What exactly are free radicals?
Monday, August 30th, 2010 at
9:27 pm
I understand free radicals cause aging and cancer. I’d like to know as much as I can about them so please tell me everything you know. I’d like to know what their chemical structure is, how they are introduced into the body, how they work, how antioxidants work to combat them, etc. There is pretty much no such thing as too much info on this question.
2) Also I heard that your body creates free radicals simply by producing the energy it needs. Is this true? So does this also mean that exercising produces free radicals?
Filed under: Alternative Medicine
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Here’s what I got from perusing onto some websites:
Most people believe free radicals are generated primarily by excessive exposure to the sun’s ultraviolet rays, radiation, air pollution, cigarette smoke and various chemicals. While these factors add to your oxidative stress, most free radicals are formed right inside your body.
We depend on oxygen to stay alive. Oxygen helps our cells produce ATP, the chemical form of energy that powers our bodies. This ATP is needed in extra quantities when we exercise. The longer and more intensive the exercise, the more oxygen is consumed. While oxygen is absolutely vital for energy production, it is also a potent free radical producer.
Furthermore, exercisers often "stoke up" on carbohydrates – called carbohydrate loading – before intensive exercise. Doing so adds fuel to the body’s biochemical furnace, but it also generates additional free radicals.
Another major source of free radicals are infection and inflammation – problems which are amplified in people who exercise vigorously, particularly when they exercise outdoors. Exertion in extremely hot and cold weather and at high altitudes, where many professional athletes train, also increases free radical production.
Free radical production during exercise can overwhelm the body’s antioxidant defense systems. Unless neutralized, these free radicals multiply in a chemical chain reaction with effects reaching throughout the body.
Free radicals may be a natural part of life, but their excessive production accelerates the aging process and the development of disease. If you exercise, which you should, it makes sense to take extra antioxidant nutrients to neutralize these unwanted free radicals. A number of studies have shown that antioxidant nutrients reduce muscle soreness after physical exertion and speed up recovery from hard workouts.
Exercise and oxidative damage
Endurance exercise can increase oxygen utilization from 10 to 20 times over the resting state. This greatly increases the generation of free radicals, prompting concern about enhanced damage to muscles and other tissues. The question that arises is, how effectively can athletes defend against the increased free radicals resulting from exercise? Do athletes need to take extra antioxidants?
Because it is not possible to directly measure free radicals in the body, scientists have approached this question by measuring the by-products that result from free radical reactions. If the generation of free radicals exceeds the antioxidant defenses then one would expect to see more of these by-products. These measurements have been performed in athletes under a variety of conditions.
Several interesting concepts have emerged from these types of experimental studies. Regular physical exercise enhances the antioxidant defense system and protects against exercise induced free radical damage. This is an important finding because it shows how smart the body is about adapting to the demands of exercise. These changes occur slowly over time and appear to parallel other adaptations to exercise.
On the other hand, intense exercise in untrained individuals overwhelms defenses resulting in increased free radical damage. Thus, the "weekend warrior" who is predominantly sedentary during the week but engages in vigorous bouts of exercise during the weekend may be doing more harm than good. To this end there are many factors which may determine whether exercise induced free radical damage occurs, including degree of conditioning of the athlete, intensity of exercise, and diet.
Recommendations
Follow a balanced training program that emphasizes regular exercise and eat 5 servings of fruit or vegetables per day. This will ensure that you are developing your inherent antioxidant systems and that your diet is providing the necessary components.
Weekend warriors should strongly consider a more balanced approach to exercise. Failing that, consider supplementation.
For extremely demanding races (such as an ultradistance event), or when adapting to high altitude, consider taking a vitamin E supplement (100 to 200 IU, approximately 10 times the RDA) per day for several weeks up to and following the race.
Look for upcoming FDA recommendations, but be wary of advertising and media hype.
Do not oversupplement.
*****
Basically, you shouldn’t overexercise, especially if you’re not trained. Olympic athletes are okay, because they train their bodies to do that. A normal person, however, should not train excessively with exercise unless their body is used to the excessive exercise. It’s better to exercise for 30 minutes everyday, then for 5 hours, one day out of a week. Nobody really knows, ’cause scientists haven’t been observing free radicals and their effects on cancer for long enough.