Gallic acid, an antioxidant found in berries, wine and tea can increase your risk of getting colon cancer

Antioxidants are considered to be the one-stop solution to most health issues. They can fight free radicals and prevent oxidative stress which delays ageing, reduces the risk of chronic diseases and even helps the body fight cancer.

However, new research conducted at the Lautenberg Center for Immunology and Cancer Research, Hebrew University of Jerusalem (HUJI) suggests that all is not so perfect in the world of antioxidants.

In particular, gallic acid, an antioxidant present in foods like tea and wine and produced by the gut microbiota, can push potentially cancerous proteins to cause tumours in the colon.

P53 and cancer

Every cell in our body has a gene called TP53 which produces a protein called p53. This protein regulates the cell cycle (the multiplication of body cells) and keeps them from turning into tumours. It is called the guardian of the genome since it prevents the replication of potentially harmful cells. So, any mutation in p53 can lead to cancer.

Cases of colon cancer

The study was reportedly done to find why about 98% of all cancers in the intestines start in the colon and only 2% in the small intestine.

To find an answer to the question, a research team led by Dr Eliran Kadosh, a researcher at HUJI, introduced a mutated version of p53 into mice that had intestinal cancer due to deletion of p53 gene.

Interestingly, it was found that p53 mutations don’t act the same in all parts of the intestines and the gut microbiome may have a role to play in this.

In the colon, a mutated p53 had the expected cancer-promoting effect, however, in the small intestine, it did not cause cancer despite the mutation. The mutated p53 still had a tumour-suppressor effect in the small intestine and they reduced the abnormal cells in this area of the intestine.

Gut microbiome and gallic acid

It was the gut microbiome that was responsible for abolishing the tumour suppressive effects of p53 in the colon.

However, the study indicated that it wasn’t the whole microbiome but only one of their metabolites - gallic acid - that was responsible for the cancer-supporting effect of mutated p53.

Even if the mutated p53 was introduced into mice that had no gut microbiota and were supplemented with an antioxidant-rich diet, the protein supported tumour growth.

“The gut bacteria had a Jekyll and Hyde effect on the mutated p53 proteins. In the small bowel they switched course and attacked the cancerous cells, whereas in the colon they promoted the cancerous growth," said, Dr Yinon Ben-Neriah, a professor at HUJI and the corresponding author of the study, in a news release.

The authors of the study also suggested that this finding may be quite important for those who have a family history of colorectal cancer. The p53 mutation is one of the most common driving factors for colorectal cancer and is considered to be a possible risk factor for the genetic susceptibility of a person to colon cancer.

For more information on antioxidants, read our article on Antioxidant food, sources, benefits and side effects .

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