Nutritionist Ann Louise Gittleman has a message for all of you Friends of Animals and lovers of green and leafy things out there -- and you're not going to like it. She says if you have a low sex drive, your vegetarian diet may be to blame.
Gittleman says she has nothing against vegetarians, per se (even though she describes the non-meat eaters' skin as "pimply" and "ugly"). Her hypothesis is something she just stumbled on. While working with vegetarian patients who were complaining of being tired all the time, she heard a common complaint: a low sex drive, or as she describes it, feeling "poopy in the bedroom." Sure enough, when she tested them, she found low levels of zinc.
"We have known for years that zinc is an aphrodisiac, that's why you're told to eat oysters, which is a high source of zinc," says Gittleman, a nutritionist and author of "Why Am I Always So Tired?" "What I've seen with women is no sex drive, and the men, they can take it or leave it ... I think their [low libido] is an unexpected side-effect of a vegetarian and vegan diet."
Zinc is a trace element that is essential for growth, development, fertility, enzyme production and the metabolism of protein, carbohydrates and fat. While the effects of zinc on fertility -- like producing sperm and ovulating -- is well-documented, there is no research showing a zinc-low sex drive connection that Gittleman has heard of.
"I think we have to be careful before we jump to a conclusion on zinc status when it could be a number of other behaviors that could be triggering the problem, like exercise, anorexia, large shifts in weight, emotional stress and alcoholism," says Linda Van Horn, Ph.D., professor of preventative medicine at Northwestern Medical School. "But my all-time favorite [reason] is fatigue. If somebody is really tired and sleep-deprived, that'll do it. I think that there are a lot of new parents who can attest that their sexual interest is really low because they haven't been sleeping."
Gittleman herself admits that her hypothesis is based on her own observations rather than rigorous scientific studies. She says out of 325 vegetarian clients, about 60-75 percent of them have complained of a low sex drive. When she tested them, using dietary and tissue mineral analyses, they were low in zinc, and had toxic metal imbalances. She also says that the trace element copper cancels out zinc, so having a diet that is high in copper (like mushrooms, seeds, chocolate and soy products) can affect the amount of zinc (which is commonly found in eggs, red meat, whole grains, beans, lentils and peas). Once she puts them on a diet with copper-free multiple vitamins and zinc supplements, the first thing they say is that their sex drive has come back.
But not everybody buys it. "When you think of the body and the whole symphony of nutrients and the synergistic effects, it's not that simplistic," says Jo Ann Hattner, a clinical nutritionist at Stanford University Medical Center and spokeswoman for the American Dietetics Association. "I think that it would be a disservice for people to think that there is one answer and that it is zinc. However, if they suspect that it is low, they should have it measured, and the same thing for iron."
While Van Horn would not necessarily support the connection, she does think it's plausible and that researchers should study the relationship between zinc and sex drive in depth. Gittleman agrees. She's calling for more research into the subject. But for now, the nutritionist is just bracing for the awaited ire from the vegetarians. "They might throw tofu balls at me, or something," she says.