ATTENTION GETTING RESULTS. Interest in the study of the effects of antioxidants on malignant melanomas has been enormous. However, criticism has also been forthcoming from people in the dietary supplements industry. Martin Bergö explains the background of the discovery, the resulting commotion – and about being nominated as this Year’s Confuser.
How has the past week been?
“The telephone has rung nearly nonstop and journalists from England, USA, China, Mexico, Argentina and so forth have called. Articles have been published all over the world and the results debated on TV, radio and podcasts.”
Did you expect the study to get so much attention?
“Antioxidants have long been assumed to be something that can counteract cancer, so it was pretty much expected when we had a larger breakthrough this time than we did with the study on antioxidants and lung cancer that we published last year. The background to the widespread “truth” that antioxidants counteract cancer is that free radicals form in all cells that use oxygen.” These are short-lived molecules that can essentially damage everything they react with, and it is well established that free radicals can cause damage to our genetic material, which can lead to cancer. And, as antioxidants can neutralize, “eat up”, free radicals, it has been thought that antioxidants must protect against cancer.”
Have there been any previous studies to check this?
“The best way to test this is by major randomized placebo-controlled clinical studies. A large number have been conducted on several different types of natural and synthetic antioxidants, but when you read them, you see there is no clear finding. In individual cases there has been a protective affect, in most cases no affect at all, and in several cases an increased risk of cancer. The fact is, that for the largest studies that were done, the studies were stopped because the people that received antioxidants received a cancer diagnosis to a significantly greater degree than did the control group. In the first study that was stopped for this reason, beta carotene was tested on tens of thousands of male smokers. In the second study, vitamin E was used on an even larger number of middle-aged to elderly men. Altogether, there is no support for antioxidants protecting against cancer, but rather that they can increase the risk of cancer. All of these studies were done before we joined the field.”
Why didn’t anyone go out with a warning about dietary supplements with antioxidants right after these studies?
“If it had concerned any other drug or foodstuff, then recommendations against using them would have come out directly after the studies. But when it comes to antioxidants it has failed to be done and the result of all of these clinical studies has been left by the roadside. A possible explanation for this, is the belief that antioxidants’ cancer inhibiting effects are deeply rooted in the general public and extremely well marketed by the dietary supplement industry.”
Explain a bit more about your study on the effects of antioxidants on lung cancer that you published in 2014.
“We discovered that the antioxidants acetylcysteine (NAC) and vitamin E worsen lung cancer. The effect was extremely strong in mice with lung cancer and we saw the same effect in human lung cancer cells. The discovery randomly appeared in other studies and in actuality, we had no initial plans to study antioxidants. The effect of antioxidants could be attributed to their ability to eat up free radicals and the effect was dose dependent. The doses are at a level expected by a person taking a dietary supplement of vitamin E or the drug NAC. The factor that compensates for the dose translation mouse-human has been developed by a large number of researchers and the American research board, the NIH.”
“NAC and vitamin E are two completely different molecules and the only thing they have in common is that they can eat up free radicals. No other overdose effects were noted and we carefully researched that both substances affected free radicals in cancer cells as expected. Thus, you can propose that other antioxidants could have same effect as long as they can eat up free radicals. But of course, we test other kinds in follow-up studies.”
Both studies were done on mice. Is it possible that the results would be different with humans?
“Mice are superb models for cancer in humans. The lung and skin tumors that we studied in mice are both molecularly and structurally extremely similar to tumors in people, and doctors specializing in tumors cannot clearly see the difference in a lung tumor from a mouse and a human. When we find an effect in mice, we always pose the question of its relevance to humans and if we cannot prove the effect in human cells then we do not continue the study.”
“In both of our studies, we looked at a large number of cell lines from humans with lung cancer and malignant melanoma, and in both studies, the effect of antioxidants has been similar to the effects on cells from mouse tumors. This in not the case in the majority of the studies that show that antioxidants inhibit cancer cells.”
But antioxidants cannot only be dangerous?
“The conclusion from clinical, genomic and experimental studies is that free radicals are damaging to both healthy and cancerous cells. Thus, antioxidants can protect a healthy cell from becoming a cancer cell – and probably also a healthy person from future cancer. Research on mice from our and other research groups has shown that if you give antioxidants to young healthy mice that are prone to develop cancer later in life, then the risk of tumor development is reduced. But the combined research also shows that as soon as a tumor occurs, antioxidants help the tumor cells either to grow faster (lung cancer) or to spread faster (melanoma).”
“Altogether, our and others’ studies show that antioxidants protect healthy cells from free radicals, but they also protect cancer cells from free radicals. Free radicals are damaging and it does not matter if it is a healthy cell or a cancer cell. But this means that the consequences of a tumor-free person and a cancer patient taking an antioxidant supplement can be the exact opposite.”
But then healthy people can continue to eat antioxidant dietary supplements?
“But the biggest problem preventing a general recommendation that healthy people take an extra dietary supplement of antioxidants is that it is impossible to discover small, undiagnosed tumors. A healthy well-balance diet that naturally includes antioxidants, is the only thing I can personally recommend.
There has been some criticism too. One site has even nominated you for This Year’s Confuser. How do you feel about that?
“Our reasoning is neither controversial nor hard to understand and it has started to take hold in the research world. But as it goes against an older view, it will take time for the results to be accepted by the general public, and the older view will get a lot of help from companies and persons with a financial interest to maintain: The so-called health experts that have complained the most about our studies are most often in the dietary supplement industry and have a lot to lose with this new view. Serious manufacturers and distributors of health food products and skin creams that contain antioxidants often call and want to meet to discuss research and products. We are all responsible for helping cancer patients and when it is discovered that a widely used dietary supplement such as antioxidants could be harmful, you have to shout loudly; and there is no harm in shouting out loud here, as there are no convincing studies that show that these products are good for these patients.”
“Before you spend any money on dietary supplements you should convince yourself that there is scientific evidence of their effect. And in the case of antioxidants, pose the questions: Are there any studies that unequivocally show that antioxidants, synthetic or natural, old or new, can help cancer patients or persons at high risk for cancer? Can I trust the manufacturer’s convincing advertisement and reference to scientific studies? “I appreciate the debate on this and welcome a common analysis of the studies that speak for and against this viewpoint, just email or call me!”
BY: JOHANNA HILLGREN
