Throughout the history of mankind, people have always looked for ways to prolong life expectancy and extend the length of human lifespan. The Fountain of Youth is a mythical and legendary body of water that has appears in the writings of Herodotus and many other authors, and is believed to restore youthful vigor and life to whomever swims and drinks of it. In the 16th century, the legend of the Fountain of Youth grew even more when a Spanish new world explorer named Juan Ponce de Leon famously searched for it throughout what is now known as Florida. Needless to say, the mythical fountain was never found. Despite this, modern science and medicine has been able to extend the life expectancy of humans with the use of medicines, vaccination, surgery, and new medical technologies such as CT scan and MRI imaging.
In the early part of the 20th century, it was discovered that mice that were placed on a calorie restricted diet would outlive mice who were allowed to eat without restriction. This principle has been found to be true for every animal species that it has been tested in to date. Mice, worms, fruit flies, and monkeys that are placed on a calorie restricted diet outlive their counterparts that are allowed to eat an unrestricted diet. In general, a 30% reduction in calorie intact over an entire lifetime results in a 25% extension of life expectancy. The proposed mechanism for these effects has included decreased metabolic rates, reduced oxidative stress and reduced free radical production, although the exact mechanism is not known and has been debated. Calorie restriction in humans is thought to have a similar effect on life extension because the same physiological and biochemical changes occur but this has never been proven.
Researchers, led by Dr. Richard Weindruch from the University of Wisconsin School of Medicine, have shown that in a closely related non-human primate, the Rhesus monkey, calorie restriction can extend life expectancy, delay aging, and prevent the occurrence of age related diseases. The results of their study were published online in the journal Science. The researchers performed a longitudinal adult onset calorie restriction study using Rhesus monkey for a 20 year period. At the time of the reported study, only 50% of the calorie unrestricted group was still alive while 80% of the calorie restricted group remained alive. In addition, the calorie restricted monkeys showed a delay in the onset of age associated diseases, such as diabetes, cancer, cardiovascular disease, and brain atrophy.
The authors wrote, “Our data indicate that adult-onset moderate [calorie restriction] delays the onset of age-associated pathologies and promotes survival in a primate species… Given the obvious parallels between rhesus monkeys and humans, the beneficial effects of [calorie restriction] may also occur in humans. This prediction is supported by studies of people on long-term [calorie restriction], who show fewer signs of cardiovascular aging. The effect of controlled long-term [calorie restriction] on maximal life span in humans may never be known, but our extended study will eventually provide such data on rhesus monkeys”.
The results are quite remarkable and give evidence that calorie restriction could also help prolong the lifespan of humans in a similar fashion. Calorie restriction is a difficult thing to do on a long term basis and is not advisable for all individuals. A more manageable method may be to have short periods of fasting, which have been shown to have some of the same physiological effects. In fact, calorie restriction has begun to be studied in humans at the University of California at San Francisco (UCSF) in a study termed CRONA (Caloric Restriction with Optimal Nutrition and Aging Study). The study findings will be intriguing.
Watch the YouTube video below on the CRONA study:
Ricki J. Colman et al. “Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys” Science 10 July 2009: Vol. 325 no. 5937 pp. 201-204 DOI: 10.1126/science.1173635
Rozalyn M. Anderson and Richard Weindruch “The Caloric Restriction Paradigm: Implications for Healthy Human Aging” American Journal of Human Biology 24:101–106 Article first published online: 30 JAN 2012 doi: 10.1002/ajhb.22243