Multivitamin Study Details Tell Different Story of Cancer Prevention
Contradicting recent studies that showed multivitamin use had little effect upon chronic disease, Harvard researchers have found that multivitamin use over a long period reduces the incidence of many cancers along with mortality.
The researchers conducted a study of male doctors called the Physicians’ Health Study II Randomized Controlled Trial. The study began in 1997 and included 14,641 physicians from the United States. They were 50 years or older at the beginning of the study, and the average age was 64 years old. The study group also included 1,312 men who had previously contracted cancer. The study continued through June 1, 2011. The study was randomized, double-blinded, and placebo-controlled.
While the study found that multivitamin use decreased all types of cancer by 12%, and decreased deaths from all cancers by 12%, these statistics do not tell the entire story. The details by cancer type tell of an even more compelling result of taking multivitamins.
The all-cancer statistics were significantly skewed by the fact that multivitamin use only reduced the risk of prostate cancer by 2%, while prostate cancer accounted for approximately half of all the cancer cases among the men. There were about 18 cases of cancer for every 1,000 men, and about 9 cases of prostate cancer for every 1,000 men. This means that the reduction in other types of cancer were significantly higher when prostate cancer is removed from the equation.
This is also evidenced that among individual cancers, bladder cancers were reduced by 28% among the multivitamin users, and lung cancer was reduced by about 16% among the multivitamin group. By the process of deduction, other cancer reductions would also certainly have been in the 15-25% range. These statistics were not well publicized by the mass media covering the study, some of which indicated that multivitamins reduced cancer incidence by as little as 8%.
Another fact not well publicized is that cancer incidence among men who had a previous history of cancer was 27% lower among those who took multivitamins.
Even the researchers largely dismissed the fact that multivitamin use reduced mortality (death) among the group by 6%. This result was considered “insignificant.”
Obviously, these statements, along with their echoes through the mass media, indicate a bias among researchers and conventional medical publications regarding natural approaches towards cancer prevention – ignoring the fact that the best cure for cancer is prevention.
It is also significant that this study reverses two previous studies that showed no evidence of benefit for chronic diseases in those who use multivitamins consistently. This prompted the following statement with the 2010 Dietary Guidelines for Americans: “For the general, healthy population, there is no evidence to support a recommendation for the use of multivitamin/mineral supplements in the primary prevention of chronic disease.”
Many natural health advocates cried foul to such an announcement, claiming that not only were the study protocols flawed amongst these studies, but the research was seemingly funded by “big pharma.” These claims have thus far remained unproven.
Now we find that multivitamins not only reduce the incidence of the type of chronic disease that strikes the most Americans outside of heart disease (and multivitamins also reduce heart disease risk), but that multivitamins reduce the incidence of death.
And the fact that this study was carried out over such a long period with very strict protocol indicates that the benefits of multivitamin usage are on solid ground.
The study utilized the Centrum Silver brand of supplements, at the RDA dosage level. These included vitamin D at 400-500 IU and vitamin A at 2,500-5,000 IU.
These results confirm other studies that have found that increasing the intake of fruits and vegetables decreases cancer incidence. However, these studies only showed moderate reductions of some 2-5% in all cancers. But their increased dosages of fruits and vegetables only accounted for 100-200 grams per day. This is the equivalent to one to two servings a day, while even the most conservative recommendations suggest 5-6 servings a day of fruit and vegetables. A 2007 study by the Centers of Disease Control found that less than a third of American adults eat fruits and vegetables two or three times a day or more – well below the 5-6 servings conservatively recommended.
In other words, adding one or two servings of fruits and vegetables a day is not that likely to make a significant impact upon the nutrient intake of an adult – especially when considering the reduced nutrient levels of most conventional (chemically-fertilized and force ripened) produce. This multivitamin study confirms this reality, along with other studies that have shown decreasing nutrient content among produce over the past few decades.
As for prostate cancer, reductions in this form of cancer has been linked to other types of phytonutrients as well as sun exposure.
J. Michael Gaziano, MD, MPH; Howard D. Sesso, ScD, MPH; William G. Christen, ScD; Vadim Bubes, PhD; Joanne P. Smith, BA; Jean MacFadyen, BA; Miriam Schvartz, MD; JoAnn E. Manson, MD, DrPH; Robert J. Glynn, ScD; Julie E. Buring, ScD. Multivitamins in the Prevention of Cancer in Men: The Physicians’ Health Study II Randomized Controlled Trial. ScD. JAMA. 2012;():1-10. doi:10.1001/jama.2012.14641.
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