Contact: Michael Bernstein
American Chemical Society
Proteins from garden pea may help fight high blood pressure, kidney disease
SALT LAKE CITY, March 22, 2009 — Researchers in Canada are reporting
that proteins found in a common garden pea show promise as a natural
food additive or new dietary supplement for fighting high blood
pressure and chronic kidney disease (CKD). Those potentially
life-threatening conditions affect millions of people worldwide.
study, which will be presented here today at the American Chemical
Society's 237th National Meeting, is the first reporting that a natural
food product can relieve symptoms of CKD, the scientists say.
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.
people with high blood pressure, our protein could potentially delay or
prevent the onset of kidney damage," says study presenter Rotimi Aluko,
Ph.D., a food chemist at the University of Manitoba in Winnipeg,
Canada. "In people who already have kidney disease, our protein may
help them maintain normal blood pressure levels so they can live
High blood pressure, or hypertension, is a major
risk factor for CKD, a condition that has been affecting an increasing
number of people in the United States and other countries. Estimates
suggest that 13 percent of American adults — about 26 million people —
have chronic kidney disease, up from 10 percent, or about 20 million
people, in the 1990s. CKD is difficult to treat, and may progress to
end-stage kidney disease that requires kidney dialysis or a kidney
transplant. That situation is fostering a search for new ways of
treating CKD and preserving kidney function.
University of Manitoba colleague Harold Aukema, Ph.D., Aluko purified a
mixture of small proteins — called pea protein hydrolysate — from the
yellow garden pea. The researchers fed small daily doses of the protein
mixture to laboratory rats with polycystic kidney disease, a severe
form of kidney disease used as a model for research on CKD. At the end
of the 8-week-long study period, the protein-fed rats with kidney
disease showed a 20 percent drop in blood pressure when compared to
diseased rats on a normal diet, the researchers say.
is significant because a majority of CKD patients actually die from
cardiovascular complications that arise from the high blood pressure
associated with kidney malfunction," Aluko notes.
rats and humans with polycystic kidney disease, the condition causes
urine output to be severely reduced and the kidneys are unable to
properly remove dangerous toxins. 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.
"That's a huge improvement," says Aluko, adding that there were no obvious adverse side effects from the pea protein.
on those promising results, the researchers plan to test the protein
extract in humans with mild hypertension within the next year at the
Richardson Centre for Functional Foods and Nutraceuticals, University
of Manitoba, in collaboration with co-investigator Dr. Peter Jones.
Scientists do not know exactly how the pea extract works. However, it
appears to boost production of cyclooxygenase-1 (COX-1), a protein that
boosts kidney function, the researchers say.
Aluko points out
that eating yellow peas in their natural state won't produce the same
potential health benefits as the purified protein extract. The
potentially beneficial proteins exist in an inactive state in natural
peas, and must be activated by treatment with special enzymes.
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.
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.
government of Canada funded the research through its Advanced Foods and
Materials Network of Centre of Excellence (AFMnet), whose scientific
director is Dr. Rickey Yada and executive director is Ron Woznow.
Nutri-Pea Ltd., a private Canadian company that specializes in making
food products from yellow peas, was the industrial partner for the
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