, in order to maximize fitness, an individual has to survive and remain healthy enough to:
1) reproduce and
2) insure offspring survive to reproductive age.
Thus, the rate of aging is tied to a species’ timing of reproductive senescence and necessary length of parental involvement. There is also evidence that among humans, women with longer reproductive stages (later age at menopause, ability to conceive at older ages) are more likely to live to age 100, which we hypothesize is because they age slower.
Using an epigenetic biomarker believed to capture biological aging (previously developed by the Principle Investigator of this study, Steve Horvath), we tested whether age at menopause, surgical menopause, and use of menopausal hormone therapies were associated with a woman’s aging rate.
We found that the blood of women who experienced menopause at earlier ages (especially those who underwent surgical menopause) was “older” than expected, suggesting they were aging faster on a biological level than women who experienced menopause at later ages. We also found that buccal epithelium samples (cells that line the inside of the cheek) were epigenetically younger than expected (signifying slower aging) for post-menopausal women who had taken menopausal hormone therapy, compared to post-menopausal women who had never taken any form of menopausal hormone therapy.
Finally, we had a number of results that suggested that the previously mentioned findings were a result of the process of menopause directly speeding up the aging process—rather than the alternative explanation, which would have been that women who aged faster experience menopause earlier.