http://www.healingwithnutrition.com/cdisease/cardiovascular/vitce.html
Vitamins C and E May Have Positive Effects on Artery Lining
Various studies have reported on vitamin C as well as other antioxidant
vitamins and their effects on blood vessels.
In a study conducted by German researchers and published in the American Heart
Association's (AHA) journal "Circulation" on July 1, 1996, the researchers
found that vitamin C helps to absorb some of the damaging chemicals (called
free radicals) in cigarette smoke that cause damage to the arterial wall.
The researchers compared blood flow in the arms of 10 healthy male non-smokers
and 10 male chronic smokers. They found that the blood vessels in chronic
smokers were more constricted. When a chemical was added to their blood to
relax and widen the vessels, the response was limited. However, when vitamin C
was injected into the same artery, it greatly improved the dilation effect.
The scientists suggest that vitamin C helps improve the ability of the thin
layer of cells in the artery called the endothelium to function properly (i.e.,
either narrow or widen). They further note that vitamin C may protect against
biochemical changes in LDL cholesterol (the "bad cholesterol) that cause it to
be deposited in artery walls (a process called atherosclerosis).
In two other studies, reported at the annual AHA scientific sessions in New
Orleans on November 12, 1996, researchers studied the effects of vitamins C and
E on arteries. The first study, led by Dr. Henry Ting of Brigham and Women's
Hospital in Boston, measured blood flow in 12 people with normal cholesterol
(averaging 180 mg/dl) and 12 people with high cholesterol (averaging 280
mg/dl). The researchers took blood-flow measurements before and after injecting
vitamin C into the artery in the forearm. They found that vitamin C improved
the blood flow and widened blood vessels in the people with high cholesterol
but had no effect on the people with normal cholesterol levels.
In another study led by Dr. Gary Plotnick at the University of Maryland Medical
center in Baltimore, the researchers gave 20 adults with normal cholesterol
levels (between 133 and 200 mg/dl) a 900 calorie meal that was at least 50%
saturated fat. They then took timed blood flow measurements using a device that
temporarily halted blood flow in order to see the extent the artery relaxed and
widened to allow blood to flow. They found that after 4 hours, the subjects'
arteries had only widened by 8%, half of what was expected by the researchers.
However, as they predicted, when the subjects took vitamins E and C with their
meals, the blood vessels widened by 18% after the four hour period.
The scientists believe that these antioxidant vitamins may help treat the
effects of a high fat diet. However, the reader should note that these
researchers have not conclusively determined the benefits of antioxidant
vitamins and the AHA does not recommend the use of antioxidant vitamin
supplements until more information is known.