I'll Take My Fish with a Side of Selenium

Trace Elements And Pancreatic Cancer Risk

A new study has found that high bodily levels of the trace elements nickel and selenium may be associated with reduced risk for pancreatic cancer, and that high levels of arsenic, cadmium and lead may increase the risk.

The study, published online Dec. 19 in the journal Gut, included 118 pancreatic cancer patients and 399 patients with other diagnoses at several hospitals in Spain. Researchers analyzed toenail samples with plasma mass spectrometry, a highly sensitive technique for detecting trace elements.

After controlling for age, sex, smoking, diabetes and other factors, the scientists found that the subjects with the highest levels of arsenic were at twice the risk for pancreatic cancer, compared with those with the lowest concentrations. Those with high levels of cadmium were at three times the risk for pancreatic cancer, while those with the highest levels of lead were at six times the risk.

Those with the highest levels of nickel and selenium, on the other hand, were at significantly lower risk for pancreatic cancer.

Dr. Núria Malats, an epidemiologist at the Spanish National Cancer Research Center and the senior author of the new study, said that it was the first to provide these kinds of results with trace elements, and that it did not mean that people should take dietary supplements.

Selenium is, of course, a required micronutrient, linked to a number of important functions including anti-cancer functions, and arsenic has been established as a carcinogen for a long time.  Nickel, however, while somewhat toxic, has not been convincingly shown to be a requirement in people.  This is a correlative study - no mechanism is proposed, so perhaps high levels of Ni are associated with something else that tends suppress pancreatic cancer.