Iron in red meat may raise risk of bowel cancer: Study

Scientists from Cancer Research UK Institute in Glasgow found that iron may switch on the bowel cancer process via a faulty gene in the gut which would normally resist the disease, the Daily Mail reported.

Red meat contains large amounts of iron and is known to increase the likelihood of bowel cancer. The study found that when a gene called APC doesn't work, it allows a build up of iron in the cells lining the gut. The discovery could lead to new treatments that can 'mop up' iron in the bowel in people who develop cells affected by the defective gene.

In studies of mice, researchers found that susceptibility to bowel cancer was strongly influenced both by iron and a gene called APC. When the APC gene was faulty, mice with a high iron intake were two to three times more likely to develop the disease.

Mice fed a low iron diet remained cancer free even if the gene was defective, but when it functioned normally, high iron levels did no harm.

"We've made a huge step in understanding how bowel cancer develops. The APC gene is faulty in around eight out of 10 bowel cancers but until now we haven't known how this causes the disease," lead scientist Professor Owen Sansom, deputy director of the institute said.

"It's clear that iron is playing a critical role in controlling the development of bowel cancer in people with a faulty APC gene," Sansom said. "And, intriguingly, our study shows that even very high levels of iron in the diet don't cause cancer by itself, but rely on the APC gene," Sansom was quoted as saying by the paper.

The study proposed another mechanism that, if confirmed in people, might help explain why people's risk of bowel cancer increases with age. Over time, cells in the bowel would be increasingly likely to develop APC gene faults and thus react to iron in the diet.

Researchers say that when the APC gene doesn't work, iron is allowed to build up in the cells lining the gut. This activates a genetic cancer 'switch' that causes cells to multiply out of control. But consumption of iron also aids the growth of cells with defective APC over time.

The study was published in the journal Cell.