We never quite realize what finely tuned machines our bodies are until we do something to throw them off, like stay up all night or fly into a different time zone. It seems like our bodies should easily adapt to whatever situation we put them in, but our individual circadian rhythms—the ways our bodies function throughout a 24-hour period—say otherwise.
Circadian rhythms are ruled by body clocks that dictate whether we’re alert, sleepy, hungry, etc., and those clocks are affected by our environment. The first sign of light sends messages to our bodies to start the arousal process and the setting sun signals the production of melatonin to prepare us for sleep. When we work against our body clocks, we feel the ill effects—insomnia, lethargy, irritability. In order to perform optimally, we need to work with our circadian rhythms rather than against them. This is the idea behind chronotherapy, a new form of treatment being investigated in the medical community.
How Chronotherapy Works
Chronotherapy is an offshoot of chronobiology, the science of examining body clocks and their resulting biological rhythms and physiological responses. Drug chronotherapy uses a person’s circadian rhythms to figure out the best time to administer medication and how much to give the person. Proponents of this treatment believe that our biological cycles include certain points throughout a 24-hour day that allow medicine to have the most beneficial effect while minimizing possible negative side effects. This is quite different from the usual prescription of “once in the morning, once at night” given by many doctors.
Chronotherapy tries to find the time of day when medication will be most useful. After all, our circadian rhythms fluctuate throughout the day, and no two people’s rhythms are quite the same. Therefore, it makes sense that treatment should be more individualized, and by analyzing the inner workings of our body clocks, that is what chronotherapy attempts to achieve.
What It Can Treat
Knowledge and familiarity with chronotherapy is emerging within the medical field. It is being investigated for illnesses like asthma, hypertension, some forms of cancer, and sleep disorders.
Asthma
Researchers have determined that lung performance hits a low very early in the morning. This is when most people are asleep, so it makes it difficult to administer medication at this time. According to the FDA, this brought about the development of a slow-acting bronchodilator (a drug that relaxes the airways and makes breathing easier) called Uniphyl. Asthma sufferers take it in the evening, but the medicine doesn’t take effect until the morning hours when lung function drops substantially. This way the patients are able to sleep through the night and minimize the occurrence of attacks.
Hypertension
Blood pressure is at its highest when you wake up. The pumping blood allows you to get out of bed without your legs collapsing beneath you. However, for those who have hypertension (high blood pressure), this means an elevated risk of heart attacks between the hours of 6 a.m. and noon. Two studies analyzing the effects of two different slow-release drugs aimed at treating hypertension concluded that the potentially dangerous blood pressure spikes in the morning were reduced significantly when medication was taken the evening before. Medicine designed to start working in the morning, when the probability of heart attacks is highest, ultimately yielded better results.
Cancer
Current cancer treatments like chemotherapy often come with a slew of adverse effects. Chronotherapy uses the same medicines as chemotherapy, but the process focuses not only when the drugs will work best, but also when they will damage the body the least. There have been studies that suggest cancerous cells operate on a different schedule than healthy, normal cells. Chronotherapy seeks to pinpoint this precise time and begin treatment accordingly.
Those who work with this form of therapy have also found that adverse side effects are limited when the medicine is given at certain points of the day. For example, one drug used to treat colon cancer is administered during the night because that is when the diseased cells are most active, and people are better able to tolerate the medication during that time. Patients are also able to get treatment via portable pumps designed to release medicine at specific times so their daily lives are altered as little as possible.
Sleep Disorders
Chronotherapy can be effective at treating sleep disorders, especially when they stem from altered circadian rhythms. Delayed Sleep Phase Syndrome (DSPS) is characterized by an inability to fall asleep, stay awake, or otherwise function in ways deemed physically and emotionally healthy. People with this disorder have trouble sleeping when it is late and getting up in the morning. Chronotherapy treatment revolves around moving the times of sleep and arousal three hours ahead every day until the person is able to rest at a standard time during the night and wake in the morning. One 1998 study demonstrated chronotherapy’s success in treating the sleep problems of a young girl in just eleven days. An essential part of this process is strict adherence to the sleep schedule, as any deviation could reset the circadian rhythm and cause problems again.
Tackling Other Conditions
Treatments for ailments like kidney disease and arthritis are also starting to include forms of chronotherapy. One study performed at a medical center in Japan found that patients suffering from renal failure responded to medicine better when it was given in the evening. Timed drug dosages work for treating rheumatoid arthritis and osteoarthritis, two diseases that flare up at different, but somewhat predictable, times during the day. Chronotherapy has even been applied to surgical procedures. One 1996 study found that surgeries to remove cancerous tumors were more successful at keeping patients cancer-free when they occurred at a certain point in the ovulation cycle.
The Consequences of Ignoring Our Body Clocks
Perhaps the best argument for incorporating the use of chronotherapy into medical practice is the negative effects of going against our circadian rhythms. Night shift workers are the best example of people who routinely fight their body clocks. We’re programmed to be awake when it’s light and asleep when it’s dark, and seeing the light of day automatically resets our body clocks to follow this pattern.
Unfortunately, night shift workers are exposed to light (such as when they’re driving home), so their body clocks are still working on a daytime schedule though their physical bodies aren’t. Such circadian rhythm abnormalities have been linked to an increased risk of weight gain, cancer, and diabetes. One study discovered that mice forced into a nocturnal life tended to eat more and to eat at all hours of the day, including when they should’ve been sleeping. In a similar study, mice also had trouble processing sugars after about four weeks of this lifestyle. Night shift workers can suffer from sleep disorders (such as insomnia), poor health, and mental or emotional stress.
Our bodies can adapt to situations, but they can only fight to a certain point before negative side effects take their toll. We’ve all experienced the under-the-weather feelings that come from throwing off our circadian rhythms, and that is all the more reason to pay attention to our internal cues. Bodies usually know what’s best—the hard part is learning how to listen to them. As chronotherapy increases in practice, that might just get easier.
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