European researchers have found that adding resistant starch to the diets of those who are genetically predisposed to certain types of cancer can cut the risk of their occurrence in half.
The new study showed that the impact was significant in cancers of the upper gastrointestinal tract such as esophageal, gastric, biliary tract, pancreatic and duodenal cancer. Resistant starch is found naturally in peas, beans, and oatmeal. As part of the study, half of the participants received a daily dose of 30 g of resistant starch, while the other half received a powdered placebo for two to four years. Although there was no difference in the incidence of bowel cancer in the two groups, fewer people developed other 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 intestinal cancer, among others. They were followed up for 10 years, supplemented by data from a further 10 years from the UK and Finnish cancer registry.
“Resistant starch is a type of carbohydrate that is not digested in the small intestine. Instead, it ferments in the large intestine, feeding beneficial gut bacteria. In effect, it acts like dietary fiber in your digestive system. We believe 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 investigation,” John Mathers, lead author of the study and Professor of Human Nutrition at Newcastle University, said in a statement.
The researchers also studied the impact of aspirin on 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 Professor Sir John Burn, professor of clinical genetics at Newcastle University. The team is now enrolling 1,800 people with Lynch syndrome to see if smaller, safer doses of aspirin can be used to help reduce cancer risk.
Oncologists and researchers have now begun to regard diet as an essential component of cancer prevention and treatment. “We now know that diet is a very important factor in the prevention and treatment of cancer. Certain diets can make cancers more responsive to treatment already being given, especially in cases where immunotherapy is used. Diets can also help the immune mechanism to fight cancer cells more effectively,” said Dr. PK Julka, former professor of radiation therapy at the All India Institute of Medical Sciences-New Delhi and current chairman of the Max Oncology Daycare Centre.
He added: “Although as far as the results of the current study are concerned, they 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 which can result in starch deficiencies.”
Renowned Indian-American oncologist-researcher Dr. Siddhartha Mukherjee had also hinted at the importance of diet during an Exchange of Ideas in The Indian Express, saying, “There are five pillars in (cancer) treatment. The four standard pillars were radiation, surgery, chemotherapy, and immunotherapy. The fifth pillar is nutritional or dietary therapy”.
One company, Faeth Therapeutics, of which Dr. Mukherjee is a part, works with diet modulation to reprogram metabolism and slow cancer growth. In a preclinical modeling study, the company showed that an insulin-suppressing diet along with medications was 500% more effective. He said that one of his areas of research was combining diets with drugs for cancer treatment. “This is not voodoo nutritional science. These are based on extremely rigorous scientific experiments in which we have shown that particular diets that lack certain substances, or have the addition of other substances, are synergistic with drugs. With targeted therapies, they make them much more effective.”