Antioxidant vitamins and atherosclerosis prevention

Low blood levels of beta-carotene (vitamin A), gamma-tocopherol (vitamin E) and vitamin C have been to be associated with an increased risk of cardiovascular disease.

• vitamin A (beta-carotene) - a modest protective effect for cardiovascular disease was found in most cohort studies (1). However there has been no benefit demonstrated in large trials and cardiovascular mortality may be increased (2)
  
  
• vitamin E - a large randomised controlled trial of vitamin E in nearly 30,000 Finnish smokers found no benefit for the use of vitamin E (3). Also the HOPE trial found no benefit for patients treated with vitamin E (4)
  
  
• vitamin C - no large scale trials have studied vitamin C supplementation alone

At present, there is insufficient evidence for the use of antioxidants in the primary or secondary prevention of cardiovascular disease (5)

• a systematic review and meta-analysis found that antioxidant supplements for primary and secondary prevention did not decrease mortality

Reference:

1. Lonn EM, Yusuf S. Is there a role for antioxidant vitamins in the prevention of cardiovascular disease? An update on epidemiological and clinical trials data. Can J Cardiol 1997;13: 957-65.
2. Egger M et al. Spurious precision? Meta - analysis of observational studies. BMJ 1998; 316: 140-4.
3. The Alpha-Tocopheral Beta-Carotene Cancer Prevention Study Group. The effects of vitamin E and beta-carotene on the incidence of lung cancer and other causes in male smokers. NEJM 1994;330: 1029-35.
4. NEJM 2000;342: 145-53.
5. Bjelakovic G et al. Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. JAMA. 2007 Feb 28;297(8):842-57