A factor in controlling lifespan in mammals may have been discovered.
In a recent study, one copy of the gene that encodes a receptor for insulin-like growth factor type 1 (IGF-1) was deleted from mice, and the altered mice lived 26 percent longer than normal mice.
Moreover, the effect varied by gender. Males with one copy of the IGF-1 receptor lived 16 percent longer than normal male mice, however, altered female mice lived 33 percent longer than normal female mice.
Despite the engineering, mice with one copy of the gene appeared to be comparable to normal mice in aspects such as size, metabolism, appetite, physical activity, fertility and reproduction.
Researchers were not sure why mice with only one copy of the IGF-1 receptor lived longer. They suggested that it might have made the mice more resistant to oxidative stress, which is damaging to cells and thought to be a factor in the aging process.
In the study, normal mice and those with one copy of the IGF-1 receptor gene were exposed to oxidative stress and it was found that the cells of the altered mice were more likely to survive.
Researchers note that blocking the IGF-1 receptor to promote longevity is not practical. Mouse embryos with only one copy of the receptor did not grow and male mice that had been altered in the study were more likely to develop diabetes because they had problems with high levels of blood glucose.
Nature Advance Online 2002;10.1038/nature01298
Though this study deals with the IGF-1 receptor and lifespan, there is quite compelling evidence that a low-calorie diet may increase life span. Many of us had long believed the major benefit of reducing your calories was to reduce your insulin levels.
Most of the damage that grains and sugar do is clearly related to their ability to increase your insulin levels. Luckily, we have insulin as without it we would go into a hyperglycemic coma and die, but nearly all of us have insulin levels that are too high.
Elevated insulin levels are one of the major biochemical mechanisms that contribute to why two-thirds of Americans are overweight.
This is one of the reasons why a low-grain, high-vegetable diet is so useful, as vegetables cause a minimal increase in insulin levels. Another product that seems to be a useful tool at lowering one’s insulin levels is Whey Protein with Aminogen. Whey Protein with Aminogen is great to have when you go on trips and don’t have access to healthy foods. I am typically away for one weekend a month and find Whey Protein with Aminogen to be a terrific alternative to unhealthy and high-priced hotel breakfasts. My individual nutritional type is a protein type and very fast oxidizer; because of this I find that Whey Protein with Aminogen works best for me if I have it with one or two raw eggs. For more information on nutritional typing, which will help you determine your own unique biochemical needs -- a foundation of my nutrition plan, I highly recommend the book "The nutritional typing Diet." It is a must-read for anyone with an interest in health and nutrition.
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