Published in The Toronto Star, November, 2010.
The secret to longevity is simple.
According to a growing number of believers, the key to tacking on an extra 20 years to your lifespan is to live on the edge of hunger — constantly.
The concept is called calorie restriction and recently got valuable air time from the grand dame of diets herself, Oprah Winfrey.
It’s a plan taken directly out of the play book of Okinawa, Japan, home to what used to be the greatest number of centenarians per capita in the world until it ceded the title to the Shimane Prefecture on Japan’s southern shoreline. According to the latest available government numbers, Shimane Prefecture boasted 74.3 centenarians per 100,000 people this year, compared to Okinawa’s 66.7.
While genetics plays an important role in longevity — it’s estimated to account for an individual’s lifespan by as much as 50 per cent — researchers also found that centenarians in Okinawa follow a lifestyle regime that is uncommonly austere, active and above all, based on moderation. Okinawans eat until they’re about 80 per cent full — sated, but not completely full — and consume a diet heavy on fruits, vegetables, soy and fish.
In principle, it’s nothing we don’t know already when it comes to healthy eating. But a group of practitioners has taken these ideas a step further, skipping meals and reducing their caloric intake by as much as 30 per cent in the hopes of also staying forever young.
The subject will be a point of discussion Wednesday and Thursday at the Canada Research Chairs conference at the Metro Toronto Convention Centre.
For Brian Delaney, president of the Calorie Restriction Society International, a typical day starts with a huge, dinner-sized bowl of whole grains, fruit and yogurt — a 900-calorie meal. That’s meant to last him for the next 10 hours until he tucks into a modest dinner of fish and vegetables.
“When I first started this program, I was interested in living longer,” Delaney said in a phone interview from Colombia, where he lives. “But now primarily what motivates me is that I feel incredibly healthy.”
Indeed, calorie restriction has been shown to reduce the risks of age-related illnesses like heart disease, cancer and overall decline, said Craig Willcox, an internationally renown gerontologist and professor who has been studying Japanese centenarians at the Okinawa International University for years.
Reduced caloric intake helps the body by increasing insulin sensitivity, lowering the metabolic rate and reducing oxidative stress which leads to chronic, low-grade inflammation — a common denominator in many age-associated diseases, explains the Calgary native and the University of Toronto graduate. And while he concedes that living to 100 like the “genetically elite” Okinawans may require “genetic rocket boosters,” Willcox estimates that for the general public, aging gracefully and healthfully is about 30 per cent genetics, and 70 per cent lifestyle-related.
“I would say lifestyle habits are very important for healthy aging,” he wrote in an email response. “Genes always work in concert with environment, and your lifestyle affects gene expression, so it is never an either-or situation.”
Calorie restriction is just one of the strategies Willcox borrows in the New York Times bestseller, The Okinawa Program, which he co-authored with his twin brother, Bradley Willcox. Instead of going hungry, however, the Willcox brothers advise filling up on foods that are lower in caloric density, which is the number of calories per amount of food.
In the last few decades, researchers have been coming out with a slew of studies showing the effects of calorie restriction on animals. Rodents that reduced their consumption by 30 to 60 per cent, for example, likewise extended their lifespan by as much as 60 per cent. Rats on a calorie-restricted diet also developed fewer age-related chronic diseases.
Some experts say that’s because when you restrict the amount of calories you consume, the body becomes more efficient. Instead of working on growth and metabolism, for example, the body’s resources are redirected to work on maintenance and repair.
It’s an evolutionary response, Delaney explains: in a famine the body kicks into survival mode and prioritizes maintenance over reproduction or growth.
But if we can eat our way into good health, does that mean we can cheat our genetically inherited expiry date as well?
According to geriatrician Michael Gordon of the Baycrest Geriatric Health Care System, the best we can do is mitigate our genetic heritage. If heart disease runs in the family, for example, the best diet and exercise may do is buy you a few more years before it strikes, and then facilitate a faster recovery.
For Bea Levis, a lifetime of healthy habits has made aging painless. The 92-year-old retired teacher eats a salad of greens and tomatoes everyday and walks at least 30 minutes daily. She eschews red meat and, aside from a touch of arthritis, she has a clean bill of health.
She’s also a busy Bea — perhaps almost as important in healthy aging as diet and exercise, experts say.
“People with positive personalities who are socially adept and enjoy people do better in old age because others like to be around them,” Gordon said. “Social interaction is important for a person’s mental health, but especially as you age”
Between her volunteer work, book clubs and family dinners, Bea is seldom idle.
“I believe strongly in participating in the community,” she said. “The more you participate in the world around you, the more you interact with people, the better your quality of life and the more impetus you have to be alive.”
Vivian Song is a Toronto freelance journalist now living in Paris. She can be reached through her website www.viviansong.com.