The journal Human Reproduction has a article soon to be published describing the amount of beef eaten by mothers being related to son’s sperm production (see here for a popular press account and here for the article). There are some interesting issues with a retrospective account of how much beef was eaten during pregnancy. Their key finding was that there was a negative correlation between sperm concentration and the mother’s number of beef meals per week:

Sperm concentration was inversely related to mothers’ beef mealsper week (P = 0.041).

Interestingly, there are 387 people in this study and with a p-value of .041, there does not seem to be a strong correlation between these variables.