- Oxidative modification of LDL (Low density lipoprotein) accelerates atherosclerosis whereas dietary antioxidants prevent LDL oxidation. These antioxidants include vitamin C, vitamin E, beta-carotene, selenium, flavonoids, magnesium, and monounsaturated fatty acids (MUFA).1
- The intake of antioxidants in the form of fruits and vegetables but not vitamin supplements is associated with a 13% reduction in risk, of diabetes.2 It is worth emphasizing that vitamin pills are no substitute for a healthy diet.
- Although an earlier study suggested some benefits from antioxidant vitamin supplementation, several subsequent studies involving more than 100,000 patients have consistently failed to demonstrate any benefit.3-5
- More recent studies suggest that possible harm may outweigh the benefit of these vitamins.5-8 In one such study the use of vitamin E and vitamin C reduced the lipid-lowering efficacy of statins and niacin by 50%. More importantly, the clinical event reduction was lowered by one-third.9 The current scientific evidence does not support any protective role of vitamins E, C, and beta-carotene supplements; their use only creates a diversion away from proven therapies.10
- The U.S. Preventive Service Task Force (USPSTF) recommends against the use of beta-carotene supplements.11 Currently, treatment with antioxidant vitamins C and E should not be recommended for the prevention or treatment of coronary atherosclerosis.12
- It is worth noting that the oxidative modification of LDL continues to be relevant, and people should obtain their antioxidant vitamins from food sources. (However, folic acid fortification is recommended in women who are pregnant or might become pregnant).
- Most researchers agree that consumption of fruits and vegetables that are high in antioxidants are an important part of a healthy diet. The U.S. Department of Agriculture recommends two to four servings of fruit and three to five servings of vegetables per day.13
1. Jha P, Flather M, Lonn E, Farkouh M, Yusuf S. The antioxidant vitamins and cardiovascular disease. A critical review of epidemiologic and clinical trial data [see comments]. Ann Intern Med. 1995;123(11):860-872.
2. Hamer M, Chida Y. Intake of fruit, vegetables, and antioxidants and risk of type 2 diabetes: systematic review and meta-analysis. J Hypertens. Dec 2007;25(12):2361-2369.
3. Garcia-Alvarez JL, Sanchez-Tovar M, Garcia-Vigil JL. [Use of antioxidants in prevention of the cardiovascular disease: meta-analysis of clinical trials]. Rev Med Inst Mex Seguro Soc. Jan-Feb 2009;47(1):7-16.
4. Papaioannou D, Cooper K, Christopher Carroll C, et al. Antioxidants in the chemoprevention of colorectal cancer and colorectal adenomas in the general population: a systematic review and meta-analysis. Colorectal Dis. Apr 19 2010.
5. Willcox BJ, Curb JD, Rodriguez BL. Antioxidants in cardiovascular health and disease: key lessons from epidemiologic studies. Am J Cardiol. May 22 2008;101(10A):75D-86D.
6. Stephens N G, Parsons A, Schofield PM, Kelly F, Cheeseman K, Mitchinson MJ. Randomised controlled trial of vitamin E in patients with coronary disease: Cambridge Heart Antioxidant Study (CHAOS). Lancet. 1996;347(9004):781-786.
7. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med. 2001;345(22):1583-1592.
8. HPS. MRC/BHF Heart Protection Study of antioxidant vitamin supplementation in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet. 2002;360(9326):23-33.
9. Brown BG, Cheung MC, Lee AC, Zhao XQ, Chait A. Antioxidant vitamins and lipid therapy: end of a long romance? Arterioscler Thromb Vasc Biol. Oct 1 2002;22(10):1535-1546.
10. Gotto AM. Antioxidants, statins, and atherosclerosis. J Am Coll Cardiol. Apr 2 2003;41(7):1205-1210.
11. Routine vitamin supplementation to prevent cancer and cardiovascular disease: recommendations and rationale. Ann Intern Med. Jul 1 2003;139(1):51-55.
12. Briasoulis A, Tousoulis D, Antoniades C, Stefanadis C. The oxidative stress menace to coronary vasculature: any place for antioxidants? Curr Pharm Des. 2009;15(26):3078-3090.
13. Gaziano JM, Manson JE. Diet and heart disease. The role of fat, alcohol, and antioxidants. Cardiol Clin. Feb 1996;14(1):69-83.