Longevity, Life Expectancy and the 120-Year Diet
In the ongoing debate on modern medicine one argument always wins out: we now live longer so today’s medical approach must have it right! However, the facts surrounding long life and how we got to this point are not always clear in everyone’s mind. First we must distinguish between life expectancy and longevity.
Life expectancy is calculated by averaging the age of death of all the people in a society. It will fall if more people die at a young age from accidents, disease or war, but doesn’t really tell us much about how long the oldest people in society live, or their longevity.
After a long period of stability, life expectancy started to increase with the industrial revolution and has more than doubled over the past few centuries. Historically, many people died prematurely from a variety of conditions. Because of poor food distribution and widespread poverty, malnutrition was endemic. Children died from complications of childhood diseases or simple infections. Those who survived into adulthood faced many more challenges. For example, not too long ago childbirth was a common cause of death for young women, and TB prematurely ended many lives.
Factors that have been credited for increasing life expectancy include improved sanitation, hygiene, increased wealth, refrigeration, improved waste removal, better water quality and so on. For example, until the late 19th century, physicians did not understand the importance of something as basic as handwashing and thus contributed to the spread of disease.
Medicine certainly played a role in this evolution, but its role has generally been overestimated. Vaccines are thought of major lifesaver, but it is a well-documented fact that most childhood diseases were no longer significant killers by the time vaccines were introduced. For a detailed and referenced discussion of this important point, see www.HealthSentinel.com and click on “vaccines.”
Although antibiotics saved many lives, the incidence of major killers like TB were already in steep decline when penicillin was first introduced, probably as a result of better hygiene and improved nutrition.
Even when life expectancy was at its lowest, a few individuals who were fortunate enough to survive into and past middle age lived out long and full lives, well into their eighties and beyond. This has been documented throughout history, and in fact longevity, or how long people can live, is a genetically predetermined limit that has never been shown to change.
Extending human life past these programmed limits is an old dream that some extremist groups are now claiming they can achieve by creating a breed of “genetically engineered” humans. In fact no drug, vitamin, or hormone has ever been shown to increase longevity. This genetic limit can simply not be exceeded through these means. However, a diet was shown to do just this: extend life past its genetic limits!
This diet is described in a book entitled “The 120-Year Diet” by Roy Walford, MD. Unfortunately this book is now out of print, probably because of lack of reader interest, but can be obtained from websites specializing in out-of-print books like www.alibris.com.
The diet described by Dr. Walford is backed by a large body of animal research that is, in all likelihood, applicable to humans. If this animal data is extrapolated to humans, then we could expect to live to be 120 if we cut back drastically on caloric intake (basically, eat much less) but without sacrificing our intake of essential nutrients to avoid malnutrition.
If you are like me, this diet may look good on paper, but it’s not too likely you’ll actually follow it for very long. However, a new study (Science, January 24, 2003; 299: 572-574) performed on genetically engineered mice suggests that it is insulin control, not calorie restriction, that is responsible for prolonging life. To control your insulin forget the dessert, bread and pasta, but enjoy your steak (organic and grass-fed, of course) and lots of fresh vegetables.
