Yogurt-eating mice were more virile, had larger testicles and a definite swagger, according to research. Females produced larger litters and were more successful at weaning than their non-yogurt consuming counterparts.
An unpublished study on the link between obesity and the consumption of yogurt led to some unexpected results for the team of researchers from the Massachusetts Institute of Technology last summer. In a report published by the Scientific American, lead scientist Susan Erdman, a cancer biologist, said that researchers noticed that the male mice "projected their testes outward, which endowed them with a certain 'mouse swagger.'"
The testicles of the male mice which were fed yogurt during the study were 5 percent heavier than the mice on a non-yogurt diet and heavier still, about 15 percent, than the testicles of mice fed a junk-food diet. Proving that size does matter, the yogurt-fed mice were quicker to inseminate their partners and produced more offspring.
Female, yogurt-eating mice bore more pups and were more successful at weaning them than their non-yogurt eating counterparts. The researchers have attributed the results of the study to the probiotics in yogurt leading to a leaner and healthier body.
Harvard nutritional epidemiologist Jorge Chavarro, has also found a link between semen quality in men and yogurt. In the Scientific American report, he is quoted as saying,"So far our preliminary findings are consistent with what they see in the mice."
The study by the M.I.T team was originally designed to test whether the probiotics in yogurt were beneficial in the fight against age-related weight gain. The 80 mice, 40 males and 40 females, were divided into two groups. One group were fed what amounts to a mouse equivalent of a junk food diet, high in fat, low in fiber and nutrients, while the other group were fed a normal diet. Half of each group was also supplemented with vanilla-flavored yogurt.
Besides the increase in virility, another effect on the yogurt-eating mice was the increase in active follicle density, resulting in shiny, silky fur.