Study: Multivitamins may lower cancer risk in men
America's favorite dietary supplements, multivitamins, modestly lowered the risk for cancer in healthy male doctors who took them for more than a decade, the first large study to test these pills has found.
The result is a surprise because many studies of individual vitamins have found they don't help prevent chronic diseases and some have even caused problems.
In the new study, multivitamins cut the chance of developing cancer by 8 percent. That is less effective than a good diet, exercise and not smoking, each of which can lower cancer risk by 20 percent to 30 percent, cancer experts say.
Multivitamins also may have different results in women, younger men or people less healthy than those in this study.
"It's a very mild effect and personally I'm not sure it's significant enough to recommend to anyone" although it is promising, said Dr. Ernest Hawk, vice president of cancer prevention at the University of Texas MD Anderson Cancer Center and formerly of the National Cancer Institute.
"At least this doesn't suggest a harm" as some previous studies on single vitamins have, he said.
Hawk reviewed the study for the American Association for Cancer Research, which is meeting in Anaheim, Calif., where the study was to be presented on Wednesday. It also was published online in the Journal of the American Medical Association.
About one-third of U.S. adults and as many as half of those over 50 take them. They are marketed as a kind of insurance policy against bad eating. Yet no government agency recommends their routine use "regardless of the quality of a person's diet," says a fact sheet from the federal Office of Dietary Supplements.
Some fads, such as the antioxidant craze over vitamins A and E and beta-carotene, backfired when studies found more health risk with those supplements, not less. Many of those were single vitamins in larger doses than the "100 percent of daily value" amounts that multivitamins typically contain.
Science on vitamins has been skimpy. Most studies have been observational - they look at groups of people who do and do not use vitamins, a method that can't give firm conclusions.
Dr. J. Michael Gaziano, of Brigham and Women's Hospital and VA Boston, led a stronger test. Nearly 15,000 male doctors who were 50 or older and free of cancer when the study started were given monthly packets of Centrum Silver or fake multivitamins without knowing which type they received.
After about 11 years, there were 2,669 new cancers, and some people had cancer more than once. For every 1,000 men per year in the study, there were 17 cancers among multivitamin users and more than 18 among those taking the placebo pills. That worked out to an 8 percent lower risk of developing cancer in the vitamin group.
Multivitamins made no difference in the risk of developing prostate cancer, which accounted for half of all cases. They lowered the risk of other cancers collectively by about 12 percent. There also was a trend toward fewer cancer deaths among multivitamin users, but the difference was so small it could have occurred by chance alone.
Side effects were fairly similar except for more rashes among vitamin users. The National Institutes of Health paid for most of the study. Pfizer Inc. supplied the pills and other companies supplied the packaging.
The main reason to take a multivitamin is to correct or prevent a deficiency, "but there may be a modest benefit in reducing the risk of cancer in older men," Gaziano said.
Cancer experts said the results need to be confirmed by another study before recommending multivitamins to the public. These participants were healthier - only 4 percent smoked, for example.
For people who do want to take multivitamins, doctors suggest:
The result is a surprise because many studies of individual vitamins have found they don't help prevent chronic diseases and some have even caused problems.
In the new study, multivitamins cut the chance of developing cancer by 8 percent. That is less effective than a good diet, exercise and not smoking, each of which can lower cancer risk by 20 percent to 30 percent, cancer experts say.
Multivitamins also may have different results in women, younger men or people less healthy than those in this study.
"It's a very mild effect and personally I'm not sure it's significant enough to recommend to anyone" although it is promising, said Dr. Ernest Hawk, vice president of cancer prevention at the University of Texas MD Anderson Cancer Center and formerly of the National Cancer Institute.
"At least this doesn't suggest a harm" as some previous studies on single vitamins have, he said.
Hawk reviewed the study for the American Association for Cancer Research, which is meeting in Anaheim, Calif., where the study was to be presented on Wednesday. It also was published online in the Journal of the American Medical Association.
About one-third of U.S. adults and as many as half of those over 50 take them. They are marketed as a kind of insurance policy against bad eating. Yet no government agency recommends their routine use "regardless of the quality of a person's diet," says a fact sheet from the federal Office of Dietary Supplements.
Some fads, such as the antioxidant craze over vitamins A and E and beta-carotene, backfired when studies found more health risk with those supplements, not less. Many of those were single vitamins in larger doses than the "100 percent of daily value" amounts that multivitamins typically contain.
Science on vitamins has been skimpy. Most studies have been observational - they look at groups of people who do and do not use vitamins, a method that can't give firm conclusions.
Dr. J. Michael Gaziano, of Brigham and Women's Hospital and VA Boston, led a stronger test. Nearly 15,000 male doctors who were 50 or older and free of cancer when the study started were given monthly packets of Centrum Silver or fake multivitamins without knowing which type they received.
After about 11 years, there were 2,669 new cancers, and some people had cancer more than once. For every 1,000 men per year in the study, there were 17 cancers among multivitamin users and more than 18 among those taking the placebo pills. That worked out to an 8 percent lower risk of developing cancer in the vitamin group.
Multivitamins made no difference in the risk of developing prostate cancer, which accounted for half of all cases. They lowered the risk of other cancers collectively by about 12 percent. There also was a trend toward fewer cancer deaths among multivitamin users, but the difference was so small it could have occurred by chance alone.
Side effects were fairly similar except for more rashes among vitamin users. The National Institutes of Health paid for most of the study. Pfizer Inc. supplied the pills and other companies supplied the packaging.
The main reason to take a multivitamin is to correct or prevent a deficiency, "but there may be a modest benefit in reducing the risk of cancer in older men," Gaziano said.
Cancer experts said the results need to be confirmed by another study before recommending multivitamins to the public. These participants were healthier - only 4 percent smoked, for example.
For people who do want to take multivitamins, doctors suggest:
- Be aware that they are dietary supplements, which do not get the strict testing required of prescription medicines.
- Ask your doctor before taking any. Vitamin K can interfere with common heart medicines and blood thinners, and vitamins C and E can lower the effectiveness of some types of chemotherapy. For people having surgery, some vitamins affect bleeding and response to anesthesia.
- Current and former smokers should avoid multivitamins with lots of beta-carotene or vitamin A; two studies have tied them to increased risk of lung cancer.
Why is it that they only created the study around male subjects? Why did they not include female subjects as well? Afgter all, we ARE 50% >/< of the population! It would have been interesting to see if the same results would have applied to female subjects.
 @LocalLady Unfortunately, women are still considered to be second class citizens far too often.
After hearing the multiple risks and side effects on TV for MANY FDA approved drugs, I don't think I'd count on them to "regulate" anything. Also there is a health risk, whether it be large or miniscule, with putting anything into your body. Some people prefer or even need a special diet or supplements. It comes down to doing your own research on what is in a specific multi-vitamin or other supplements, knowing what is in them, the amounts, and what their health benefit is. Also the test above is flawed because of individual diet, quantity of exercise, quantity of water consumed each day, age, and location; all proven to be health related factors.
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Personally I take supplements for weight lifting but I'm careful in what I purchase to make sure unnecessary fillers aren't in them. In the end it all depends on why you need a supplement, or if you even need one at all.
People who take multivitamins are more likely to be concerned about their health and what they eat.
@graciegal This. This article could have been about a study that claims that opening more childproof plastic bottle caps may lower cancer risk, and it would have made no change in the informational value of either the study or the article.
@graciegal - I think it also applies to people who believe if they don't eat their n veggies, cant afford healthy foods or have a medical condition like lactose intolerance or IBS they use vitamins under the guise that they supplement their dietary needs. So it's not what you pointed out solely.
It's all so confusing. They were saying not too long ago that vitamins were a waste of money and that they didn't do anything at all.
 @alildifferent Some vitamins for some people ARE a waste of money, others are not.
Multivitamin can mean so many different things, the way the media reports these studies is so much hoopla. You can bet that if there was a negative correlation to cancer the headlines would infer that ALL vitamins and supplements are bad for you. There are too many variables. Just one addition or deletion, type or dosage variance in a multi makes comparison for scientific reasons null. Just because this study is broadcast as positive for vitamins does not mean it should be exempt from the same scrutiny as similar studies for negative results. Do the research on your own and ignore mainstream media propaganda.
While Aspartame has show to increase Brain cancer by 57%. People, you need your vitamins and organic produce and grass fed or free range meats! Stay away from the garbage foods and GMO products such as corn and Soy by products.
 @TheSkyIsFalling To my knowledge there have never been any double blind test studies done to support your statements. There HAVE been collection of anecdotal evidence that would lead to a support of these statements but no definitive proof.
 @TheSkyIsFalling Citation, please?
The medical community has been slow to recognize that there are things people can do to help them stay healthy. I have an autoimmune disease, it's called psoriasis. Sounds like no big deal? Autoimmune disease are on the rise because of diet choices and antibiotic use and abuse.
Some people are genetically predisposed to this disease, but it takes something to get it going. I have never been offered diet or supplement choices for this by my general physician or my dermatologist. They received thousands of dollars for helping me mask the problem with powerful coticosteroids instead of clearing it, and causing damage with those drugs. It's taken me a thousand hours of reading and rating info on the web, and I am being successful. It had gotten into my joints but I am reversing it. I can almost teach a course on this now but understanding is the first step. I guess everybody is still learning. I enjoy it. It's easier to find the information now, just takes TIME and PERSEVERANCE.
It does not matter how slowly you go so long as you do not stop. Confucius
 @Elvis Doctors know medicines (A pill for every ill), not Nutrition. Food can make us sick, it can also heal you. Our immune system is a very powerful thing, if you feed it right. I highly suggest that you take the time to watch "Fat, Sick and Nearly dead", along with "Food Matters" It is amazing what food can do for your health, bad or good!
 @TheSkyIsFalling  @Elvis Thanks for that. Severe psoriasis is more common in obese people, so diet is very important. Getting enough fiber to regulate sugar is important I have learned more than the average layman about bacterial relationships with many processes that are the gears of the machine. These bacteria need our tender loving care because like the bees, we need them more than they need us. Antibiotics in the environment and the food chain need to be reevaluated.
It's been recently found that the plaques on the psoriasis afflicted skin is the same as that found in the vascular system of people with heart disease. It is a good idea to get it under control. If they could cure psoriasis, they could cure heart disease.