Longevity & calorie restriction

Townsend Letter for Doctors and Patients,  Dec, 2005  by Jule Klotter

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Animal studies have shown that calorie restriction extends lifespan and reduces the risk of developing chronic disease in old age--if the diet contains the required amount of all essential nutrients (vitamins, protein, minerals, etc). Roy L. Walford, MD, and Richard Weindruch, PhD, performed hundreds of animal experiments involving calorie restriction. In some cases, the animals had access to a balanced diet for a restricted time period (e.g., 12 hours every other day). In other experiments, the animals received 40 to 70% of the amount usually ingested by similar animals who were free fed. Supplements were included when necessary to prevent deficiencies. Calorie restriction without malnourishment led to increased longevity and disease reduction, even in animals that were bred with a tendency to develop cancer or other degenerative illnesses. Dr. Walford was the physician for the Biosphere II team, who lived in a man-made, closed ecological system in Oracle, Arizona, for two years (1991-92). The eight-member team was put on 1800 calories/day when food supplies ran lower than expected. After six months, the team exhibited improved biological measurements: an average 15% weight loss, 18% lower blood glucose, 35% lower blood cholesterol and 18%/21% (systolic/diastolic) lower blood pressure. Other experiments have shown that calorie restriction increases insulin sensitivity, making it easier to move glucose into the cells.

In his article "Diet, Fasting and Reduction of Disease" (posted at www.healthy.net), Leon Chaitow, ND, DO, RO, says, "Fasting in the treatment of chronic disease has been used for centuries, and research into its effectiveness has been carried out for at least 100 years." When no solid food is eaten and only water is consumed, the body's basic metabolic rate will decrease about 1% each day until it levels off at 75% of its normal rate. Slowing the metabolic rate decreases the amount of free radicals produced by the body and fosters longevity. If a fast continues for too long, however, the body will use up essential protein reserves and starve to death. Chaitow recommends that anyone who wants to fast for more than 48 hours do so under the guidance of a health professional with experience in fasting techniques.

Even with a promise of increased longevity and less illness, few people are motivated to adhere to a program of caloric restriction with adequate nutrition (CRAN) for a prolonged time. Ben Best has practiced CRAN since 1994 (www.benbest.com). In an article, first written in 1998, Best says, "Learning to accept various levels of hunger is like building a muscle. It takes practice." Best includes exercise in his regimen to help maintain lean tissue and to counter the weakness, lack of energy, and depression that other CRAN practitioners experience. Increased sensitivity to cold, especially in the hands and feet, is another common complaint. Best has also found that hemorrhoids can be a problem if adequate fiber is not included in the diet. He warns that losing weight too quickly can deplete potassium and damage the heart, leading to cardiac arrhythmia. At one point in his program, Best, who is 5 feet 8 inches tall and medium-boned, ate less than 1600 calories a day for six months. Near the end of that period, he experienced lightheadedness, physical weakness, periodic cardiac acceleration and gastrointestinal pains, and contracted the flu, which persisted. His weight had fallen to 112. During Best's annual physical, his physician detected extra systoles (heartbeat irregularities) and told him to gain weight. Best now keeps his weight around 135 pounds.

Best makes an interesting observation about stress and voluntary calorie restriction. He has found that practicing CRAN has some "difficult social consequences." Because so many social gatherings center around food and eating, he must often choose whether to take part or to stick to his program. An additional stress lies in people's response to his appearance; at times, some had assumed that he had AIDS or cancer. Best believes that voluntary CRAN practitioners experience more psychological stress than those who live in a protected environment, such as the Biosphere, and that at some point, this stress may be physically damaging. Best, Ben. My Practice of Caloric Restriction with Adequate Nutrition. (Accessed at www.benbest.com on 7 September 2005)

Chaitow, Leon, ND, DO, MRO. Diet, Fasting and Reduction of Disease. (Accessed at www.healthy.net on 10 January 2005)

Heilbronn LK et al. Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. American Journal of Clinical Nutrition January 2005. (Abstract accessed 7 September 2005)

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