|LE Magazine March 2000|
Fish Oil and Carb Restriction on the Anti-Aging Front
A review of The Anti-Aging Zone, a new book by Barry Spears, Ph.D.
Book review by Ivy Greenwell
Anti-aging medicine is really a very ancient field, Dr. Barry Sears points out in his latest book, The Anti-Aging Zone. There exists an Egyptian papyrus, written 2,600 years ago, called "Book for Transforming an Old Man into a Youth of Twenty." Likewise, Taoist sages prescribed diet regimens, herb potions and special exercises in the hope of preserving vigor and attaining physical immortality. Stories of magical elixirs and immortality-giving, youth-preserving "food of the gods" are a common theme in mythology and literature, showing humanity's longing to conquer aging. Amazingly, for millennia humans believed that the right special food could preserve eternal youth; that there existed something the gods ate or drank that prevented aging.
This aging-retarding food of the gods is right in our kitchen, Sears announces. But the secret is not so much in what we eat, as what we do not eat. If we eat less, we will live longer. Or, as Sears puts it, "The fewer calories you consume, the less energy is required to process the incoming food and the fewer free radicals you make. The fewer free radicals you make, the longer you live." And no, we do not have to go hungry. Sears promises that by using food wisely, we can slow down aging and still have plenty of energy and no feeling of deprivation at all.
Calorie restriction: the "Holy Grail" of anti-aging
The first rule of anti-aging seems a harsh one: we must eat less. "There is only one consensus in the world of anti-aging: the only proven way to reverse aging is to restrict calories," Sears explains. There is nothing new here, as attested by the old saying to the effect that most people dig their own graves with a fork. Yes, we readily agree that many people, perhaps most, in effect kill themselves by eating too much. There are no obese centenarians.
But what about the usual contention that Americans, the fattest people in the world and in the history of the world, are incapable of practicing calorie restriction? Sears finds that the main problem is ignorance about proper food choices. He asserts that it is indeed possible to feel perfectly sated and have a lot of energy if one eats the correct carbohydrate-restricted diet that includes sufficient protein and fat-the two macronutrients that will stabilize blood sugar in the longevity-promoting low-normal range and provide sustained energy. Then, instead of the government recommended 2000 calories/day for the average woman and 2500 calories/day for the average man, one can go down to 1200 calories for the average woman and 1500 calories for the average man. Health benefits should be enormous.
Why? Because, Sears explains, 90% of free radicals in our bodies are generated through the utilization of food. In spite of the outcry about pollution and radiation, these are relatively marginal sources of free radicals. The sad truth is that the more calories we eat, the more free radicals we generate. And if most of these calories come from high-glycemic carbohydrates (bread, cereal, pasta, pastry, most fruit juice, overcooked vegetables, etc.), then we also begin to suffer from hyperinsulinemia and hypercortisolism, with a corresponding drop in beneficial hormones such as DHEA and growth hormone. The result of both excess calories and the endocrine imbalance that follows is the creeping middle-age spread (as the saying goes, "middle age starts when you start growing in the middle"), and no end of degenerative disorders.
What is the secret of being able to reduce calories without going hungry? According to Sears, the crucial concept is the inversion of the USDA food pyramid, with its bizarre, pro-aging recommendation of up to eleven daily servings of starchy foods. Starches-cereal, bread, pasta and other refined carbohydrates-are placed at the very top of Sears' anti-aging pyramid, with the admonition: "Use sparingly." While the government urges us to eat mainly bread, cereal, pasta and the like refined carbohydrates, Sears says that these should be severely reduced, even eliminated. Instead of being the main staple, they should hardly be consumed at all. Humans evolved to thrive on the kind of food that was available before the relatively recent development of agriculture and food processing.
Sears is impressed with the diet of our remote ancestors. The Paleolithic hunter was a world-class athlete; the mostly vegetarian agricultural people who followed later were stunted and disease-ridden by comparison. According to Sears, if all bread disappeared from the earth, we'd be better off. Bread, including the so-called whole-wheat bread, is very efficient at raising our blood sugar and insulin. If you ever see the insulin curve after a "meal containing bread," you would be quite motivated to eliminate all forms of bread except perhaps a bit of coarse rye. If we eliminated bread from our diet, most likely we'd live longer and remain practically free from heart disease and cancer. What would we eat in the place of bread and other cereals? Lots of vegetables, as long as they are not overcooked, and moderate servings of low-glycemic fruit.
When refined starches are used sparingly (if at all), and all meals including snacks contain adequate protein and fat, blood sugar and insulin stay in the optimal low-normal range. Calorie intake can thus be easily controlled, without insulin-induced hunger and the obesity that generally results from a low-fat, high-carbohydrate diet, especially when such diet is combined with the modern sedentary lifestyle rather than hard physical labor in the fields.
I think that in this volume Sears succeeds at last in clarifying the misunderstanding that followed his first book. He emphatically points out again and again that the Zone diet is not a weight-loss diet. It is a life-long calorie-restricted, carbohydrate-restricted diet aimed at controlling blood sugar and insulin. In other words, it is a special form of calorie restriction that should work to slow aging.
Sears thinks that anyone interested in extending life span should follow his plan-no ifs, ands or buts. The plan can be modified according to individual needs (athletes can use more fat, for instance; some people have genetically better metabolism and can do well on a higher carbohydrate protein ratio). But it is still the same idea: restrict high-glycemic carbohydrates. The typical American diet has become the very opposite of calorie restriction. With the emergence of breakfast cereals and fast food, it has also grown to be very unbalanced: cold cereal and fruit juice for breakfast, a white-bread sandwich for lunch, followed by a pasta dinner, with sugary junk food snacks in between. It is a high-carbohydrate prescription for obesity, disease and rapid aging.
Sears calls his nutritional regimen a "protein-adequate diet," rather than a high-protein diet. Yet it is hard to deny that no macronutrient looks as good as protein in terms of the benefits it provides. For one thing, Sears attributes the dramatic increase in longevity (as well as the equally dramatic increase in the average height) during the twentieth century chiefly to greater consumption of protein. Adequate protein means an adequate immune system-and Sears convincingly documents that the decline in the rate of mortality from infectious diseases started even before the advent of antibiotics.
Protein plays a starring "good guy" role also because it stimulates the release of glucagon, the little-known but extremely important pancreatic hormone. Glucagon helps us sustain normal blood sugar levels. Unlike insulin, which is a storage hormone and thus keeps energy stored as fat, glucagon releases our energy stores. Protein-induced release of glucagon also makes it unnecessary for the body to rely on cortisol in an attempt to maintain an adequate supply of glucose. Cortisol can do the job, but at a big price.
In addition, certain amino acids play an important physiological role. Arginine, for instance, is necessary for the production of nitric oxide, which is of great importance for vasodilation, short-term memory and immune function. Sears recommends frequent consumption of turkey and soy protein as sources of arginine.
Healthy fats (Sears basically means fish oil and olive oil) also look extremely good: the benefits include lower and more stable blood sugar, lower insulin, higher metabolic rate and increased immune function, among others. Fat slows the rate of carbohydrate entry, thus helping keep blood glucose and insulin steady and normal, without harmful surges. In addition, fat signals the brain to produce the message: "Stop eating." Because fat is essential for controlling blood sugar, every meal, including snacks, should include fat, just as it should include protein.
It is, alas, carbohydrates, especially the grain-derived processed carbohydrates (bread, cereal, pasta) so beloved of many diet gurus, that lead to most trouble and can seriously accelerate aging.
There are essential amino acids and essential fatty acids, but insofar as we know, there are no essential carbohydrates. If we are to practice calorie restriction in order to live longer, this is the part of the diet that is most dispensable-and, according to Sears, the most pro-aging. Sears states, "The key to practical calorie restriction is to determine the minimum level of carbohydrates you need to function efficiently."
Still, it is unfair to accuse Sears of trashing all carbohydrates. He trashes only the high-glycemic, grain-derived starches and excess fruit and fruit juice. Otherwise, unlike Atkins and the high-protein school, he is in emphatically in favor of including a certain minimum of low-glycemic carbohydrates in order to avoid ketosis.
The argument with Atkins is not successfully resolved. It has not yet been established whether mild ketosis is actually harmful-after all, mild ketosis is the state we wake up in every morning. Some experts claim that our Paleolithic ancestors were often in a state of mild ketosis, especially hunters out on a long hunt.
If the transition is slow rather than sudden, side effects such as a feeling of weakness (which in any case is transient) should not happen. What goes wrong in some cases is that a person on an 80% carbohydrate diet reads one of Atkins' books, and the next day it's nothing but cottage cheese for breakfast, and meat and salad for lunch and dinner. Then s/he goes for an evening run and discovers that s/he doesn't seem to have the energy to do it. With a slow transition to a ketogenic diet, the initial side effects are minimized, and a sense of well-being, alertness and high energy follows.
On the other hand, there is also something to Sears' argument that ketosis results in increased urination, and thus the risk of electrolyte loss. Since bananas are definitely the forbidden fruit when one is on a very carbohydrate-restricted, ketogenic diet, getting sufficient potassium may be difficult. But here again, the counterargument is that the kidneys do adapt, and the body learns how to preserve electrolytes.
Maybe the worst thing for those who rely on ketosis for weight loss is that fat cells also adapt to ketosis and are said to become "fat magnets," becoming more efficient in accumulating fat once more carbohydrates start coming in. This has indeed been observed: if a person returns to considerably higher carbohydrate consumption, the regain of lost fatty tissue is shockingly rapid. But this seems to happen after any low-calorie diet. The solution is basically to stay on the diet on a life-long basis-and here Sears' plan has an advantage, since his diet is not so extreme, and does include a satisfying amount of plant food.
And there is a truly compelling reason that Sears cites for our need to consume a certain minimum of low-glycemic carbohydrates: it is the only way to obtain many valuable phytochemicals, so important for the prevention of heart disease and cancer. And if we eat this plant food raw, we are also getting the benefits of natural, live, enzyme-rich food.
Type II diabetics: "Canaries in the coal mine of aging"
Sears points out that type II diabetics, with their high blood sugar and high (but ineffective) insulin, their greater rates of free radical formation, lipid peroxidation, glycation, and higher levels of inflammation are the very picture of accelerated aging. The higher the level of blood sugar, the more severe and frequent the problems typical of diabetes (and also of aging): impotence, depression, cataracts, glaucoma, atherosclerosis, kidney failure, dementia and more.
The main reason for this, according to Sears, is that insulin is our "passport to accelerated aging." Let us bear in mind that type II diabetics actually have elevated insulin levels; the problem is that they are insulin-resistant, so their pancreas keeps pumping out more and more insulin in the effort to lower blood sugar. Unlike diabetics and most of the elderly, individuals with low blood sugar and low insulin have been found to be healthiest and to live the longest. Diabetics, with high blood sugar and high insulin, age fast and die prematurely.
Insulin is a potent accelerator of aging for many reasons. By now many people know that it promotes obesity, with disastrous consequences for the cardiovascular system. But few know that insulin is a very powerful growth factor. It drives more frequent cell division, thus leading to faster telomere shortening. It makes tumors proliferate faster. Insulin also decreases the levels of cyclic AMP, the "second messenger" used by many hormones to communicate with the cells, thus decreasing endocrine regulation of body functions. The result is hormonal miscommunication and metabolic chaos. In addition to this, insulin also inhibits the release of glucagon, thus promoting the release of cortisol, another hormone whose levels tend to rise with aging. Excess cortisol has its own pro-aging consequences. That's why Sears calls elevated insulin "your worst aging nightmare."
It should be emphasized that this applies to elevated insulin-and aged people typically have higher insulin levels than young people. They also have higher blood sugar; the problem is insulin resistance. A certain level of insulin is essential for health. The same is true of "bad" prostaglandins. One of the virtues of Sears' book is that it stresses the notion of balance.
Calorie-restriction, Okinawan centenarians and Luigi Coronaro
The island of Okinawa is famous for having four times as many centenarians per 100,000 people as the rest of Japan. Compared to other Japanese, Okinawans have 60% lower mortality due to heart disease, stroke and cancer. According to Sears, the secret of the superior health and longevity of the Okinawans is their Zone-like diet: less rice, more protein (fish and pork), and three times as many vegetables.
It is of special interest that Okinawans eat twice as much fish than the average Japanese. People for whom fish is the main source of protein seem to be the healthiest in the world, healthier by far than strict vegetarians. They have the lowest rates of heart disease and Alzheimer's disease. Part of the answer lies in the anti-inflammatory benefits of omega-3 fatty acids; we are becoming increasingly aware that inflammation plays an important part in most degenerative diseases of aging. At the same time, Sears points out, fish protein is the only animal protein that is a poor source of omega-6 fats; thus a fish-eater is not loading up on excess linoleic acid.
Sears quotes yet another example of calorie restriction: the longevity of Luigi Coronaro, a sixteenth-century Italian nobleman. Coronaro started his Spartan diet of coarse dark bread, red wine, meat broth and eggs only at the age of fifty, in a state of poor health, and still managed to live until 98-back then, an unheard-of great old age. It is a great pity that Coronaro began calorie restriction so late in life.
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