Recent studies show that consumption of even moderate amounts of coffee (3 cups a day) can affect a man's ability to have normal children. Several studies have been conducted to show the adverse effect of modern life on the quality and quantity of sperm.
Research into this by the US govt. has shown that modern men have only one third (60 million/ml) the quantity of sperm as a hampster (160 million/ml). The sperm count has declined worldwide over the past 50 years from 150 million/ml.
The report on the research by scientists at Bradford University and the University of California, Berkeley, done on normal men between 22 to 80 was published this week in the journal Human Reproduction . It found increased genetic damage in the sperm of men who consume even average amounts of caffeine. Unsuccessful pregnancies, or children with deformities or genetic disease could result from this DNA damage.
The study also found that the age affects the quality. But the report concludes: "Independent of age, men with substantial daily caffeine consumption have increased sperm DNA damage."
This damage has been linked to genetic defects , cancer and infertility in their children. In fact lead author Dr Andrew Wyrobek said that the damage was of the type which leads to chromosomal rearrangement in the embryo, which can lead to death of the foetus, birth defects, cancer or genetic disease in the babies which do get born.
It is not certain how the DNA damage happens . Scientists are of the opinion that is is the present day lifestyle, along with stress and the presence of pollutants which has affected the quantity of sperm produced. In fact younger men are not as fertile as their fathers.
Other contributing factors are thought to be - taking anti-depressants, over usage of mobile phones, wearing tight jeans , and sitting for long hours at a desk job or with a laptop on the lap.