Thursday, July 12, 2007

Are Antioxidants Dangerous?

Since the late 1980s antioxidants have been heralded as molecules that are dramatically important to our health. Multivitamins shout their antioxidant concentrations on their labels and food and beverages are promoted based on their antioxidant properties.

Antioxidants work by neutralizing free radicals, the byproducts of oxidative stress in the body - put simply, they are supposed to be working to protect us by neutralizing dangerous and damaging molecules that have been touted as being theoretical culprits in a myriad of disease processes.

This week a study was pre-released by the Annals of Internal Medicine that looked at the long term effects of selenium supplementation on the risk of developing diabetes. The reason researchers chose selenium is because it's a potent antioxidant and oxidative stress has been proposed as an important mechanism in the development of insulin resistance and diabetes and therefore researchers postulated that if they provided folks with more protection against oxidative stress, it might translate into protection against diabetes.

What the researchers found was that the more selenium provided to the study patients, the greater their risk (yes, I did say greater) of developing diabetes.

So what's going on here? I thought it was supposed to lower risk.

What's going on here is further proof that common sense does not dictate treatment response and that our bodies are big black boxes that don't always behave as predicted.

Interestingly that can be said about a few other heavily promoted antioxidants.

Beta-carotene, once expected to be a contender at reducing the risk of cancer development was actually shown to increase the risk and rate of lung cancer growth in Finnish smokers.

Vitamin E, once expected to help reduce the risk of heart disease, Alzheimer's, cancer and more, was shown in fact to be associated with increased rates of all cause mortality and increased risk of congestive heart failure.

At the end of the day, I'm not suggesting you should immediately stop your antioxidant containing multivitamin. The risks we're talking about here are far from astronomical and there may indeed be benefits to other disease processes. I do however think that consumers need to bear in mind that we really don't have nearly the understanding that folks think we have in terms of how individual micronutrients impact on our health and simply because something theoretically sounds healthy, doesn't make it a smart choice.

My recommendation is to remember that while we might still lack data about the individual components of food, where we've got a great deal of data is about food itself. Diets higher in fruits, vegetables, whole grains, nuts and fish and lower in red meats, refined carbohydrates and salts indeed have been shown to reduce the burden of chronic disease.

Focus on your food, not on your vitamins.

Bookmark and Share