Tuesday, July 14, 2009
CALORIE RESTRICTED DIETS FOR LONGEVITY
The journal, Science, recently featured a fascinating study that has huge implications for anti-ageing and longevity medicine. The report said that rhesus monkeys who were fed a calorie-restricted diet for 20 years were two-thirds less likely to die of an age-related disease than counterparts fed on a standard diet. The risk of dying from heart disease, cancer or diabetes fell by more than two-thirds in the calorie-restricted group.
The 76 animal subjects ate 30% fewer calories. Researchers noted, “The rates of cardiovascular disease and pre-cancerous cell growth were twice as high in the control group compared with the calorie restricted group.” Furthermore, none of the calorie restricted (CR) animals became diabetic or even pre-diabetic. Brain scans were also significant and showed that the CR animals demonstrated less atrophy.
The researchers also remarked that the CR monkeys “appear to be biologically younger than the normally fed animals.’ This latest study adds to the pool of data that has been accumulating for decades supporting the low-calorie intake theory of nutrition. Going back to the 70’s, Professor Roy Walford, a researcher from UCLA, studied this theory. He was his own best subject as one of the original Biosphere scientists who lived for two years in the man-made, sealed ecological dome in the Arizona desert. Walford followed a significantly calorie-restricted diet for most of his adult life.
I remember meeting Dr. Walford in 1985 when I was working as a staff physician at the Pritikin Longevity Center in Santa Monica. We were teaching the low fat diet at that time. His approach was even more intense. Walford not only limited the percentage of fat in the diet, but the total calorie intake as well. At Pritikin, the diet we taught reflected similar calorie ranges, and was quite successful in promoting weight loss, blood pressure reduction, and reducing the need for diabetic medications. The major criticism of the diet was that it was difficult to stay on for extended periods of time.
The diet program that I teach now is similar in principle to the CR diet and is called “The Paleo Diet”. I encourage people to follow a regime that is similar to what we understand was practiced in Paleolithic times. I believe this approach works best of all for avoiding age-related diseases because we were genetically designed in that bygone era, and our success as a species was dependent on the kind of food that was available at that time.
It is highly unlikely that people during the Paleolithic period ate more than 1200 to 1800 calories per day—which is the equivalent level of the CR diet. Typical Western diets are 3000 calories per day or even more. It seems logical that lowered caloric intake would dramatically reduce the risk of age-related diseases. One of the simplest ways to accomplish this is to just cut out all man-made, dense starchy carbohydrate foods such as bread, pasta, cereal, and grains. The Paleo Diet ends up looking a lot like a CR diet as long as the target food groups are not over consumed.
A comparison of the incidence of obesity that exists today with what might have existed in Paleolithic times provides food for thought. It is safe to say that obesity simply did not exist in ancient times, and by contrast with today’s diets, is a very good indicator of how much we were originally designed to consume. Just imagine the difference between the volume of food available in today’s local supermarket as compared to what was on the Paleolithic menu. The greatest challenge for early humans had nothing to do with choice—it had everything to do with securing enough food for survival.
One of humanity’s greatest accomplishments has been the ability to produce large amounts of food to assure propagation of the species. But, this achievement has a downside and not only has been detrimental to our health and longevity, but to the environment and survival of other species. As we start out to correct our own eating problems, we must first discipline ourselves to avoid the modern tendency to overindulgence, overproduction, and overconsumption. Our well-being as an evolving species and the health of our increasingly fragile planet are both at stake.
(Thanks to Geico for the Cavemen Dining image)
Thursday, July 9, 2009
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