Men May Have Biological Clocks, Too
Some researchers say a man's age may affect not only his ability to father a child -- but the health of his offspring.
Lifestyle: Another Break in the Sperm Chain continued...
"It is very difficult to separate the effects of natural aging from
environmental effects like smoking, drinking, drug use, and radiation exposure.
There are a whole battery of environmental assaults that may accumulate over
time, causing at least some of the reproductive issues we now attempt to link
solely to age," says McCulloh.
Silverman agrees, suggesting that much the way lifestyle practices affect
the health of other systems in the body, such as the heart, so too might they
affect male reproduction. "The longer a man lives, the more exposure he has
-- which might make a difference," says Silverman.
At least one study indicated that oxidative damage -- one type of
environmental assault -- can increase chromosomal damage in sperm.
In animal research published in 2005 in the journal Fertility and
Sterility, researchers found that not only was the DNA of sperm
susceptible to oxidative damage, but the older the male, the more susceptible
the sperm was to developing breaks in the DNA.
It is this kind of genetic upset that experts say could be behind some of
the birth defects and other problems that until recently were thought to be
exclusively related to the mother.
The American Society of Reproductive Medicine now recommends that sperm
donors be men that are "ideally less than 40 years of age to minimize the
potential hazards of aging."
What Men Can Do
While evidence seems clear that at least the possibility of a male
biological clock exists, not everyone believes it comes with a fertility alarm.
Indeed, some experts cling steadfastly to the notion of omnipotent and
virtually indestructible sperm at any age.
"I'm not at all convinced [age is a factor]. These are not prospective
studies and you cannot pick the disease state and then work backwards. You
can't do it that way because you're going to come up with the wrong conclusion.
You may have the observation, but you don't have the link," asserts Andrew
McCullough, MD, director of sexual health and male infertility at NYU Medical
Center in New York City.
He tells WebMD that until there is a study that controls for all the
variables -- which may be impossible -- all we have are assumptions and no
"These are observations worth noting, but to say 'Aha, this is the
answer' -- well that's a real stretch," says McCullough.
Silverman comments that while the evidence may be too new to draw finite
conclusions, he says the findings thus far are relevant and a portent of things
"Eventually I believe we will have the research to show that when it
comes to fathering a child, time isn't always on a man's side," says
In the meantime, as embryologist McCulloh points out, every man can protect
his parenting potential at any age by taking better
care of his overall health.
McCulloh tells WebMD, "If you don't smoke, drink in moderation, exercise
daily, and eat a healthy diet, you are likely to remain healthier in general --
and that means a healthier reproductive system overall."