Environmental contaminants, such as persistent organic pollutants, may contribute to an increased risk for chronic disease if they occur for long enough or at high enough levels. Research has shown that some hazardous chemicals may even cause the body to be more vulnerable to such medical conditions as cancer, poor immune system response, altered nervous system function, and cardiovascular disease. The good news is that certain dietary strategies may provide a defense for combating the effects of these contaminants while improving your overall health.