Aspirin and flavonoids in fruits and vegetables could help prevent colorectal cancer

A diet rich in fruits and vegetables and a daily dose of aspirin have one thing in common-;both can help prevent colorectal cancer. Yet scientists have struggled for decades to find the source of their ability to inhibit cancer cell growth.

The answer may lie in the compounds produced when the body breaks down, or metabolizes, aspirin, and flavonoids present in fruits and vegetables, according to associate professor Jayarama Gunaje of SDSU's Department of Pharmaceutical Sciences. He proposes "the metabolite hypothesis" in the May issue of Molecules, an international peer-reviewed journal.

Only 40 to 50% of aspirin and less than 15% of flavonoids are absorbed in the bloodstream, Gunaje explained. Therefore, substantial amounts of aspirin and flavonoids reach the intestines, where host and bacterial enzymes degrade the compounds. This process results in simpler phenolic acids, specifically hydroxybenzoic acids, or HBAs, that may contribute to colorectal cancer prevention.

"Plants also have the capacity to make these metabolites. Fruits and vegetables are loaded with free HBAs, which act as antioxidants and also help the plants fight infections," Consumption of fruits and vegetables in the diet is another source HBAs, Gunaje pointed out.

Identifying the metabolites and the gut bacteria responsible for degradation of aspirin and flavonoids will help scientists develop probiotics and possibly supplements to help prevent colorectal cancer.