If you want to have babies, you might want to stay away from tofu. Or not. You know, whatever.
The news was all over the place last week that a study has shown that soy foods lower sperm count.
Then there were more articles that said things were inconclusive. I had to wonder, if soy is so bad, then why is China so densely populated?
Riddle me that, would you?
Meanwhile, it got me poking around to see what else affects male fertility, and, well, there are a lot of things that might make you shoot blanks. Among them are obesity, pesticides, stress, heat, smoking and drinking. Some you can control, others you can't, like what your mom did while you were in the womb.
What the experts say
"We found that soy food intake was associated with lower sperm count compared to that of men who did not consume any soy foods. But no other semen quality parameters - motility, morphology, total ejaculate volume - were affected. What does it mean? We really don't know. Ours is the third study to evaluate whether intake of soy foods or soy supplementation during adult life has any impact on sperm quality, and the results are very inconsistent. The first, a very small study, showed absolutely no relationship. The second, focused mostly on men who were known to have fertility problems, found that those who consumed more soy foods had better semen quality than those who did not. And now we've found the exact opposite. You don't have to be a scientist to know that if this is the information you have, you really know nothing."
JORGE CHAVARRO, research fellow, department of nutrition, Harvard School of Public Health
"Problems with the hypothalamus or the pituitary can affect the normal hormones that drive sperm production. Estrogens [soy contains phytoestrogens] and steroids can affect sperm count. Marijuana may have a similar effect. In the testicle itself, genetic problems and a number of chemicals can interfere with sperm production. Mumps can infect the testicles and damage them. One of the most common conditions is a varicocele (varicose veins around the testicle). Anything causing heat around the testicle is bad. Tight underwear can reduce sperm quality very dramatically. Laptops are an issue if you put them on your lap, because they get hot. Chefs can be exposed to high levels of heat around the groin."
KEITH JARVI, director, male infertility program in the division of urology, University of Toronto
"Herbalists have a long history of treating low sperm count. Epimedium multiflorum (horny goat weed) is another - Chinese medicine practicitioners noticed their goats were more aggressive and had more kids after eating the plant, so they started taking it and found it did the same for them. The South American plant Ptychopetalum olacoides (fertility wood) is an endocrine stimulant. Panax ginseng works as an endocrine stimulant, so there's more activity in the pituitary hypothalamus and adrenals and testes. Foods high in zinc are good. Also, saving yourself. If you want to have children, don't expend seminal fluid all the time. Get the man's cycle in sync with the woman's."
JOHN REDDEN, herbalist, Toronto
"On average it looks like sperm counts have been declining, at least in Western countries. Sperm counts also differ regionally. For example, in central Missouri (an agricultural area), the men had only half as many moving sperm as men in Minneapolis, which is a huge difference. I found a significant difference in the level of pesticides in the urine of men with good and bad semen quality. It's known that mothers who smoke have sons with lower sperm counts. We found that those whose mothers ate more than one beef meal a day when pregnant had significantly lower sperm counts. Phthalates, which are ubiquitous in our homes, lower testosterone in the fetus, which later affects the ability to produce sperm. Things that might help include reducing exposure to pesticides, eating organic food, drinking properly filtered water, avoiding the use of certain chemicals in the home, as well as limiting lifestyle factors like alcohol consumption, being very overweight or very stressed."
SHANNA SWAN, professor of obstetrics and gynaecology, University of Rochester, New York