Some Hope to Add On to Their Years by Cutting Back How Much They Eat
By DAN CHILDS
ABC News Medical Unit
Nov. 28, 2006 —
When you look at Joe Cordell, it's hard to imagine you're seeing someone who worries about counting calories.
At 5-foot-9 and 130 pounds, Cordell defies the stereotype of the overweight American, but this 48-year-old divorce lawyer is an experiment in progress.
He is one of a rarified group of Americans who practice caloric restriction (CR) -- a significant reduction in food intake that they believe leads to added longevity and health.
For the last five years, Cordell has cut his caloric intake by a third.
"If you'd asked me before I started CR if I could possibly enjoy a diet like that, I would have said no," he said. "Like almost every other American, I thought that variety was essential, but I know now that that's not true."
Caloric restriction is an intriguing idea -- and a controversial one.
Though studies show that restricting calories in mice and other animals leads to an extended life span, definitive results have not yet been seen in humans.
Yet, researchers like Dr. Luigi Fontana of the Washington University School of Medicine say caloric restriction holds promise -- as long as the regimen is followed properly, that is.
"Caloric restriction is not eating half a hamburger, half a pack of French fries, and half a can of one of these sugary beverages," he said. "It is eating a healthy diet, where you get rid of empty calories, and you eat lots of nutrient-dense food."
Fontana says the trick is to ensure that you still get 100 percent of your required nutrients every day, all while keeping additional calories to a minimum.
The principle is already being studied in rhesus monkeys, the closest thing to a human yet.
"The monkeys on CR look like they're aging at a slower rate and their health is staying better longer," said geriatric researcher Rick Weindruch, associate professor in the department of medicine at the University of Wisconsin in Madison, Wis.
He says he expects that some of the calorie-restricted monkeys will live 30 percent to 40 percent longer than their counterparts in the control group.
"We're starting to see clear differences in terms of how old the animal looks in the two different groups," he said. "Appearance is another indicator of biological age."
At Washington University, researchers are now seeking volunteers for a two-year study to determine the effects of caloric restriction in humans.
Bringing Metabolism to a Simmer
Despite the lack of definitive data in humans, researchers have a couple of ideas on how caloric restriction might lead to longer life.
"The theoretical basis for this is that burning fuel comes at a cost to an organism, just as it does to any vehicle," said Dr. David Katz, associate clinical professor of public health & medicine at the Yale University School of Medicine in New Haven, Conn.
"If you can meet the needs of body tissues while burning less fuel, you generate less heat, expose the body to fewer metabolic byproducts, and potentially reduce the net exposure to factors likely to damage DNA," Katz said.
"Calorie restriction in animals may induce certain proteins or enzymes, which may account for the longevity," said Dr. Sethu Reddy, chairman of endocrinology, diabetes and metabolism at the Cleveland Clinic in Cleveland.
Whether or not it works, one thing is clear: Such a drastic cut in calories is not a simple proposition.
"Restricting calories simply by reducing the amount of food is difficult to sustain because people get hungry," said Dr. Dean Ornish, founder and president of the Preventive Medicine Research Institute and clinical professor of medicine at the University of California, San Francisco.
"If chronic calorie restriction is going to make people feeling miserable, deprived, or unhappy with life, it may not be worth it even if there could be solid evidence for it," said Keith-Thomas Ayoob, associate professor at the Albert Einstein College of Medicine in Bronx, N.Y.
"There is something to be said for quality of life and personal satisfaction. Maybe how long someone lives isn't the bottom line for everyone," Ayoob said.
Too Skinny on Evidence
Not everyone is convinced that caloric restriction lives up to its reputation as a life extender.
"I have seen a college professor who was doing CR a few years ago," said Dr. Donald Hensrud, associate professor of preventive medicine and nutrition at the Mayo Clinic College of Medicine in Rochester, Minn.
"He had biochemical evidence of malnutrition with abnormalities of various tests. In his case I have a tough time believing it would extend his longevity. I also believe that in him, as perhaps with others, it developed into a variant of an eating disorder," Hensrud said.
"Even in previously healthy individuals, one need only look at the spectrum of eating disorders typified by anorexia nervosa in order to demonstrate the potential risks of excessive caloric restriction," said Dr. Peter Pressman, assistant professor of clinical medicine at the University of Southern California in Los Angeles. "To suggest that caloric restriction is the answer to slowing the human aging process is at best simplistic and at worst seems quite misleading and dangerous to the public."
Others say that while whittling down the calories may help, it may be just one piece of the puzzle.
"The process of human aging is an extremely complex phenomenon," Pressman said. "Merely restricting calories in and of itself may be one contributor to certain aspects of metabolic rate, but it is likely not by any means the entire story."
"Longevity is about genetics, lifestyle, attitude, and possibly variables we don't yet know," said Connie Diekman, a registered dietitian and director of university nutrition at Washington University in St. Louis, Mo. "Changing one aspect of the equation can't guarantee longevity."
As the current obesity epidemic grows, it is unlikely that caloric restriction will become a widespread trend.
"CR is not an idea that will be widely embraced in a population gaining weight even as we speak," said Carla Wolper, research associate at the Obesity Research Center at St. Luke's Hospital in New York.
"After all, if we cannot get people to reduce their caloric intake modestly to lose weight, how will we ever get large numbers of Americans to reduce their weight below ideal?" Wolper said.
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From The Los Angeles Times
FOUR years ago, Joseph Cordell wasn't looking to lose weight. At 5 feet 9 and 165 pounds and exercising regularly, the then 43-year-old divorce lawyer was in pretty good shape.
But he didn't have anything against adding a few years to his life -- and so, in 2002, he overhauled his diet. He cut his daily caloric intake from about 3,000 to 1,900. He turned to a diet rich in walnuts, berries, apple peels, broccoli, mountains of salad and lean protein. He says he now weighs 129 pounds and almost never gets sick anymore.
His heart, it appears, is reaping the benefit.
Last month, scientists at the Washington University School of Medicine in St. Louis published a study showing that the hearts of Cordell and 24 others who had been practicing "caloric restriction" were more youthful-looking when viewed by ultrasound than the hearts of people on regular American diets.
The 25 subjects, who had consumed about one-third less calories than most people would normally eat for an average of 6 1/2 years, had heart walls that were more elastic, with ventricles that relaxed more readily to fill with blood.
"The hearts looked 10 to 15 years younger," says Dr. Luigi Fontana, an assistant professor of medicine at the university and principal author of the paper. The scientists now plan to study what restricting calories does to other parts of the body such as arteries, lungs and kidneys.
The findings, published in the Journal of the American College of Cardiology, is a promising sign that a science rooted in animal data might help humans extend their life span. Researchers have found that mice and rats fed 30% fewer calories from an early age live 30% longer than those given regular amounts of chow. Such animal findings have inspired a cadre of caloric restriction enthusiasts, Cordell among them, and a Calorie Restriction Society, which has several thousand members.
It's not yet clear whether calorie restriction can also extend maximum life span in humans, but scientists are continuing to investigate the issue. Because most people probably don't have the discipline to drastically reduce their calorie intake for the rest of their lives, research labs and biotech companies meanwhile are looking for drugs that mimic its effects so people could reap the benefits without self-denial.
If caloric restriction prolongs life, a major question is why. Fontana thinks reducing inflammation may be key. Inflammation usually increases with age and induces effects similar to wound healing, which makes tissues stiffer. Fontana's study found reduced blood levels of two inflammation-linked proteins (TNF-alpha and CRP) in the subjects practicing caloric restriction.
Stiffening could also result from simply turning food into energy. That process creates so-called free radicals, reactive oxygen molecules that can damage tissues. Caloric restriction might reduce the accumulation of such radicals because it reduces the intake of food.
Although scientists say the heart study is compelling, they point out that people undergoing caloric restriction may be unusual in ways beyond consuming fewer calories. (Cordell, for example, is a stickler for good nutrition: One of his strategies is to eat only the peel of an apple because it contains more micronutrients.)
"It's hard to sort out what's causing what," says Dr. Evan Hadley, director of the geriatrics and clinical gerontology program at the National Institute on Aging in Bethesda, Md.
To help surmount such issues, the National Institute on Aging has initiated a clinical trial that will randomly assign either a caloric restriction diet or a normal diet to 240 people. The trial will follow people on caloric restriction for two years and examine the health benefits and risks. Recruitment is expected to start in August.
Meanwhile, several research labs and biotech companies are looking for drugs to mimic caloric restriction. GeroScience in Pylesville, Md., is seeking compounds that trick cells into "thinking" they are fed when they aren't. LifeGen Technologies in Madison, Wis., is studying nutrients that can activate certain genes the way caloric restriction does.
Other companies are focusing on drugs that activate proteins known as sirtuins. Sirtuins appear to be key in caloric restriction. Doubling sirtuin dosage in flies and worms extends their life span by 30% to 50%, says MIT researcher Leonard P. Guarente, a co-founder of Elixir Pharmaceuticals of Cambridge, Mass.
Another Cambridge-based company -- Sirtris Pharmaceuticals Inc. -- will test the safety of some sirtuin-activating compounds in human clinical trials this year, says co-founder David Sinclair, a Harvard researcher. In 2003, Sinclair's lab identified resveratrol, a sirtuin-activating compound that is found in red wine.
Sinclair is optimistic that the first drugs mimicking caloric restriction will be available in five to 10 years.
But Dr. John Holloszy, a Washington University School of Medicine gerontologist and a co-author on the heart study, is not so sure that proteins such as sirtuins can explain all the effects of caloric restriction.
"I think it's more complicated," he says -- only to admit that he takes resveratrol every day, and drinks red wine with dinner.
"It's very nice if it works," he says.
January 13, 2006 - 5:20pm
People who follow a low-calorie, high-nutrition diet are among the young at heart, a new study from Washington University shows.
Caloric restriction, as the diet is known, has been shown to increase the life span of a variety of animals, including dogs, mice, rats and even creatures such as yeast. But no one knew whether severely cutting back on calories would have the same effect on humans.
This new study, which compared people who voluntarily followed calorie-restricted diets with healthy people who ate average diets, showed that the low-cal group had hearts that worked as well as those of people 10 to 15 years younger. It is the first clear evidence that calorie restriction is associated with delayed aging in humans, the study's authors say.
The study, led by Dr. Luigi Fontana of Washington University and the Instituto Superiore di Santi in Rome, Italy, will appear Tuesday in the Journal of American College of Cardiology.
Fontana and his colleagues measured heart function in 25 people on the calorie-restricted diet and 25 healthy people of average weight who ate a standard diet. None of the study participants exercised more than 20 minutes twice a week. The restrictive dieters ate fruits, vegetables, whole grains, beans, lean proteins, nuts and other foods for optimum nutritional value. They consumed 1,400 to 2,000 calories per day - about 25 percent fewer calories than an average American.
"It's not that draconian," said Joseph Cordell, 47, a divorce lawyer who started calorie restriction four years ago. Cordell eats about 1,850 calories a day.
He started the regimen after becoming dissatisfied with the "mediocre success" he had in improving his health with exercise. Since he started following the lower-calorie diet, Cordell says, his blood pressure, cholesterol and pulse rate have all dropped substantially. And the new study shows that he has "the heart of a 10-year-old," he said.
The researchers saw a marked change in the diastolic heart function of the calorie-restricted group over their peers.
During the diastolic phase, the left ventricle fills up with blood in a two-step process. During the first step, the ventricle relaxes and blood flows in, filling the chamber about 80 percent full in young people. In the second phase, the atrium contracts to top off the ventricle. Once full, the ventricle pumps the blood into the body.
As people age, their hearts become less elastic. That means that less blood gets in during the passive filling phase and the atrium must work harder and pump in more blood as it contracts. The decline in diastolic heart function is a good measure of aging, Fontana said.
People on the restrictive, nutritious diets filled their ventricles with more blood during the passive filling phase than the average eaters did. The low-cal dieters have been on the diet for an average of only six years, but their hearts appeared as much as 15 years younger. That could mean the diet reverses aging, Fontana said.
The CRONies, as the people on Calorie Restriction-Optimal Nutrition diets call themselves, also had lower levels of two proteins involved in inflammation, as well as lower levels of a protein involved in depositing collagen and scar tissue in wounded or inflamed tissue. That is important because it could indicate that restricted-calorie diets help prevent the heart from losing elasticity as people age and protect them from damaging inflammation.
The difference between the two groups was not attributable to genetics, Fontana said. People in both groups had family histories of heart disease, and some of the people in the calorie-restriction group had previously taken medications to lower blood pressure or cholesterol. Those problems improved once the people started calorie restriction.
"These people are not genetically lucky," Fontana said.
He also cautioned that simply cutting calories is not enough to improve health. Low-calorie diets that don't provide optimal nutrition may actually speed up aging and be dangerous, he said. But avoiding weight gain and improving the diet by eating fresh fruits and vegetables, whole grains, fish, nuts and beans also could improve overall health for average people, Fontana said.
(c) 2006, St. Louis Post-Dispatch. Distributed by Knight Ridder/Tribune News Service.
The only scientific proven way to increase longevity. In 1935 it was found that the lifespan of laboratory rats could be extended by as much as 50% on severely calorie restricted diets, the rodent equivalent of a human life stretched past the age of 160. And it isn’t just a mouse. Yeast cells, spiders, worms, monkeys have all been shown to benefit from CR’s life-extending effects.
In 1991 a team of eight bioscientists sealed themselves up for a two-year stint inside a giant, airtight terrarium in the Arizona desert, and promptly discovered that the hypothetically self-sustaining ecosystem they’d settled into could barely grow enough food to keep them alive.
This revelation might have doomed the experiment (known as Biosphere 2) but for the fact that the team’s physician, UCLA pathologist Roy Walford, had been studying Calorie Restriction for decades and convinced his fellow scientists that—as long as they all ate carefully enough to get their daily share of essential nutrients—a year or two of near starvation wouldn’t hurt.
When at last the Biosphere 2 crew emerged from their bubble, tests proved them healthier in nearly every nutritionally relevant respect than when they’d gone in, and the case for Calorie Restriction in humans was no longer purely circumstantial.
So what are the benefits of CR?
Dr. John Holloszy, principal investigator of a long term study on CR has this to say, "There's no chance of CR practitioners getting type 2 diabetes, they have very low blood pressure, and the risk of them developing heart disease and cancer is markedly decreased," "The calorie restriction protects them from the same diseases that exercise protects against, and more potently than exercise,"
And exercise? Not an option as C.R. dieters simply don't have the calories for it, unless they increase their calories accordingly.
Dr Hellerstein a professor at UC Berkeley, says "It's the only thing that is known to extend the life span in animals," he studies human nutrition and metabolism. He recently started recruiting people for a study where subjects will eat a near-fasting diet every other day, alternated with a normal one. "It's the most amazing thing in all of biology."
And there is a growing impetus to find out if humans reap the same benefits, over time, as lab animals. The Baby Boomers are aging, and just as they felt the need to revolutionize attitudes toward child rearing and midlife, they are interested in a better old age. They are the ones who promoted 50 as the new 40. Could 100 will be the next 90 - or 80?
The National Institute on Aging and National Institutes of Health are both funding research at major universities. Private industry is also studying the metabolic effects of CR, working to create a pill that will mimic it and bypass the need for a rigid diet.
An example is 47 year old Joseph Cordell who eats about 30 % fewer calories than most people. The recommended minimum is 2,500 calories for adult males. Those males practicing CR commonly consume 1800 to 2000 calories daily while some women might consume as few as 1300 calories to 1500 calories daily.
Cordell's doctor says that he has the blood pressure of a child, the cholesterol of a teenager, and his risk of heart disease is close to zero. Average middle-aged men have 23 to 25 percent body fat; Cordell's is 7 percent.
"If there wasn't a substantial benefit to C.R., no one would do it," he says.
For Cordell, the potential payoff is worth eating this way, something many of us might have a hard time with. It's not about a short term New Year’s resolution; it's about a complete diet overhaul that Cordell will stay on for what he believes will be a longer, healthier life.
Barry Gamble a 67 year old CR advocate says his benefits are more energy, fewer digestive problems, better measures of heart health and mobility than his peers and although there are no guarantees, a longer life. "The real reason I do it is because I feel better.”
The focus of those practicing CR is health. Nobody is trying to figure out how to eat less and disappear. The constant thought is, ‘How can I pack more nutrition into my calories?’
Theory of how CR promotes longevity
Inside our cells the process of cellular respiration breaks down a molecule of glucose into carbon dioxide, water, and energy. This energy is stored as ATP. An adult produces 70kg of ATP a day. The process of breaking down sugar in the body is not completely efficient. About 40% of the sugar is converted into ATP. A significant amount of free radicals are produced during this process. When calories are restricted our bodies rely more on fat stores as fuel.
Since fat consumption is several times as efficient at producing ATP than burning glucose, the same amount of energy can be created with much lower levels of free radicals. Fewer free radicals mean lower levels of free radical damage particularly to the mitochondria. Recent studies have shown that a calorie restriction of 40% leads to a 45% decrease in the rate of mitochondrial free radical generation and a 30% reduction in the level of oxidative damage to mitochondrial DNA.
The net effect of these changes decreases the rate of aging by about 50%. Unfortunately humans cannot live reasonably by cutting 40% of their calorie intake. But by decreasing our calorie intake by 15% one achieves almost as much of an anti-aging benefit. It becomes a more realistic achievement than the tough 30% reduction often used by the calorie restriction purists.
CR followers say it is "a way of living" instead of a diet. The Calorie Restriction Society, based on the work of the late UCLA gerontology researcher Roy Walford, was founded in 1994 by a small group of people interested in the science behind CR and an estimated 1,400 people have taken up the diet as a full-time, lifelong practice.
What should you do while waiting for the long term human studies? If you are overweight or you want to experience the potential anti-aging benefits of CR it would be prudent to reduce calories by 15%.
We need to work together with our health practitioner and monitor our blood levels of glucose, insulin, cholesterol and inflammation levels. We need to do this slowly over time and according to the CR followers we will then experience optimal health.
Researchers evaluate health benefits of calorie restriction
(Republished with permission from the St. Louis Post-Dispatch. This article originally ran in the Health & Fitness section on Monday, February 18, 2008.)
By Harry Jackson Jr.
St. Louis Post-Dispatch
Washington University scientists want to find out if eating a lot less can improve your health to a nearly perfect condition.
That's why they're conducting human studies of a movement called "calorie restriction."
It's supposed to work this way: If you reduce your calorie intake by 25 percent to 30 percent, your physical fitness will improve to a nearly perfect level of health.
For example, a calculator used by the Mayo Clinic says an active man of 6 feet, 200 pounds, needs about 2,900 calories a day to maintain his weight. For a 25 percent reduction in calories, he'd go to 2,175 per day.
An active woman, 5-5, 140 pounds, needs 2,050 calories a day to maintain her weight.
She'd drop to about 1,550 calories.
The first phase of CALERIE — Comprehensive Assessment of the Long Term Effects of Reducing Intake of Energy — began several years ago when doctors examined a small number of people from a group called the Calorie Restriction Society. The group has about 3,000 members.
Early tests showed the practitioners, who call themselves "CRONies," (Calorie Restriction, Optimal Nutrition), had virtually no risks of cardiovascular disease or cancer even though their medical records said they were less healthy when they started the program.
What also intrigued researchers were claims that practitioners would live 20 to 30 percent longer and in better health.
Dr. John Holloszy, professor of medicine in the Division of Geriatrics and Nutritional Sciences at Washington University School of Medicine and the lead researcher on the project, says researchers can't wait half a century to see if the longevity claims are true.
However, he wrote after the preliminary round of studies, "It's becoming clear from studies with the CRONies — and from this brief, prospective study — that calorie restriction does change some of the markers we associate with aging."
The federal National Institutes of Health agreed and is paying for a bigger study of several hundred people in three research centers — Boston, Baton Rouge, La., and St. Louis. These will be people new to calorie restriction.
WHAT THEY FOUND
Proponents of calorie restriction, which they call "CR," boast of disappearing triglycerides, healthy cholesterol levels, the elimination of low-level inflammation through the body caused by oxidation damage, lowered and more stable blood sugar, nonexistent cardiovascular disease and even instances of being cured of early stage diabetes.
Holloszy says he's not put off by claims that the practice could stretch useful and healthy life spans up to 120 years.
"With calorie restriction, it seems like the metabolism goes into slow motion," Holloszy says, adding that the slower metabolism means slower aging.
"We'll look at the (physiological changes) in the reduction of the processes that we know cause aging," Holloszy says.
He added that early research shows some health benefits can come from reducing calories by 10 or 15 percent. "We think the effects may hold true (in proportion). We just don't know yet."
A seven-year practitioner of calorie restriction is Joseph Cordell, a St. Louis divorce attorney who specializes in men's rights.
He adopted calorie restriction years ago. He was in good condition but wanted more. He read a book, "Beyond the 120 Year Diet" by Dr. Roy Walford, who's considered the founder of the movement. Walford believed the rodent tests would translate easily to humans even before human studies were performed.
Today, Cordell has a breakfast of berries and apple peels. Through the day he'll eat mainly vegetables, fruit and for dinner vegetables with a small amount of lean meat, such as salmon, chicken or even lean red meat.
"That's the thing about calorie restriction," Cordell says. "What I eat probably weighs more than what you're eating, but it's much more dense in nutrients and a lot fewer calories."
WHERE IT STARTED
The attraction to CR by researchers was sparked by more than 60 years of uncommonly consistent tests on laboratory mice and rats, Holloszy says. When laboratory animals were placed on calorie restricted diets, "their life spans increased 20 to 40 percent."
Washington University performed the tests more than 10 years ago and came up with the same results, Holloszy said.
Bob Cavanaugh, a spokesman for the Calorie Restriction Society, says the group was founded on Walford's principle. Thousands use the group's website, calorierestriction.org.
NOT A DIET
Both Cavanaugh and Cordell emphasized that calorie restriction is a way of life, not a diet; it's not simply eating 25 percent fewer calories at each meal.
And it's not easy, which is why CR practitioners created a supportive community. St.Louis doesn't have a local group, although people here practice CR.
This is a simplified description:
— Examine your diet closely, detect the high-calorie, low nutrient foods, then eliminate them. They suggest weening, not simply turning them off cold turkey.
This will involve logging what you eat, maybe even seeking help from dietitians or other CR practitioners.
— As you eliminate empty calories, replace them with nutrient-dense foods, primarily vegetables and fruits. Cordell says he eats apple peels rather than the whole apple because that's the source of the most nutrients. He also avoids high-sugar fruit such as pineapples.
— Once your whole diet is nutrient-dense foods, you can calculate the calories you're eating and begin cutting back until you've eliminated 25-30 percent.
Cavanaugh says the CR Society offers a calorie and nutrition calculator to anyone who pays the $35 signup fee. Another, called "Cron-o-meter," is free online.
Holloszy, however, recommended against doing this on your own because off the downsides. And even the CR Society lists risks, most of which come during the transition process.
For example, practitioners find that they lose both fat, muscle and bone mass. That's why people who can't afford loss of bone mass or muscle need to be cautious or reject CR alone or work closely with their personal physician.
As for others, "The body is marvelous at regulating itself," Cordell says. "Your body maintains the amount of bone mass and muscle you need for good health. If you're not carrying around so much weight, you don't need the bone mass or muscle mass."
He says he dropped to about 130 pounds from 170, living on about 1,500 calories a day.
Holloszy wasn't ready to dismiss the loss of bone mass and muscle. He suggested daily exercise for people trying CR.
For maximum safety, Holloszy suggests joining the Washington University study. Researchers still need about 60 people.
Those accepted will be monitored by physicians, dietitians and physiologists who'll meet with them weekly and help set up their diets.
The first month will be a tightly scrutinized eating plan to get you started. After "boot camp," participants will be be given a stack of eating plans and recipes from various diets such as the Mediterranean Diet and diets based on low fat, low glycemic index or vegetarian.
For two years, they'll have weekly contacts with the researchers and frequent blood tests.
"It's quite a commitment," Holloszy says.
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