Foods rich in resistant starch may benefit health

A new comprehensive review published in Nutrition Bulletin examines the potential health benefits of resistant starch, a form of starch that is not digested in the small intestine and is therefore considered a type of dietary fiber. Some forms of resistant starch occur naturally in foods such as bananas, potatoes, grains, and legumes, and some are produced or modified commercially and incorporated into food products.

There has been increasing research interest in resistant starch, with a large number of human studies published over the past 10 years looking at a variety of different health outcomes such as postprandial glycaemia, satiety, and gut health. In this review, the authors described human evidence on the health effects of resistant starch consumption, with the aim of identifying any benefits of resistant starch-rich foods and resistant starch as a functional ingredient. The reduced glycemic response consistently reported with resistant starch consumption, when compared with digestible carbohydrate, has resulted in an approved European Union health claim. Thus, the authors concluded that resistant starch-rich foods may be particularly useful for managing diabetes.

There appears to be little impact of resistant starch on other metabolic markers, such as blood pressure and plasma lipids, though data are comparatively limited. Promising results on markers of gut health suggest that further research may lead to the classification of resistant starch as a prebiotic. Microbial fermentation of resistant starch in the large intestine to produce short-chain fatty acids likely underpins some of its biological effects, including increasing satiety. However, effects on appetite have not resulted in notable changes in bodyweight after long-term consumption. Emerging research suggests potential for resistant starch as an ingredient in oral rehydration solutions and in the treatment of chronic kidney disease.

“We know that adequate fiber intake—at least 30 g per day—is important for achieving a healthy, balanced diet, which reduces the risk of developing a range of chronic diseases. Resistant starch is a type of dietary fiber that increases the production of short chain fatty acids in the gut, and there have been numerous human studies reporting its impact on different health outcomes,” said co-author Stacey Lockyer, British Nutrition Foundation. “Whilst findings support positive effects on some markers, further research is needed in most areas to establish whether consuming resistant starch can confer significant benefits that are relevant to the general population; however, this is definitely an exciting area of nutritional research for the future.”

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