A large international study revealed that suppressing reproduction in mammals is linked to longer lifespans, often increasing life expectancy by approximately 10 percent. The research, conducted by a team led by the Max Planck Institute for Evolutionary Anthropology and published January 16, 2026, examined a wide range of mammalian species and found a consistent trade-off between reproduction and survival.

The study indicated that the reasons for increased longevity differed between males and females. According to researchers, castrated males often avoided the detrimental effects of testosterone, which can contribute to health problems and shorter lifespans. Females, on the other hand, appeared to benefit from avoiding the intense physical demands of pregnancy and nursing.

"These findings underscore a fundamental biological principle," said Dr. Anya Sharma, lead author of the study and a researcher at the Max Planck Institute. "The energy and resources an animal invests in reproduction are directly linked to its ability to maintain its own health and longevity."

The implications of this research extend beyond basic biology. In many cultures around the world, animal husbandry practices, including castration, have been employed for centuries, often with the unintended consequence of extending the animal's lifespan. For example, in some parts of Asia, oxen used for plowing are routinely castrated, a practice that not only makes them more docile but also contributes to their longer working lives.

The study also raised ethical questions about the potential for manipulating reproductive capabilities to extend human lifespan. While the research focused on mammals in general, the findings could potentially inform future studies on human aging and longevity. However, researchers cautioned against drawing direct parallels, emphasizing the complex interplay of genetic, environmental, and social factors that influence human lifespan.

"It's important to remember that humans are not simply biological machines," said Dr. Kenji Tanaka, a bioethicist at the University of Tokyo, who was not involved in the study. "Cultural values, social structures, and individual choices all play a significant role in determining how long we live and how we experience aging."

The research team plans to continue investigating the specific mechanisms by which reproduction affects aging in different mammalian species. They hope to identify potential targets for interventions that could promote healthy aging without necessarily suppressing reproduction. The study's findings are expected to stimulate further research into the evolutionary trade-offs that shape lifespan across the animal kingdom.