The U.S. Preventive Services Task Force (USPSTF) recommends against the use of beta-carotene or vitamin E supplementation for the primary prevention of cancer or cardiovascular disease, according to an updated recommendation statement published in the Annals of Internal Medicine. “The USPSTF found adequate evidence that supplementation with [beta-carotene] increases risk for lung cancer in persons who are at increased risk for this condition,” the statement noted.
Two trials—the Alpha-Tocopherol, Beta-Carotene Cancer Prevention trial and the Carotene and Retinol Efficacy Trial—showed an increased risk for lung cancer incidence and mortality and all-cause mortality in participants with a high baseline risk for lung cancer. A meta-analysis of beta-carotene trials reported an increased risk for lung cancer (pooled odds ratio= 1.24 [95% CI = 1.10 to 1.39]) in current smokers, according to the recommendation statement.
Since its 2003 recommendation on vitamin supplementation, “new evidence on the use of vitamin E increased the USPSTF’s certainty about the lack of effectiveness in preventing cardiovascular disease or cancer.” This includes four randomized controlled trials that found no significant effect on cancer incidence or mortality rates and five trials showing no effect on all-cause mortality.
After conducting a systematic review of the evidence, the task force concluded that the current evidence is insufficient to assess the balance of benefits and harms of the use of multivitamins or single-nutrient or paired-nutrient supplements (with the exception of beta-carotene and vitamin E) for the prevention of cardiovascular disease or cancer.
“This recommendation applies to healthy adults without special nutritional needs (typically age 50 years and older),” the task force stated. “This recommendation does not apply to children, women who are pregnant or may become pregnant, or persons who are chronically ill, hospitalized, or have a known nutritional deficiency.”
The task force added that “clinical decisions involve more considerations than evidence alone. Clinicians should understand the evidence but individualize decision making to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms.” ■
Moyer V, on behalf of the U.S. Preventive Services Task Force, Ann Intern Med. February 25, 2014 (early release online).