April 06, 2022
The American Journal of Clinical Nutrition
TAKE-HOME MESSAGE
- This double-blind, placebo-controlled, randomized clinical trial of 21,422 US adults aged ≥60 years evaluated whether daily multivitamin–multimineral (MVM) supplementation reduced the incidence of total invasive cancer among older adults. Daily MVM supplementation was not associated with a reduced incidence of total invasive cancer; however, it protected against lung cancer (HR, 0.62). Daily MVM supplementation had no significant effect on CVD-related mortality or all-cause mortality, and no safety concerns were identified.
- The study findings suggest that daily MVM supplementation does not prevent cancer and cardiovascular disease in older adults.
Influence of cocoa flavonoids and multivitamins on cardiovascular health and cancer: The COSMOS Trial
COSMOS is a prospective study of 21,442 US adults who were followed for 3.6 years. These two papers1,2 wanted to determine if taking a multivitamin (MVI), Centrum Silver, was associated with a lower incidence of cancer or if the bioflavonoid cocoa (in the form of a cocoa extract supplement of 500 mg flavanols found in cocoa beans + 80 mg epicatechins found in green tea) reduced cardiovascular (CV) events and death.
The study was sponsored by both Pfizer, the maker of Centrum Silver, and Mars Edge, a segment of the company that makes chocolate candy. It is interesting that one of the leading producers of candy is supporting health-oriented research. However, it is understandable when you look at the potential market share of cocoa beans, a rich source of flavonoids.
There was no association with reduced cancer incidence in these rather well-nourished Americans who took MVI. Some would argue that this finding is due to the short duration (3.6 years) of the study.
Other recent studies of vitamins have also not shown a significant benefit. The D-Health Trial studied healthy Australians and found no mortality benefit with vitamin D supplementation, but this finding was in tanned Aussies! MVIs likely don’t have a benefit unless there is an underlying deficiency. The Linxian trial of 29,584 rural Chinese, followed for over 6 years, supplemented beta carotene, vitamin E, and selenium. There was a 9% to 21% reduction in cancer mortality that lasted for up to 10 years after completion of the study.3 One may speculate that the rural Chinese had more vitamin deficiencies. However, this was not tested. Most humans with a diverse, multicolored plant–based diet will not be vitamin-deficient and would not benefit from taking an MVI. But tell that to the 70% of Americans aged >60 years who take supplements; a multibillion-dollar industry with MVIs is leading the way.
The cocoa flavonoid arm of the study had more promising results. Although the reduction in the incidence of CV events was not statistically significant, the overall CV mortality was reduced by 27% with cocoa and green tea flavonoids supplementation (see graphic).
Flavonoids are found in dark-colored grapes and berries, apples, pears, green tea, and dark chocolate. To get a therapeutic dose of cocoa flavonoids, one needs to eat one-fourth of a dark chocolate bar with at least 70% cocoa. Flavonoids have been found to enhance the flexibility of the endothelium. Research has shown that they reduce systolic but not diastolic blood pressure,4,5 suggesting that flavonoids maintain the flexibility of the blood vessels as we age. One large handful of blueberries a day improves endothelial function and lowers systolic blood pressure by an average of 5 mm Hg.6
Furthermore, COSMOS suggests that you may be less likely to die of a cardiac event; not bad for eating flavonoids found in dark chocolate and green tea!
References
Abstract
BACKGROUND
Although older adults commonly take multivitamin-multimineral (MVM) supplements to promote health, evidence on use of daily MVMs on invasive cancer is limited.
OBJECTIVES
The study objective was to determine if a daily MVM decreases total invasive cancer among older adults.
METHODS
We performed a randomized, double-blind, placebo-controlled, two-by-two factorial trial of a daily MVM and cocoa extract for prevention of cancer and cardiovascular disease (CVD) among 21,442 U.S. adults (12,666 women aged ≥ 65 years and 8776 men aged ≥ 60 years) free of major CVD and recently diagnosed cancer. The intervention phase was from June 2015 through December 2020. This article reports on the MVM intervention.
INTERVENTION
Participants were randomly assigned to daily MVM or placebo. The primary outcome was total invasive cancer, excluding non-melanoma skin cancer. Secondary outcomes included major site-specific cancers, total CVD, all-cause mortality, and total cancer risk among those with a baseline history of cancer.
RESULTS
During a median follow-up of 3.6 years, invasive cancer occurred in 518 participants in the MVM group and 535 participants in the placebo group (hazard ratio [HR]=0.97, 95% confidence interval [CI]: 0.86, 1.09; P = 0.57). We observed no significant effect of a daily MVM on breast cancer (HR = 1.06, 95% CI: 0.79, 1.42) or colorectal cancer (HR = 1.30, 95% CI: 0.80, 2.12). We observed a protective effect of a daily MVM on lung cancer (HR = 0.62, 95% CI: 0.42, 0.92). The composite CVD outcome occurred in 429 participants in the MVM group and 437 participants in the placebo group (HR = 0.98, 95% CI: 0.86, 1.12). MVM did not significantly affect all-cause mortality (HR = 0.93; 95% CI: 0.81,1.08). There were no safety concerns.
CONCLUSION
A daily MVM supplement, compared with placebo, did not significantly reduce the incidence of total cancer among older men and women. Future studies are needed to determine the effects of MVMs on other aging-related outcomes among older adults.
Journal Abstract
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