Men who eat fruits and vegetables with higher concentrations of pesticide residue, such as strawberries, apples and spinach, could have lower sperm counts and more unhealthy sperm, a new observational study suggests.
The study, conducted by public health researchers at Harvard University in the US, is believed to be the first to investigate the relationship between eating fruit and vegetables containing pesticide residues and the quality of a man's semen. And it could be a boon for the organic fruit industry.
The researchers analysed 338 semen samples from 155 men between the ages of 18 and 55, who were taking part in an ongoing fertility study.
The volunteers were questioned about their intake of different types of fruits and vegetables per day, which were classified by the researchers as having high, moderate, or low concentrations of pesticide residue, according to information from the US Department of Agriculture's Pesticide Data Program.
The fruits and vegetables considered low in pesticide residues included peas, beans, grapefruit and onions, while those with high residues included peppers, spinach, strawberries, apples and pears.
After adjusting for factors such as smoking and body mass index, which are known to affect sperm quality, the team found that men who ate the most fruit and vegetables with high concentrations of pesticide residue had a 49 percent lower sperm count than men who ate the least.
These men had an average total sperm count of 86 million sperm per ejaculate., while the men eating the least were producing an average of 171 million sperm.
Men with the greatest intake of high pesticide residue foods were also 32 percent less likely to produce normally formed sperm, which suggests that inadvertent pesticide consumption could have adverse effects on fertility. The results have been published in the journal Human Reproduction.
"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 epidemiologist and lead author, Jorge Chavarro, in a press release.
The good news is the authors say men shouldn't ditch fruit altogether, but suggest that it might be a good idea, just to be safe, to go organic.
"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… may be the way to go."
Of course, the study does have some important limitations, which the authors acknowledge. The participants, who had presented to fertility clinics, tend to have lower quality sperm than men in the general population. Furthermore, the study didn't account for changes in diet over time; it didn't assess whether the participants were eating organic or conventionally grown produce; and it didn't actually measure the levels of pesticide exposure.
Haroon Siddique from The Guardian spoke to Allan Pacey, an andrologist at the University of Sheffield in the UK, who was not involved in the study. He told Siddique that other factors could be influencing the lower sperm counts, given that the Harvard results came from an observational study.
"He said there was no evidence that switching to organic fruit and vegetables would improve semen quality but hoped the paper would encourage studies that could help provide a definitive answer," writes Siddique.
All of a sudden, the apple I packed for lunch is looking less appealing.
Source: The Guardian