What makes you think keeping ovaries influences rate of aging, instead of simply providing protection against a major disease, such as cancer?

There is another aspect of our data pattern that gives us further confidence that ovaries really do matter when it comes to successful aging. A simple explanation for the observation that ovaries promote longevity would be that taking away ovaries increases the risk for a major lethal disease. In Rottweilers, cancer is the major killer. We found, however, that by conducting a subgroup analysis that excluded all dogs that died of cancer, the strong association between intact ovaries and exceptional longevity persisted. After excluding all cancer deaths, females that kept their ovaries the longest were 9 times more likely to reach exceptional longevity than females with shortest ovary exposure. Thus, we observed a robust ovarian association with longevity that was independent of cause of death, suggesting that a network of processes regulating the intrinsic rate of aging is under ovarian control. This work positions pet dogs, with their broad range of lifetime ovary exposure, to become biogerontology’s new workhorse for identifying ovary-sensitive physiological processes that promote healthy longevity.