Warren Rosenberg, Ph.D. Life Expectancy vs. Lifespan.
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Over 200 genes influence the aging process
Hutchinson-Gilford progeria syndrome
INDY gene – doubles the life of fruit flies (150 yrs humans)
daf genes (nematode worms) increase lifespan by 5X -increases enzymes that detoxify ROS
SIR genes (SIR2-yeast, worms ; SIRT1-humans) - activated by caloric restriction also activated by polyphenols (apples & tea), and resveratrol (grapes & red wine)
-possible action on blunting the p53 tumor suppressor gene and blocking programmed cell death (apoptosis)
Klotho gene – produces klotho protein which supresses insulin pathway (20-30% life extension in mice)
“You can drop cigarettes. Avoid alcohol. But there’sone toxin you just can’t dodge: oxygen. With everygulp of air, oxygen gives you life. Some of it, howevergets converted inside your cells into a radical moleculethat can wreak havock, degrading those same cells andothers. A growing number of scientists say this damageis what causes aging.”
Scientific American 2000
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