|
 The damage - which may stem from factors like obesity, stress and
even cell phone use - could affect men's ability to conceive as well
as the genes passed to their children, researchers say.
Semen analysis usually looks at the numbers and the condition of
whole sperm. But the authors of a small study in Poland believe the
degree of breakage, or fragmentation, in DNA strands in the sperm
might be a better indicator of fertility. DNA carries the cell's
genetic information and hereditary characteristics.
Men with fragmentation have lower odds of conceiving naturally and
through procedures like in vitro fertilization, they write in the
International Journal of Impotence Research.
Researchers have noticed before that lifestyle factors can influence
the level of sperm DNA fragmentation, said Ricardo P. Bertolla of
Sao Paulo Federal University in Brazil, who was not part of the new
study.
“More importantly, we do expect that environmental and lifestyle
factors may influence male fertility, but the degree of response is
highly variable among individuals,” Bertolla told Reuters Health by
email.
Dr. Marian Radwan of Gameta Hospital in Rzgow, Poland, focused their
study on 286 men under age 45 who were attending an infertility
clinic.
Radwan did not respond to a request for comment.
Most of the men were overweight, nonsmokers, and with moderate
levels of work stress and life stress. Half had been using a cell
phone for 6 to 10 years.
The men all had normal semen concentrations, but older men and those
with higher work stress had more fragmentation of the DNA in their
sperm.
Men who were obese or had used a cell phone for more than 10 years
also tended to have a higher percentage of immature sperm than
others.
Coffee or alcohol use, smoking and physical activity levels were not
linked to DNA fragmentation, the researchers report.
There is some evidence that DNA damage, beyond affecting a man's
fertility, may be passed along to offspring, raising their risk of
gene mutations linked to various illnesses, the study team notes.
Even men with otherwise normal sperm parameters, like ejaculate
volume and sperm concentration, may have increased levels of free
radicals and DNA damage in their sperm, said Rima Dada of the All
India Institute of Medical Sciences in New Delhi, who was not part
of the new study.
[to top of second column] |
Up to 40 percent of reproductive-age men have some issue with sperm
production, Dada told Reuters Health by email.
But they wouldn't know it, because standard semen analysis does not
involve testing for DNA damage in sperm, she added.
“The important thing is that majority of factors which cause
oxidative stress which result in DNA damage are due to our poor
social habits and unhealthy lifestyle, and simple lifestyle
interventions and quitting smoking and doing yoga and meditation can
reduce both psychological stress and oxidative stress and oxidative
DNA damage,” she said.
Bertolla, however, is “currently not convinced” that cell phone use
damages sperm. “I do not see any definitive proof that this is
true,” he said.
The new study does not prove that any lifestyle factors cause DNA
damage in sperm, only that they are associated with each other, he
noted.
“There are some companies that produce antioxidants specifically
designed to improve male fertility, but it is my opinion that
antioxidants are useful only for those men that need it,” he said.
“I know this sounds very simple and obvious, but there are many men
that end up taking antioxidants without a real need for them (or who
will not benefit from them), and this ends up giving a general
notion that antioxidant supplementation will not work.”
SOURCE: http://bit.ly/1pF9pxA The International Journal of Impotence
Research, online April 14, 2016.
[© 2016 Thomson Reuters. All rights
reserved.] Copyright 2016 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed. |
