Fiber Present in Banana May Help Reduce Risk of Some Hereditary Cancers

Resistant starch is a type of carbohydrate that doesn’t get digested in the small intestine. Instead, it ferments in your large intestine and feeds beneficial gut bacteria. This type of starch provides numerous health benefits and has fewer calories than regular starch, having only 2 calories per gram, while regular starches contain 4 per gram. 

There are 4 types of resistant starches:

  • Type 1: present in milled seeds and grains. 
  • Type 2: present in starchy foods like raw bananas and potatoes. 
  • Type 3: present in foods that have been cooked and cooled, like bread and cornflakes. 
  • Type 4: man-made and is usually found in bread and cakes.

In a recently published study, researchers from Newcastle University and the University of Leeds in the United Kingdom found that using a resistant starch powder supplement may help prevent cancer in people with Lynch syndrome. Their results appear in the journal Cancer Prevention Research. 

60% Reduction in Non-Colorectal Cancers

Lynch syndrome is a disease caused by a germline pathogenic variant in one of the DNA mismatch repair (MMR) genes that increase the risk of many types of cancer, particularly colorectal cancer, but also endometrial, ovarian, gastric, small intestine, pancreas, brain and skin cancers. 

The trial analyzed the long-term effects of aspirin and resistant starch on cancer onset in patients with Lynch syndrome. Earlier research during the trial found that aspirin reduced colorectal cancer by 50%.

The trial included a total of 463 participants. They took 30 g of resistant starch for up to 4 years, and 455 took a placebo. 

The dose used by the team is the equivalent of eating one slightly unripe banana daily. They found no difference in the number of colorectal cancer cases. However, non-colorectal cancers were a different case. Those taking the supplement had fewer cases of non-colorectal cancers. 

A reduction of 60% in the risk of non-colorectal cancer in Lynch syndrome patients was observed during the study. 


John C. Mathers, et al. Cancer Prevention with Resistant Starch in Lynch Syndrome Patients in the CAPP2-Randomized Placebo Controlled Trial: Planned 10-Year Follow-up. 2022. Cancer Prev Res. 

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