New Scientific Definition of Fiber
Before you go through the article you should understand what is resistant starch. Here is the definition – Resistant starch (RS) is a fraction of starch that resists digestion within the small intestine, reaching the large intestine intact. RS is then fermented by microbes in the large intestine, producing short-chain fatty acids (SCFAs). The term ‘resistant starch’ was coined by Englyst and colleagues in the 1980s.
Technically speaking, what can be defined as dietary fiber is decided by Association of Official Analytical Chemists (AOAC). They have created a method which can extract fiber from carbohydrates. The material which is extracted using the method defined by AOAC is called dietary fiber.
Till some time back dietary fiber was which were extracted using the AOAC methods included non-starch polysaccharides (NSP), lignin, some inulin and some resistant starches and non-digestible oligosaccharides, but not all of them considered as dietary fiber.
The current AOAC method which has been published since 2009 measures all carbohydrates that with the following attributed –
- Can’t be digested in the small intestines
- Can’t be absorbed in the small intestine and
- Have a degree of polymerisation of three monomeric units or more. Examples are – non-digestible oligosaccharides, all resistant starches and polydextrose, plus lignin
Article on Resistant Starch (Time Magazine)
Not all carbs are created equal—and thank goodness for that. New research suggests that a certain kind of carbohydrate called resistant starch may improve health by keeping you full, checking blood sugar and supporting the gut.
Resistant starch, a special type of fiber found in potatoes, bananas, chickpeas, grains and other foods, is the focus of a new study in the journal Nutrition Bulletin. Researchers from the British Nutrition Foundation and University College Dublin, in Ireland, analyzed everything published research has shown about the health benefits of resistant starch, and found more than a few reasons to fill up.
Eating resistant starch may support gut health and increase feeling of fullness, according to the studies reviewed. There’s also some evidence that eating resistant starch can counteract the negative health effects of eating a lot of red meat on colorectal cancer risk, though the study authors say more research is needed to understand these potential health claims.
The reason resistant starch seems to be so uniquely healthy is likely because of the way it’s digested. The starch bypasses the small intestine, the site of digestion for most food, and is instead metabolized in the colon. It’s then fermented and becomes short-chain fatty acids that provide energy. Short-chain fatty acids, which can act as gut-healthy prebiotics, have been linked to a lower risk of inflammation-related diseases like diabetes and heart disease.
In one small study of 10 people reviewed in the new report, healthy adults ate crackers containing about 30 grams of a type of resistant starch for about three weeks, and a couple weeks later they ate crackers without the starch. The study authors found that even during the short study period, eating crackers with resistant starch increased healthy gut bacteria and lowered the levels of less healthy types.
” Resistant starch appears to aid blood glucose control and may confer other health benefits,” says study author Stacey Lockyer, a n utrition scientist at the British Nutrition Foundation. ” This is an exciting area for future research. Overall, regular consumption of a variety of fiber-rich foods is important.”
The new findings don’t offer an excuse to overload on carbohydrates like white bread and pasta, though they also contain some resistant starch. ” Wholegrain varieties of foods tend to contain higher amounts of resistant starch—and other fiber types—than ‘white’ versions of these foods,” says Lockyer. “We know that adequate intake of dietary fiber overall is important for achieving a healthy, balanced diet and reduces the risk of developing a range of chronic diseases including colon cancer, type 2 diabetes and heart disease.”
There has been increasing research interest in resistant starch, with a large number of human studies published over the last 10 years looking at a variety of different health outcomes such as postprandial glycaemia, satiety, and gut health. The review summarises reported effects and explores the potential mechanisms of action that underpin them. For example, there is consistent evidence that consumption of resistant starch can aid blood sugar control. It has also been suggested that resistant starch can support gut health and enhance satiety via increased production of short chain fatty acids.
“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 fibre 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 Dr. Stacey Lockyer, co-author of the Nutrition Bulletin review.
“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.”
Source – http://time.com/4623598/resistant-starch-carbohydrates/