CORVALLIS, Ore. - One of the largest, longest, placebo-controlled clinical trials ever done on the use of a daily multivitamin/mineral to prevent cancer in men has shown a remarkable 8 percent drop in overall cancers during a 13-year study period - findings that may have repercussions on health care around the world.
Scientists in the Linus Pauling Institute at Oregon State University, who have studied related issues for years but were not involved in this research, say it conclusively shows that multivitamins are safe to take, help fill important nutritional gaps, reduce cancer risk and in turn will help cut health care costs.
"An 8 percent drop in overall cancer rates is not small," said Balz Frei, professor and director of the Linus Pauling Institute, and an international expert on the role of vitamins and micronutrients in promoting health and preventing disease.
"Given that more than 1.6 million new cancer cases are diagnosed in the U.S. each year, this translates into about 130,000 cancers prevented every year, and with it all the health care costs and human suffering."
The research, titled "Multivitamins in the Prevention of Cancer in Men," was published today in the early online edition of the Journal of the American Medical Association, by a group of scientists from Harvard Medical School and Brigham and Women's Hospital.
It's important, Frei said, because this is the type of controlled study that can establish cause and effect.
"And it's worth noting that the research was done with 14,600 physicians," Frei said. "This highly-educated group has a better diet, knowledge base and health habits than the average person, so it's reasonable to believe that the impact of multivitamin use in the general population will be even greater."
For decades, a standard tenet of conventional medicine has been that people will get all of the vitamins and micronutrients they need in a normal healthy diet. That's often not true, Frei said.
"We've known for a long time that something as simple as a multivitamin can help fill nutritional gaps, even if you try to eat right," Frei said. "Research has shown that over 90 percent of the U.S. population, for instance, doesn't get enough vitamin E, and that 40 percent of elderly Americans have inadequate zinc in their diet."
"Quite simply, at around a penny a day a multivitamin is the cheapest health insurance a person will ever buy," he said. "Of course it's just a supplement, and it's not a substitute for a good diet and healthy lifestyle. But this study should finally answer all the doubters out there who still think multivitamin supplements have no value. And it further confirms they are completely safe to take."
The mechanisms by which vitamins and micronutrients can help prevent cancer are still not certain, Frei said, and the fact this study confirmed the value of a multivitamin - instead of single vitamin supplements - is important. The combined effect of a range of vitamins and minerals working together is probably more important than any one of them separately, he said.
In this research, the scientists concluded that use of a multivitamin cut overall cancer rates by 8 percent. But by far the most prevalent cancer in men of this age group was early-stage prostate cancer diagnosed by prostate-specific antigen levels, and the research showed multivitamin usage had no impact on it. When prostate cancer was excluded from the analysis, the overall drop in all other cancers was 12 percent.
Only the drop in "total" cancer rate was what researchers call "statistically significant," with large enough numbers to scientifically prove cause and effect.
Several types of cancers were reduced more than others in the group who took multivitamins, although because of the relatively small number of individual cancer types it was not possible to designate them as statistically significant, Frei said.
The reduction in total cancers appeared to be driven by fewer cases of leukemia and colorectal, lung and bladder cancers in those who took the multivitamin. Types of cancer that showed little or no reduction, in addition to prostate cancer, included melanoma, pancreatic cancer and lymphoma, although again these results were not statistically significant.
"It's encouraging to think that we could have such a profound effect on the health of millions of people for something that is so inexpensive, while also reducing the enormous costs of treating cancer, both in terms of actual dollars and human suffering," Frei said. "A multivitamin/mineral is now known to reduce cancer risk in humans."
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Balz Frei, 541-737-5078