Did you know that our bodies contain an elaborate mechanism for telling the time? This device, which tracks regular rhythmic cycles of 24 hours, one week, one month, and one year, is called the biological clock and is found in a diverse variety of living things—not only mammals like us but even some bacteria. It is said to be one of the earliest functions acquired 3.8 billion years ago when life first appeared on Earth.
Living things have a variety of somatic rhythms produced by the activity of the sun, the moon, and the earth. These include the 24-hour circadian rhythm that follows the revolution of the earth, the 90-minute cycle found in REM sleep, and the 28-day cycle seen in women’s menstruation. The biological clock regulates various somatic rhythms that act on our bodies for sleeping, waking, and autonomic nervous activity, as well as hormone secretion, body temperature, blood pressure, and pulse rate, and evolved so that we could live comfortably, adapted to the rhythms of the earth.
What throws off the biological clock?
One thing that has drawn a lot of attention in recent years is the physical and mental difficulties triggered by irregularities in the biological clock. The first is a lack of sleep, which leads to lower concentration, fatigue, and irritation. Lower quality sleep brings a reduction in appetite-suppressing hormones and promotes the secretion of appetite-stimulating hormones, increasing susceptibility to obesity. We also know that it reduces lifespan by lowering immunity, increasing the risk of lifestyle diseases like high blood pressure and diabetes, increasing the risk of cancer, and accelerating the aging process.
Irregularities in the biological clock have a variety of causes, but one issue in recent years is “social jet lag,” caused by incompatibility between social time and the biological clock. Our sleep habits are constrained by the time of social events such as work, going to school, and housework, and on weekdays we often have to get up earlier than our natural waking time. Many people try to make up for a lack of sleep during the week by sleeping in late or for longer periods on weekends, but such imbalance between weekdays and the weekend can throw off the biological clock. An irregular lifestyle due to shift work, long working hours, or staying up late at night can also result in social jet lag. In other words, a contemporary lifestyle is frequently the cause. If so, the more diverse lifestyles of the future seem likely to make the problems arising from social jet lag even more serious.
What if there were tuning rooms for the biological clock?
At Teijin, we believe that contemporary residential spaces can contribute to social jet lag. LED lighting that emits mid-day intensity light even at night, electronic devices such as computers, televisions, and smartphones that emit strong blue light, black-out curtains installed to address insomnia—all create a light environment far removed from the natural cycle, which throw off the biological clock and disrupt the circadian rhythm.
Resetting the biological clock is important for improving our quality of life. Factors for correcting it include exposure to sunlight when waking up, the stimulation of meals that are effective in shortening the cycles of the biological clock, and melatonin, known as the sleep hormone. Tailoring residential space to include these three elements might well be able to lower the risk of social jet lag.
Next time we’ll take a look at Teijin’s unique approach to the relationship between residential space and the biological clock.