This two-year study found that some pea fractions provided better glycemic control than others. The key might lie in understanding the role of gut microbes in this process.

A growing body of scientific evidence is establishing the health benefits of pulse crops. As one example, consumption of peas has been associated with better glycemic control among people with Type 2 diabetes.

University of Alberta scientists Catherine Chan and Jocelyn Ozga have found that the coat of the pea seed – and not the inside of the pea, called the embryo – may be responsible for many of its health benefits.

In 2014, with funding from Alberta Pulse Growers and others, U of A colleague Ben Willing began a two-year project to take this insight further. He investigated how pea seed coats affect gut microbes and how this helps control blood sugars.

“When we consume a diet, such as something with peas, those peas can have a direct effect,” said Willing, “by their nutritive value, as well as by interacting with the intestine after they’re absorbed. But they can also have important effects on the population of microbes. If we can understand the mechanism of how peas provide a benefit, then we can make peas better and

Results vary by pea variety and processing

As Willing explains, this investigation included both laboratory experiments and experiments on mice. For the mice, a study group was fed a high-fat diet to achieve weight gain. These mice were then fed different pea fractions, coat included. The effect on weight, or rate of weight gain, was observed.

The pea formulations fed to the mice differed in two respects. First, they were higher or lower in polyphenolic compounds. Generally, peas that were higher in these compounds resulted in mice gaining weight more slowly. Second, some pea formulations were hydrolyzed, which also was associated with slower weight gain.

“One of the things we found that was really striking was, the high polyphenolic-containing peas had a very different effect on the microbial population than a similar pea that didn’t have those molecules,” said Willing. “You could tell what type of peas a mouse was consuming based on the microbial population. So it’s not just saying that peas have this effect, but that each type of peas has a distinct effect.”

If a person has diabetes or struggles with weight control, including peas in their diet can help. As Ben Willing has shown, hydrolyzed fractions of higher-polyphenolic peas could accelerate this effect, providing better glycemic control and slower weight gain within an otherwise high-fat diet. This knowledge could one day lead to new pea varieties being developed with this application in mind.

“We’re not there yet, so we’re continuing to work on this,” said Willing, “but that’s the ultimate goal: to be able to create cultivars of peas that will maximize health outcomes.” 

Project at a glance

Project title:                Microbial modifying properties of pea seed coat and their role in improved intestinal integrity and reduced insulin resistance

Project lead:                Ben Willing, University of Alberta

Total value of project: $372,875

Start date:                   March 15, 2014

Completion date:        March 15, 2016