Franz Halberg showed that timing really is everything

From fluctuations in blood pressure to the best time to treat cancer, Franz Halberg has found bodily rhythms that we ignore at our peril.

When Erna Halberg was diagnosed with late-stage ovarian cancer, her husband, Franz Halberg, saw to it that she was treated not at any old time of day, but when the drugs were likely to be most effective. She ended up living far longer than the average for patients in her condition, thanks in large part to Franz Halberg, a legendary University professor, having discovered the critical role of innate rhythms in governing our lives.

A member of the University faculty for more than 55 years, Halberg is one of three great pioneers in chronobiology, the scientific study of biological time structure. He even coined the word, along with the term "circadian rhythm" (from circa, meaning "approximately," and dies, meaning "day") to describe bodily cycles, such as sleep-wake, that last about 24 hours.

Now a retired professor of laboratory medicine and pathology, Halberg has found rhythms in everything from the timing of cell growth and division to white blood cell counts. He also discovered that the rhythms of both people and cells could be shifted by experimentally altering feeding schedules or the duration of "day" and "night." His work has implications for when to administer drugs, when to take measurements, and even when to exercise (the human body reaching its peak performance in late afternoon).

In studying blood pressure, Halberg found that certain subtle patterns in timing and intensity meant a heightened risk of stroke, while others, along with lower variability in heart rate, predicted a heart attack. But the patterns only showed up with close monitoring for a week or two. Taking blood pressure readings only occasionally, he found, told as much about a person's heart health as a single frame tells about a movie.

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Visit Halberg's own website to learn more about chronobiology, the computer-aided science of life's structure in time.

Chronobiology examines the cyclic nature of living organisms. These cycles are known as biological rhythms, and influence everything from sleeping to eating.

Perhaps nowhere was Halberg's work more crucial than in his discovery that the timing of cancer chemotherapy could make the difference between a patient living or dying. For example, some drugs work hardly at all during the day but quite well at night, when the body's normal cells "sleep" and absorb little of the drug. This leaves more of the drug to be absorbed by cancer cells, which have lost their internal clocks. Halberg was the first to increase cancer survivability by administering chemotherapy for oral tumors at the time when tumor temperatures were highest. Also, credit him with the now-common practice of giving many prescription medicines at certain times of day.

Also varying with time of day was the body's susceptibility to loud noises, reaction to or percent survival after exposure to drugs, bacteriological agents, and whole-body irradiation.

Not all the biological rhythms Halberg has discovered are circadian; many follow a seven-day cycle. For example, as a young doctor, he noticed that patients with pneumonia either recovered or died in a week. These days, another seven-day rhythm of the immune system has become all too familiar: organ rejection.

In laying the foundation for the application of timing to human medicine and physiology, Halberg has yet to find a normal bodily function that operates independently of any rhythm. His biggest frustration has been that more doctors don't realize the importance of timing, especially in the diagnosis and treatment of cardiovascular diseases. The time will never be ripe for him to give up.