Kristie McNealy M.D.
Family Health Guide
Wednesday, July 22, 2009
Since the beginning of recorded history, humans have searched for the key to immortality and eternal youth. From the epic of Gilgamesh, recorded on clay tablets around 2000 B.C., to Ponce de Leon’s famed search for the fountain of youth in the new world, the extension of life has been a recurring theme for humanity.
Today, scientists are coming closer than ever to making real medical breakthroughs that will “cure” aging and eventually bring an end to natural death. Pharmaceutical discoveries, and advances in the fields of nanotechnology, cloning, stem cell research and cryonics offer tantalizing glimpses at a future free from old age, and the ability to actually reverse the aging process itself – possibilities that life extension experts feel could become a reality by 2019. Of course, along with these discoveries come ethical questions about the meaning of life in the absence of death and the fate of religion, as well as concerns about overpopulation, boredom and why anyone would really want to live forever.
If the claims of life extension proponents sound far fetched, consider the fact that the average human lifespan has doubled since 1900 and continues to increase. Enormous medical advances occurred during the 20th century, resulting in the development of medications and technology that were once unthinkable. Less than 100 years ago, insulin was unknown and type 1 diabetes was a fatal and mysterious disease. Now, insulin is an inexpensive and easily obtainable drug that saves lives every day. Other medical devices that are common today, like internal pacemakers and contact lenses, were unthinkable just 100 years ago, and the rate of medical and scientific advances continues to increase.
In humans, like all mammals, aging begins almost as soon as we reach physical maturity. In fact, with an average lifespan of 70 years and maximum verified lifespan of 122 years, a typical person today spends the majority of their life aging. In biological terms, aging can be defined as an accumulation of damage to macromolecules like DNA, as well as cells, tissues and organs. The differences in life span between species are determined by genetics, differences in the ability to repair damaged DNA, as well as differences in antioxidant enzymes and free radical production. The science of life extension seeks to exploit these differences and alter the biological pathways involved in aging, with the ultimate goal of immortality. In this feature, we’ll discuss some of the most promising approaches in life extension science.
Chemical Life Extension
For years it’s been common knowledge that drinking red wine (in moderation) is good for your heart. What we didn’t know was why. Then, in 1992, a chemical named resveratrol was suggested as the cause of the cardioprotective properties of wine. Unfortunately, you’d have to drink hundreds of bottles of wine each day to consume enough resveratrol to see a significant effect, so work on a pharmaceutical form of resveratrol was begun. Researchers have since shown that resveratrol extends the lifespan of yeast1, but studies in other species have had conflicting results. A 2008 study on mice found that while resveratrol causes changes in gene expression that are similar to those caused by dietary restriction and mice had fewer signs of old age, unfortunately they didn’t live any longer than typical mice2.
In 2008, pharmaceutical giant Glaxo Smith Kline purchased Sirtris, the company which is developing a proprietary form of resveratrol, for $720 million dollars. Their product, SRT501 is now in Phase 2 clinical trials, and could be available in as little as 6 years. It will be years though, before we will know whether resveratrol will extend the human lifespan.
The latest discovery is a naturally occurring substance found in the soil of Easter Island, in the southeastern Pacific Ocean. Rapamycin has shown to extend the life expectancy of laboratory mice by up to 38% . Professor Randy Strong, of the University of Texas Health Science Center, said: “We believe this is the first convincing evidence that the ageing process can be slowed and lifespan can be extended by a drug therapy starting at an advanced age.”
Another leading researcher Dr Arlan Richardson was quoted as saiyng “I never thought we would find an anti-ageing pill for people in my lifetime; however, rapamycin shows a great deal of promise to do just that.”
Despite the recent hype, there is not yet conclusive evidence and a UK expert has warned that it can suppress immunity.
This article was posted: Wednesday, July 22, 2009 at 4:01 am