Dietary supplement reduces risk of hereditary cancer by 60%, according to scientists

Resistant starch is a type of starch [ref. 1] that passes through the small intestine and then ferments into the large intestine, where it feeds the beneficial intestinal bacteria called "probiotics". It can be bought as a fiber-like supplement and is naturally contained in a number of foods, including unripe bananas, oatmeal, boiled and chilled pasta, and rice, peas and beans.

This starch works as a type of soluble fiber and promotes the sensitivity to insulin of cells, helping to control blood sugar and control appetite.

Besides all this, it turns out that resistant starch may have benefits associated with reducing the risk of inherited cancer. Dr John Mathers' team from Newcastle University in the UK came to this conclusion. 

The CAPP2 study examined the long-term effects of aspirin and resistant starch on cancer incidence in patients with Lynch syndrome. People who inherited the genes of Lynch syndrome have a significantly increased risk of developing colorectal cancer, as well as cancer of the stomach, endometrium, ovaries, pancreas, prostate, urinary tract, kidneys, bile ducts, small intestine, and brain.  [ref. 3] 

Participants were assigned to a randomized double-blind study in which there were two groups, one receiving 30 grams of persistent starch daily and the other receiving a placebo for up to 4 years. The scientists presented the long-term cancer development projections based on the planned 10-year follow-up from the start, complemented by data from the National Cancer Registry for up to 20 years in England, Wales, and Finland. Overall, 463 participants received persistent starch and 455 participants received a placebo, or a total of 918 people.

"We found that resistant starch reduced the risk of developing a number of cancers by over 60 percent.

The results are encouraging, and the degree of protective effect in the upper gastrointestinal tract is unexpected even for the scientists themselves. They are doing further research to establish their credibility. Cancer of the upper gastrointestinal tract includes cancer of the esophagus, stomach, and pancreas.

During the follow-up period, there were only 5 new cases of upper gastrointestinal cancer among the 463 people who took the resistant starch. This compares to 21 cases of upper digestive tract cancer among the 455 people in the placebo group – a pretty notable difference.

"These results are extremely important as upper gastrointestinal cancer is difficult to diagnose and often not caught in time," the lead researcher said.

However, there is one area in which persistent starch does not have the same positive effect, namely in the rate of bowel cancer.

Researchers say that it is likely that resistant starch can reduce the development of cancer by changing the bacterial metabolism of bile acids and reducing these types of bile acids, which can damage our DNA and ultimately cause cancer. However, further research is needed to make a firm statement in this regard.

One final clarification to note is that this study was conducted on people who are already genetically predisposed to cancer development and do not necessarily apply to the general public. The original study was named CAPP2, and now the team is conducting a follow-up called CaPP3 involving more than 1,800 people with Lynch syndrome.

The initial study also looked at whether taking aspirin on a daily basis could reduce the risk of cancer. As early as 2020, the team published results showing that aspirin reduces the risk of colorectal cancer in patients with Lynch syndrome by 50 percent.  [Ref. 4]