A mineral common in everyday foods may have cancer-fighting potential when it comes to esophageal cancer, according to a new study.
Acid reflux is one of the most common conditions, experienced by more than 60 million Americans every month. It occurs when food, drink, or stomach acid leaks back into the esophagus, causing heartburns and other unpleasantries. However, a far more serious consequence of acid reflux is esophageal cancer. This cancer makes up about 1 percent of all cancers diagnosed in the United States. But despite the low prevalence, the cancer has a high mortality rate because the disease goes unnoticed until the late stages. And this happens more often than it should, as the cancer is difficult to spot and so goes undiagnosed until too late.
Researchers have previously noted that patients with esophageal cancer are more prone to a zinc deficiency, suggesting a link between the disease and the mineral. However, there have been no studies to further explain this relationship.
To provide some answer to this question, researchers from the University of Texas at Arlington and colleagues started with basic cell biology. In particular, they exposed human esophageal cancer cells to zinc and compared the responses to that of healthy human cells.
In the esophageal cancer cells, the team found the zinc mineral blocked a calcium channel known as Orai1. This calcium channel was previously found to be highly expressed in esophageal tumor tissues. So with these calcium signals suppressed by zinc, cancer cell proliferation seemed to also stop.
When they treated health cells to zinc, they did not observe similar effect, which suggest that the zinc mineral acts selectively against calcium channels specific to tumor cells.
"Previously we didn't know why the same physiological concentrations of zinc inhibit cancer cell growth but not normal cells," said Dr. Zui Pan, the study’s senior author. “Our study, for the first time to our knowledge, reveals that zinc impedes overactive calcium signals in cancer cells, which is absent in normal cells, and thus zinc selectively inhibits cancer cell growth. It now appears that zinc and calcium can have a cross talk, meaning that they can be linked."
Based on their results, the team thinks zinc could have promise in the prevention and treatment of esophageal cancer. However, further research is required before we can conclusively say if zinc supplementation will have an effect on esophageal cancer outcome in people.
Nevertheless, getting in your daily recommended amount of zinc is a good idea. According to the National Institute of Health, men should get around 11 milligrams of zinc per day, and women should get around 8 milligrams of zinc per day. Among others, zinc-rich foods include spinach, beef, beans, and oysters.
Additional sources: MNT
