Only one intervention has been scientifically documented to extend life. In the medical world, it’s called calorie restriction. For the rest of us, it’s called cutting out excess calories – and excess weight.
The optimal plan for reducing calories and extending both years of life and years of health is the Pritikin Program, promulgated the late UCLA scientist Roy Walford, MD, internationally regarded as the pioneer in anti-aging research.
Fewer Calories, More Life
From worms to rats, mice to monkeys, several studies over the last several decades have found that decreasing the number of calories animals eat by 30% increases their life span by about 30% compared to those on an ordinary diet. And much of that extra life is healthier life. The animals are more resistant to cancers. Their hearts are in better shape. They retain cognitive sharpness. Even their fur grays more slowly, and they hold onto their shiny coats much longer.
Anti-Aging: Human Research
Now, scientists are starting to document that dramatically cutting calories benefits humans as well. In 2002, the National Institute of Aging launched scientific trials involving about 200 people at three locations: Louisiana State University, Tufts University in Boston, and Washington University in St. Louis. The volunteers have reduced calorie consumption by 25 to 30%, often from about 2,500 to 1,750 calories daily.
The researchers are looking for answers to two key questions: Will cutting calories 1) enhance health, and 2) enhance the likelihood of a longer life?
The first findings, published last year, are promising. The study was the first ever to examine people who had been on reduced-calorie diets for a long period of time. Lead researcher Luigi Fontana, MD, and colleagues at Washington University compared 18 individuals who for 3 to 15 years had been voluntarily following diets ranging from 1,100 to 1,950 calories daily with 18 other people, the control group, who consumed a typically American diet of 1,975 to 3,550 calories per day.
One key dietary difference between the two groups: the low-calorie dieters ate mostly fiber-filled, unrefined carbohydrates like fruits, vegetables, and whole grains; the higher-calorie group ate a lot of refined, processed carbs.
Compared to the higher-calorie diet, the low-calorie diet had a “powerful protective effective against atherosclerosis,” concluded the authors. The low-calorie diet had “profound and sustained beneficial effects on the major atherosclerotic risk factors that usually increase with advancing age,” including total cholesterol, LDL cholesterol, triglycerides, levels of inflammation, insulin resistance, and blood pressure. (1)
Blood Pressure Like a 10-Year-Old
The average blood pressure of the reduced-calorie group was about 100/60, akin to the blood pressure of an average 10-year-old.
Slowing the Aging Process
Because the human life span is so much longer than that of laboratory animals, scientists won’t know for many years – probably a generation or more – as to whether a reduced-calorie diet will actually slow the aging process and help us live years, maybe decades, longer.
But the new study from Washington University certainly suggests that calorie cutting can enhance the health of the years we do live by reducing the risk of cardiovascular-related ills like heart attacks, strokes, and diabetes.
“And because 40% of Americans die of these diseases, it only makes sense that preventing their occurrence would increase many people’s life expectancies,” reasons Dr. Jay Kenney, Nutrition Research Specialist at the Pritikin Longevity Center®.
If calorie-reducing diets worked in humans as they have in animals, people who now live into their 80s might very well live until age 110 or beyond, predict scientists.
Honolulu Heart Program
Newly published data from a large group of men from Hawaii suggest that a reduced-calorie diet does in fact add years to life.(2) In 1968, 1,915 middle-aged men, part of the long-running Honolulu Heart Program, filled out questionnaires describing the various foods – and quantities of foods – they ate each day.
Of the 1,915 men, 779 were still alive in 2004, at the study’s 36-year follow-up. They ranged in age from 85 to 105. Analyzing the data of all 1,915 men, the researchers found that those who averaged between 1,700 and 2,000 calories daily had the lowest risk of mortality.
Critics of calorie-restriction diets argue that low-calorie diets may not help you live longer; you may just feel as if you’re living longer because you’re hungry all the time.
That’s why the type of calorie-controlled diet you follow is so important, argued Dr. Roy Walford, who in the 1970s and 80s spearheaded the concept of a calorie-restricted diet as the key to human longevity.
Dr. Roy Walford
In his laboratories at UCLA, the gerontologist discovered that mice on low-calorie diets outlived mice on regular diets by two years, nearly doubling their normal life span. Moreover, their risk of cancers and cardiovascular-related diseases declined.
In the 1990s, part of his widely publicized Biosphere 2 project in Tuscon, Arizona, Dr. Walford and eight others lived in a self-contained glass and steel dome, eating fewer than 2,000 calories daily, and emerged two years later the picture of health: far thinner and with far healthier numbers for markers like cholesterol, blood pressure, insulin sensitivity, and blood sugar.
Pritikin Eating Plan: Bigger Meals, No Hunger
The optimal diet for people wanting to cut calories, Dr. Walford often advised, was the Pritikin Eating Plan because its abundance of high-volume foods, like fruits, vegetables, whole grains, and beans, would provide big, filling meals on a minimum of calories. Another plus of Pritikin foods: their high nutrient density.
Affirms Lisa Walford, daughter of Roy Walford, who today continues her father’s work and has published several practical “how to” books on calorie restriction. “In the 1980s, my father found the Pritikin Program to be the most complementary to his research.”
To be sure, a day’s menu from Dr. Walford’s best selling book Beyond the 120-Year Diet reads like a day’s menu at the Pritikin Longevity Center: hot oatmeal, wheat bran, bananas, skim milk, halibut, big green salads, low-fat salad dressing, steamed cabbage, whole-wheat bread, oysters, pasta primavera, kale, and watermelon. Yes, a lot of food. Hunger was rarely an issue for Dr. Walford.
Nor of many Pritikin people. “Pritikin satisfies all my food cravings,” says Michael Pouls of Gladwyne, Pennsylvania, who has lost more than 80 pounds on the Pritikin Program, shrinking from a size 44 waist to size 34. “For breakfast, I’ll have oatmeal with raisins, Splenda, and cinnamon, or an egg white omelette with veggie cheese and roasted vegetables, or a whole wheat bagel, or I can combine all that – plus fruit. That’s a big breakfast.”
“The Perfect Program…”
“For lunch and dinner,” continues Mr. Pouls, “I love the Pritikin whole-wheat pita pizzas. I also enjoy grilled seafood, baked potatoes, sweet potatoes, pastas, veggie burgers, salads with a zillion different types of dressings, fruit, and chicken. All I have to stay away from is the white starchy, sugary stuff, and that’s no problem. If I want ice cream, I can have fat-free frozen yogurt. If I want pudding, I can have chocolate mousse. There are so many foods you can eat on Pritikin. It’s the perfect program. I don’t ever walk around being unsatisfied.”
100+ Peer-Reviewed Studies
The benefits of the Pritikin Program echo the new findings sponsored by the National Institute of Aging. Like the reduced-calorie dieters in the Washington University study, followers of the Pritikin Longevity Center realize extraordinary health benefits.
More than 100+ studies in peer-reviewed medical journals have chronicled the Pritikin Program’s effectiveness in reducing virtually all heart disease risk factors, doubling the effectiveness of statin therapy, lowering blood pressure, controlling diabetes, achieving healthy, long term weight loss, eliminating the need for angioplasty and bypass surgery, and reducing key risk factors for breast, colon, and prostate cancer.
Most recently, in an exhaustive 27-page invited review of diet, exercise, and disease prevention, a meta-analysis by UCLA scientists of 1,117 people with high blood pressure who attended the Pritikin Longevity Center found that in less than four weeks systolic blood pressure fell on average 9%; diastolic pressure also fell 9%. Of those on hypertension drugs, 55% returned home free of their drugs, their blood pressures in the normal range. (3) (See Figure #1)
Figure 1 – “Pre” and “Post” Results for 1,117 Participants With High Blood Pressure
In the same review, a meta-analysis of nearly 300 type 2 diabetics found that 74% who arrived at Pritikin on oral drugs to control their blood sugar no longer needed their drugs when they left the Center. (See Figure #2)
Figure 2 – “Pre” and “Post” Results for 864 Type 2 Diabetes
Optimal Calorie Level
For maximum quality and length of life, experts theorize that people should probably reduce their caloric intake by roughly one-third, from 2,500 calories per day to 1,750 for a moderately active person.
Biology of Anti-Aging
How might calorie restriction prevent disease and retard aging? Scientists are not sure but speculate that eating fewer calories makes the body more efficient at metabolizing food, resulting in the creation of fewer “free radicals,” highly reactive atoms that can damage cells and DNA.
Other theories: Calorie restriction reduces inflammation, now emerging as a major risk factor for many degenerative diseases, including heart disease. Reducing calories may also suppress growth-factor hormones, a good thing because growth hormones promote cell proliferation, which may increase the risk of cancers. Calorie cutting would also reduce body fat, which science shows has many benefits.
A Midlife Start
In animal studies, the biggest life extension happens when calorie restriction begins in young adulthood. But there is evidence that dietary changes in midlife also yield benefits. At the University of Wisconsin, Dr. Richard Weindruch found that middle-aged mice placed on calorie restriction diets lived 10 to 20% longer than control mice, and their risk of cancer dropped significantly.(4)
Much research on anti-aging in humans remains to be completed. But numerous studies on animals document the power of calorie restriction to both improve health and lengthen life span. And newly published studies on humans show that calorie-reduced diets markedly decrease risk factors linked with the top killers in America today: heart disease, stroke, diabetes, and cancer.
If you remove the killers, you add life. “If you follow low-calorie-dense, nutrient-rich diets like the Pritikin Program and exercise regularly, you give yourself the best chance of staying thin without having to live with chronic hunger, and the best chance of maximum years of great health,” sums up Dr. Kenney.
1 Proceedings of the National Academy of Sciences, 2004; 101:6659.
2 Journal of Gerontology Series A: Biological Sciences and Medical Sciences, 2004; 59: B789.
3 Journal of Applied Physiology, 2005; 98: 3.
4 Federation of American Societies for Experimental Biology, 1997; 11: 573.