European researchers have found that adding resistant starch in the diets of those who are genetically predisposed to certain cancers can halve their risk of occurrence.
The novel study showed that the impact was significant on cancers of the upper gastro-intestinal tract like oesophageal, gastric, biliary tract, pancreatic and duodenum cancers. Resistant starch is found naturally in peas, beans and oats. As part of the study, half the participants received a daily dose of 30 g of resistant starch while the other half had a placebo powder for two to four years. Although there was no difference in the incidence of bowel cancer in both the groups, fewer people developed several other types of cancers in the intervention group. The study involved nearly 1,000 people with a genetic condition called Lynch Syndrome – an inherited cancer syndrome that increases the risk of developing colorectal, endometrial and bowel cancers among others. They were followed for ten years, supplemented with data for another 10 years from the UK and Finnish cancer registry.
“Resistant starch is a type of carbohydrate that isn’t digested in your small intestine. Instead, it ferments in your large intestine, feeding beneficial gut bacteria. In effect, it acts like dietary fibre in your digestive system. We think that resistant starch may reduce cancer development by changing the bacterial metabolism of bile acids and reducing those types of bile acids that can damage our DNA and eventually cause cancer. However, this needs further research,” said John Mathers, lead author of the study and professor of Human Nutrition at Newcastle University, in a release.
The researchers also studied the impact of aspirin in these patients. “Based on our trial, NICE (National Institute for Health and Care Excellence) recommends aspirin for people at high genetic risk of cancer. The benefits are clear – aspirin and resistant starch work,” said Prof Sir John Burn, professor of clinical genetics at Newcastle University. The team is now enrolling 1,800 people with Lynch syndrome to look at whether smaller, safer doses of aspirin can be used to help reduce the cancer risk.
Oncologists and researchers have now started looking at diet as an essential component of prevention as well as treatment of cancers. “We now know that diet is a very important factor in preventing and treating cancers. Certain diets can make the cancers more receptive to the treatment already being given, especially in cases where immunotherapy is used. Diets can also help the immune mechanism tackle cancer cells more effectively,” said Dr PK Julka, former professor of radiotherapy at the All India Institute of Medical Sciences-New Delhi and the current Chairman for Max Oncology Daycare Centre.
He added, “Although when it comes to the results of the current study, it cannot be extrapolated to the general population. This is because people who have Lynch Syndrome are also prone to developing conditions such as ulcerative colitis that may result in deficiencies of starch.”
Renowned Indian-American oncologist-researcher, Dr Siddhartha Mukherjee, had also hinted at the importance of diet during an Idea Exchange at The Indian Express, saying, “There are five pillars of (cancer) treatment. The four standard pillars were radiation, surgery, chemotherapy and immunotherapy. The fifth pillar is nutritional or dietary therapy.”
A company, Faeth Therapeutics, of which Dr Mukherjee is a part, works with modulating diet to re-programme metabolism and slow down cancer growth. In a pre-clinical modelling study, the company showed that an insulin-suppressing diet along with medicines were 500 per cent more effective. He said one of his research areas was combining diets with drugs for the treatment of cancer. “This is not voodoo nutritional science. These are based on extremely rigorous scientific experiments in which we’ve shown that particular diets which lack certain substances, or have the addition of other substances, are synergistic with drugs. With targeted therapies, they make them much more effective.”