Controversy over how soy reduces sperm count

A regular diet despite modest amounts of soy foods can also reduce sperm density, US scientists estimate.

Animal studies have speculated that large amounts of soybeans in the diet affect fertility, but other human studies show conflicting results.

The Harvard School of Public Health investigated the diet of 99 men, and their semen samples. These people are divided into 4 groups depending on the amount of soybeans they eat. When comparing the spermatozoa density of the soy-fed group with the least-consumed group, the scientists found a significant difference.

The average sperm density of men is between 80 and 120 million in a milliliter, and the average of the moderate soy group in all days is reduced by 41 million.

(Photo: BBC)

Dr Jorge Chavarro, who led the study, said chemicals called isoflavones in soybeans could affect sperm production. These chemicals may also have similar effects on human estrogen hormones.

Chavarro also noted that overweight or obese men seem to have a stronger influence.

However, a British expert stressed that most men in Asia eat this food with no problems with reproduction. And the consumption of soybeans in many parts of Asia is significantly higher than the maximum in the above volunteers.

Dr. Allan Pacey, senior lecturer at the University of Sheffield, said if soybeans are indeed detrimental to sperm production, the birth will be affected here, but there is practically no evidence. Any thing about that.