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Ask Dr. Mike: Can Supplements Increase Your Risk of Cancer?

Here you'll find the answers to a wealth of health and wellness questions posed by Healthy Talk fans. Listen in because what you know helps ensure healthy choices you can live with.

Today on Healthy Talk, you wanted to know:

I came across the headline on Fox News Health that supplements may raise and now lower cancer risk. Do you know anything about this?

Dr. Mike has heard about this and has a rebuttal that he wants you know to know about. The first thing he wants you to know is that these statements the media is headlining have not come from research, but rather a lecture presentation. There's no new evidence that was presented in Dr. Tim Byers lectures about this, but instead studies from over 20 years ago that have several flaws and which doctors have revisited.

One of the studies Dr. Byers described was a 1996 study in which synthetic beta carotene vitamin A increased lung cancer risk in some people. However, Dr. Byers failed to mention that the participants in the study were smokers and also asbestos workers.

Dr. Mike has over 13 clinical trials that show benefits for heart disease, cancer, and brain health with all kinds of supplements.

It's hard as a consumer to completely trust everything that you read and watch on the news. Most studies have flaws, which is why it's so important that you look at all the research available so you get all the facts on studies.

If you have a health question or concern, Dr. Mike encourages you to write him at This email address is being protected from spambots. You need JavaScript enabled to view it. or call in, toll-free, to the LIVE radio show (1.844.305.7800) so he can provide you with support and helpful advice.

RadioMD Presents:Healthy Talk | Original Air Date: April 28, 2015
Host: Michael Smith, MD

It's time for you to be a part of the show. Email or call with questions for Dr. Mike now. Email: This email address is being protected from spambots. You need JavaScript enabled to view it. or call: 877-711-5211. What are you waiting for? The doctor is in.

DR MIKE: Alright. This This first question comes from a gentleman named Scott. He says, "Hi Dr. Mike. I love your show."

Thanks. I appreciate that, Scott.

He says, "I came across the headline on Fox Hews Health: 'Supplements may raise, not lower cancer risk' Do you know anything about this? Thanks, Scott."

Scott, I do. You know working at Life Extension we are often leading the industry in writing the rebuttals to these types of reports and reviews and presentations and studies. We have a whole department. Our scientific affairs department here led by Dr. Luke Huber, who is just an amazing guy and I have the rebuttal right here to what you are talking about.

So, let me just pull this out. There's a lot here but I've summarized it for us, Scott.

First of all, I think, Scott, you are right. It wasn't just on Fox News, by the way. I think this was played in many different media outlets but the same basic headline – 'Supplements May Actually Raise Cancer Risk'. So, what's interesting about this, Scott, is this didn't come from research. It actually came from a presentation by guy Dr. Tim Byers of the University of Colorado. And he was speaking at the American Association for Cancer Research, which, I think, was may be like a couple of weeks ago. Something like that. He reviewed in this presentation old studies with known flaws. Flaws that we've already brought out in several of Life Extension's publications.

So, no new evidence, nothing new, was presented by Dr. Byers in his lecture. And Dr. Byers reviewed findings from previous studies. I'm reading this from some of that rebuttal we wrote. One from nearly 20 years ago--so, this wasn't anything new--in which specific dietary supplements were linked with small increases in risk of certain types of cancer and select populations. Now, what's really amazing is how the media picks this up and describes that as a new study and then implicates all dietary supplements. When it really was old studies about very specific nutrients and, of course, these studies have all kind of flaws as well.

And here is something interesting you should know, Scott. In Dr. Byers' presentation, he didn't present any of the studies that showed multivitamins and specific nutrients actually reduce cancer risk. He didn't present any of that. He only presented the old studies showing potential problems with specific nutrients. And again, those studies have a lot of flaws.

So, I wanted to just kind of review some of this with you. One of the studies that Dr. Byers described was from a 1996 study that was published in the New England Journal of Medicine in which synthetic beta-carotene along with Vitamin A increased lung cancer risk in some people. He presented this information. Here's what was interesting about this. The study subjects and the study that Dr. Byers presented, that eventually the media picked up and said, "All supplements have a problem"? The study subjects Scott, were smokers and asbestos workers only. As a matter of fact, this study that Dr. Byers described, the conclusion of the study actually says: "After an average of 4 years of supplementation, the combination of beta carotene and Vitamin A may have an adverse effect on the incidence of lung cancer and on the risk of death from lung cancer, cardiovascular disease at any cause in smokers and workers exposed to asbestos."

And somehow that becomes extrapolated to the general population. You can't do that in science. As a matter of fact, Scott, in this same study—the same study that Dr. Byers is presenting, again, published in the New England Journal of Medicine in 1996--in that same study they reported-- the original investigators, researchers-- reported former smokers in the beta-carotene and Vitamin A supplement group actually showed a trend towards less cancer. Less. But he did not mention that. Many of the studies that Dr. Byers used in his presentation, many of the stats that he used never reached what we call "statistical significance". To know if a difference between two groups, like a control group and a test group, to know if the difference you are seeing in the study is real, and something you can trust, the difference has to be at a certain level and that's called statistical significance. Most of the data that Dr. Byers presented did not reach that kind of statistical significance. There are other problems, you know, in that same study.

We already know that synthetic beta-carotene is probably not the best thing to use. Also, synthetic beta-carotene has a toxic interaction with alcohol. And that was never teased out in this study. Of course, Dr. Byers never read that as a caveat during his presentation. And by the way, Scott, another different New England Journal of Medicine study published the same issue, 1996, found no risk for long term beta-carotene supplementation. This was a larger and longer study; there was no association between beta-carotene supplementation and cancer, heart disease or mortality.

In fact, in the beta-carotene group, there were slightly fewer cases of almost all cancers, including lung cancer and fewer heart attacks or strokes. These results were confirmed later on in 1999 in a study of nearly 40,000 women that found no increase in risk of cancer or heart disease from beta-carotene supplementation. Dr. Byers decided not to present that data. Another study that Dr. Byers talked about was published in 2009 in the Journal of the National Cancer Institute. The study found and increased risk of prostate cancer among users of folic acid supplements. But, of course, this study definitely has some flaws in it, some design flaws. First of all, in the study that Dr. Byers presented, Scott, no attempts were made to detect cancer at baseline through systematic screening of study participants. So, men with pre-existing prostate cancer at baseline, they were never identified.

So, that just adds some credibility issues when you look at the final results. Plasma folate was actually associated with decrease risk of prostate cancer. A 44% reduction in the risk for prostate cancer was seen for the people with the highest levels of plasma folate. So again, there are some issues with design, initial baseline reporting of the patients that were involved follow up and, of course, none of those types of potential problems were brought up in Dr. Byers' presentation.

Just to kind of sum up, there is a whole bunch more here that I could go through. Let me just tell you this real quick, Scott. I have here evidence supporting dietary supplements and vitamins. I have 14 large prospective clinical trials showing benefits for heart disease, cancer, brain health with all kinds of different supplements. But here is the thing that happened.

Dr. Byers presented a very biased presentation against supplements. It wasn't really against supplements. It was about specific nutrients like synthetic beta-carotene. He did not present positive studies, and there are plenty and the media picked this up and kind of grouped this to become all supplements have some issues with cancer.

Not just like, say, the beta-carotene. And that's what we are dealing with. That's what we are fighting against, Scott, is the type of science bias, media bias against supplements and I think it's just something we have to be diligent in counteracting. So this wasn't even a study, nothing new. It was simply a presentation and it was very biased.

This is Healthy Talk on Radio MD. I am Dr. Mike. Stay well.