Do Women Really Outlive Men? Sex Cells May Explain The Reason

The belief that women generally live longer than men is widely supported by various factors, including better stress management and biological differences. Women often place more emphasis on their health and benefit from larger social networks, contributing to their increased longevity. However, it's important to note that life expectancy can vary significantly among individuals, regardless of gender.

Recent biological research has provided new insights into the gender disparity in life expectancy, particularly focusing on reproductive factors. A study published in Science Advances by researchers from Osaka University has revealed that germ cells, which develop into eggs in females and sperm in males, play a crucial role in determining lifespan differences between genders in vertebrate animals.

The researchers conducted their study on the turquoise killifish, a species known for its short lifespan of only a few months. They observed that, similar to humans, female killifish tend to live longer than males. Interestingly, when the germ cells were removed from both male and female killifish, the lifespan differences between the genders disappeared.

"After removing the germ cells, male killifish lived longer than usual, and female lifespans became shorter," revealed lead author Kota Abe.

"We wanted to understand how germ cells could affect males and females so differently. Our next step was to investigate the factors responsible," he added.

The study uncovered that female killifish without germ cells exhibited reduced levels of oestrogen and increased growth factor signaling. These changes were associated with health problems and accelerated aging. In contrast, male killifish without germ cells demonstrated improved health and increased vitamin D signaling, suggesting a potential role of vitamin D in enhancing longevity. This finding has spurred further research into the effects of vitamin D supplements on lifespan.

"When we administered active vitamin D, we found that the lifespans of both males and females were significantly extended, suggesting that vitamin D signalling provides health benefits throughout the body," said senior author Tohru Ishitani.

"Our work suggests that vitamin D signalling could influence the longevity of other vertebrates, including humans," he added.

The discovery that germ cells have sex-specific effects on longevity offers valuable insights into the complex interplay between reproduction, ageing, and lifespan. Understanding these mechanisms could pave the way for new approaches to addressing age-related health issues and improving life expectancy across genders.