The probable causes of testicular cancer have long eluded scientists. What they do know is that it most often strikes men between the ages of 15 and 34, and that northern Europenotably Denmarkhas the highest incidence of the disease. Now a new hypothesis may explain that pattern. According to a report published in the February issue of the journal Cancer Causes and Control, a toxin found in contaminated cereal grains, pork products and coffee could be the culprit.

That toxin, says Wake Forest University researcher Gary G. Schwartz, is ochratoxin A (OTA), a by-product of molds that grow on a variety of plant products and grains (especially rye) and a known carcinogen in animals. When animals consume the moldy grains, they also ingest the OTA. Pork products in particular exhibit high levels of contamination, and citizens of Denmark, Schwartz notes, consume the most pork products and rye per-capita in Europe.

Schwartz proposes that individuals are exposed to OTA either in early childhood or in the womb. Once internalized, he hypothesizes, the OTA damages the testicular DNA. This alteration then lies dormant until testicular growth during puberty, when the cancer begins to grow.

Further analysis of the effect of OTA when present in high levels in the diet of mothers and their male children is necessary, Schwartz concludes. But should future research bear his suspicions out, certain compounds known to inhibit OTAs effects in animalsaspirin and vitamins A, C and E, for examplemight offer similar protective effects to humans.