Couch potatoes have lower sperm counts
MEN who watch television for 20 hours per week have almost half the sperm count of those who watch very little television or none at all, according to a study published yesterday.
United States researchers recruited 189 young men aged between 18 to 22, questioned them about their exercise, diet and TV habits and asked them to provide a sperm sample.
Men in the top quarter of TV-watchers - those who watched for 20 hours or more - had a 44-percent lower sperm count than those who watched least, meaning they said they watched "none or almost none."
Another big factor was exercise, according to the study, published online in the British Journal of Sports Medicine.
Men who exercised for 15 or more hours weekly at a "moderate to vigorous" rate had a 73-percent higher sperm count than those who exercised less than five hours per week.
None of the sperm levels was so low that the man would have been unable to father a child.
Semen quality appears to have declined over several decades, according to studies conducted in several countries.
It is unclear why this has happened but scientists suspect that sedentary lifestyles may warm the scrotum and affect semen concentrations. Physical inactivity has also been linked to increased levels of oxidative stress, in which rogue oxygen compounds degrade cells.
"We were able to examine a range of physical activity that is more relevant to men in the general population," said Jorge Charravo, assistant professor of nutrition and epidemiology at Harvard School of Public Health, Massachusetts.
United States researchers recruited 189 young men aged between 18 to 22, questioned them about their exercise, diet and TV habits and asked them to provide a sperm sample.
Men in the top quarter of TV-watchers - those who watched for 20 hours or more - had a 44-percent lower sperm count than those who watched least, meaning they said they watched "none or almost none."
Another big factor was exercise, according to the study, published online in the British Journal of Sports Medicine.
Men who exercised for 15 or more hours weekly at a "moderate to vigorous" rate had a 73-percent higher sperm count than those who exercised less than five hours per week.
None of the sperm levels was so low that the man would have been unable to father a child.
Semen quality appears to have declined over several decades, according to studies conducted in several countries.
It is unclear why this has happened but scientists suspect that sedentary lifestyles may warm the scrotum and affect semen concentrations. Physical inactivity has also been linked to increased levels of oxidative stress, in which rogue oxygen compounds degrade cells.
"We were able to examine a range of physical activity that is more relevant to men in the general population," said Jorge Charravo, assistant professor of nutrition and epidemiology at Harvard School of Public Health, Massachusetts.
- About Us
- |
- Terms of Use
- |
-
RSS
- |
- Privacy Policy
- |
- Contact Us
- |
- Shanghai Call Center: 962288
- |
- Tip-off hotline: 52920043
- 沪ICP证:沪ICP备05050403号-1
- |
- 互联网新闻信息服务许可证:31120180004
- |
- 网络视听许可证:0909346
- |
- 广播电视节目制作许可证:沪字第354号
- |
- 增值电信业务经营许可证:沪B2-20120012
Copyright © 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.