Compounds that color fruits and veggies may protect against colon cancer

Understanding the molecular structures of compounds that give certain fruits and vegetables their rich colors may help researchers find even more powerful cancer fighters, a new study suggests.

Evidence from laboratory experiments on rats and on human colon cancer cells also suggests that anthocyanins, the compounds that give color to most red, purple and blue fruits and vegetables appreciably slow the growth of colon cancer cells. The findings also bring scientists a step closer to figuring out what exactly gives fruits and vegetables their cancer-fighting properties.

“These foods contain many compounds, and we’re just starting to figure out what they are and which ones provide the best health benefits”, said Monica Giusti, the lead author of the study and an assistant professor of food science at Ohio State University.

Giusti presented the findings, which represent the collaborative efforts of Giusti and her colleagues, on August 19 at the national meeting of the American Chemical Society in Boston.

Giusti and her colleagues found that in some cases, slight alterations to the structure of anthocyanin molecules made these compounds more potent anti-cancer agents.

In their studies on human colon cancer cells grown in laboratory dishes, the researchers tested the anti-cancer effects of anthocyanin-rich extracts from a variety of fruits and vegetables. They retrieved these anthocyanins from some relatively exotic fruits and other plants, including grapes, radishes, purple corn, chokeberries, bilberries, purple carrots and elderberries…

…The researchers found that the amount of anthocyanin extract needed to reduce cancer cell growth by 50 percent varied among the plants. Extract derived from purple corn was the most potent, in that it took the least amount of this extract (14 micrograms per milliliter of cell growth solution) to cut cell numbers in half. Chokeberry and bilberry extracts were nearly as potent as purple corn. Radish extract proved the least potent, as it took nine times as much (131 μg/ml) of this compound to cut cell growth by 50 percent.

“All fruits and vegetables that are rich in anthocyanins have compounds that can slow down the growth of colon cancer cells, whether in experiments in laboratory dishes or inside the body,” Giusti said.

Press release from Eurekalert Website

TAKE HOME MESSAGE

We know from previously published medical literature that beans are rich in anthocyanins. However, processing of beans and other legumes may lead to degradation of anthocyanins. We need to conduct studies to assess the effects of canning, freezing, and other processing techniques on anthocyanin composition and antioxidant activity prior to communicating health benefits associated with anthocyanins in legume products.