Israeli researchers correlate antioxidant rich foods with colon cancer

What drove the researchers to their focus, was the peculiar fact that only 2% of cancers take root in the small intestines, while 98% of cancers running along the digestive path occur in the colon.

Antioxidant smoothie (photo credit: VERA BELLO)
Antioxidant smoothie
(photo credit: VERA BELLO)
Researchers at the Hebrew University of Jerusalem found that the production of high levels of metabolites in the gut microbiome – which can be correlated with the consumption of certain bacteria found in antioxidant rich foods such as black tea and hot cocoa – can be linked to the development of certain types cancer, the university announced on Wednesday.
While the Hebrew University notes that cancer mutations are "not necessarily bad actors, in and of themselves," they explain that these types of diets create gut floras that act as hospitable environments for mutated genes and more specifically the development of colorectal (colon) cancer.
What drove the researchers to their focus - correlating gut microbiomes to cancerous mutations – was the peculiar fact that only 2% of cancers take root in the small intestines, while 98% of cancers running along the digestive path occur in the colon.
More notably affirming their journey down the rabbit hole, the researchers explained that while small intestines hold a low level of gut bacteria, the colon holds a significantly higher level of said bacteria - the major difference between the two organs.
“Scientists are beginning to pay more and more attention to the role gut microbiomes play in our health: both their positive effects and, in this case, their sometimes pernicious role in aiding and abetting disease,” explained Prof. Yinon Ben-Neriah at Hebrew University’s Lautenberg Center for Immunology and Cancer Research, who led the research team.
To test their assumptions on gut flora's role, the research team introduced mutated p53 proteins – formulated as "cancer-driving" proteins – into the guts of field mice.
P53 proteins, found in every cell, works as a barrier for the cell while suppressing genetic mutations. When the p53 protein is damaged, however, it no longer works as a backstop protecting the cell – in turn driving cancer development.
What they found is that along the protein's path down the digestive track, when reaching the small intestines the organ will turn the mutated proteins back into stronger normal proteins which effectively turn them into "super-suppressors," more efficacious in protecting the cell than the original.
In contrast, when this same mutated protein is introduced into the colon it maintains its cancerous structure, promoting the spread and growth of mutated genes.
“We were riveted by what we saw,” said Ben-Neriah. “The gut bacteria had a Jekyll and Hyde effect on the mutated p53 proteins. In the small bowel they totally switched course and attacked the cancerous cells, whereas in the colon they promoted the cancerous growth.” 
To further their theorized notion, the researchers administered antibiotics to kill of gut flora in the colon before introducing the cancerous p53 protein into the gut. What they found is that without the presence of the flora, the mutated p53 was unable "to go on its cancer spree."
“Scientifically speaking, this is new territory. We were astonished to see the extent to which microbiomes affect cancer mutations – in some cases, entirely changing their nature,” concluded Ben-Neriah. "Looking towards the future, those at high-risk of colorectal cancer may want to screen their gut-flora more frequently and think twice about the foods they digest, antioxidant and otherwise."
Colorectal cancer is the second leading cause of cancer death in the US, with an estimated 51,000 Americans dying from it each year, according to the Centers for Disease Control and Prevention.
Established risk factors for the disease include a personal or family history of colorectal cancer, irritable bowel disease, certain syndromes that cause colon polyps, type 2 diabetes, obesity, heavy drinking, smoking and being over the age of 50, according to the American Cancer Society.
Symptoms of advanced colon cancer typically include diarrhea or looser stools, unintentional rapid weight loss, abdominal pain, anemia and rectal bleeding.
To screen for colorectal cancer, experts advise that anyone over 50 should receive an annual test to detect blood in the stool and a colonoscopy every 10 years. Those with family histories of colon cancer should be tested more frequently and at a younger age.

Reuters contributed to this report.