Bisher AKIL, MD

Vitamin C & E: do they prevent heart disease?

In Heart on March 17, 2009 at 11:59 pm

Data have suggested possible benefit from antioxidants, especially vitamin C &E in preventing cardiovascular events. However, this benefit has never been confirmed. The Physician’s Health Study II (PHS II) trial was designed to answer this question. The data were presented by Dr. J. Michael Gaziano at the American Heart Association Annual Scientific Sessions, New Orleans, November 2008. The study was placebo controlled, randomized, blinded, parallel and factorial. It screened 273,360 and enrolled: 14,641 male US physicians with mean follow-Up of 8 years and mean age: 64.3 years. Patients were randomized in a 2 x 2 x 2 x 2 factorial trial to either vitamin E (400 IU synthetic α-tocopherol) or placebo every other day, vitamin C (500 mg synthetic ascorbic acid) or placebo daily, multivitamin (Centrum Silver) or placebo, and beta-carotene (50 mg of Lurotin) or placebo every other day. A total of 14,641 healthy males were randomized, 3,656 to active vitamins E and C, 3,659 to active vitamin E and placebo vitamin C, 3,673 to placebo vitamin E and active vitamin C, and 3,653 to placebo vitamins C and E. Baseline characteristics were fairly similar between the four groups. About 61% exercised at least once every week, about 44% were past or current smokers, 77.4% were on aspirin, 42% had a history of hypertension, 36% had a history of hypercholesterolemia, 6% had a history of diabetes, and about 5% had a self-reported history of cardiovascular disease. Compliance was about 72% at 8 years.
Results:
Vitamin E: There was no difference between patients receiving vitamin E or placebo in the incidence of major cardiovascular events (8.5% vs. 8.5%, hazard ratio [HR] 1.01, 95% confidence interval [CI] 0.90-1.13, p = 0.86). There was also no difference in the incidence of myocardial infarction (MI) (3.3% vs. 3.7%, p = 0.22), stroke (3.2% vs. 3.1%, p = 0.45), congestive heart failure (4.0% vs. 4.0%, p = 0.80), or all-cause mortality (11.5% vs. 11.2%, p = 0.15). However, there was a significant increase in the risk of hemorrhagic stroke in the vitamin E arm (0.53% vs. 0.31%, HR 1.74, 95% CI 1.04-2.91, p = 0.04).

Vitamin C: There was no difference between patients receiving vitamin C or placebo in the incidence of major cardiovascular events (8.4% vs. 8.6%, HR 0.99, 95% CI 0.89-1.11, p = 0.91). There was also no difference in the incidence of MI (3.5% vs. 3.4%, p = 0.65), stroke (3.0% vs. 3.4%, p = 0.21), or all-cause mortality (11.7% vs. 11.0%, p = 0.16).

Conclusion:

The results showed  that neither vitamin C nor vitamin E supplementation is associated with a reduction in major cardiovascular outcomes, as compared with placebo, although vitamin E may be associated with a slightly higher incidence of hemorrhagic stroke, compared with placebo.

Comments: No women were enrolled in this study which limits its benefit; questionnaire were used to assess the results. These may make the results a bit weaker, but they are still valid. Next time you decide to buy vitamins, make sure you are buying them for a good reason, otherwise save your money.BA

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