Longevity through frugal diet?

Excerpt from the book
"Ageless Body, Timeless Mind" by Deepak Chopra

For centuries the literature of longevity has been filled with testimony about the virtue of strict dietary abstinence. A fifteenth-century Venetian nobleman named Luigi Cornaro is famed in gerontology because he resolved, after a roaringly dissolute youth, that he would mend his ways, pursue a healthy course of life, and try to survive to at least 100. He succeeded spectacularly.

In an age where the average person was fortunate to live to 35, Cornaro lived to 103 and remained active and clear-headed to the end. His method for achieving this feat was to abstain from drinking and to eat very sparingly: In essence, he fasted from age 37 onward, following ancient Greek and Roman notions of frugal diet as the secret of longevity.

Cornaro's prescription gained scientific credence centuries later, at least in animal experiments. In the 1930 Dr. Clive McKay of Cornell University took newly weaned rats and fed them only 60 percent of the calorie intake of a rat with food available all the time. This restricted diet was supplemented with adequate vitamins and minerals. The diet-restricted rats grew very slowly compared to normal rats, but they appeared extremely healthy throughout their long lives; they could be held in a growth-retarded cycle for a thousand days, by which time all the rats on unrestricted diets had died. When the restricted rats were allowed to return to a full diet, they started growing normally, and they showed interest in sexual activity, which had been missing before.

To date, McKay's method of "undernutrition" - supplying complete nutrients on a very-low-calorie-diet - is the only proven way to extend the maximum life span of animals. Follow-up research indicated that he average maximum life span of approximately a thousand days for fully fed rats could be extended to sixteen hundred day for undernourished rats, an increase of 60 percent. Would the technique work for humans? Perhaps. But the test cannot be done on newly weaned babies, given the risk of stunting their growth and the obvious ethical objections. A human diet restricted to 60 percent of normal calories - roughly fourteen hundred calories per day for an average adult - is on the borderline of fasting. I would be intolerable to impose this on children, and since young adults can't see signs of the aging process yet, they don't have much incentive to prevent it. Cornaro took up his fast in middle age, which may be early enough.

Dr. Roy Walford, a noted gerontologist at UCLA and an outspoken advocate of undernutrition, is one of the few scientists actually to take up the method himself. Walford believes that cutting back on calories is safe and effective long after infancy. To support this view, he started mice on a restricted diet at the equivalent age of 30 to 33 in humans and found that they lived 20 percent longer. Unlike the animals who followed a restricted diet from birth, these did not outstrip the maximum age of mice. On the other hand, a 20 percent increase in life span represents about fifteen years for humans. The animals displayed excellent health all their lives and aged with a fraction of the heart disease and tumors of fully fed mice.

Walford did not subject the animals to total fasting every day. Earlier research had shown that eating a restricted diet only every other day was highly effective in increasing life span. In addition, the mice were tapered into their new diet gradually, allowing their bodies to shift their metabolic set point to accommodate dietary restrictions without abrupt changes.

Your metabolic set point is a brain mechanism that regulates how fast your body burns fuel. It also indicates when you feel hungry or satisfied. If you try to impose a diet on yourself that disagrees with your metabolic set point, the brain will create cravings for food until more is supplied. By changing the metabolic set point gradually, Walford coaxed it into line with the meager calories called for in undernutrition. He advises the same tapering process for people who adopt his method, taking several months or years to adjust to a 40 percent reduction in caloric intake.

This graduated plan forms the basis of Walford's diet, which he believes will allow anyone to surpass Cornaro and live to age 120 or older. "The idea is to lose weight gradually over the next four to six years," he says, "until you're 10 to 25 percent below your set point. That's the weight you'll drift toward if you neither overeat nor undereat. Usually it's what you weighed between ages 25 and 30."

The gradual restriction of calories has to include careful food selection to make sure that all vitamins and minerals are included - undernutrition is not the same as malnutrition. From a physician's viewpoint, Walford's diet would lead to almost certain improvements in health, particularly in the areas of cancer and cardiovascular disease.

Instead of eating anything like the 37 percent fat that the average American consumes daily, or even the 30 percent advised by prevention experts, Walford's regime cuts fat to a marginal 11 percent - approximately the fat in one tablespoon of vegetable oil, plus traces in grains, vegetables and fruits. Although this intake is so minimal that only them most intensely motivated person could realistically expect to live on it, 11 percent fat is normally not dangerous over the short term. The widely publicized program for reversing heart disease devised by cardiologist Dean Ornish contains only this much fast, as does the Pritikin Plan and the Duke University "rice diet" that preceded it.

Another advantage of dietary restriction is its elimination of useless calories and processed foods. On a regimen of twelve hundred to fifteen hundred calories a day, there is no room for cakes, cookie, ice cream, hamburger and French fries. Sugar and fat have to be excised to make room for an abundance of whole foods. This is desirable even if longevity doesn't result from Walford's plan. Some gerontologists point out that the animals who are of real interest are not the diet-restricted ones but those that were allowed to eat all they wanted. Dr. Leonard Hayflick, one of the country's leading research gerontologist's, says that the argument should be reversed: "The restricted mice are merely being allowed to reach the limit of their life span. It's overfeeding that kills the control group."

This contention makes a good deal of sense when applied to human; the rampant degenerative disease that afflicts our society in old age indicates that we are being held back from the long, healthy life spans that a few achieve - approximately 15 percent of people over 65 have no major degenerative disorder such as heart disease, cancer, diabetes, arthritis or osteoporosis.

No one has yet discovered why calorie restriction extends life span in animals. Walford speculates that it postpones a breakdown in the immune system. Presently a huge government facility in Arkansas has been turned over to undernourishing thirty thousand rats, with similar extensive rails being run on monkeys. In the near future, announcements of the results, which have been favorable so far, will no doubt be widely aired.

It seems unlikely that many people ill ever undertake severe calorie restriction as a longevity program, given its rigors, but my cultural background predisposes me to favor the principle of occasional fasting. In India there is a tradition, centuries old, that longevity can result from taking little or no food one day a week (in the form of fruit juice, warm water with honey, or low-fat milk). The principle at work is simple: The digestive system is allowed to take a rest, to recover its balance and flush out accumulated impurities. Modern physiology has not accepted these principle, yet every spiritual tradition boasts long-lived people who adhered to them.

The success of frugal eating, I believe, is that it must be blended with a lifestyle in which fasting is neither a punishment nor a discipline a respite from daily activity.

The time one would ordinarily devote to eating would be spent quietly, alone. Fasting would then allow the body to participate in a feeling of peaceful non-doing.

It seems to me that centenarians tend to be far ahead of gerontologists in what they know about living. There's something woefully lacking in any fragmentary approach to life, however intriguing any single fragment happens to be. Dietary restriction doesn't address the rich psychology of humans, and what we know about longevity so far indicates that this facto is extremely important. I recently read an interview with an inspiring 100-year-old woman named Edna Olson. She is very devout; all her life she has sung and prayed and written poetry expressing her faith. When asked about her life, she said, "I was only about 2 years old when God spoke to me. He told me he was God and He wanted me to believe in Him, and He said, 'I will take care of you.'

"And He has. He said, 'Don't tell your mother yet. She'll just say you're a silly child and you don't know what you're talking about. I will send you dreams.' And God did send me dreams in the morning - before I woke up - and they would always be true dreams. They would tell me what I should do. That's how I've lived my whole life."

A woman nourished by visions, or thirty thousand rats on short rations - I know the juxtaposition seems strange, but I cannot conceive of survival without vision. Even if I don't wake up to dreams from God, every new day has to mean something to me, and if it does, I believe the battle is won. However, this emphasis on personal qualities of heart and mind is at odds with current gerontology. The cutting edge of the field lies in biotechnology, and the most exciting breakthroughs, reported with extravagant hopefulness by the media, have to do with youth hormones and genetic engineering.

Are these the true hope? There is an appealing simplicity to the idea that youth is only a matter of injecting the right chemical or manipulating a wayward gene. In many people's minds (including those of many gerontologists) the science of longevity ultimately boils down to finding a magic bullet, a substance that will chemically alter our cells' propensity to age. We therefore need to evaluate this perspective and ask why the kind of longevity that seems to be achievable in test tubes is so far removed from the kind achieved by real-life centenarians.-