Eating fruit and vegetables containing pesticide residues could adversely affect men’s fertility, leading to fewer and poorer quality sperm, a study suggests.
Research by Harvard University found that men who ate the greatest amount of fruit and vegetables with high levels of pesticide residue had a 49% lower sperm count and a 32% fewer normally formed sperm than those who consumed the least.
The authors of the study, published online in Human Reproduction on Tuesday, said more research was needed and that their findings should not encourage men to reduce their consumption of fruit and vegetables.
Jorge Chavarro, assistant professor of nutrition and epidemiology at Harvard’s TH Chan school of public health, said: “We found that total intake of fruit and vegetables was completely unrelated to semen quality. 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.”
The paper is believed to be the first on the consumption of fruits and vegetables with high levels of pesticide residue in relation to semen quality.
The researchers analysed 338 semen samples from 155 men aged between 18 and 55 attending a fertility centre between 2007 and 2012, asking them about their consumption of fruit and vegetables. The produce consumed was categorised as being high, moderate or low in pesticide residues based on data from the annual United States Department of Agriculture pesticide data programme.
The men were divided into four groups, ranging from those who ate the largest amount of fruit and vegetables high in pesticides residues (1.5 servings or more a day) to those who ate the least amount (less than half a serving a day).
The group with the highest intake of pesticide-heavy fruit and vegetables had an average total sperm count of 86m per ejaculation compared with men eating the least, who had an average of 171m per ejaculation. The amount of normally formed sperm was an average of 7.5% in the group with the lowest consumption and 5.1% in the group with the highest intake.
Limitations of the study identified by the authors included the fact that men presenting to fertility clinics tend to have semen quality problems, making it difficult to know whether the results would be similar in the general population. Also, diet was only assessed once and could have changed over time and researchers did not have information on whether or not the food was grown conventionally or organically.
Dr Jackson Kirkman-Brown, science lead at Birmingham Women’s Fertility Centre, said the paper highlighted a growing body of evidence that diet could affect male fertility but, because the level of pesticide intake iwas not measured, it was possible the choice of fruit and/or vegetable was affecting sperm parameters.
“Men wishing to optimise their sperm quality should still eat a healthy, balanced diet until more data is available,” she said.
Dr Allan Pacey, professor of andrology at the University of Sheffield, also said other factors could be at play, 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.
