Sperm counts in Western men have declined by more than 50 per cent over the past 40 years, according to a major new study.
The study, led by Israeli researchers, reviewed hundreds of studies into sperm quality between 1973 and 2011. In all, 43,000 men were studied.
"These findings strongly suggest a significant decline in male reproductive health, which has serious implications beyond fertility concerns," the authors said.
Researchers found an increasing proportion of men had sperm counts below the threshold for infertility.
"The high proportion of men from Western countries with concentration below 40 million/ml is particularly concerning, given the evidence that sperm concentration below this threshold is associated with a decreased monthly probability of conception," the authors said.
Professor Rob McLachlan from the Hudson Institute of Medical Research in Melbourne said it was too soon to know if the fall in sperm count would be reflected in natural conception rates.
"This latest analysis presents the challenge to identify and address potential negative impactors on male fertility such as lifestyle, obesity and comorbidities that are rising in developed countries particularly, and generally the role of environmental toxicants for which there is certainly evidence in more select populations," he said.
What can be done to improve sperm counts?
Eating a healthy, balanced diet including your five a date and maintaining a healthy weight are “essential” for keeping your sperm in good condition, according to the NHS Choices website.
So eat well and try to lose weight through diet and exervices if you are overweight not just for your own sake, but also to be more likely to have children.
Smoking can reduce fertility - so you should also try to kick the habit if you want to boost your chances.
Try the NHS Smokefree website or helpline to get advice or support for quitting.
Drinking too much alcohol can also affect sperm quality. You are not recommended to drink more than 14 units a week, spread evenly over three or more days.
Some drugs can also damage sperm, including cocaine, cannabis, anabolic steroids, amphetamines, heroin and methadon
Article source: The research was published in the Human Reproduction Update Journal.