LONDON — Peas aren’t typically atop the average person’s list of favorite vegetables, but there’s good reason to give them consideration. Scientists say a type of wrinkled peas could be added to the list of “superfoods” that reduce the risk of diabetes.
The research suggests that incorporating these naturally occurring wrinkled peas into food, in the form of whole pea seeds or flour, may help tackle the global Type 2 diabetes epidemic. This so-called “super pea” may help control blood sugar levels, thus reducing the risk of developing the condition.
Unlike regular smooth peas, the wrinkled version contains higher amounts of “resistant starch,” which takes longer for the body to break down. The study reveals that these peas can prevent “sugar spikes,” in which blood sugar levels rise sharply after a meal. The same effect was seen when consuming flour made from wrinkled peas incorporated in a mixed meal.
Researchers say that could be important as frequent, large sugar spikes are thought to increase the risk of diabetes.
They added that flour from their “super peas” could potentially be used in commonly consumed processed foods which, if eaten over the long term, could prevent these sugar spikes.
“Despite national campaigns to promote healthy eating, type 2 diabetes diagnosis rates continue to rise,” says first author Dr. Katerina Petropoulou, of Imperial College London, in a university release. “An alternative dietary strategy to maintain normal blood glucose rates among the population is to improve the composition of commonly consumed foods. There is much evidence that diets rich in a type of carbohydrate called resistant starch have a positive impact on controlling blood glucose levels, and hence reduce susceptibility to type 2 diabetes.”
Where are the wrinkled ‘super peas’ found?
The peas used in the research are similar to frozen peas sold in the supermarket. They are also the same as those used by the scientist Gregor Mendel in the 1800s, to show how dominant and recessive genetic traits can be passed on through selective breeding.
For the latest experiments, researchers used larger, mature versions of those typically found in the freezer aisle. That’s because larger, mature peas contain more so-called “resistant starch.” The high amount of resistant starch is due to the way the starch is made in the cell, and the fact that the cells themselves are more resistant to digestion.
Starch is a compound that the body breaks down to release sugar. Resistant starch, however, is broken down more slowly, so that sugar is released more slowly into the bloodstream, resulting in a more stable increase rather than in a spike.
For the study, the researchers used a type of wrinkled pea with a naturally occurring genetic mutation, or variant, that produces a greater amount of resistant starch, but a lower overall carb content. “These starches are not completely digested in the upper parts of the digestive tract and are available for fermentation by bacteria in the colon,” says study lead author Gary Frost, head of Imperial’s Centre for Translational and Nutrition Food Research.
Over a series of experiments, the team gave healthy volunteers a mixed meal including 50 grams of wrinkled peas. In a series of control experiments, participants consumed regular “smooth” peas. Working with the University of Glasgow, researchers also added a tracer molecule to the peas, so that they could trace how they were absorbed and digested by the human gastrointestinal tract. They repeated the experiments using flour made from wrinkled peas or control peas.
To further investigate the impact of long-term consumption they recruited 25 volunteers and asked them to consume pea hummus and mushy peas (made from wrinkled or control peas) for a period of four weeks.
Discovery opens up ‘new possibilities for making healthier foods’
Previous research from the same group suggests that, as these bacteria ferment the starch, they produce compounds called short chain fatty acids. The compounds in turn help boost the function of cells that produce insulin, which helps control blood sugar.
Further tests using a mimic of the human gut, carried out by researchers at Quadram Institute Bioscience, show that the way that the peas were prepared and cooked affect how quickly they’re digested. Researchers also say that there are significant benefits to our gut microbiota because of the fermentation process taking place there.
“This study has shown us that by preparing these peas in certain ways we can further reduce blood sugar spikes, opening up new possibilities for making healthier foods using controlled food processing techniques,” explains professor Pete Wilde, of the Quadram Institute.
The researchers are now planning further trials involving volunteers with early stage type 2 diabetes. It will also involve a major pea breeding program with help from industry partners to develop more “super peas” with the resistant starch. Other research is focusing on breeding the mutation into staple crops, such as rice and wheat.
“This research has emphasized the value of developing the pea lines used in this study, which could be compared meaningfully and involved many years of breeding,” says professor Claire Domoney of the John Innes Centre. “Longer term it could become policy to include resistant starch in food. We have precedents for this kind of intervention, such as iron being added to bread to tackle anemia. It could potentially be policy that food should contain a certain amount of resistant starch to tackle type 2 diabetes and other metabolic illnesses.”
The study is published in the journal Nature Food.
SWNS reporter Stephen Beech contributed to this report.