Germ cells are the reason that women tend to live longer than men

The age-old question of why women tend to outlive men has puzzled scientists for centuries. Is it genetics? Lifestyle choices? Or something more fundamental?

Researchers at Osaka University have recently made a remarkable discovery that sheds new light on this intriguing phenomenon. Their findings suggest that germ cells – the very building blocks of life – may play a crucial role in determining sex-dependent differences in lifespan.

Turquoise killifish (Nothobranchius furzeri)

To investigate the complex relationship between reproduction and aging, researchers turned to the turquoise killifish (Nothobranchius furzeri), a species known for its exceptionally short lifespan.

This characteristic allows scientists to observe and study the aging process in a compressed timeframe, providing valuable insights into the underlying mechanisms.

Notably, the killifish exhibit a pattern observed in many other species, including humans, where females generally outlive males.

This sex-dependent difference in lifespan makes the killifish an ideal model organism for investigating the factors that contribute to longevity disparities between males and females.

Germ cell removal alters lifespan

In a remarkable experiment, researchers surgically removed germ cells, the precursors to eggs and sperm, from both male and female killifish.

The results defied expectations: Male killifish without germ cells experienced a significant extension of their lifespan, while female killifish experienced a reduction.

This surprising outcome, as described by lead author Kota Abe, challenges the traditional understanding of the connection between reproduction and aging, suggesting a more complex and nuanced relationship than previously thought.

These findings have significant implications for the field of aging research, prompting scientists to reconsider established theories and explore new avenues of investigation.

Hormonal imbalance

The researchers delved deeper into the mechanisms underlying this phenomenon, discovering striking differences in hormonal signaling between males and females.

Female killifish without germ cells experienced a significant decrease in estrogen signaling, a hormone known to increase the risk of cardiovascular disease and potentially shorten lifespan.

However, this decrease came at a cost, as these females also exhibited increased growth factor signaling, leading to larger body size but suppressing signals crucial for maintaining health and slowing aging.

It’s a delicate balancing act, with germ cells seemingly playing a pivotal role in maintaining hormonal equilibrium.

“After removing the germ cells, male killifish lived longer than usual and female lifespans became shorter,” explained Abe. “We wanted to understand how germ cells could affect males and females so differently. Our next step was to investigate the factors responsible.”

The sunshine vitamin

In a twist of fate, male killifish without germ cells experienced a surprising improvement in muscle, skin, and bone health.

This unexpected finding led the researchers to uncover a fascinating link between germ cell removal and increased vitamin D signaling in these fish.

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

“Our work suggests that vitamin D signaling could influence the longevity of other vertebrates, including humans.”

Germ cells and lifespan link in humans

While these findings were observed in killifish, they have far-reaching implications for our understanding of human health and aging process.

The intricate relationship between reproductive cells, hormones, and lifespan is likely to be conserved across many species, including humans.

Could manipulating these factors offer a new avenue for extending human lifespan and improving health outcomes?

The potential is tantalizing, and the Osaka University study has ignited a new wave of research into this exciting possibility.

Quest for a longer, healthier life

The research has fundamentally transformed our understanding of the intricate relationship between reproduction, aging, and lifespan.

The revelation that germ cells, the foundation of reproduction, significantly influence the aging process and longevity has paved the way for innovative research directions and potential interventions.

As scientists delve deeper into the mechanisms of aging, this groundbreaking study offers a promising glimpse into a future where extended healthspans are not merely aspirational but achievable.

By investigating the manipulation of germ cells, hormonal pathways, and vitamin D signaling, researchers may uncover the secrets to unlocking a longer and healthier life.

While the journey towards this goal is ongoing, the Osaka University study marks a significant milestone, propelling us towards a future where the limitations of aging can be overcome.

The study is published in the journal Science Advances.

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