Researchers at Michigan State University have established a link between the ingestion of fish oil and colon cancer in mice having inflammatory bowel disease:
The study, published in the journal Cancer Research, found an increase in the severity of the cancer and an aggressive progression of the cancer in not only the mice receiving the highest doses of DHA but those receiving lower doses as well.
Our findings support a growing body of literature implicating harmful effects of high doses of fish oil consumption in relation to certain diseases," Fenton said. "Currently, there is a call by academics and the food industry to establish dietary guidelines for omega-3 consumption.
However, Fenton cautioned people may not need to avoid fish oil -- with any nutrient, there is a "bell curve" effect, with those on the left deficient in a nutrient and those on the right in excess.