A Stanford study claims that older-age fathers promote longevity in the population.
But old-age male sperm has more random mutations (another 2 per year of father’s age, usually bad, of course, but out of 1.6 billion or so, probably mostly harmless), so this means more losers even though those who reproduce are going to have better long-life-promoting genes.
It turns out that the mother’s contribution to mutational load is constant (because the eggs were produced earlier?); the benefits of younger motherhood come from elsewhere. Still, older fathers aren’t unambiguously awful; mutational load aside, it may be general health more than just age that’s at work in reducing older men’s sperm quality.
Diana Vaamonde, a researcher at the University of Cordoba and lead author of the study said in a press release, “We have analysed qualitative semen parameters like the ejaculated volume, sperm count, mobility and sperm morphology.” [that’s what *she* said!]
For the study the men were also tested for hormone levels that included follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), cortisol (C) and the T/C ratio that the researchers explain provides a better picture of the environment needed for sperm creation, in addition to giving a picture of the general health of the 31 men included in the study.
The results showed men who exercise more had faster swimming sperm that was more perfectly formed, compared to their sedentary counterparts. Exercising appears to create a more favorable environment for sperm creation that comes from healthy hormone levels.
The good news is the researchers say it only takes moderate exercise to keep your sperm in good shape.
According to the CDC, it’s possible to change a man’s sperm with healthy lifestyle changes.
2. Diet improves sperm in 45+ year old men.
3. A study finds that the risk of autism goes up considerably more in the children of older mothers in all age ranges than it does in the children of older fathers.
The older a mother is when she gives birth, the higher her child’s risk of autism, new data show.
A smaller effect also is seen for the age of the father, but only when the child is born to a father over age 40 and a mother under age 30.
All of the above are just studies of correlations in existing populations, of course. There was no control group.