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By: Jerry Brainium
One scientist who has studied the effects of CR in rats and other animals found that reducing calories by only 10 percent but combining the diet with weight-training exercise showed the same beneficial effects as those seen in rats who didn't exercise but consumed a 30 percent CR diet. That's good news, since even staunch advocates of CR admit that few people have the willpower to follow a 30 percent CR diet for the rest of their lives'however short or long that may be. Several people have followed such a regimen for more than 10 years, and judging by photos, none made a dent in the aging process. They all looked skeletal'nary a muscle anywhere. On the other hand, none of them lifted weights. One known effect of extended CR is an increase in cortisol'which is catabolic to muscle.
You may eventually be able to cull the benefits of CR without the pain. Drugs that mimic the effects of CR are currently in experimental stages, and preliminary studies with animals show that they produce the same effects as CR without the hunger or the pain. One compound in particular, 2-deoxy-D-glucose, enables rats to eat as much as they please yet experience all the beneficial effects of CR. The problem with that compound, which is nothing more than glucose with two missing oxygen atoms, is that it's a bit toxic in large doses. But continuing research will likely yield other formulas that will provide similar effects with less toxicity.
One thing to keep in mind is that CR alone can be dangerous if you don't take in enough essential nutrients. Even CR advocates like Roy Walford advise taking plenty of vitamins and minerals. Walford's Biosphere-2 diet consisted of 76 percent carbs, 12 percent fat and 12 percent protein'a prescription for muscle catabolism. Anyone engaging in weight training would be well advised not to curtail protein intake, even if you're contemplating a modified, or 10 percent, CR diet.
Since one of the primary mechanisms thought to underlie the benefits of CR is a decrease in oxidation, a primary cause of aging, it's also prudent not to skimp on antioxidants. That includes the entire spectrum of dietary antioxidants, since they work best as a team. Recall that superoxide dismutase, one of the body's primary antioxidants, won't work without zinc and manganese. Other vital antioxidants include vitamin E (at least 800 units daily), vitamin C (2,000 milligrams daily) and selenium (200 micrograms daily).
Eating the recommended five daily servings of fruits and vegetables is a definite plus for anyone seeking longevity. Those foods contain compounds that aren't yet available in supplement form, including many substances that have potent antioxidant activity. They're known to help prevent many degenerative diseases, such as cardiovascular disease and cancer. One study showed that not eating the suggested five daily servings of fruits and vegetables led to a 50 percent increase in mortality.5
Since much of the damage caused by free radicals occurs in the cellular mitochondria, you might want to consider preliminary evidence that certain nutrients may shield mitochondria from oxidative damage. They include acetyl L-carnitine, alpha lipoic acid and coenzyme Q10. Increasing the level of a vital antioxidant called glutathione in the body is also known to help prevent age-related degeneration. Glutathione levels can be elevated by taking alpha lipoic acid, N-acetyl cysteine and whey protein, which has a high content of the amino acid precursor to glutathione, cysteine. As noted in a recent review in this magazine, glutamine may also offer protective effects against rampant mitochondrial internal oxidation.
1 Akisaka, M., et al. (1996). Energy and nutrient intakes of Okinawan centenarians. J Nutr Sci Vitaminol. 42:241-48.
2 Zachwieja, J., et al. (2001). Short-term dietary energy restriction reduces lean body mass but not performance in physically active men and women. Int J Sports Med. 22:310-16.
3 Almurshed, K., et al. (2000). The effects of dietary energy restriction on overloaded skeletal muscle in rats. British J Nutr. 84:697-704.
4 Ballor, D.E., et al. (1988). Resistance weight training during caloric restriction enhances lean body weight maintenance. Am J Clin Nutr. 47:19-25.
5 Kant, A.K., et al. (1993). Dietary diversity and subsequent mortality in the First National Health and Nutrition Examination Survey epidemiologic follow-up study. Am J Clin Nutr. 57:434. IM
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