The Body Clock Guide To Better Health

Read an Excerpt

In 1996 the American Medical Association (AMA) asked the Gallup Organization to see if the nation's physicians and the general public knew that symptoms of many common illnesses worsen at predictable times of day or night, and improve at other times. When do heart attacks and asthma attacks occur most often? When are stuffiness, runny nose, sneezing, and other allergy and hay fever symptoms worst? When is blood pressure highest?

* Most physicians got every answer wrong.

* The typical adult flunked, too.

* Even persons with the target illnesses lacked vital facts that could improve their health, and possibly save their lives.

* Both doctors and patients wanted more information about how time of day affects illness and well-being.

This book addresses that quest for knowledge. It starts with this claim: Most of us don't know how to tell time. Body time.

We pay more attention to watches we wear on our wrists than to clocks we acquire in the womb.

A wristwatch tells only one kind of time: world time. You must heed world time if you are getting married in the morning, have to catch a train, or want to see the six o'clock news. But no wristwatch tells when you think fastest, add numbers best, or swing a tennis racquet most deftly. A glance at your watch might make you think "time to eat," or "time for bed," even if your stomach isn't rumbling, or you haven't started to yawn. Feeling hungry or sleepy, however, requires a watchful brain, a brain with its own clock. A biological clock. A hard-wired program that ties your daily behavior to the rhythms of our planet and runs in the background of your life, adjusting automatically, as circumstances demand.

Most of us think we run our lives by the world's clock. Indeed, we often protest that this clock runs us, griping, as did Shakespeare's King Richard III, "time is wasting me." Life in the fast track both seduces and enslaves us. At work, we churn out faxes and E-mail, sometimes even to the person in the office next door. We've revved up our pace to Internet Time, fretting at the few seconds' delay signaled by the icon on our computer screens depicting the now obsolete hourglass.

Who has time to visit with friends? To read the books and magazines piled on the nightstand? Where do we find so-called quality time for our partners or children? Some 47 million Americans now work at paid jobs on weekends.

Recognition that nighttime is the right time for sleep has faded with the availability of hundreds of television channels at any hour, and the ease of ordering pizza around the clock even in small towns. If we can't fall asleep or stay asleep, or can't get going in the morning, we grumble about bad sleep, but the real problem may be bad timing. Most people don't know they can fix this broken clock themselves.

While we drive, we gulp coffee, gobble fast-food meals, and gab on the phone. Some cars now boast fax machines. Cats nip the heels of dogs as Americans' favored pets; cats don't need to be walked. A New York woman earns her living as a personal shopper. She picks out clothes for her busy clients ... from catalogs. We're under the sway of what Stephen Bertman, author of Hyperculture, calls "the power of now." We mimic the March hare, constantly complaining, "I'm late. I'm late, for a very important date."

The brain's clock governs whether or not you're crabby before you have your morning coffee, how quickly you can write a letter and how accurately you can proofread it, how long it takes you to bike ten miles, whether or not you fall asleep at the symphony, when your ulcers act up, and more. Like the crocodile in Peter Pan, we carry this clock around inside of us. Many of us don't hear it tick.

Sara Discovers Her Body Clock

Sara liked to bound out of bed in the morning, pull on her jogging clothes, and go for an easy run. When her knees and back started hurting, she added ten minutes of warm-ups and cool-downs. The pain, unfortunately, did not go away. To give herself more time to stretch, she put off running until she came home from work. Happily, her pain disappeared. What's more, Sara could run faster and farther. She certainly enjoyed her exercise more.

A specialist in chronobiology, the science of body time, could tell Sara why. Peak performance in most sports occurs in late afternoon and early evening, when body temperature reaches its daily high. Respect for this body rhythm may decrease your likelihood of injuries, whether you're a neighborhood jogger or an elite athlete. Training and competition times may influence who wins Olympic games and other high-powered sporting events. Stanford University scientists found that players' biological rhythms predicted winners of Monday Night Football games better than the Las Vegas point spread did.

If Sara wants to maintain or lose weight, or become a partner in her law firm, tuning into her body rhythms can help her achieve those goals more effectively. If she develops a cold, suffers from hay fever, or becomes pregnant, body rhythms will move to center stage in her life.

These findings represent a major leap in scientific understanding: a new way to maintain and optimize health, and to prevent and treat illness. Known as chronomedicine, it holds implications for vastly improving all of our lives.

What Chronomedicine Means to You

Chronomedicine can help you cope better with short-lasting illnesses such as colds and flu, episodic ones such as headaches and back pain, and persistent ailments such as arthritis, high blood pressure, heart disease, cancer, and more. This book details important recent advances to help you in your everyday life.

We report evidence from studies at leading medical centers worldwide showing that:

* Many illnesses disrupt normal body rhythms. Upsets in the body's most dominant rhythm, the daily wake/sleep cycle, provide an important clue to alert you that something is wrong. Complaints about fatigue and poor sleep trigger visits to the doctor for diseases as diverse as AIDS, diabetes, depression, and multiple sclerosis.

* The signs and symptoms of many illnesses vary across the twenty-four-hour day, over the month, and around the year. Some disorders peak in the morning; heart attacks, strokes, cluster headaches, hay fever, and rheumatoid arthritis are some examples. Others flare at night, including asthma, gout, colic in infants, gastric ulcers, and heartburn. Most chronic illnesses in women worsen in the days just before a menstrual period. Over the year, premenopausal women are most likely to discover a cancerous lump in a breast in the springtime, and men to find a testicular cancer in the winter.

* Time of day patterns help identify causes of many illnesses. Bringing symptom patterns to your doctor's attention may help your doctor figure out what's wrong faster and more accurately. The predictable morning spurt in blood pressure and clotting of red blood cells, for instance, make heart attacks and strokes peak in the morning, too. Disruptions in the flow of oxygen to the brain in sleep may produce morning headaches.

Chronotherapy, or timed treatment, aims to correct these underlying causes or reduce their adverse impact. Knowing symptoms' time of origin may enable your doctor to use more precise and effective treatment.

itches in the body clock itself may undermine health, making you fall asleep too late, wake up too early, or suffer blue moods. Chronotherapy offers new ways to reset your body clock and resolve such problems.

The time of day you take diagnostic tests or undergo medical procedures alters the results. If you have asthma, for example, your airway function will vary over the day. It probably is best in mid-afternoon, and poorest in the early morning. If you routinely go for a checkup in the afternoon, your doctor may think your treatment is working fine. But if you routinely go for a checkup first thing in the morning, the severity of your illness will be more apparent.

* Time-of-day norms are known for many rhythms. In the majority of the population, persons who stay awake in the daytime and sleep at night, who follow fairly regular schedules, the ups and downs of most daily rhythms prove quite predictable from day to day. Some labs already report findings with a time-of-day correction factor. New ambulatory monitoring devices can show your doctor how your blood pressure, heart rate, activity/rest cycle, and other indicators of your health change around the clock. Computer programs can analyze the data, making its collection and assessment practical.

* The time you take medicine matters. Taking the right medicine at the right time for your body and your illness may boost the medicine's efficacy and cut its unwanted side effects. The upshot is that you probably will feel better, be more willing to continue taking the medicine, need to see the doctor less often for symptom flare-ups or adverse drug reactions, and need fewer hospitalizations for chronic illnesses.

* Nondrug treatments may help correct underlying disturbances in the body clock. Exposure to sunlight-equivalent light, as one example, is now held to be the treatment of choice for persons with winter depression. Light exposure also benefits elderly persons who sleep poorly and wander at night, as well as shift workers and jet-lagged travelers.

* How you organize your daily life, with respect to sleep, meals, exercise, and other factors may make symptoms better or worse, and hasten or slow your recovery. If you have insomnia but stick to a regular wake-up time seven days a week, however bad the night, for instance, you'll probably sleep better in the long run than if you succumb to the impulse to sleep in.

How This Book Can Help You

We will show you

* the time of day, month, and year that symptoms flare in asthma, arthritis, diabetes, headaches, and many other common diseases

* how to observe and chart your personal symptom patterns by using do-it-yourself tests and diaries

* which times are best for many medical tests and procedures

* When to take your medicine to ensure that it works best and causes the fewest unwanted side effects

* how to monitor your own treatment

* Which times are best for different types of exercise

* how to instill good sleep habits in young children, why not to hassle your teenagers when they sleep late on weekends, and how to get a good night's sleep yourself

* how to reach and maintain your ideal body weight

* What time of day is best for intercourse if you want to conceive

* how to prevent or minimize jet lag

* how to cope with working outside the traditional 9 to 5 hours

This information has never before been gathered in one place for both doctors and the general public. This book aims to be the first comprehensive guide to chronomedicine and chronotherapy.

What Doctors Don't Know about Health and Body Time

Chronomedicine is a brand-new concept, not only to the average person but also to most doctors. More than half of the 320 primary care physicians surveyed in 1996 for the American Medical Association said they were not familiar with chronobiology. One in four asserted that biological rhythms are not important in diagnosis or treatment.

Most of the doctors — even those who claimed to know something about chronobiology — did not know that some common illnesses predictably flare in the morning, afternoon, evening, or night, or they picked the wrong time. They did not know that blood pressure varies significantly over the day or that labor pains spontaneously start most often at night. They thought that diagnostic tests give the same results whenever they are performed, and that medications and other treatments work equally well, and are equally likely to cause unwanted side effects whenever they are given. They were wrong. We will show you why.

These were experienced physicians in their peak professional years. Most were under age fifty and had been practicing general family medicine or internal medicine for ten years or more. Nearly all saw 400 patients or more each month, persons with all of the illnesses or conditions included in the survey. Yet they knew only slightly more than their patients about the time patterns for high blood pressure, arthritis, respiratory allergies, asthma, chest pain, heart attacks, and migraine headaches.

Only one out of three physicians, most under age forty, said they had learned about chronobiology in medical school. Most of those who had at least some familiarity with the topic said they had gotten their information from reading medical journals. In 1996, the year of the survey, about two thousand articles on chronobiology were published in the world's scientific journals, far more than any one doctor was likely to read, but perhaps still not a critical mass.

Doctors and their patients also learned about chronobiology from news media reports. In recent years, The New York Times, The Washington Post, The Wall Street Journal, Time, Newsweek, and many other leading newspapers and magazines have reported advances in chronobiology. All of the television networks have produced stories on such topics as timed treatment for cancer and other illnesses, drowsy driving, the genetics of the biological clock, sleepy teenagers, jet lag's impact on athletes, melatonin, light therapy, and more.

Such stories still may be too infrequent, or too diverse and seeming unconnected, to reshape attitudes and behavior. Among the general public, even persons who had the illness in question rarely recognized the predictability of its time course.

* Now that you mention it, I do often wake up with a migraine.

* My hay fever is worse in the morning.

* My osteoarthritis acts up in late afternoon. Guess I try to do too much early in the day.

* I just got to work when wham! The pain hit me. It's lucky I wasn't driving when I had my heart attack that morning.

Same Dose of Medicine Sometimes "Too Much" or "Too Little"

Think how often a doctor has handed you a prescription, saying, "Take this medicine three times a day." By linking pill-taking to mealtimes, the doctor knows you'll be more likely to remember to take your medicine. A "four times a day" prescription adds bedtime to the list. This approach is obsolete.

In prescribing equal doses over the day, your doctor presumes that your need for medication is the same all day, and that a consistent amount of medication confers a uniform benefit at all times. This belief is wrong.

If your symptoms wax and wane over the day, you need proportionately more medication to control them at some times, and less at others. Moreover, the way your body absorbs, uses, and excretes drugs varies over the day. The same dose of medicine may be too much at one time, and too little at another. Medicine that may help you at one time may not work as well at another. It may not even work at all. At some times, it may even be harmful.

Consider aspirin, the staple of the family medicine cabinet and one of the world's most widely used medications. Aspirin has a high safety record, particularly when taken in relatively small doses now and then. The problems come mainly with prolonged use, since aspirin may irritate the lining of the stomach and cause stomach ulcers and bleeding. These effects may occur even with the "baby aspirin" dosage (75 to 100 milligrams) that millions of Americans, particularly those in their forties and older, take once a day to prevent a heart attack or stroke. Taking aspirin at the proper time dramatically lowers your risk of developing stomach irritation and injury. Aspirin is least likely to cause irritation if you take it at night, and most likely to do so if you take it in the morning. Some persons who cannot tolerate aspirin when they take it in the morning have little or no difficulty when they take it at night. (See page 209.)

Asthma attacks are one hundred times more frequent at night than in the day. Persons with severe unstable asthma who live on a conventional awake-in-the-daytime, asleep-at-night schedule get the most relief and greatest protection at night by taking their tablet steroid medication around 3 p.m. If you are a night worker, your doctor will need to synchronize treatment time with your schedule. (See page 220.)

Most medications used to ease peptic ulcers work best when taken once a day, around 6 p.m., with dinner. Taken at this time, they help block the normal late-night peak in daily secretion of stomach acid. (See page 323.)

In cancer, cells are most vulnerable to damage when they are dividing. Anticancer medications attack different stages of the cell reproduction rhythm. Some, such as 5-fluorouracil, which is used to treat cancers of the intestinal tract, are best tolerated and cause the fewest side effects when given by infusion while the patient sleeps at night. Others, including adriamycin and doxorubicin, which are used to treat bladder, ovarian, and other cancers, are best tolerated when given in the morning. When cancer medications are given in a chronobiological manner, that is, according to body rhythms, patients may be able to tolerate higher, more potent doses than would be possible otherwise. (See page 229.)

Monthly Rhythms May Alter Symptoms, Too

In the AMA's 1996 survey, only three out of four doctors agreed that the menstrual cycle is a biological rhythm. All doctors should know this is true. Women know it: most recognize that their weight, energy, mood, sleep, cravings for particular foods, interest in sex, skin eruptions, frequency of migraines, asthma attacks, and symptoms of other illnesses predictably wax and wane over the month. Numerous factors, including stress, work, sleep, diet, and even the weather, may make some months more troublesome than others. Some women suffer more intensely than others, a reason some physicians and even some women dismiss or trivialize these symptoms.

Being tuned into these rhythms, however, can afford women a hardy measure of equanimity. A woman who is watching her weight may feel less guilty about nibbling a brownie right before her period starts. For many women, this is "the chocolate time of month," a few days with increased craving for chocolates and other sweets. A female athlete or actor may tolerate slight slips in performance, if she knows it's normal to be less coordinated, less "together," when she's menstruating.

Many women don't know that a routine test for cervical cancer, the Pap smear, gives the most accurate results if performed near ovulation. A woman can boost her odds of having this cancer detected at its earliest, most curable stage simply by scheduling this exam midway between her periods. (See chapter 11: "Time for Sex.")

Many chronic illnesses flare around the time of menstruation. Consider asthma: three out of four adults admitted to the hospital for treatment of life-threatening asthma attacks are female. Their hospital admissions occur four times more often just before or after menstruation than at any other time of month. Knowing that this is a more vulnerable time should heighten women's attention to their symptoms, and prompt physicians to fine-tune treatment. That won't happen until both patients and doctors focus their attention on body clocks. (See chapter 15: "Sickness and Health from A to [nearly] Z.")

The time of month also may influence the success of treatment. Fifteen studies involving more than 5,000 women with breast cancer show that those whose surgery is performed in the early part of the later half of their menstrual cycle live longer on average than women who undergo surgery earlier or later in the month. But many cancer experts still are skeptical about these findings, and most operations for breast cancer are scheduled according to the surgeon's convenience. (See page 233.)

Ancient Cultures Recognized Body Time

"Of themselves, diseases come among men, some by day and some by night" the Greek poet Hesiod wrote in 700 B.C. "Whoever wishes to pursue the science of medicine in a direct manner," the great Greek physician Hippocrates observed three hundred years later, "must first investigate the seasons of the year and what occurs in them." Yet generations of physicians have paid little heed.

Nei Ching, the classic Chinese medical text written in 300 B.C., set forth the notion of health as a balance of opposites: cold and warm, moist and dry, passive and active. Yin and Yang, moon and sun, night and day, wife and husband, together represent the whole universe. Yin/Yang remains a central concept in Chinese medicine. It is represented pictorially by a circle that shows the moon and sun embracing. The American Academy of Sleep Medicine, the sleep field's leading professional organization, uses this symbol to signify its goal of optimizing both sleep and wakefulness.

Monuments built by ancient civilizations reflect knowledge of body time as well as planetary time. Shadows cast by the sun on the towering slabs at Stonehenge constructed in southwestern England some 4,000 years ago show changes in day length over the year. One circle at Stonehenge holds the correct number of markings to calculate the length of a woman's menstrual cycle or the likelihood of pregnancy, chronobiologist Sue Binkley reports.

Twenty-four baboons carved into the face of a cliff at Abu Simbel 3,200 years ago guard the entrance to a temple to Pharaoh Ramses II. The baboons represent the twenty-four hours of the day, a way of dividing up time the ancient Egyptians devised some 400 years earlier. The baboons symbolize the Pharaoh's round-the-clock rule, gaining this honor by dint of the Egyptians' belief that they urinated once an hour: an overstatement, researchers who specialize in baboon behavior today say.

The words of Ecclesiastes remind us that our ancestors took rhythmic behavior for granted: "To every thing there is a season, and a time to every purpose under the heaven." The list includes "a time to be born, and a time to die," as well as "a time to heal."

Even the notion of body clocks is not brand new. The English writer Robert Burton observed, in the seventeenth century, "Our body is like a clock; if one wheel be amiss, all the rest are disordered, the whole fabric suffers: with such admirable art and harmony is a man composed."

Early in the twentieth century, most physicians in the United States attended to all sorts of ills. When called in the late evening, they could predict their patient might have a flare of a peptic ulcer. If roused closer to dawn, they could anticipate seeing a patient with an asthma attack or a woman about to give birth. The morning brought heart attacks. Today, a person with stomach ulcers might see a gastroenterologist; one having trouble breathing, an allergist or lung specialist; and one with chest pain, a cardiologist. Births more often are induced, typically at the convenience of mother and doctor, and in the daytime. Only the sickest patients go to hospitals, where activity around the clock blurs the distinction between night and day. The present-day lack of appreciation for body time thus is a relatively recent phenomenon. The rise of specialization in medicine has eroded physicians' recognition of the ubiquity and significance of daily rhythms for health and disease.

The history of medicine is studded with facts that were known, lost, and later rediscovered. Body rhythms are "hot" again today. Some formidable hurdles, however, still stand in the way of their widespread acceptance.

Copyright © 2000 Michael Smolensky, Ph.D., and Lynne Lamberg