|Centrum Silver and other MVTs|
The daily use of multivitamins may reduce the risk for cancer in men, according to the results of a very large randomized trial in the US
A number of trials of individual vitamins, administered at high doses, have not shown any effect at preventing cancer. Observational studies have also not provided evidence of an association between multivitamin use and a reduction in cancer incidence or mortality.
However, the current study is unique in a number of ways, the first being that it is the only large-scale placebo-controlled trial evaluating a multivitamin in the prevention of cancer.
It is also of long duration and involved physicians themselves as the subject.
After about 11 years, multivitamin use resulted in a modest but statistically significant reduction — specifically, an 8% reduction in total cancer incidence.
The study involved 14,641 male US physicians initially aged ≥50 years (mean age, 64.3 years), including 1312 men with a history of cancer at randomisation, enrolled in 1997 with treatment and follow-up through to June 1, 2011. They received either daily exact same brand multivitamin (Centrum Silver) or placebo. The main outcome measures were total cancer (excluding non-melanoma skin cancer), with prostate, colorectal, and other site-specific cancers among the secondary end points.
During a median follow-up of 11.2 years:
• There were 2669 men with confirmed cancer, including 1373 cases of prostate cancer and 210 cases of colorectal cancer.
• Compared with placebo, men taking a daily multivitamin had a statistically significant reduction in the incidence of total cancer (multivitamin and placebo groups, 17.0 and 18.3 events, respectively, per 1000 person-years; hazard ratio [HR], 0.92; 95% CI, 0.86 to 0.998; p=0.04).
• There was no significant effect of a daily multivitamin on prostate cancer (multivitamin and placebo groups, 9.1 and 9.2 events, respectively, per 1000 person-years; 0.98; 0.88 to 1.09; p=0.76), colorectal cancer (multivitamin and placebo groups, 1.2 and 1.4 events, respectively, per 1000 person-years; 0.89; 0.68 to 1.17; p=0.39), or other site-specific cancers.
• There was no significant difference in the risk of cancer mortality (multivitamin and placebo groups, 4.9 and 5.6 events, respectively, per 1000 person-years; 0.88;, 0.77 to 1.01; p=0.07).
• Daily multivitamin use was associated with a reduction in total cancer among 1312 men with a baseline history of cancer (0.73; 0.56 to 0.96; p=0.02), but this did not differ significantly from that among 13,329 men initially without cancer (0.94; 0.87 to 1.02; p=0.15; p for interaction=0.07).
Reduction in Total Cancers
"Our main message is that the main reason to take a multivitamin is for nutritional deficiencies but it certainly appears that there may be a modest benefit in preventing cancer in men over the age of 50," lead author John Michael Gaziano said.
The study has also been published online October 17, 2012 in the Journal of the American Medical Association Published:
Gaziano JM, Sesso HD, Christen WG, Bubes V, Smith JP, MacFadyen J, Schvartz M, Manson JE, Glynn RJ, Buring JE. Multivitamins in the Prevention of Cancer in MenThe Physicians' Health Study II Randomized Controlled Trial . JAMA. 2012;():1-10. doi:10.1001/jama.2012.14641.
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