Eating bacon can significantly lower a man’s sperm quality, Medical Daily reported.

In a study presented at the American Society for Reproductive Medicine’s 2013 Annual Meeting in Boston, researchers from Harvard University gathered data from 156 men who were undergoing in vitro fertilization (IVR) with a partner. Each couple was asked questions about their diet, including how often they consumed processed meat, red meat, white meat, poultry, and fish.

Overall, men who consumed more than half a portion of processed meats such as bacon each day had significantly lower levels of “normal” sperm, compared to men who ate less than half a portion of processed meats per day.

Additionally, the researchers also discovered that some foods seemed to increase sperm quality.

“We found the effect of processed meat intake lowered quality, and fish raised quality,” said study author Dr. Myriam Afeiche, from the Harvard School of Public Health (HSPH).

However, some health professionals have expressed doubts about the study’s findings. Dr. Allan Pacey, chairman of the British Fertility Society, took issue with the way the researcher’s measured sperm quality and pointed out that the study included a small sample size.

“The relationship between diet and men’s fertility is an interesting one, and there is certainly now convincing evidence that men who eat more fresh fruit and vegetables have better sperm than men who don’t,” Pacey said. “However, less is known about the fertility of men with poor diets and whether specific foods can be linked to poor sperm quality.”

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