Vitamin C & Heart Disease
Chester J. Zelasko, Ph.D. | December 5, 2000

This was a recent headline that appeared in the news services online and in print.
"Vitamin C Supplements May Promote Atherosclerosis"

The data was reported by Dr. James Dwyer at an American Heart Association Conference on Cardiovascular Disease held in San Diego in March. The news article stated that supplementing with vitamin C (500 mg per day) seemed to cause the carotid arteries (in the neck) to become thicker in a manner consistent with progressive atherosclerosis. The increase in arterial wall thickness was 2.5 times greater in those using vitamin C than in those not taking vitamin C supplements, with a five-fold increase in those who smoked cigarettes and took vitamin C supplements. The study was conducted on over 500 men 40-60 years old, with tests taken 18 months apart.

Time to throw out the vitamin C supplements?

Maybe not.

We know very little about the data because it has not been published in a scientific journal yet. We were able to get a little more information from a longer article in the Los Angeles Times. The study used B-mode ultrasonography, a technique typically used to diagnose blockages found in the carotid arteries. After reviewing many research articles on the validity and reliability of this method to monitor changes in the size of the wall of the carotid artery, the following is what we found.

The ability to monitor changes over time is suspect due to large variability in the precision of sonograph readers-they're only human, after all. The average difference between the same reader reading the same sonograph was 27 microns, while the difference between two different readers reading the same sonograph was 41 microns. How big is that? A hair from your head is about 100 microns thick. The technology wasn't designed for this degree of precision.

So if the difference over time was less than 27 microns-and the same reader did the reading-he or she might not even detect it. And if different readers were used, a difference less than 41 microns might be missed.

The mean difference in the study for those who didn't use vitamin C was 12 microns. For those using vitamin C, the mean difference was 28 microns. That's just 16 microns more for the vitamin C group. When the difference is so small compared to the rate of reader variability, how confident can we be in the findings?

However, the thickening in the carotid arteries was over 50 microns for the smokers. This study may be another argument for quitting smoking.

But let's assume what they found was true. The average diameter of the carotid artery is 0.9 cm or 9 millimeters or 9,000 microns. If the arteries narrowed at the rate of 28 microns every 18 months, it would take over 450 years for complete blockage to occur. That's a "risk" we're willing to take.

This is a small study using technology in a way it wasn't designed to be used. With the hundreds of positive studies in vitamin C's favor, there is simply no reason to stop supplementing with vitamin C.

Here's another way of looking at it. Go out to your local football field. Start at the goal line and count out 100 giant steps. You should end up on the other goal line. Go back 18 months later. Step it out again. If you don't come out exactly on the goal line, would you assume the field had changed? Hardly.
BBBOnLine Reliability Seal © 2011 Better Life Unlimited™
A division of Better Life Institute © (BLI, Inc.)
 Contact Us  |  Privacy Policy
SecurityMetrics Credit Card Safe