Proteins from the garden pea may help fight high blood pressure, kidney disease

Proteins found in a common garden pea could be used in future as a food additive or dietary supplement for fighting high blood pressure and chronic kidney disease (CKD), according to new research to be presented at the American Chemical Society's 237th National Meeting.

Peas long have been recognized as nutritional superstars, with healthful amounts of protein, dietary fiber, and vitamins wrapped in a low-fat, cholesterol-free package. The new research focuses on the yellow garden pea, a mainstay pea variety enjoyed as a veggie side-dish and used as an ingredient in dozens of recipes around the world.

"In people with high blood pressure, our protein could potentially delay or prevent the onset of kidney damage," says scientist Rotimi Aluko, a food chemist at the University of Manitoba, Canada.

"In people who already have kidney disease, our protein may help them maintain normal blood pressure levels so they can live longer."

The reseachers purified the pea protein hydrolysate from the yellow garden pea. Small daily doses of the protein mixture were fed to laboratory rats with polycystic kidney disease, a severe kidney condition, over an eight week period. Rats fed the pea protein showed a 20 percent drop in blood pressure compared with diseased rats on a normal diet.

Lead researcher, Rotimi Aluko commented:

"This is significant because a majority of CKD patients actually die from cardiovascular complications that arise from the high blood pressure associated with kidney malfunction."

In addition to this, the researchers showed that their pea extract caused a 30 percent boost in urine production in the diseased rats, bringing their urine to within normal levels. This is an important benefit as polycystic kidney disease often causes urine output to be severely reduced and the kidneys are unable to properly remove dangerous toxins.

"That's a huge improvement," says Aluko, adding that there were no obvious adverse side effects from the pea protein.

Eating yellow peas in their natural state won't produce the same potential health benefits as the purified protein extract. The proteins exist in an inactive state in natural peas, and must be activated by treatment with special enzymes.

Scientists do not know exactly how the pea extract works. However, it appears to boost a protein associated with boosting kidney function.

The pea extract does have a very welcome social advantage over fresh peas:

"It won't give you gas," notes Aluko. That's because the purified proteins don't contain the complex plant-sugars found in fresh beans that are known to trigger flatulence. The extract itself does not appear to have any unpleasant taste or odor, he adds.

If studies continue to show promise, Aluko estimates that the extract could hit the consumer market within the next two to three years. The extract could be made into a soluble powder that can be added to foods and beverages or it could be developed into a pill, the scientists say.

This article was published on Mon 23 March 2009