Antioxidants Prevent Heart Disease Progression after Transplant
A clinical trial published in this week’s issue of Lancet concluded that supplementation with vitamins C and E could help prevent hardening of the arteries (atherosclerosis) in the first year after heart transplantation.1
In this double-blind clinical trial, 40 people who had recently undergone cardiac transplant surgery were randomly assigned to receive either a placebo or the combination of vitamin C (500 mg twice per day) plus vitamin E (400 IU twice per day). After one year of supplementation, there was no significant narrowing of the arteries of the heart in the group taking the vitamins, but in the group taking placebo those arteries narrowed by an average of 8%
Atherosclerosis is a common cause of heart attack and stroke. Some researchers believe that free-radical damage to the walls of blood vessels is the initial insult that causes this disease.2 3 Since vitamins C and E work by making free radicals inactive, it is logical to expect that they may help prevent atherosclerosis. Atherosclerosis is thought to be the most significant problem facing patients after heart transplant. Up to 70% of heart transplant patients will have measurable atherosclerosis within three years of the procedure.4
Prior clinical trials that have studied the ability of antioxidants to prevent atherosclerosis have yielded mixed results. A clinical trial from 1996 found that people with proven hardening of the arteries who took vitamin E (either 400 or 800 IU per day) had a greater than 75% reduction in risk of nonfatal heart attack.5 No change in cardiovascular mortality was seen in this study. A newer clinical trial found no cardiovascular benefit from supplementation with 400 IU of vitamin E for four and a half years.6
In a double-blind trial, supplementation with 250 mg of time-release vitamin C twice daily for three years resulted in a 15% reduction in the progression of atherosclerosis, compared with placebo, although this improvement was not statistically significant.7 An older study found significant regression of atherosclerosis in the arteries of the legs in some patients treated with 500 mg of vitamin C three times per day.8 No long-term clinical trials have analyzed the ability of vitamin C to prevent heart attack.
From the data that preceded the new study, it would appear that antioxidant supplementation is beneficial for at least some people at high risk of developing atherosclerosis. Future clinical trials in specific risk groups will be necessary to determine exactly who may benefit the most. Based on this new report, it would appear that patients receiving heart transplant should be on this list.
1. Fang JC, Kinlay S, Beltrame J, et al. Effect of vitamins C and E on progression of transplant-associated arteriosclerosis: a randomised trial. Lancet 2002;359:1108–13.
2. Cai H, Harrison DG. Endothelial dysfunction in cardiovascular diseases: the role of oxidant stress. Circ Res 2000;87:840–4.
3. Stroes ES, van Faassen EE, van Londen GJ, Rabelink TJ. Oxygen radical stress in vascular disease: the role of endothelial nitric oxide synthase. J Cardiovasc Pharmacol 1998;32 Suppl 3:S14–S21.
4. Kapadia SR, Ziada KM, L’Allier PL, et al. Intravascular ultrasound imaging after cardiac transplantation: advantage of multi-vessel imaging. J Heart Lung Transplant 2000;19:167–72.
5. Stephens NG, Parsons A, Schofield PM, et al. Randomised controlled trial of vitamin E in patients with coronary disease: Cambridge Heart Antioxidant Study (CHAOS). Lancet 1996;347:781–6.
6. Yusuf S, Dagenais G, Pogue J, et al. Vitamin E supplementation and cardiovascular events in high-risk patients. The Heart Outcomes Prevention Evaluation Study Investigators. N Engl J Med 2000;342:154–60.
7. Salonen JT, Nyyss?nen K, Salonen R, et al. Antioxidant supplementation in atherosclerosis prevention (ASAP) study: a randomized trial of the effect of vitamin E and C on 3-year progression of carotid atherosclerosis. J Intern Med 2000;248:377–86.
8. Willis GC, Light AW, Cow WS, Canad MA. Serial arteriography in atherosclerosis. Can Med Assoc J 1954;71:562–8.
Matt Brignall, ND, is in practice at the Seattle Cancer Treatment and Wellness Center and at the Evergreen Integrative Medicine Clinic in Kirkland, WA. He specializes in integrative treatment of cancer. He is a contributor to Healthnotes and Healthnotes Newswire.
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