Vitamin C Can Lower Blood Pressure
CORVALLIS, Ore. (AP) - Heart patients with high blood pressure may receive substantial benefit from a daily dose of vitamin C - something researchers said could be an inexpensive alternative to prescription drugs.
A dose of 500 milligrams each day lowered blood pressure by up to 9 percent, a level comparable to expensive prescription drugs, according to researchers from the Boston University School of Medicine and the Linus Pauling Institute at Oregon State University.
"It may provide a way to bring their blood pressure back within acceptable levels without the cost or possible side effects of prescription drugs," said Balz Frei, director of the Linus Pauling Institute and one of the lead researchers.
He was quick to caution, however, that more study is needed and that vitamin C is not a substitute for medication.
"It's not an alternative therapy," Frei said. "We certainly don't want people to discontinue their medication." Others said the study was far too small to be conclusive. "I think it would be unfortunate if people with hypertension went out and started taking extra vitamin C on the basis of a single study," said Alice Lichtenstein, spokeswoman for the American Heart Association and a nutrition professor at Tufts University in Boston.
Still, other researchers said the study published this week in the British medical journal Lancet shows promise.
"This is one of the best studies to date," said Dr. Kenny Jialal at the University of Texas Southwestern Medical Center in Dallas. "When you get 500 milligrams of vitamin C you clearly show a reduction." The study divided a group of 39 patients with mild to moderate hypertension into two groups. About half took daily doses of 500 milligrams of vitamin C, also known as ascorbic acid, while the others took a placebo.
After one month, the average blood pressure of patients who took vitamin C dropped 9.1 percent, significantly more than the patients in the placebo group, who averaged a 2.7 percent decline.
Both groups continued to take their regular medication for hypertension during the vitamin C study. Frei said vitamin C may improve the way the body synthesizes nitric oxide, a compound important for keeping blood vessels relaxed. The vitamin also may work to improve anti-hypertension medication, he said.
Researchers say there is growing evidence that shows vitamin C plays an important role in maintaining health, primarily as an antioxidant - something that scavenges the body for roaming oxygen molecules known as "free radicals" suspected of triggering cancer and other disease.
"What is encouraging about this study is that it adds to the evidence we need to keep this antioxidant network in our body and our blood and our cells working on these noxious elements, such as cancer cells," said Jialal, one of the nation's leading researchers in antioxidants.
But Jialal and others warned against megadoses of vitamin C, saying studies indicate that doses greater than 200 milligrams a day are wasted and even potentially harmful.
The 500-milligram dosage in the study was more than eight times greater than the recommended daily allowance of 60 milligrams for adults, but Frei said researchers wanted to be sure the patients got enough to be effective.
The National Institutes of Health has recommended raising the daily allowance for vitamin C to between 100 and 200 milligrams.
Researchers said a balanced diet filled with vegetables and fruits are probably more important than taking vitamin C as a supplement.
"By and large the evidence shows that fruits and vegetables help reduce the risk of cancer," Frei said. "But it's not any particular agent, it's the whole mixture of fruit and vegetables."
Copyright 1999 The Associated Press. All rights reserved.
CORVALLIS, Ore. (AP) - Heart patients with high blood pressure may receive substantial benefit from a daily dose of vitamin C - something researchers said could be an inexpensive alternative to prescription drugs.
A dose of 500 milligrams each day lowered blood pressure by up to 9 percent, a level comparable to expensive prescription drugs, according to researchers from the Boston University School of Medicine and the Linus Pauling Institute at Oregon State University.
"It may provide a way to bring their blood pressure back within acceptable levels without the cost or possible side effects of prescription drugs," said Balz Frei, director of the Linus Pauling Institute and one of the lead researchers.
He was quick to caution, however, that more study is needed and that vitamin C is not a substitute for medication.
"It's not an alternative therapy," Frei said. "We certainly don't want people to discontinue their medication." Others said the study was far too small to be conclusive. "I think it would be unfortunate if people with hypertension went out and started taking extra vitamin C on the basis of a single study," said Alice Lichtenstein, spokeswoman for the American Heart Association and a nutrition professor at Tufts University in Boston.
Still, other researchers said the study published this week in the British medical journal Lancet shows promise.
"This is one of the best studies to date," said Dr. Kenny Jialal at the University of Texas Southwestern Medical Center in Dallas. "When you get 500 milligrams of vitamin C you clearly show a reduction." The study divided a group of 39 patients with mild to moderate hypertension into two groups. About half took daily doses of 500 milligrams of vitamin C, also known as ascorbic acid, while the others took a placebo.
After one month, the average blood pressure of patients who took vitamin C dropped 9.1 percent, significantly more than the patients in the placebo group, who averaged a 2.7 percent decline.
Both groups continued to take their regular medication for hypertension during the vitamin C study. Frei said vitamin C may improve the way the body synthesizes nitric oxide, a compound important for keeping blood vessels relaxed. The vitamin also may work to improve anti-hypertension medication, he said.
Researchers say there is growing evidence that shows vitamin C plays an important role in maintaining health, primarily as an antioxidant - something that scavenges the body for roaming oxygen molecules known as "free radicals" suspected of triggering cancer and other disease.
"What is encouraging about this study is that it adds to the evidence we need to keep this antioxidant network in our body and our blood and our cells working on these noxious elements, such as cancer cells," said Jialal, one of the nation's leading researchers in antioxidants.
But Jialal and others warned against megadoses of vitamin C, saying studies indicate that doses greater than 200 milligrams a day are wasted and even potentially harmful.
The 500-milligram dosage in the study was more than eight times greater than the recommended daily allowance of 60 milligrams for adults, but Frei said researchers wanted to be sure the patients got enough to be effective.
The National Institutes of Health has recommended raising the daily allowance for vitamin C to between 100 and 200 milligrams.
Researchers said a balanced diet filled with vegetables and fruits are probably more important than taking vitamin C as a supplement.
"By and large the evidence shows that fruits and vegetables help reduce the risk of cancer," Frei said. "But it's not any particular agent, it's the whole mixture of fruit and vegetables."
Copyright 1999 The Associated Press. All rights reserved.