Too much coffee harms male fertility; but, a pint of beer can improve it, according to a new study.
Men in the study, who drank two or more cups of strong coffee daily, had significantly lower - to say one in five- chances of succeeding in IVF treatment than those who consumed less, The Telegraph reported.
Interestingly, drinking a pint and a half of beer at night improved male fertility and chances of IVF success.
Researchers from the Massachusetts General Hospital in Boston, led by Dr Anatte Karmon, an obstetrician, reached the conclusion after closely following 105 men and their partners enrolled in IVF treatment at the hospital. At the time of the study, all men were aged around 37.
Sperm shape, number, or swimming ability remained unaffected irrespective of coffee and beer intake. However, researchers found that these drinks played a huge role while trying for a baby, through IVF treatment.
IVF success came down by 20% with two or more cups of coffee per day, while drinking less than a cup of the popular beverage improved IVF success by 52%, helpmeoutDOC reported.
On the other hand, IVF success doubled with just 22 g of alcohol daily.
The caffeine in coffee is not good while undergoing IVF, according to the researchers.
"High male caffeine consumption appears to reduce couples' chance of achieving a clinical pregnancy, while male alcohol consumption appears to enhance their chances," lead author of the study Dr Karmon, said, according to the Irish Independent.
"Anything that is good for your heart health is also good for your fertility. So do physical exercise and eat a well-balanced diet."
Experts assumed that the stress-relieving power of alcohol helped in this occurrence. "I firmly believe that moderate social drinking within guidelines (3 to 4 units per day) can be of benefit for couples trying to conceive, either naturally or during assisted conception because it helps to reduce stress," Dr Allan Pacey, Senior Lecturer in Andrology at the University of Sheffield, told The Telegraph.
Researchers presented their findings at the annual meeting of the American Society for Reproductive Medicine in Hawaii.