Tag Archive for: vitamin B6

B6, B12, and Lung Cancer

The overwhelming message from the study I’ve been reviewing this week: don’t smoke cigarettes. Period. That’s the true cause of most cases of lung cancer. There was no increase in lung cancer in subjects taking high doses of B6 or B12 who never smoked or in those who quit more than 10 years before the study began. While the increased risk applied only to men, women shouldn’t smoke either: 44% of those who got lung cancer were women.

For those men who still insist on smoking or quit less than ten years ago, is there anything to be concerned about if you megadose on B6 or B12? It’s hard to know for sure.

I spoke with the primary author via email. Dr. Ted Brasky and I have battled over omega-3s in the past but minor disagreements in methodologies aside, he is a top-notch researcher. He doesn’t think the B vitamins cause cancer. What he thinks may be happening is that the carcinogens in cigarette smoke cause damage to lung cell DNA, and the excess B vitamins may be enhancing the initiation of cancer. I agree with him.

The question is why might this be happening? The lack of B vitamins seems to reduce the DNA repair process, so increasing to normal levels seems to help. But overdoing it may not be beneficial. Some smokers are taking high-stress B supplements with hundreds or thousands of micrograms of B12. Those are the smokers who could be at risk.

There are two explanations that make sense to me. First, there may be a mutation in the gene that manufactures the enzyme methylenetetrahydrofolate reductase, the enzyme that helps convert homocysteine to methionine. That enzyme requires B12, but perhaps it malfunctions and the B12 becomes toxic to the cells damaged by smoking.

The second explanation comes from the article itself. When trying to explain the factors that could impact this relationship between smoking and vitamin intake, researchers suggest there may be a difference in the absorption, utilization, or distribution of the vitamins. In other words, some people may absorb more vitamin B6 or B12 than others, resulting in a higher circulating amount and thus more available for cells to use. In normal conditions that may be fine but with smoking-induced damage, it may not. The fact is we just don’t know at this time.

 

The Bottom Line

Back to addressing those headlines. If you don’t smoke, there is no problem based on this study. If you do smoke, taking a multivitamin, a B-complex with reasonable amounts of B vitamins, or using energy drinks should present no problem: the study showed no increases with the amounts found in those types of products. If you do smoke, until there is research to clarify the actual cause, limit your intake of high-stress Bs or megadoses of vitamins B6 and B12.

Or maybe the best idea is to just quit smoking. I know it’s hard; I smoked back when I was young and thought myself immortal. You have my sympathy, but my advice is to quit any way you can.

What are you prepared to do today?

Dr. Chet

 

Reference: J Clin Oncol. DOI: https://doi.org/10.1200/JCO.2017. 72.7735

Behind the Misleading B Vitamin Headlines

Headlines are designed to be provocative. With so many sources of news to choose from, something must get you to click on that link. The problem is when the articles and posts are misleading and, in some cases, just wrong. There were primarily two things wrong about the two online articles I cited in Tuesday’s Memo. I could have picked just about any articles about the study but these were the highest profile.

First, the headlines and the body of the text in both articles implied that the increased risk applies to everyone who uses high doses of vitamins B6 and B12. That’s false. There were so few cases of lung cancer in non-smokers, they saw no reason to analyze that data. Either that’s outright deception or the reporters didn’t read the study.

Second, the word “cause” was used in some headlines, and that’s just false. This was an observational study; the original data on supplement use was collected at the beginning, and then the researchers observed the health of the subjects via a centralized medical database. That type of study shows there’s a link of some kind but cannot show cause and effect.

What did the study actually say and what did the study author say about the results? I’ll let you know on Saturday.

One more thing: we try to make our Memo headlines grab your attention by using key words or asking an intriguing question. That’s part of the business of online information. But if we ever have a headline that’s truly misleading, I expect you to call me on it. Being reliable, trustworthy, and factual are our goals.

What are you prepared to do today?

Dr. Chet

 

Reference: J Clin Oncol. DOI: https://doi.org/10.1200/JCO.2017. 72.7735

 

Do Vitamins B6 and B12 Cause Cancer in Men?

The headline in The Atlantic said: “Vitamin B6 and B12 Supplements Appear to Cause Cancer in Men.” The Huffington Post said: “Men: Taking Vitamins B6 and B12 Could Increase Your Risk of Lung Cancer.” There were few news sources that didn’t pick up this provocative headline. As you might expect, I started to get questions about the study almost immediately from people who take B vitamins and who drink energy drinks. Exactly what is going on? That’s what we’ll examine in this week’s Memos. Today we’ll take a look at the study.

The Vitamin and Lifestyle study (VITAL) collected information from over 77,000 men and women in western Washington State. The subjects were 50 to 76 when data collection began in 2000–2002. Participants completed a detailed questionnaire on supplement use, a food frequency questionnaire for diet, and a lifestyle questionnaire focusing on risk factors for cancer. The focus was to recruit supplement users.

In an analysis of the data on smoking patterns and the use of folic acid and vitamins B6 and B12, researchers found that men who smoked while taking high amounts of vitamin B6 and B12 had a significantly increased risk of lung cancer. The same results were not found in women.

Those are the results. We’ll take a closer look at the accuracy of the headlines on Thursday.

What are you prepared to do today?

Dr. Chet

 

Reference: J Clin Oncol. DOI: https://doi.org/10.1200/JCO.2017. 72.7735