The Okinawan people in Japan are known to have the largest percentage of centenarians, (those living to or past the age of 100). They have an incredibly healthy diet, consisting of nutrient dense foods: large amounts of green vegetables and sweet potatoes, small amounts of fish and soy-based foods, whole grains and no meat, eggs, or dairy products. While the foods they eat are essential to their longevity, how they eat may be equally vital.
Okinawans eat 17 per cent less food overall than the Japanese average and 40 per cent less than the typical North American. Recent studies suggest a major key to longevity is calorie restriction. Eating foods rich in nutritive value but low in calories may be the most important step towards joining ranks with centenarians around the world.
Hara hachi bu is a reminder used by Okinawans, meaning eat until you are 80 per cent full. In his book *Secrets of Longevity: Hundreds of Ways to Live to Be 100*, Dr. Maoshing Ni says, “After analyzing the diets of about 100 centenarians, I found that the majority lived under modest circumstances. They ate less than the average amount, and some fasted at times because they were poor and simply had no food.” Ni also found that most centenarians he surveyed around the world follow the “three-quarters” rule: they stop eating when they are three-quarters full.
This likely doesn’t sound like the average Westerner. A person can tell when they are about 80 per cent full by eating mindfully. Start by eating less than normal, waiting 20 minutes and assessing hunger levels. Try putting about 20 per cent less food on the plate – or taking a smaller plate. The stomach's stretch receptors take about 20 minutes to tell the body how full it is.
North Americans are beginning to catch on and scientists are continually interested in the topic. Could a diet lower in calories help Westerners live longer? Calorie Restriction (CR) is one of the few dietary disciplines that has been documented to increase both the median and maximum lifespan in a variety of species, among them yeast, fish, rodents, dogs and non-human primates. For mice and rats, there is a 30-40 per cent increase in lifespan.
American scientists have been researching the theory that calorie restriction is beneficial for health and perhaps a prerequisite for leading a longer life. One reason for this has to do with free radicals. According to a study at the Pennington Biomedical Research Center, calorie restriction in non-obese people results in less oxidative damage to muscle cells; oxidants, otherwise known as free radicals are created when food is converted to energy by mitochondria. By inducing the formation of efficient mitochondria, less free radicals form. Oxidative damage is linked to aging. The idea is that a CR diet, when executed correctly, provides all the nutrients necessary for optimal health, but minimizes the energy, or calories provided by food.
Recently, the *New York Times* published a report about calorie restriction and the rhesus monkey. After 20 years of a CR diet, the monkeys are showing less diabetes, cancer, and heart and brain disease. This was a breakthrough study because most previous evidence of calorie restriction showed longevity in rodents. Here, evidence that a calorie restrictive diet slows aging in primates, makes it more likely that humans would benefit as well.
A 2009 research paper showed that a calorie restricted diet can improve memory in normal to overweight elderly. The diet also resulted in decreased insulin levels and reduced signs of inflammation. Scientists believe that memory improvement in this experiment was caused by the lower insulin levels, because high insulin levels are usually associated with lower memory and cognitive function. Calorie restriction benefits people of all ages (although one needs to start calorie restriction after they are fully grown).
A CR diet does not mean malnourishment or anorexia, which cause more harm than good to the body. It means smaller portions of intensely nourishing foods. The CRON-diet (calorie restriction with optimal nutrition) was developed from data by the late Dr. Roy Walford and compiled during his participation in Biosphere 2. In their book, *The Longevity Diet*, Lisa Walford (Roy’s daughter) and Brian M. Delaney (president of the Calorie Restriction Society) propose three meals a day, with variation allowed according to life schedules. The idea is to create meals to combine calorie-dense foods and calorie-lean foods in different ways.
This particular approach works well because the body does not have to deal with empty calories, excess fat slowing down the system, or processing tremendous amount of waste. Those who practice calorie restriction take vitamins as well as nutrient-rich foods such as kombu, brewers yeast, wheat bran, wheat germ, soybeans and tofu. CR calls for a diet reduced in intake of calories by 20 to 40 per cent. However, observations from a study in Free Radical Biology and Medicine indicate that even an eight per cent reduction in calories may provide protective effects against muscle and skeletal aging.
The caloric needs of a person are determined by their Basal Metabolic Rate (BMR), which is the energy needed for normal metabolic activities such as breathing, digestion, maintaining body temperature, etc., plus the energy required for physical activities. According to Dr. Roy Walford, caloric reduction should take place gradually while intensifying the nutritive value of food choices – rapid weight loss releases harmful toxins into the body.
To find out more about the CR diet, visit www.crsociety.org and www.walford.com
Beyond the 120 Year Diet: How to Double Your Vital Years by Dr. Roy Walford
The Longevity Diet by Brian M. Delaney and Lisa Walford
The CR Way: Using the Secrets of Calorie Restriction for a Longer, Healthier Life by Paul Mcglothin and Meredith Averill
Detailed meal plans and suggestions are included in these books.
JANUARY 2010 SENIOR LIVING VANCOUVER AND LOWER MAINLAND
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