Cadmium exposure is known to cause prostate cancer. Now, a new study has suggested that zinc may offer protection against the risk factor.
The study, led by Van Wijngaarden, an assistant professor in the Department of Community and Preventive Medicine at the University of Rochester Medical Centre, zinc stimulates production of a protein that binds cadmium thereby taking it out of circulation and reducing its toxic effects.
The study was based on data from a sample of 1,320 men registered in the National Health and Nutrition Examination Survey (NHANES) 2001-2002, which was the first time PSA levels were available.
PSA is a protein produced by the cells of the prostate gland. The higher a man's PSA level, the more likely cancer is present.
The analysis found that PSA levels were 22 percent higher among American men who had zinc levels below the median (less than 12.67 mg/daily) and cadmium levels above the median.
In men over age 40, urinary cadmium levels were measured in about one-third of the sample and dietary zinc intake was reported based on 24-hour recall. Information on all three variables was available for a total of 422 men.
In contrast, among men with a greater than median zinc intake, little evidence of an association between cadmium and PSA was found.
"Your health is based on the complex interplay of many factors," Wijngaarden said.
"Environmental exposures play out differently in people. It's important to identify those subpopulations that may be more sensitive to toxicities," he added.
Cadmium exposure occurs mostly through smoking and diet, the latter as a result of fertilizer-soaked soil used for growing crops. Cadmium is also a by-product of the industrial process used for making fungicides, batteries, pigments and coatings that protect metals from corrosion.
Workers in those areas are at risk for much higher exposures. When ingested or inhaled, cadmium collects in the liver, kidneys and prostate.
Zinc is an important nutrient to maintain health.
The study is published in the journal The Prostate.