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Vitamins And Cancer: Looking In The Wrong Places

by Dr. Len November 05, 2008

Are we looking for cancer prevention clues in all the wrong places?  That is the question I am asking myself as another vitamin theory bites the dust.


A report in this week’s Journal of the American Medical Association (and supported in part by research funding from the American Cancer Society) examined the relationship between folic acid, vitamin B6 and vitamin B12 and breast cancer.


The bad news? A combination vitamin pill did not reduce the risk of breast cancer. 


The good news? A combination vitamin pill did not increase the risk of breast cancer, or any other cancer.


In the study, the researchers examined the effect of giving a daily dose of the three vitamins in a single pill to a group of women who were at high risk of heart disease.  Half the participants received the vitamins, and the other half took a placebo (or dummy pill) that did not contain the vitamins.


After a little over 7 years of treatment, there was no difference between the two groups of women with respect to the incidence of breast cancer or any other cancer.  There was also no difference in the frequency of cancer deaths between the two groups


The theory behind this research was that these particular vitamins play an important role in orderly cell growth, and therefore may prevent cancer. 


The reason the theory is so attractive is the same as it is for every vitamin claim: vitamins are easy to take, inexpensive, and thought to be harmless.  For many of us, they are a part of our daily routine.  What could be easier than popping a vitamin pill in the morning to prevent cancer and a host of other diseases?


The problem is—as it has been for many years—that when the vitamin claims are subjected to the magnifying glass of a well-done clinical trial, the claims simply don’t hold up.


Trust me, I know.  Years ago, vitamin C and vitamin E were the rage.  I took them until the research didn’t support the claims that they reduced the risk of cancer and heart disease, respectively. 


Then there was folate, which many of us take that as part of our daily multivitamin tablets.


First folate was reported to reduce the risk of colorectal cancer.  More recently, some research suggests that folate may promote polyp growth for people who already have colon polyps possibly resulting in an increased risk of colon cancer.


To be honest, the research on the risks and benefits of folate in colorectal cancer is conflicting and confusing to medical experts, let alone people who are trying to make the right decisions about their health.


This is important, since beginning in 1998 folate was added to our food in an effort to reduce the incidence of a certain birth defect in the spinal cord.  The food fortification program has been successful, and blood levels of folate in our bodies have increased over the past decade.


But now there is concern—in part because of the research results noted above—that too much folate may actually cause harm, and increase the risk of some cancers.


That’s why this study’s negative outcome is so important: folate did not increase the incidence of colorectal cancer or any other cancer.


Do you find yourself asking the question how something so simple—and so “natural”--as a vitamin can hurt people? 


If we hadn’t done the research, we would all be taking large doses of vitamin C to prevent cancer (it doesn’t).  We would never have found out that beta carotene leads to an increased risk of lung cancer in heavy smokers.  We wouldn’t know that vitamin E and selenium—alone or in combination—did nothing to reduce prostate cancer in men.


Next on my list is vitamin D.  But we won’t have definitive answers to questions about the cancer-related benefits and risks of the “sunshine vitamin” for years.


Maybe we are looking for cancer prevention in all the wrong places, and maybe not. 


It would be great if something as simple as a vitamin pill would ward off the risk of cancer.  Right now, however, the vitamins aren’t scoring any home runs in the cancer prevention arena.    


For now, we are just going to have to do things the old fashioned way: eat your five fruits and vegetables a day, maintain a healthy weight, eat a balanced diet, and exercise, exercise, exercise.


I know.  That’s much more complicated than taking a vitamin pill once a day.  But at least we know those are strategies that work for reducing your risk of cancer.


Broccoli, anyone?







Filed Under:

Breast Cancer | Prevention | Vitamins

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About Dr. Len

Dr. Len

J. Leonard Lichtenfeld, MD, MACP - Dr. Lichtenfeld is Deputy Chief Medical Officer for the national office of the American Cancer Society.