High levels of the trace elements selenium and nickel may help cut the risk of deadly pancreatic cancer, according to new research.
The elements, which are found in certain foods, appear to offer a protective effect against the disease.
Pancreatic cancer is frequently diagnosed at an advanced stage and kills 80% of people in under a year. Only 5% of patients are still alive five years after diagnosis.
The latest study, published in the journal Gut, focused on patients with exocrine pancreatic cancer, the most common form of the disease. Researchers found high levels of selenium and nickel could lower the risk whereas high levels of lead, arsenic and cadmium could boost the chances of developing the disease.
In the research, experts assessed 12 trace element levels in the toenails of 118 patients with pancreatic cancer and compared them with 399 hospital patients without cancer.
Levels of certain trace elements were found to be significantly higher or lower among the cancer patients than among those in the comparison group.
Patients with the highest levels of arsenic and cadmium in their nails were between two and 3.5 times more likely to have pancreatic cancer than those with the lowest levels. And those with the highest levels of lead were more than six times as likely to have the disease.
However those with the highest levels of nickel and selenium were between 33% and 95% less likely to have the disease compared with those with the lowest levels.
The experts, from the US and Spain, said the findings may have an impact on clinical practice in future. Selenium intake could be tested in clinical trials as a preventative measure for people at high risk of pancreatic cancer, they said.
They added: "Our results support an increased risk of pancreatic cancer associated with higher levels of cadmium, arsenic and lead, as well as an inverse association with higher levels of selenium and nickel. These novel findings, if replicated in independent studies, would point to an important role of trace elements in pancreatic carcinogenesis."