photo: Patrick Feller
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
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:
http://www.webmd.com/cancer/news/20140129/could-antioxidants-speed-up-cancer-progression;
http://www.sciencedaily.com/releases/2014/07/140710094434.htm;
http://www.cancer.gov/cancertopics/causes-prevention/risk/diet/antioxidants-fact-sheet.
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!
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