For years, the fact that women tend to outlive men has been a topic of interest and speculation among scientists and the general public alike. Now, researchers believe they may have cracked the code to this enduring mystery.
In a groundbreaking study that could be described as a ‘crucial step’ towards unraveling the secrets of longevity, scientists have linked the longer lifespans of women to chromosomes. Let’s delve deeper into this discovery.
Published in the journal Biology Letters, the study suggests that having an extra X chromosome provides a robust cellular defence that shields against gene mutations and diseases, potentially contributing to a longer life.
The team of researchers from the University of New South Wales conducted an extensive analysis, examining the sex chromosomes and lifespan data of 229 species, ranging from insects and fish to mammals. Their findings revealed a fascinating pattern: animals with two identical sex chromosomes, such as birds with two ‘Z’ chromosomes, tend to live nearly 18 per cent longer than their counterparts with differing chromosomes.
This research builds upon the ‘unguarded X hypothesis,’ which posits that one X chromosome can act as a protective buffer against illness. In females, only one X chromosome is active in each cell, meaning that a harmful mutation in one cell is less likely to affect all cells.
This could result in mutation-related disorders being ‘masked’ more frequently in females, providing them with an additional layer of protection.
Conversely, males, with their XY chromosome configuration, have only one X chromosome and are therefore more susceptible to mutations affecting all cells.
Interestingly, in species where males possess two identical sex chromosomes, they tend to outlive females. Overall, on average, males live about 7 per cent longer than females in these species.
However, when the chromosome pattern is reversed, as in humans, women have a significant edge, living nearly 21 per cent longer than men. But chromosomes aren’t the only factor at play.
The study’s authors, including co-author Zoe Xirocostas, point out that behavioural factors such as fighting, risk-taking, and the pressures of finding a mate and establishing territory are typically less common in females, which could also influence longevity.
Steven Austad, an expert on ageing from the University of Alabama at Birmingham, finds the study promising, though he was not involved in the research. He suggests that social roles, such as childcare, might also be linked to lifespan.
‘For instance, owl-monkey males live longer than females—and the males play a big role in infant care in that species,’ he said.
As we delve into the complexities of what determines lifespan, this study opens up new avenues for understanding how our genetic makeup influences our health and longevity. It’s a reminder that the chromosomes within our cells play a critical role not just in who we are, but also in how long we might live.
For our readers over 50, this research might offer a glimpse into the biological advantages that could be contributing to your longevity or that of the women in your life. It’s a testament to the resilience built into our very DNA and a fascinating piece of the puzzle in the quest to understand the human body.
Do you believe that genetics play the most significant role in determining lifespan, or do you think lifestyle and environmental factors are more influential? Share your thoughts and experiences with the YourLifeChoices community in the comments below.
Also read: Shining a light on longevity: The life-extending power of the sun
