June 15, 2015

Antioxidant Supplements: Bad Idea?

By Tiffany Reiss

This is a post by Cranky Fitness contributor Tiffany Reiss, a university professor who, unlike the slothful Crabby McSlacker, actually knows a lot about nutrition and bothers to go beyond the headlines with some actual research and thoughtful analysis. As I've mentioned before, Tiffany is one of the innovators behind the website The Hub Edu, which lets users to build a digital library of resources and share with others.  (In beta but very cool, and free!) More about Tiffany can be found by scrolling down on our info page.  --Crabby

Antioxidants: the pros and the cons: This concept is something that more often than not confuses my students, and at the very least is very eye opening for them.

We have all heard it, read it, been bombarded with it over the past couple of decades. Aging is bad. And what causes aging?  Why it's those little free radicals (or Reactive Oxygen Species (ROS) flying around in our bodies that damage cells and even our DNA that in turn, cause aging and possibly any number of physiological dysfunction (including cancer).

It sounds really bad doesn’t it? I envision something akin to evil flying monkeys from the Wizard of Oz flying around in my body wreaking havoc on my cell structures, and even worse, damaging my DNA which then replicates. And before I know it, I am damaged, diseased and old looking because of my damaged cells and DNA. The horror.

I obviously need to be doing something about this and look, up in the sky, it’s a bird, a plane – no it’s Super-Antioxidants to the rescue!

It's wonderful to think there is something I can eat in natural foods and even better, take in pill form, that will stop these flying monkeys and prevent all of this damage in my body. And because I exercise, I am also theoretically probably producing more free radicals and therefore I should be consuming lots more of these Super-Antioxidant things to beat up all of those free radicals before they can cause any damage. It’s Vitamins E and C flying around in capes in my body beating those little free radicals to death, it’s all out war!

Well actually, in theory those antioxidants should really be absorbing (or bonding with) those free radicals, not just beating them up. Maybe Pacman is a better analogy…but you get the picture.

Aside from the problem of a multi-billion dollar supplement industry that will sell us anything and everything that gives us the illusion that we can somehow pop a pill and make ourselves “healthier” and “happier,” here is where the whole antioxidant supplement promise goes awry:  We have villainized something that is not only natural, but might actually be helpful under certain circumstances: free radicals.

Ask any person on the street and I assume most would tell us that free radicals are “bad” and antioxidants are “good”. Even if they don’t know the context, most people at least know that much. Well, free radicals can be bad but they can also be good…just like antioxidants.

We probably all know that we should avoid those synthetic supplements and eat lots of fresh fruits and vegetables to get our antioxidants that way. And yes, we should eat lots of fresh fruits and vegetables. But when might antioxidants not be such a good thing, especially in supplement form?

Free radicals damage cells and our DNA. Check. How can this ever be good? Well perhaps when we already have a cancer diagnosis or are beginning to develop cancer itself. There is emerging evidence that a) free radicals might actually be a natural defense mechanism against cancerous cells and b) if we are loading up with antioxidants that block the free radicals…well, now the cancer cells have free reign. In addition, our cells seem to kind of sequester both ROS’s and antioxidants as their own defense mechanism, especially cancer cells. Lots of new evidence to back this up and when you think about it, it actually kind of makes sense.

For example:

Now I don’t think anyone is suggesting antioxidants might actually cause cancer. The cells in our body are constantly multiplying and dying. There is a lot of opportunity for something to go wrong and for cells to start proliferating out of control (cancer). And much of that does seem to be caused by….free radicals.

Here is another example of when free radicals are actually good for us. When we exercise, we damage our tissue. The higher the intensity and the longer the duration of the activity (or the more novel it is), the more damage we do. Well any exercise enthusiasts knows that from this perspective, damage is a good thing, because without it, we would never adapt. When exercising, our bodies literally need to be broken down to build them back up.

Well, what do you think causes all of that damage, so eventually we can adapt and improve? Free radicals. Without them, the damage doesn’t occur or doesn’t occur to the same degree and therefore the adaptations are lessened as well. There is a growing body of evidence to support this as well:
http://www.ncbi.nlm.nih.gov/pubmed/22060178; http://www.jissn.com/content/11/1/4. Again, the benefits of supplements are certainly called to question, as might be the overconsumption of natural antioxidants.

So what does all of this tell us? I don’t think this means you no longer have to eat your spinach…but it does suggest this is way more complex than we originally thought or that my super hero analogy would suggest. The literature is pretty consistent on the idea that consuming antioxidants in supplement form at best isn’t helping and at worst might actually be doing more harm. However, there is no evidence to suggest that natural antioxidants found in natural foods cause or worsen cancer or prevent exercise adaptations and the literature seems to suggest that as long as we don’t over-consume too many natural foods loaded with antioxidants, we should also be okay.

In other words, consume a balanced, varied diet including fresh fruits and vegetables and yes, keep exercising! Only take supplements if you are deficient in something and a medical professional recommends it. All this science and it may really be that simple!


  1. I'm pretty up to date on this information as I have blogged about it also :-)

    I still take Vit C and E as well as chromium picolinate and melatonin, and quercetin occasionally. I'm a believer in Linus Pauling (and I like Linus from Charlie Brown too :-)

  2. "In other words, consume a balanced, varied diet including fresh fruits and vegetables and yes, keep exercising! Only take supplements if you are deficient in something and a medical professional recommends it."

    After many years of reading news stories about the latest and greatest health findings, this is pretty much where I stand.

  3. Well Dr. J it's like I tell my students, we will all die eventually, statistically from some kind of chronic disease or complication from a chronic disease no matter how well we eat or how much we exercise! I do think the evidence is beginning to pile up against the benefits of supplements, but will we truly ever know if they are helpful are harmful given the complexity of the human body and individual genetic constructs? I don't know...that's an entirely different field of study.

    You might find this pretty thorough synopsis of this topic here interesting: http://www.theatlantic.com/health/archive/2013/07/the-vitamin-myth-why-we-think-we-need-supplements/277947/

    Worth a read anyway.


    1. I decided long ago I couldn't wait for medicine to make up its mind while my life was ticking away. So I made my choices and have stuck with it. If you knew me, you would think what I'm doing is working.

  4. Death Ride GrandmaJune 15, 2015 at 1:12 PM

    Thank you! I love reading anything that reminds us that magic solutions almost never turn out to be, well, magical. I just finished a book, "Vitamania" by Catherine Price. Like your post here, it may help us all think harder about the whole supplement world, and keep us going for variety and freshness in our diets. If we were to go back over the last twenty years and list the supposed villains and heroes in the food and supplement worlds, we'd find almost everything but vegetables (heroes) and sugars (villains) spends a bit of time in both categories (dairy, fats, carbs, vitamin A, whole grains, margarine, alcohol, coffee, eggs, bran muffins...the list is endless). So I plan to keep on eating potatoes, and to accept the fact that I just don't like kale - but always keep working towards a better overall mix.

    The trouble is, your so-wise final paragraph doesn't sell fancy new stuff. I wish we could get smarter about that!

  5. There is no magic bullet. Eat a well balanced diet, exercise, take a vitamin if you and your doctor agree it's right for you, and for heaven's sake, buckle your seat belt! The younger you are, the more likely you are to die from something accidental.

  6. Today it's anti-oxidant A, tomorrow it's B. Get enough sleep, eat a balanced diet, get enough physical activity, don't smoke, relax. I believe clean lifestyle habits are more effective than the next star supplement.

  7. I have watched the antioxidant debate across the years with detachment, since I decided quite young that the only dietary restrictions I would accept were from allergy. (Not being able to breathe through your nose is quite a convincing reason.)

    Mary Anne in Kentucky

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  9. An antioxidant supplement is very beneficial to human health in conjunction with good nutrition and regular exercise. We can also buy some good health supplements by some online store which is very beneficial for health.


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