How to Prevent Cancer: Zinc Could Stop Esophageal Tumor Cells From Growing

Could zinc stop cancer in its tracks? It's possible, according to new research done by biologists at the University of Texas at Arlington.

Zui Pan and her team study how esophageal cancer cells grow. She and many other scientists have noticed that zinc seems to slow down cancer cell growth, but no one understood why or how that happened. "There's a lot of evidence to show that zinc deficiency is associated with esophageal cancer incidence, both with patient data and a lot of animal studies," Pan tells Newsweek.

The findings of her latest paper, published September 19 in The FASEB Journal, solve the mystery behind zinc's anti-cancer activity. The researchers tested four kinds of cell lines, including three that were derived from patients with the type of esophageal cancer associated with smoking and drinking alcohol. (Other esophageal cancers are linked with acid reflux disease or other conditions.)

The cancer cells used in the experiment had a high quantity of a calcium channel called Ora1. This channel allows calcium to come into the cells, which then grow and divide. Cancer cells have more of these channels than normal cells, and the higher amounts of calcium allowed in could encourage cells to grow out of control and cause cancer.

Zinc put into the environment around the cells bound to a few specific points in the calcium channel and blocked it from allowing calcium in, preventing the cells from growing and dividing. And the zinc was definitely responsible for this effect. When researchers prevented the element from binding to the channel, calcium was able to come into the cells again.

The findings confirm Pan's initial hunch about why zinc prevents cancer growth. "We suspected there must be some difference between the normal cell and the cancer cell," she says. The calcium channel had also been implicated in earlier work.

The growing evidence leads Pan and her team to wonder if zinc could stop tumor growth in humans. The current findings are preliminary—the work was done on cell lines, not human or animal tumors—so more research is needed to determine if zinc could work as an anti-cancer intervention.

But is it wise to pick up some zinc supplements? That's an ongoing debate, Pan says. "Some say that zinc deficiency rarely happens in normal people, only in certain severe diseases," she says. But mild zinc deficiency may be more common than people think, she adds.

Though Pan emphasizes that she's not a physician, she says that ensuring a well-balanced diet is never a bad idea. According to the National Institutes of Health, the recommended amount of zinc adults should get from food each day can range from 8 to 12 milligrams. Foods that are high in zinc include oysters, beef and crab. For vegetarians, some beans and nuts may be good sources of zinc.

Pan plans to do more research to determine what else might contribute to esophageal cancer growth and if zinc's ability to block this particular channel might inspire new chemotherapy drugs.