Men who are hoping for offspring may need to eat more organic fruit.
A study conducted by the Harvard School of Public Health has found that men who consumed vegetables and fruit that were high in pesticides, had poorer semen quality and less sperm than those who ate less fruit and vegetables exposed to pesticides.
"To our knowledge, this is the first report to link consumption of pesticide residues in fruits and vegetables, a primary exposure route for most people, to an adverse reproductive health outcome in humans," said Jorge Chavarro, assistant professor of nutrition and epidemiology.
The study was published in the journal Human Reproduction.
The researchers followed 155 men from Environment and Reproductive Health (EARTH) study, which is an ongoing research project being conducted at a fertility centre in Boston.
Researchers took 338 semen samples between 2007 and 2012 and asked the men about their diets.
Some fruits and vegetables, such as peppers, strawberries, spinach, pears and apples, absorb more pesticide than others. Others, such as peas, beans, and onions, have lower residual rates of pesticide according to the US Department of Agriculture Pesticide Data Program.
Those who ate more than one and a half servings of pesticide-heavy fruit had a 49% lower sperm count and a 32% lower percentage of normal sperm than men who ate less than one and a half fruits a day.
"These findings should not discourage the consumption of fruit and vegetables in general," said Chavarro. "In fact, we found that consuming more fruits and vegetables with low pesticide residues was beneficial. This suggests that implementing strategies specifically targeted at avoiding pesticide residues, such as consuming organically grown produce or avoiding produce known to have large amounts of residues, may be the way to go."
Researchers say it is the first study to look at semen quality and pesticide exposure.