Do B-Vitamins Cause Lung Cancer?

Last week, I told you about the incredible effectiveness of biotin (vitamin B7) for helping with hair loss.

After that article came out, I was reminded of an article in The Atlantic that caused a stir a few years ago. The article claimed that some B vitamins can cause cancer in men.

The writer reported that men taking even modest doses of the vitamins B6 and B12 had three to four times the risk of getting a particular kind of lung cancer than men not taking the supplements.

So, if you are like me and for the past 30 years have been taking fairly stiff doses of all the B-vitamins including B6 and B12, what should you do?

If you listen to this type of reporting, it sounds like you might as well take up smoking! Well, hold on for a second, and don’t immediately throw your vitamins under the bus. There’s a lot more to this story.

For one, the so-called risk was only discovered in men. The study failed to show any increased risk in women. Now, that’s really interesting because, statistically, among non-smokers, women are twice as likely to get lung cancer as men. If the vitamins were really playing a role in why the men had an increased risk of lung cancer, it would mean that the vitamins protected the women against the same cancer that it caused in the men. And that’s impossible.

A much more likely answer is that either there are other factors that increased the risk in men or there was a flaw in the study. The reality is that the increase in lung cancer only in men is a self-contradictory finding.

Secondly, the increased risk found in men was seen only in certain cancers. Specifically, it was not seen in adenocarcinoma lung cancers. If something really does cause lung cancer (like cigarettes, for example), the increase in cancer goes up across the board. The fact that it did not go up in what happens to be the most common lung cancer in non-smokers also indicates a probable flaw in the study.

Third, there are other studies that reach very different conclusions. For example, one study titled, “Cancer incidence and mortality after treatment with folic acid and vitamin B12” looked at over 3,000 men and women. Some of them were taking B12 and another B-vitamin folic acid, and some were not.

At the end of the study, there was an increase in lung cancer in the vitamin group, but it was nowhere close to three to four times the risk. It was only 0.2 times increased risk. If either of these studies were anywhere close to valid, why do the results differ by a factor of 20? And then there’s the study that appeared in the Archives of Internal Medicine in 2012.

That study looked at 2,501 men and women between the ages of 45 and 80. The researchers divided the participants into four groups. They supplemented group one with the B-vitamins folate, B6, and B12, group two with fish oils, group three with the same B-vitamins and fish oils, and group four with a placebo. They were looking for any kind of increased cancer risk.

Here’s what the authors had to say about their results: “There was no association between cancer outcomes and supplementation with B vitamins.” That seems pretty clear. No increase in cancer of any kind, including, of course, every kind of lung cancer.

So, not only do the results of this new study appear self-contradictory, they also contradict at least two other studies looking at the same thing. And then there’s always common sense. How could any substance, much less a natural one like a B vitamin, cause lung cancer in men but not in women? These are the reasons why I’m going to ignore the improbable results in this study and continue to take my B vitamins.

Yours for better health,

Frank Shallenberger, MD