For years, there has been talk about how tomatoes may protect against prostate cancer. A recent study suggests that they may do so by lowering levels of one of the main risk factors for that malignancy: testosterone.

A November, 2006 study using rats found that a four-day diet enriched with tomato extract was enough to lower testosterone levels significantly. In particular, lycopene and phytofluene from the fruit led to a 1.7X increase in the enzyme 17 beta-hydroxysteroid dehydrogenase, which breaks down the male juice. It was suggested that this may explain why men that suck down lots of tomatoes are less likely to develop prostate cancer than those who rarely eat the red balls.

While testosterone is a risk factor for prostate cancer, it is an Indirect risk. One of its breakdown products (dihydrotestosterone or DHT) is implicated as the real culprit. Genetics has dictated that some men convert a little testosterone to DHT, while others convert a lot. Men that have male pattern baldness produce lots of DHT, which also signals some hair follicles to shut off.

Does that mean that eating tomatoes will make someone less of a man? The research doesn't go that far. Testosterone is essential to manliness as we know it, but more is not always better, and a slight reduction is not necessarily bad if everything else is working fine. For the average middle aged male, a sedentary lifestyle and extra pounds around the waist seem to be far more damaging to libido - overactive fat cells crank out estrogens, and exercise is needed to maintain testosterone and HGH.

Aphrodisiology will keep an eye on this story, but I am confident that real men have nothing to fear if they want to eat tomatoes with their quiche.

External Reference PMID: 17056806