How Smokers Can 'C' Better Blood Flow
Sept. 11, 2000 -- Smoking is unhealthy for your heart -- that's a well-established fact. The bad news is that the damage smoking causes may be more extensive than previously realized. The good news is that stocking up on citrus fruits and other produce packed with vitamin C may help reverse some of the damage.
An international team of researchers has found that not only does smoking affect the large vessels of the heart, but it may also cause damage to the extensive network of tiny blood vessels that supply blood to most of the heart muscle. In a study appearing in Circulation: Journal of the American Heart Association, researchers found that smokers had a much lower blood supply to the heart during stress compared with nonsmokers.
Previous research has suggested that vitamin C and other nutrients may help decrease the risk of heart disease. Also, smoking may deplete vitamin C levels in the body, and the researchers wanted to see if giving large doses of the vitamin might improve the heart's blood flow.
The researchers used a scan to measure blood flow in the blood vessels of eight healthy male nonsmokers and 11 male smokers.
All of the subjects were given a large dose of vitamin C through the veins, and then their blood flow was measured again. The vitamin C didn't make a difference in the nonsmokers, but it had an immediate effect on the smokers. In fact, the circulation in the tiny blood vessels was almost back to normal after the smokers were treated with vitamin C.
Richard Hoffman, MD, MPH, points out that these results certainly won't change medical practice. "We already discourage tobacco smoking because we know smoking increases the risk for [heart] disease," he tells WebMD, but adds that the results of this study are very interesting, in that vitamin C reversed circulation changes caused by smoking. Hoffman, who was not involved in the study, is an associate professor of medicine at the University of New Mexico in Albuquerque.
Even though the number of people studied was very small, study author Paolo Camici, MD, feels that it did not affect the outcome and that using a larger population would not have changed their results. Camici is a professor at the Imperial College School of Medicine in London.
Hoffman points out that the vitamin C in this study was given in a controlled, experimental setting with a small number of patients receiving a large, single dose. If the research works in the real world, he says, smokers will need to take oral supplements for many years to see whether the risk of heart disease is truly reduced.
Camici agrees. "Unfortunately, I did not address this specific point in my study," he says, but adds that both blood and tissue levels of vitamin C have been previously measured in smokers and found to be lower than in nonsmokers. "Therefore, I presume that only after [long term] treatment you would achieve a lasting effect."