antioxidants, beta carotene, do antioxidants work?, pseudoscience, science, skepticism, vitamin C, vitamin supplements
“Antioxidants don’t work, but no one wants to hear it.”
Simply put, we have no evidence that antioxidants are beneficial in humans. Worse yet, as they are commonly sold and taken, they may in fact be dangerous to our health.
According to a clinician writing at Slate:
Their story began in the 1940s when a physician-chemist named Denham Harman set out to determine the biochemical explanation for aging. As a young man, he had worked in the lubricating department of Shell—a place where the problems of a chemical spoilage caused by “free radicals” were well-known. By the mid-50s Harman hit upon the theory that the same free radicals that were cutting into petroleum industry profits could also simply and completely explain the phenomenon of aging. Better yet, he said, their effects could be ameliorated by something called antioxidants.
Before we dive in to what the science has to say, let’s take a look at the background behind antioxidant theory.
Radicals (often referred to as free radicals) are atoms, molecules, or ions with unpaired electrons on an open shell configuration. By shell is meant valence shell, which is the outermost region of an atom, molecule, or ion that is occupied by electrons. This shell is where electrons are exchanged in chemical reactions and bond forming. Free radicals may have positive, negative, or zero charge. With some exceptions, the unpaired electrons cause radicals to be highly chemically reactive. Radicals, if allowed to run free in the body, are believed to be involved in degenerative diseases, senescence and cancers. These diseases are thought to be caused by the radicals “grabbing” electrons off of important genetic material, such as RNA and DNA, resulting in cell deterioration or damage.
The Free-Radical Theory
The free radical theory of aging was conceived by Denham Harman in the 1950s, when prevailing scientific opinion held that free radicals were too unstable to exist in biological systems, and before anybody had invoked free radicals as a cause of degenerative diseases.
Two sources inspired Harman: 1) the rate of living theory, which holds that lifespan is an inverse function of metabolic rate. In turn, this is proportional to oxygen consumption, and 2) Rebbeca Gershman’s observation that hyperbaric oxygen toxicity and radiation toxicity could be explained by the same underlying phenomenon: oxygen free radicals.
Noting that radiation causes “mutation, cancer and aging” Harman argued that oxygen free radicals produced during normal respiration would cause cumulative damage which would eventually lead to organismal loss of functionality, and ultimately death. In later years, the free radical theory was expanded to include not only aging per se, but also age related diseases.
[Via Wikipedia and independently sourced]
What The Science Says
This section will quote heavily from scientific papers and journals. I apologize for the long quotes, but if we are to get to the bottom of this, we should go to the source.
[If you want a general conclusion, you can skip ahead to the section with the title “Conclusions”. However, if you want to know the sources behind the conclusion, I suggest that you keep reading.]
Mount Sinai Department of medicine Symposium
To illustrate just how seriously clinicians take the supposed claims of antioxidants, I will select excerpts from a Symposium: Prooxidant Effects of Antioxidant Vitamins, which contains the aggregate findings from five leading researchers in the field who have contributed to the literature.
Their take on the mechanism of oxidation:
Every antioxidant, including vitamin antioxidants, is in fact a redox (reduction-oxidation) agent, protecting against free radicals in some circumstances, and promoting free radical generation in others. Excessive antioxidant action can adversely affect key physiological processes.
The potential harms of antioxidant supplements are also outlined:
Harms reported from pharmacological amounts (beyond the recommended daily amount) of antioxidant vitamin supplements include promotion of heart disease, cancer and liver and kidney disease.
The symposium also disagreed with how the antioxidant vitamin supplements were marketed:
For truth in advertising, all supplements should be labeled, ‘Physiological amounts of supplements help some people, hurt others, and have no effect on most. Because of their potential for harm, pharmacological amounts should not be taken without the advice of a licensed health professional’.
It certainly seems as though the antioxidant vitamin supplements have no practical value for the consumer. If your goal is health, taking something that either may do nothing, a tiny bit, or harm you is not your best bet.
The symposium then dispels a common myth that all free-radicals in your body are bad:
The reduction of molecular oxygen to water by the addition of four electrons is the major source of energy for animal life. Free-radicals, sometimes called ‘the price we pay for breathing’, are essential for health and life in moderation and harmful to health and life in excess.
Free-radicals are integral to normal body function, and your body has evolved to make the most of these oxidation-reductive processes to remain healthy.
The symposium then outlines a general guideline for nutrition:
Moderation in all things is the essence of sound nutrition. Too little or too much of any nutrient is harmful. More is sometimes better, sometimes worse, but always more expensive.
The concern with excessive intake of antioxidants is a key point. Although some antioxidants may have a small effect, most do nothing, and only are safe in small amounts. As they are marketed, antioxidant vitamin supplements use mega-doses of antioxidants, way beyond the RDA (recommended daily amount). The excess is what then leads to health risks such as kidney disease and cancer, as mentioned above.
Finally, somewhat putting a scientific nail in the coffin of the antioxidant vitamin supplement industry, the authors continue:
The ubiquitous advertising blanketing the lay and professional literature claiming that ‘the safety of antioxidant vitamins E, C and beta carotene is well established (verbatim quote)’ is a deception for profit.
Journal of the Brazilian Chemical Society
A quote from the Journal of the Brazilian Chemical Society:
New terms such as oxidative stress, antioxidant products or pro-oxidant risks are becoming familiar and an increasing number of international scientific conferences and the publication of thousands of scientific articles is an indication of the growing interest that the subject awakens [… ] Currently, the incidence of oxidative stress on the onset and evolution of more than 100 diseases is claimed by several researchers. All these are “realities”, which on the other hand, are lacking of more clinical evidence, are considered by both physicians and health regulatory bodies, either as “myths” or of “secondary” importance.
Journal of the American Medical Association
Furthermore, the science shows that antioxidants may even be harmful. Here’s a quote from The Journal of the American Medical Association:
We searched electronic databases and bibliographies published by October 2005. All randomized trials involving adults comparing beta carotene, vitamin A, vitamin C (ascorbic acid), vitamin E, and selenium either singly or combined vs placebo or vs no intervention were included in our analysis.
Conclusions: Treatment with beta carotene, vitamin A, and vitamin E may increase mortality. The potential roles of vitamin C and selenium on mortality need further study.
Simplified: many common antioxidants, such as beta carotene and vitamin A, offer no mortality-reducing properties, and may even increase the risk of death from certain diseases and cancers.
The National Center for Complementary and Alternative Medicine
If one organization was going to have evidence for the positive effects of antioxidants, it would be the NCCAM. However, the National Center for Complementary and Alternative Medicine has declared that:
There is limited scientific evidence to support the use of antioxidant supplements to prevent disease.
Large, long-term studies (randomized, controlled trials) funded primarily by NIH have generally found that antioxidant supplements have no beneficial effects.
So what we have, on the whole, is every major medical body (some of it sampled here) concluding that antioxidant vitamins and supplements have no benefit and are potentially dangerous.
Axioms of Health
According to doctors Stephen Barret and Victor Herbert, authors of the book highly critical of the supplement industry, The Vitamin Pushers, there are a number of general rules that you can follow that will lead you to good nutrition and health, and away from pseudoscience and falsity.
These are the rules that science would apply to alternative medicine claims, and this is what we can apply to antioxidant claims, with all of the data that we have now gone through.
- What is true about nutrition is not magic, and what is magic about nutrition is not true.
- Science is not about what one believes, but about what the evidence says.
- Nutrition is a science and not a religion.
There are no miracles in nutrition, no quick and easy ways to get thin and toned, no antioxidant super vitamins that will increase your resistance to aging or disease. It doesn’t matter what intuitions you have about the human body or what Chinese priests have been using for a thousand years, nutrition is a science backed by evidence. If there is no evidence, or the evidence shows that it does not work, it does not work. Simple.
- No therapy is effective until it has been objectively, reproducibly and reliably demonstrated to be more effective than a suggestion, a placebo or nothing. [This is why acupuncture, for example, has been shown not to work]
- No therapy is safe until it has been objectively, reproducibly and reliably demonstrated to be as safe as doing nothing.
- If there is any question with respect to safety, before using a product, it must be objectively, reproducibly and reliably demonstrated that the potential for benefit exceeds the potential for harm.
As we have seen many times before, “alternative medicine” is usually deemed as such because it is not recognized in western medicine. But this lack of recognition is not because doctors are in the pockets of “big pharma” or some other such nonsense. It is because these “medicines” are continually shown not to work. This is now the case with antioxidants.
To sum up the antioxidant discussion, I will again quote from the Mount Sinai Medical University Symposium:
Selling megadoses of antioxidant vitamins to fight cancer, enhance the immune system and retard aging, with representations that the products have been demonstrated to do so and have also been demonstrated to be safe is yet another multibillion dollar alternative medicine fraud. [It is a $23 billion U.S. vitamin and supplement market]
And with respect to alternative medicine in general:
The term alternative medicine cloaks many frauds, because the term conceals that there are three types of alternatives: genuine, questionable, and fraudulent […] No matter how compelling or exiting a hypothesis is, we don’t know whether it works without clinical trials.
And as we have seen, the clinical trials tell the same, consistent, verified, repeatable story: antioxidant supplements do not work and may in fact be dangerous.
Especially with “natural” products, there is a seduction that can take many consumers beyond mere concern for their own health. The Naturalistic Fallacy, as I call it, is a tendency for people to assume that anything natural is intrinsically better than an alternative, simply because it is natural. I believe that this fallacy is at the heart of the alternative medicine fraud, along with superstitious human tendencies, wishful thinking, and wanting to take control of your own health.
Of course, it does not help that America has created an industry of pseudoscience sellers to counteract the blinded study, the peer review, and the consensus. With “alternative” and “natural” books, magazines, and TV shows, the public is presented with two powerful, yet entirely unequal viewpoints about the science of medicine. With cranks out there like Dr. Oz and Deepak Chopra, getting across the benefits of science-based medicine has become ever the more difficult. When supposed health gurus like Oz and Chopra go outside their own field and claim “miracle cures”, they are not only setting themselves up for failure, they are promoting bad science. [and raising red flags by going against our skeptical 10 commandments]
Alternative medicine, as it stands today, has on the whole been shown not to work. There are, as far as science can tell, no miracle cures or healing energy fields. If we can get ourselves beyond the confusion between natural and medicine, we can progressively increase our well-being and life-span, but only with a process that has been proven to work. Western medicine is not afraid of alternatives, quite the contrary, any proven alternatives would be embraced wholeheartedly, as doctors are in the business of helping people, not dismissing them. What western medicine is afraid of, however, are people taking advice from health gurus who have no idea how the body works, taking supplements that have not been tested for safety, and leaving their own health in the hands of pop-culture and magical thinking.
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What a load of rubbish, did you actually bother to research the other side?!
Kyle Hill said:
Yes I did. The point of a systematic review study is to look at both sides of the evidence and make a conclusion. The conclusion is that antioxidants do not provide any substantial health benefits and many be harmful as they are marketed.
Well this article certainly played into the pharma-complex real nicely.
Kyle Hill said:
You got me, I’m a lone blogger paid to evaluate evidence about products they most likely also sell.
Thanks so much for this. My only concern is that this article did not appear until the third page of my google search on “do anitioxidants work?” Everything else described how awesome antioxidants are in saving your life. Keep it up; we need more of this.
Just had a cancer specialist from a British hospital on tv here singing the praises of antioxidants – feel so strongly that the public both sides of the atlantic are being duped into believing this anti cancer message. The scientific community need to be more vocal and get the message out there – se well done and keep up the work
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I’ve never commented on any Blog in my entire life but while researching for my thesis in antioxidant behaviour, this article made my jaw drop. First of all you’re attacking antioxidant production and marketing, do not attack antioxidants themselves. Researching quotes and facts about the levels of chemicals and extracts that corporations use in their products is an entirely different topic. Think of the thousands of health benefits that fruits and vegetables provide and then turn to these people and say, “none of these benefits are due to antioxidants”.
Please, for the sake of credibility, change the title of this article to something which is more suited to your argument. Also to the readers, please do not look at a picture of a man wearing a lab coat, holding a test tube, and making the point that his communications degree is focused in ”science communication”, before making your assumptions on these “dangerous to our health” antioxidants. If there are any reasonable questions or comments and if anyone would like to ask anything I have access to almost 40 years of knowledgeable experience in the field of plant physiology and at least two Ph.D’s minimum in antioxidant research behaviour and medical applications.
Kyle Hill said:
I clearly state that interventions that claim to use the power of antioxidants have no evidence for efficacy and have been shown to be potentially harmful. Antioxidants perform many functions in our bodies, but that was not the point of the post. Products that supposedly use antioxidants to treat health problems have no evidence behind them and may be harmful.
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SO should I stop eating stuff with anti-oxidants in it if it’s harmful? I thought fruits and veggies were good for you. I like a lot of tomato products. Is that bad?
And if it’s bad, what is good?
Kyle Hill said:
I apologize for the confusion. What the literature basically says is that there is no significant health benefit from supplementing with anti-oxidants. Anti-oxidants are still necessary for proper body functioning, and therefore you should not be scared away from ingesting them, but they are not “miracle” foods that need to be ingested in large amounts. It is when anti-oxidants are taken in mega-doses (as they are in multi-vitamins and other supplements) that they potentially become dangerous. You should definitely still eat your fruits and veggies, but don’t expect to get amazing results if they have anti-oxidant properties to them.
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Without Antioxidants repairing the cells of your body you would not live to read the end of this post, having said that taking too many extra Antioxidants in the form of supplements can have negative effects on your health. Your body can only use a small percentage of the Antioxidants you take in with a good balanced diet and this reduces rapidly with age from 100% at age 13 to 10% at age 70.
The latest understanding of how Antioxidants are used by the body is on our video at aseahealthdrinks (dot) com
A lot of the vitamin and antioxidant supplements are poor quality and extracts which the body can’t absorb anyway. I’d like to see a study on fresh organic berries. Why isn’t that cited if this is a scrutiny of antioxidants in general?
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