Researchers from the Loma Linda University Medical School in southern California said vegetarians were harming their chances of having children. That was despite the fact that a diet rich in fruit and vegetables could prolong life and protect against illness.
Vegetarians and vegans had lower sperm counts compared to meat eaters – 50M sperm per milliliter (ml) compared with 70M per ml – according to the research.
Sperm mobility
Sperm motility was also lower in vegetarians and vegans, with only one in every three sperms active, compared to 60% for meat eaters.
It is thought that vitamin deficiencies may be to blame. However, researchers also claimed that replacing meat with soy could be responsible.
High amounts of phyto-oestrogens, which have similar properties to the hormone oestrogen, were thought to be a causal factor.
The study compared the sperm of 443 meat eaters with 26 vegetarians and five vegans in San Bernardino. The town has a large population of Seventh-Day Adventist Christians, who are strict vegetarians and believe meat is impure.
Higher in pesticides
Meanwhile, a second study suggested sperm count in vegetarians and vegans was lower because they were consuming a diet higher in pesticides.
Pesticides in fruits and vegetables could have a negative effect on sperm count, researchers from Harvard University said.
Samples were taken from 155 men who visited the Massachusetts General Fertility Centre between 2007 and 2012.
Those with higher intakes of fruit and vegetables had 70% and 68% lower sperm motility respectively than those who consumed fewer fruits and vegetables.
“Men who want to optimise their reproductive health need to take care to choose fruits and vegetables grown with lower levels of pesticides,” said Paul Turek, md and president of the Society of Male Reproduction and Infertility.
“Nutrition is important to good reproductive health, but food that is good for you can contain other substances, not so good for you.”