Status: 01/02/2023 06:41 a.m
Women grow older than men. And apparently this is not only because they are more health-conscious in many areas. A study suggests that there are biological causes for this.
By Daniela Remus, NDR
On average, women all over the world live significantly longer than men. For a long time, researchers assumed that the different behavior of women and men was the reason for this: women often eat healthier, pay more attention to their health, smoke less and drink less alcohol. In the wealthy countries with state health care, they attend check-ups more often than men and are often more likely to see a doctor if they have symptoms.
It’s not just the lifestyle
But data from around the world is now showing that women are also living longer than men in other cultures and in poorer countries without a well-developed health system. It is therefore a global phenomenon, which is also supported by historical studies. These look at time periods that go back several hundred years.
Therefore, researchers from the Max Planck Institute for the Biology of Aging in Cologne, together with a team from University College London, asked themselves why there is this difference in the lifespan between men and women. Molecular biologist Yu-Xuan Lu names the hypothesis that guided the researchers: namely physiological-biological differences between the sexes that influence the aging processes.
Molecular Biological Sex Differences
In order to track down these causes, the international team first examined the aging processes in fruit flies. Because their female animals also live longer than the males. And since fruit flies usually only live for three months, aging processes can be studied much more quickly using this model organism and results can be achieved more quickly. The researchers wanted to find out to what extent rapamycin – a drug that some scientists regard as a promising anti-aging compound – can extend the lifespan of fruit flies.
And that was actually the case, but only for a part of the flies, says Lu about the result study: “We found that rapamycin only increased the lifespan of female fruit flies and that it only reduced or delayed age-related diseases in female flies.”
Does the “garbage collection” of the cell make the difference?
The researchers explain this research result by saying that the rapamycin in the female flies intensified a cellular process in the gut that is responsible for the cell’s recycling system stimulated by the drug in female flies but not in male flies. The researchers therefore concluded that the intensified autophagy halted the aging processes in the female flies.
This finding fits with the knowledge that has been gained for some time that autophagy has an influence on the aging of living beings. “Recycling in the cell also doesn’t work so well anymore,” says Ina Huppertz from the Max Planck Institute for the Biology of Aging in Cologne, who did not participate in the study. “That means: Normally, bad or broken products are removed from the cell degraded, and that also gets worse with age. This process is called autophagy.”
Females also live longer than males in fruit flies.
Image: picture alliance / dpa
Rapamycin is also effective in mice
Rapamycin also had a gender-specific effect in mouse experiments at the Max Planck Institute in Cologne. The male mice could not benefit from this, while the female animals lived longer and remained healthier. The researchers therefore suspect that gender could also be a decisive factor in determining whether anti-aging drugs are effective or not. However, this requires further complex and cost-intensive studies on humans.
Animals age differently
One thing is already certain: not all organisms age. Some animals, such as male ants or the giant Pacific octopus, die immediately after reproduction. But those who age do so extremely differently. Greenland sharks are believed to live more than 400 years. The small freshwater polyp Hydra, on the other hand, hardly seems to age and, according to current knowledge, can live to be at least a thousand years old. However, some mayflies only live for a few hours.
According to the researchers, these differences depend on environmental influences, metabolic processes and a wide variety of molecular biological and cellular processes. Many of these are not yet sufficiently understood. Researchers repeatedly succeed in recognizing individual processes or identifying genetic damage to tissue and cells. However, it is not yet clear what triggers this. And therefore it is also unknown why these processes can no longer be corrected in the course of a lifetime, while this is quite possible at a young age.
Effectively stopping aging with a pill, a superfood or the highly hyped intermittent fasting – of it, one of them study from the German Center for Neurodegenerative Diseases on the multifactorial nature of aging – in any case, humanity is still a long way off.