According to a study published online in Gut, high levels of the trace elements nickel and selenium in the body may lower the risk of developing the most common type of pancreatic cancer, whilst high levels of arsenic, lead, and cadmium could increase the risk of developing the disease.
The researchers examined almost 518 individuals, 118 were patients with exocrine pancreatic cancer, the most common form of the disease, whilst just less than 400 were hospital patients without cancer.
Given that nails and toenails in particular are believed to be more reliable indicators of trace element levels compared with dietary assessment because of their ability to store intake/exposure from other sources over the long term, the researchers examined the study participants' toenails for 12 trace element levels.
The findings revealed levels of certain trace elements were substantially higher or lower amongst cancer patients compared to those in the control group. The researchers observed that the higher or lower the level of trace elements, the greater or lower was the risk of having the disease.
They discovered that the likelihood of having pancreatic cancer was between double and 3.5 times higher in patients with the highest levels of arsenic and cadmium compared with those who had the lowest levels, whilst those with the highest levels of lead were over six times more likely to have the disease.
Furthermore, those patients with the highest levels of nickel and selenium in their toenails were between 33% and 95% less likely to have the disease than those with the lowest levels.
The findings remained unchanged after researchers accounted for other known risk factors like smoking, diabetes, and being overweight.
A third of all pancreatic cancer cases are thought to be due to smoking. Tobacco contains cadmium as well as other trace metals. Cadmium is a known carcinogen and has been linked to an increased risk of lung, kidney, and prostate cancers, whilst high levels of selenium have been linked to offering protection against certain cancers. Earlier research suggests selenium may counter the harmful effects of arsenic, cadmium and lead.
The authors highlight that the causes of pancreatic cancers are still largely unknown despite decades of research, concluding:
"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."
Written by Petra Rattue