The anti-vitamin supplement brigade, which appears mainly to consist of doctors and scientists schooled in the standard variety of drugs-and-surgery medicine, seems to believe that this, and other reports, has vindicated their steadfast view - that we can get all our nutritional requirements from food, and that vitamin pills are useless and possibly dangerous.
The problem is that the actual science behind these pronouncements isn't nearly sturdy enough to merit this wholesale demolition job. For instance, the vitamin C story represents a serious departure from standard scientific practice and also betrays a certain amount of ignorance about the role of vitamin C in human health.
The much-trumpeted Vitamin C Study, conducted by a team at the University of Southern California, examined 573 supposedly healthy middle-aged men and women who work for a utility company, about a third of whom took various vitamins. Those taking vitamin C pills had accelerated thickening of the walls of the big arteries in their necks. The more they took, the faster the thickening. The study concluded that those taking 500 mg of vitamin C daily for at least a year had a two and a half times greater rate of thickening than did those who avoided supplements. The greatest effect was among smokers, whose rate of thickening was five times greater than those who didn't take supplements. Nevertheless, there was no evidence of any actual harm from the vitamin.
The paper was under peer review at the time the story was leaked to the media, and had not yet been accepted for publication. It had only been presented to a meeting of the American Heart Association. Under the usual rules of scientific publishing, papers under review are not supposed to be circulated or publicised, lest the review team rubbish the paper and recommend against publishing.
Furthermore, the USC team used a particular imaging technique which is experimental, and is still in the midst of its own clinical trials by the National Institutes of Health in the US, to determine whether it is accurate enough to be of any use in examining the state of arteries. The team also used only one of the imaging technique's indicators of arterial health — the one demonstrating thickness. The other two indicators, which were not used, examine plaque index and velocity ratio, both of which would have been better able to demonstrate possible blockage.
In fact, as the Vitamin C Foundation points out, all the study actually showed was that the arteries of test subjects were thicker — a situation that would have been expected. The Foundation quotes Dr Robert Cathcart, a leading proponent of high dose vitamin C treatment, who postulates that thickening of the carotid artery with vitamin C is simply reversing the thinning that occurs with aging. In other words, there is no evidence that vitamin C furs up arteries, only that it strengthen—thickens—arterial walls.
According to Owen Fonorow, director and co-founder of the vitamin C Foundation, 'This is exactly what you want to avoid heart disease. Vitamin C is needed for collagen, and stronger collagen-reinforced blood vessels can better resist injury. Plaque forms in response to injury.'
As the Foundation points out, other evidence demonstrates that vitamin C may be beneficial to arteries. In one study, after subjects given 2 g of vitamin had a significant reduction in ‘augmentation index’, which measures arterial stiffness and also a reduction in platelet aggregation (tendency to clot). As the study concluded, ‘vitamin C supplementation might prove an effective therapy in cardiovascular disease.’(1) There's also evidence that vitamin C can help with arterial dilation in patients with chronic -heart failure.(2)
There's no doubt that treatment and study of vitamins is individual and complex. A single vitamin supplement taken on its own without balancing it with levels of other micronutrients can be dangerous, particularly when dispensed by GPs who have no training in nutrition. New evidence shows that folic acid, which GPs are blithely dispensing to any woman considering becoming pregnant, can increase the risk of spontaneous miscarriage. Furthermore, nutritional needs, like everything else in life, are an individual, moveable feast. What's optimum for you may be toxic for me.
Nevertheless, the wholesale industrialisation of food production has made it virtually impossible for us to get all the nutrition we need from modern-day foods. Vitamin supplementation represents a necessary revolution in healthy eating, necessitated by the demands of a strange new environment of approximately 20,000 chemicals in our food, air and water. It is best studied and managed by people who appreciate what human beings are up against in staying healthy in the 21st century.
Lynne McTaggart is editor of What Doctors Don't Tell You, a monthly newsletter which exposes dangers and unproven practices in modern medicine.
1. J Cardio Vas Pharma, 1999; 34: 690-93
2. Circulation, 1998; 97: 363-8
This article first appeared in the Ecologist June 2000