A recent study on rats has for the first time confirmed that flavonoids such as those found in cocoa can potentially have a protective effect against colon cancer. Headed by scientists from the Institute of Food Science and Technology and Nutrition (ICTAN), the study was recently published in Molecular Nutrition & Food Research.
For eight weeks, scientists fed the rats with a cocoa-rich (12%) diet and carcinogenesis was induced. Rats fed a cocoa-rich diet had a significantly reduced number of aberrant crypts in the colon caused by the cancer. (It's not clear whether the study included a control group of cocoa-free rats.)
These same rats also saw an improvement in their bodies' antioxidant defenses and an increase in programmed cell death, a mechanism that prevents the development of the carcinogenesis.
The researchers concluded that the protective effect of cocoa can block pathways involved in cell proliferation and, as a result, inhibit tumor formation.
More research is required to determine which bioactive compounds in cocoa are responsible for these effects, but they know it's rich in phenolic compounds, mainly flavonoids like procyanidins, catechins and epicatechins, which are believed to help prevent cardiovascular diseases and colorectal cancer.