Beet pigments may help prevent cancer

Nothing conveys the hue of extreme anger or embarrassment like the red of beets. Now, a new finding suggests beet red may signify something else: cancer protection.

A team of researchers led by UW–Madison food scientist Kirk Parkin has shown that beet pigments may boost levels of proteins, called phase II enzymes, that help detoxify potential cancer-causing substances and purge them from the body.

A patent application covering Parkin’s discovery has been filed by the Wisconsin Alumni Research Foundation.

In a study published in the Nov. 6 issue of the Journal of Agricultural and Food Chemistry, the team tested four color varieties of beets: white, orange, red and dark red. Only extracts from the red beets triggered higher levels of the protective enzymes.

“It turns out that the active fraction [of beet extract] is highly enriched in red beet pigments,” called betalains, says Parkin. “But the fraction contains multiple pigments, so if a specific pigment is responsible for the effect, we don’t know what it is yet.”

The group demonstrated the effect by using a well-established mouse liver cell assay that models human liver function. The National Institutes of Health endorses the assay as one of 12 principal techniques for screening possible new cancer preventive agents.

Preventive is the key word, Parkin emphasizes. “Elevating phase II enzyme levels is useful in preventing the initial stages of carcinogenesis, but not in treating the effects of cancer that has been allowed to progress.” Parkin’s next needs to show that beet pigments can be absorbed by the body in sufficient amounts to protect against cancer. He points out that roughly 15 percent of people naturally absorb large amounts of betalains — a harmless condition that announces itself with dark-red urine.

Alarming as beet-red urine may sound, it’s a promising phenomenon. “It means that when beet pigments are absorbed, they aren’t transformed metabolically by the body,” Parkin says. “So the [phase II enzyme-inducing] agent we’ve tested in the assay is going to be the same one present in the body.”