COLUMBUS, Ohio – 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.
The plants vary both in the amount of anthocyanins they contain and in which particular anthocyanins they contain. The anthocyanins vary in their anti-cancer properties. Since they mostly do not get absorbed they seem like a fairly safe way to cut down on colon cancer risk.
If yellow corn is less potent than blue corn then do we need to get back to multi-colored corn?
The researchers determined the amount of extract needed from each plant to cut the growth of human colon cancer cells in half. Altering pigment structures slightly by adding an extra sugar or acid molecule changed the biological activity of these extracts.
The researchers added different extracts to flasks that contained colon cancer cells. They used an analytical technique called high-performance liquid chromatography – mass spectrometry in order to determine the exact chemical structure of each compound. They used biological tests to determine the number of cancer cells left after anthocyanin treatment.
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.
In additional laboratory studies, she and her colleagues found that anthocyanin pigments from radish and black carrots slowed the growth of cancer cells anywhere from 50 to 80 percent. But pigments from purple corn and chokeberries not only completely stopped the growth of cancer cells, but also killed roughly 20 percent of the cancer cells while having little effect on healthy cells.
Note that they are not using whole corn or whole berries. So an ounce of blue corn won't necessarily have more potent anti-colon cancer activity than an ounce of radishes. We need to know what the concentration of the most active anthocyanin compounds are in each of these foods in order to say which will deliver the most benefit. Still, blue corn muffins or pancakes with berries for breakfast might reduce your odds of dying from colon cancer.
If you know someone recently diagnosed with colon cancer note that dietary changes can make a big difference on outcomes. Also see my post Western Diet Boosts Colon Cancer Recurrence.
In the long run genetic engineering of plants to boost their levels of the most potent anti-cancer anthocyanins seems like the ticket.
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