Do B Vitamins Cause Lung Cancer In Men

Written by Dr. Steve Chaney on . Posted in B Vitamins and Cancer

Do B Vitamins Cause Lung Cancer In Men?

Author: Dr. Stephen Chaney

 

do b vitamins cause lung cancer in menLast week one of my readers contacted me and asked me to comment on an article in The Atlantic titled: “Vitamin B6 and B12 Supplements Appear to Cause Cancer in Men”. I did what any good scientist would do. I read the original study (T.M. Brasky et al, Journal of Clinical Oncology, 35: 3440-3448, 2017 ) and analyzed the data, so I could provide you with the truth behind the headlines.  Continue reading to find the answer to “Do  B vitamins cause lung cancer in men?”

I will give you my analysis in a minute. First, let me use the internet chatter about this study as a perfect example of how nutrition myths are born.

 

How Did Journalists Interpret The Clinical Study?

Journalists are not trained scientists. They seldom read the whole article. They rely on the abstract of the article and interpret it through their “filter” of reality. The author of The Atlantic article did a reasonably good job of reporting the information in the abstract. However, news articles need to be spectacular to attract readers, so the information was presented selectively.

do b vitamins cause lung cancer in men headlinesThe author was clearly trying to grab your attention by hyping the risk. For example, in page one of his article, he makes the claim that “taking vitamin B6 and B12 supplements in high doses (like those sold in many stores) appears to triple or almost quadruple some people’s risk of lung cancer.”  That is enough to get your attention!

If you read to page 4 of his article, you discover that the 3-4-fold increase in risk only applies to smokers. If you read to page 5, you discover that this only applies to people taking 20 times the RDA of B6 or B12 from individual supplements.

However, in today’s world many readers have the attention span of gnats. They will read the headline and perhaps the first couple of paragraphs. Most readers of The Atlantic article will conclude that supplementation with B6 and B12 causes a 3-4-fold increase in lung cancer in men.  A nutrition myth will be born!

The headlines were similar from other news sources: CNN led with “High Doses of Vitamin B Supplements Tied to Lung Cancer, Study Says”. Huffington Post said: “Men: Taking Vitamin B6 and B12 Could Increase Your Risk of Lung Cancer.”  USA Today said: “Risk of Lung Cancer Increases with Vitamin B, Study Says.”

In all fairness, the articles themselves offered a more balanced interpretation of the study, but many people do not read beyond the headlines. The headlines alerted people to the potential of B6 and B12 supplementation to increase the risk of lung cancer, but readers may miss the fact that this risk is only seen in men, only associated with mega-doses of individual vitamins, and only seen in smokers.

How Will Bloggers Interpret The Clinical Study?

do b vitamins cause lung cancer in men bloggersIt is only a matter of time before the same headlines start appearing in your favorite nutrition blogs. Many bloggers like to create sensational headlines and hype the results of clinical studies. They don’t let the facts get in the way of a good story. Of course, once the claim that vitamins B6 and B12 increase the risk of lung cancer gets repeated often enough on the internet, people will start to believe it must be true. The food myth will become firmly established.

How Will The Medical Community Interpret The Clinical Study?

The medical community usually filters studies like this through a belief system that supplements do more harm than good. They tend to ignore dozens of studies showing the benefits of supplementation and focus on the one of two suggesting they might cause harm. I predict that doctors may start advising their male patients to avoid supplements with vitamins B6 and B12. I also suspect many doctors may start measuring your blood levels of B6 and B12 and warning you to cut back if they are above average.

How Does A Scientist Interpret The Clinical Study?

do b vitamins cause lung cancer in men scientistDo B vitamins cause lung cancer in men?  For a scientifically accurate evaluation of a study like this, one needs to read the study carefully, analyze the data, and evaluate the statistics. Let me walk you through stepwise what I found when I did that.

  • The increased lung cancer risk was only seen in men, not in women. That would be the expected result for prostate cancer, but it is a bit unexpected for lung cancer. There is no apparent mechanism for explaining this effect.
  • There was no effect of folic acid on lung cancer risk.
  • Vitamins B6 and B12 were associated with a 30-40% increased risk of lung cancer in men.  However, that statistic is misleading because:
    • The increased risk of lung cancer was only seen when B6 or B12 were taken as individual supplements. There was no increased risk when B6 and B12 were in a multivitamin where all the B vitamins are in balance.
    • The increased risk of lung cancer was only seen when B6 or B12 were taken as mega-doses greater than 20 times the RDA. There was no increased risk of lung cancer for doses of B6 or B12 that were less than 20 times the RDA.
  • Mega-doses (>20 times the RDA) of vitamins B6 or B12 were associated with a 2-fold increased risk of lung cancer in men. However, that statistic is misleading because:
    • The increased risk of lung cancer in men taking mega-doses of B6 or B12 was only seen in smokers. In the words of the authors: “There were too few [lung cancer] patients among never smokers to evaluate associations [between B vitamins and lung cancer].”

 

Do B Vitamins Cause Lung Cancer In Men?

do b vitamins cause lung cancer in men answerMuch of what you read on the internet about this study is misleading. For example:

  • The claim that vitamins B6 and B12 increase lung cancer in men by 30% was entirely driven by men who were taking >20 times the RDA of B6 or B12 as individual supplements. The risk was zero for anyone taking lower doses B6 and B12.
  • The claim that mega-doses of B6 or B12 increase lung cancer risk in men by 2-fold was entirely driven by male smokers. The risk was zero for non-smokers, even non-smokers taking mega-doses of B6 or B12.
  • The only unambiguous conclusion from this study is that male smokers who take >20 times the RDA of either B6 or B12 as individual supplements have a 3-4-fold increased risk of lung cancer.

So, do B vitamins cause lung cancer in men?

What Does This Mean For You?

The take home lessons from this study are clear.

  • It is almost never a good idea to take mega-doses of individual vitamin and mineral supplements. The only exception is when they are prescribed for a specific medical condition by your health professional and that health professional is monitoring you for potential toxicity.
  • If you smoke, mega-doses of vitamins won’t protect you, and they may harm you. The best advice is to stop smoking.

Those are the scientifically based recommendations from the study. However, you are more likely to hear recommendations that you shouldn’t take B vitamins if you are a man. After all, nutrition myths don’t need to be based on science.

 

The Bottom Line

 

The internet is ablaze with claims that a recent study shows the vitamins B6 and B12 increase the risk of lung cancer in men. These claims are misleading because:

  • The claim that vitamins B6 and B12 increase lung cancer in men by 30% was entirely driven by men who were taking >20 times the RDA of B6 or B12 as individual supplements. The risk was zero for anyone taking lower doses B6 and B12.
  • The claim that mega-doses of B6 or B12 increase lung cancer risk in men by 2-fold was entirely driven by male smokers. The risk was zero for non-smokers, even non-smokers taking mega-doses of B6 or B12.
  • The only unambiguous conclusion from this study is that male smokers who take >20 times the RDA of either B6 or B12 as individual supplements have a 3-4-fold increased risk of lung cancer.

The take home lessons from this study are clear.

  • It is almost never a good idea to take mega-doses of individual vitamin and mineral supplements. The only exception is when they are prescribed for a specific medical condition by your health professional and that health professional is monitoring you for potential toxicity.
  • If you smoke, mega-doses of vitamins won’t protect you, and they may harm you. The best advice is to stop smoking.

Those are the scientifically based recommendations from the study. However, you are more likely to hear recommendations that you shouldn’t take B vitamins if you are a man. After all, nutrition myths don’t need to be based on science

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

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Comments (3)

  • JaNiece

    |

    B does not cause cancer in men

    Reply

    • Dr. Steve Chaney

      |

      That was my message. B vitamins don’t increase men’s risk of lung cancer unless they are a smoker AND take mega-doses

      Reply

  • Linda Fietz

    |

    Thank you again for reminding us to read such articles in Toto
    And that taking individual vitamins can be risky as the body needs all the essential nutrients not just a select few

    Reply

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Latest Article

Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the study, read the article above.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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