The public in industrialized countries is bombarded with a bewildering array of information on the effects of dietary factors on health. However, the only well-established means of improving health through diet is maintaining a relatively low caloric intake.
—MARK MATTSON, CHIEF OF THE LABORATORY OF
NEUROSCIENCES AT THE NATIONAL INSTITUTE ON AGING1
THERE IS CREDIBLE BIOMEDICAL EVIDENCE THAT fasting improves health span, both in animal and human studies. This is what inspired me to distill some of this evidence and provide easily understood explanations of how fasting can improve your health, including your health span. Calorie restriction (CR) or fasting delays the development of age-associated diseases and increases health span in rodents, monkeys, and humans.
What is health span? Simply put, it is the time of life in which we are free from disposition to disease. A strong health span reflects an increased quality of life and prolonged health during our senior years. Radically different from life span, health span involves prolonged delay in the onset of age-associated diseases. While we all want to live to an old age, we want that to be a healthy, disease-free existence. While research on short-lived animals has conclusively shown that fasting can and does prolong life span, studies on humans are ongoing and seek to ascertain whether calorie restriction can also increase human life span. Still, most scientific studies involving primates and human beings reveal this: in virtually all studies fasting improves almost all indicators of good health measured in humans.
As I said in chapter 1, fasting can significantly reduce your risk of cancer, stroke, diabetes, and such neurodegenerative diseases as Parkinson’s and Alzheimer’s. I haven’t included any statements that aren’t substantiated by more than seventy years of biomedical research. Studies on animal models have already conclusively proven the improvements on those species’ health span. And while researchers need to conduct more randomized, clinical trials involving large numbers of subjects, I will show that several studies involving humans have revealed that fasting consistently reduces health risk markers across the spectrum. In fact, while reviewing available scientific support for fasting to improve brain health, physicians from the National Institute on Aging’s Intramural Research Program had this to say:
We are now at a stage where our knowledge of both the genetic and environmental factors which have been linked to unsuccessful brain aging, and their cellular and molecular consequences, can be utilized to provide the general population with advice on aging successfully. In this review, we will discuss two dietary strategies, caloric restriction and intermittent fasting, which could potentially be used to mediate successful aging and forestall the onset of certain neurodegenerative disorders.2
Increased health span
This book is doing exactly what these doctors and others are advocating: utilizing the vast body of current scientific evidence in support of fasting to provide the general public with advice on successful aging and increasing their health span. Still, before one can dispense such pertinent advice, it will be helpful to call our attention directly to the body of scientific proof that strongly supports the idea of fasting’s benefits.
Many in the scientific community tend to assume that popular culture does not have either the appetite or the capacity to understand scientific facts. This assumption is wrong for two reasons:
• First, it tends to underestimate the ability of individuals to seek out information or change when motivated to do so.
What could offer more motivation than living a healthy life and avoiding early onset of chronic, debilitating diseases? Other dreams and aspirations of life tend to hang on this health factor. I am betting on the idea that you are rational enough—and motivated enough for self-survival—to be willing to spend a few hours assimilating information that could literally alter the trajectory of your health.
• The other false assumption about the general populace is its capacity, or lack thereof, to absorb scientific facts.
Could it be that scientists have been rather guilty of using too much jargon and parochial language in describing their findings to be of help to any person (including other scientists) who doesn’t earn a living from that particular discipline? Now, it is true that the nature of scientific inquiry, and the specificity required, lend themselves to specialty-specific language. Yet it seems almost an understatement that science can do a better job of communicating its findings to those not directly involved in that area of research. I am convinced that our friends and family members are capable and willing to digest relevant scientific information—that is, when it is written in the same kind of language they use for day-to-day communication.
Therefore, I set out within these pages to perform the delicate dance between describing the most up-to-date scientific findings regarding fasting and health and using language that anyone on the street can understand and appreciate. While this is possible, it is certainly not an easy undertaking. It underscores why most scientists tend to leave this task alone. As a scientist, educator, and medical writer, I hope to utilize my experience and training to bridge the gap between science and people who may need its findings.
Why eating less is healthy
In a study published by the National Institutes of Health, the authors wrote: “Put simply, high energy intake increases, while low energy intake decreases, the risks of cardiovascular disease, type 2 diabetes, stroke, cancers and possibly neurodegenerative disorders.”3 Some scientists speculate that perhaps the reason certain regions of the world where people eat much less (either due to lack or cultural and religious considerations) seem to have less incidence of cancer, stroke, and other diseases may be due in part to the hormetic effect of calorie reduction.
Inversely is it possible that the high prevalence of diseases associated with developed and industrialized nations stems—at least in part—from our overindulgence in food? Many scientists involved in healthy aging, nutritional studies, and physiology seem to think so. For example, after reviewing studies involving hormetic effects of fasting, a researcher with the NIH concluded: “The public in industrialized countries is bombarded with a bewildering array of information on the effects of dietary factors on health. However, the only well-established means of improving health through diet is maintaining a relatively low caloric intake.”4
In chapter 4 I discuss the role of hormesis in relation to fasting in some detail. But suffice it to note at this point that the theory of hormetic effect suggests that repeated exposure to mild stress (which includes fasting, among others) increases resistance of cells to other forms of disease pathways.
There are five main determinants of health used by medical and health practitioners around the world to gauge or guide the health-care system:
• Genetic disposition—because of their parentage, certain people have predispositions to certain diseases.
• Social circumstances—people with lower socioeconomic status tend to die earlier and have more disabilities.
• Environmental exposure—this includes exposure to such toxic materials as lead paint, polluted air and water, dangerous neighborhoods, and lack of outlets for physical activity.
• Behavioral patterns—this includes obesity, inactivity, tobacco or alcohol use, and drug intake.
• Health-care access—namely, doctor visits and inpatient or outpatient treatment and care.
It may surprise you to know that of all these five health determinants, the biggest contributor to premature death in the United States is behavioral patterns. Dr. Steven A. Schroeder spelled this out in an article published in the New England Journal of Medicine titled, “We Can Do Better—Improving the Health of the American People.” He spelled out how behavior contributes to a whopping 40 percent of all preventable diseases in this country. Meanwhile, health care contributes only 10 percent.5 In other words, out of every one hundred persons who die prematurely (before reaching good old age) in this country, forty of them could have lived if they had changed their behavior as it relates to their health. Only ten of those deaths were a result of an inability to get the right, or adequate, health care.
High cost of health care
Given these statistics, I find it quite surprising that health care takes an overwhelming chunk of the money allocated to health. In 2006 alone the United States spent a whopping $2.1 trillion on health care, which accounted for 16 percent of the nation’s gross domestic product.6 Most professionals in the health field agree that the health-care system, as currently structured, is probably not equipped to handle behavioral determinants. Many doctors do their best to help patients embrace changes in their lifestyle. However, it is also widely accepted that behavioral factors may be beyond the scope of traditional medical training programs, even if only in terms of their focus.
Sadly, what this means is that there is little or nothing your medical doctor can do about a major determinant of your health. Health care is different from health. A doctor’s training prepares him well enough to solve your health problems rather than address prevention. Fortunately current efforts in preventive medicine are gaining more ground. As such, more and more doctors are going out of their way to venture into behavioral issues in order to help their patients. But beyond that, there is not much more a doctor can do for you when it comes to living in good health, aging successfully, and delaying the early onset of age-associated diseases.
To boil it down to a simple fact, your health is your responsibility. Dr. Schroeder’s article also pointed out that obesity and corresponding inactivity, and smoking account for a much larger percentage of preventable deaths in the United States—all behavioral choices. When Schroeder’s article appeared in 2007, more than 435,000 persons died from smoking, a figure that has since risen above 440,000. Another 365,000 individuals died from obesity- and inactivity-related complications.7 Considering the preventable nature of these sad statistics, it seems a tad astonishing that these aspects of our nation’s health appear to receive significantly less attention and money than matters dealing with health care.
In fact, in his discussion of smoking, Dr. Schroeder writes: “Given the effects of smoking on health, the relative inattention to tobacco by those federal and state agencies charged with protecting the public health is baffling and disappointing.”8 And he concludes: “The single greatest opportunity to improve health and reduce premature deaths lies in personal behavior.”9
It is this “single greatest opportunity to improve health” that I am focusing on; in other words, how we can benefit from fasting and intentionally reducing our caloric intake.
Imagine being able to cut your chance of dying prematurely by 40 percent or more. Put another way, there is a huge opportunity to increase your health span—if not always your life span—by about 40 percent. The key is to take personal responsibility for your health. Too often we like to put too much blame on doctors and the health-care system, and disregard the fact that about 40 percent of our health depends squarely on our lifestyle.
Clearly quitting smoking is one sure way to improve your health span. This is one area where the news is good. Smoking has declined generally in the United States, from 57 percent of adults in 1955 to 23 percent in 2005, although a small uptick to 25 percent occurred between 2006 and 2010.10 Since a majority of us do not smoke, that brings us to perhaps the single greatest opportunity there is to improve your health—caloric restriction. While there are different forms of fasting, the underlying principle behind scientific fasting is simply profound: eating less could prolong your life and will definitely increase the disease-free period of your life.
In reviewing more than seventy years of research on the role of caloric restriction (CR) on health, I discovered overwhelming evidence that caloric restriction or fasting prolongs the life span of animals, from small creatures all the way up to primates. And while scientists are continuing to investigate the possible role of fasting in human health, most credible research has found significant improvements in health markers in humans and other primates. Later I will go into detail about how scientists conduct these tests and what they are looking for. But suffice it to note at this point that CR research has reached a fairly mature stage. The consensus emerging in the scientific community is significant; namely, that eating less could save your life or make it much healthier.
This book is not about prescribing specific diets, although I will offer some general suggestions based on the results of these findings. Nor is this book about weight loss, although eating less will almost surely help you lose weight. It is also not about using fasting to cure existing diseases, although fasting in some cases may help the healing and regeneration process. This book is about fasting intentionally for a healthy and spiritually wholesome life.
The opportunity to positively impact your health also comes with a responsibility to act. In fact, the biggest advantage of CR—unlike exercise—is the opportunity to do little or nothing. Just eat less by skipping a meal or two occasionally. Exercise and dietary considerations are two of the most important behavioral health determinants, yet research has shown that the single most important dietary factor is to skip a meal or two every now and then. In other words, eat less and live better.
You have the ability to fast occasionally. Except for those with health problems, almost everyone can and should fast. Your health depends on it. Even if you are not a religious person, you can fast for the sake of your health. And if you are a person of faith, now is the time to get back to this age-old spiritual discipline. It will help your body and soul heal in ways that will surprise you. I have dedicated a whole chapter to discussing the possibilities that exist when fasting for health purposes is intentionally integrated into moments of spiritual renewal.
In recent years one of the popular books embraced by our culture is The Seven Habits of Highly Effective People by the late Stephen Covey. With more than fifteen million copies sold in thirty-eight languages (and another 1.5 million audio copies), it is one of the best-selling nonfiction books in history. Part of the book’s popularity derives from the challenge that Covey threw at all of us: there is a space between the stimulus (what happens to us) and response (what we do about it). That space is where we can choose how to respond. In other words, we are capable of changing our path in life. We are capable of choosing what to do about our health. That is one of the unique things that make us human. Don’t surrender this ability to choose your response about one of the most important health determinants. Whether you are overweight or not, we all need to stay in good health. There is abundant scientific evidence that eating less or fasting periodically could profoundly impact our health. So what is stopping you from doing something?
There is no such thing as gaining “something for nothing.” As with all new habits, fasting may be painful at first. It may not be easy skipping a breakfast when you have gotten used to eating every morning. Fasting a whole day may seem almost impossible—that is, until you actually try it. Skipping sweets and junk foods and living only on vegetables, fruits, and whole grains for a few days or longer may seem daunting. But it can be done. More than seventy years of research from some of the world’s most brilliant minds supports its practice. In other words, the facts are on your side.
Don’t attempt to start in an overly ambitious manner. Initiate a fasting journey slowly and progressively. I have a few suggestions that may be helpful; however, no matter what someone else says or what examples they offer from their experience, your journey is just that—yours. Embark on it slowly, deliberately, cheerfully, and intentionally. Find out what works for you and adjust accordingly. It is your life, your journey, and your health. I won’t be presumptuous enough to assume that I know what is best for you. My only goal is to give you some of the information currently available on fasting’s nature, substance, and duration. It is your decision if, when, and how you will embark on this journey. I feel the facts will be persuasive enough to prod you to start, but that is where my role ends. The rest is up to you.
We can only imagine the health revolution that will come to our nation if people take behavioral matters into their own hands and start a fasting lifestyle. Imagine reducing the risk of cancer, stroke, diabetes, cardiovascular diseases, and possibly neurodegenerative diseases by 20 to 50 percent. That is the vision driving the release of this work, which simultaneously presents a huge opportunity and huge responsibility.
It serves no use to read the facts supporting fasting if you don’t intend to fast. You cannot be an author until you have written the book. You cannot reap dividends until you have invested. The health benefits are just that: benefits. Fasting is the cause, and health is the effect. Knowing about something isn’t the same as experiencing it. Learning and doing are not quite the same. One leads to the other, but you can learn all the facts in the world without doing anything about them. The world is filled with folks who have a lot of knowledge but do not act on it. Those who have made a difference in life are those who have taken a fact—even a simple one—and done something about it.
A precautionary principle
A precautionary principle in good science stresses the “wisdom of acting, even in the absence of complete scientific data, before the adverse effects on human health or the environment become significant or irrevocable.”11 Let us agree that while the studies on humans are not yet conclusive, the overwhelming evidence from animal and primate studies thus far adequately justifies taking the precautionary step of periodic fasting. Then it behooves us to develop a consistent, workable plan.
As another group of scientists summarized the situation after an extensive review of the health benefits of fasting: “Whether current positive results will translate into longevity gains for humans remains an open question. However, the apparent health benefits that have been observed with CR suggest that regardless of longevity gains, the promotion of healthy aging and disease prevention may be attainable.”12
Given the promise of fasting, particularly during the staggering health crisis that burdens the American system, initiating a plan would seem a wise and prudent course of action. To paraphrase a familiar commercial: “Your stomach deserves a break today.”