There is a growing belief that calorie restriction is the key to longevity. Dr. John B Carrigan is now in search for a potential drug that might enlighten the quest for longer human lifespan.
The debates on calorie restriction are swinging from one side to the other. Is it really the elixir of youth or just another anti-aging search? In the recent years, we are increasingly hearing more contradictory conclusion on obesity, eating disorder and diets, what is the key to longevity?
It is certain that the answer isn’t straightforward. In the world of science calorie restriction, is being proven to be one of the only confirmed ways to lengthen our longevity. But, the full story of science has not been fully clarified; there are empirical studies that refute the strong claimed benefits of calorie restriction (CR).
In 1935, a nutritionist at Cornell University, Dr. Clive McCay, concluded that depriving our body from the full energy need could actually increase the longevity of at least mice. At that time, it was found that if mice were fed with 30 percent less than the control groups, they tended to live 40 percent longer in compared to their counterparts. The study on mice CR identified that calorie restriction improved mice immunity to disease, and they became equally more physically active.
The experiment conducted by Dr. McCay has been replicated on a dozen of other species, like roundworms, fruit flies and other mice. The main conclusion of these studies, is that CR, alters biochemical pathways to either Off or ON modes, which enhances insulin sensitivity, cardiovascular function, resistance to cellular stress and decrease inflammation and muscle wasting that occurs with age. The result is that aging is delayed, equally are age-linked diseases such as cancer and diabetes. In general, CR has scientifically shown that CR can increase our longevity with an estimated 30 percent.
Another, famous writer and researcher on calorie restriction was ‘Dr. Roy Walford’ a pathologist from the University of California, Los Angeles. He spent his last three decades to practice a calorie restriction regime. However, he passed-away in 2004, suffering from ‘Lou Gehrig’s disease’, at the age of 79 years. So, upcoming studies which were released suggested that long-term calorie restriction does lead to faster progression of amyotrophic lateral sclerosis (Lou Gherig’s disease) even in mice models, which can ironically reduce lifespan.
Weight Loss – Advocates of Dr. Walford’s – legacy
Brian M Delaney who is the President of Calorie Restriction Society in the US says that there is thousands of people practicing calorie restriction. However, it should be noted that CR is different from common weight-loss diets. In contrast to weight loss diets, which are mainly meant for people who are overweight the CR diet is aimed to extend lifespan. The reduction in weight is simply a side-advantage of the CR diet.
CR is not about increasing exercise, or maintaining calorie intake, or losing weight. It is a full-fledge health programme, aimed to follow Food and Drug Administration’s recommended intake of 20 to 30 percent nutrition level.
The BMI (Body Mass Index) score that Dr. Walford aimed at was below 20. Another supporter of Calorie restriction regimes is Dr. Luigi Fontana, who is the Director of the Division of Nutrition & Aging at Istituto Superiore Di Sanita (Italian National Institute of health) and equally an Associate Professor of Medicine at Washington University in St. Louis. He investigated members from the CR Society, and published a very insightful report in the Proceeding of the National Academy of Science, in 2004. It was concluded that CR leads to a comfortable metabolic rate which reduces the potential rate and risk of developing heart diseases to nearly zero.
Monkey Study – Species Almost Like Humans
The most relevant CR animal study conducted, in correlation to humans, is the 20-year CR studied done on our genetic neighbours (rhesus monkeys). The results were flagrant. In 2009, it was published that monkeys on a normal diet had a 50 percent survival rate in contrast to CR-treated monkeys with an 80 percent survival rate. The appearance of the monkeys was even more fascinating. The monkey on a normal diet looked significantly older than the one ones on CR diets.
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Is CR Really That Good?
CR is according to scientific evidence the secret to longevity. However, the studies have their own weaknesses. If we evaluate epidemiological data, we cannot say that the thinnest people have the longest lifespan. A few years ago, a long-term research conducted by Tohoku University’s Graduate School of Medicine on middle-aged & elderly people gave contradictory findings. People who were slightly overweight in their 40s lived on average 6 to 7 years more in comparison to their thinner counterparts. Thinner people lived on average 5 years less than obese people.
In order to make the study more comparative, thinner people who died earlier from sickness or bad lifestyles such as smoking were eliminated. However, the result was still the same. Thus, calorie restriction appears to have various effects not to re-mention Lou Gehrig’s disease.
CR Society Warnings
Announcement from the CR Society has highlighted that some advocate of CR tends to go beyond reasonable limits into unhealthy CR practices. Extreme CR practice has been associated with psychological disturbance such as food fantasies, anorexia and bingeing.
Insight on CR Theory
Richard A. Miller and his co-workers from the University of Michigan, in 2009, found that rampaycin (a bacterial natural products), blocks TOR kinase and this tend to increase the lifespan of mice. So scientists now believe that inhibiting TOR is the key to extending longevity – it doesn’t matter whether it is done through CR, Rapamycin Treatment or Genetic Mutation. The blocking of TOR reduces cells expansion; reducing ribosome production, amino acid transport and protein synthesis.
In addition, the organism is also strengthened and become resilient against various forms of stress.
Going into more depth, Fontana found that Vegetarians, who practiced CR diets experienced more consistent delay in aging. This suggests that it is not only calorie restriction that is required but maybe a protein restriction diet to increase longevity.
Drugs – Copy Study Effects
The pharmaceutical industry is investing huge in mimetics of these CR benefits. It might be possible to induce the CR benefits without even reducing consumption. Simply consuming CR supplements might be enough. There are already a few CR mimetics supplements on the market but non-of the drugs have demonstrated proven longevity benefits for humans.
The most marketed and popular CR mimetic is the resveratrol. Yet, there is a lack of empirical results purporting that it really increases the lifespan of mammals.
An early research showed that resveratrol increased the lifespan of mice who were on high-fat diets. Yet, the media highlighted that the study showed no relevant figures for mice being on a typical diet.
In general, resveratrol is considered as safe and healthy. It is also naturally present in blueberries, peanuts and grapes.
Most studies suggest that CR is safe and effective. However, the debate on whether eating less or taking pills will lead to a healthier and longer life will continue for years. Some people are even questioning whether it is worth living longer if you have to forego peppercream sauce and steaks.
Source: Irish Time
Sun, Aug 21, 2011
Anti Aging, Health And Aging, Longevity