CHASING THE SUN

An exploration of the effects of the sun on our physical and mental health.

Light plays a critical part in the daily and seasonal rhythms of our lives. It touches on all manner of bodily function—particularly hormonal and enzyme release—and synchronizes the body’s cellular clock. As science journalist Geddes (Bumpology: The Myth-Busting Pregnancy Book for Curious Parents-To-Be, 2014) writes in this bright and curiosity-stoking introduction to chronobiology, these processes are closely linked to circadian rhythms. As a species, we haven’t shuffled to the circadian beat for centuries, and we have paid a price for not paying attention to the natural cycles of light and dark. Interrupt the master clock, and the first thing to go is intricate thinking. The brain uses sleep time to replenish energy molecules expended during waking hours. Without adequate sleep, alertness suffers, speed and reaction time diminish, and depression lurks. Even the moderately sleep-deprived human has their hormones disrupted and will experience muscle degeneration, an increase in fat tissue, and general sickness. “Sleep deprivation,” writes the author, “winds its tentacles around pretty much every physiological process going….Chronic inadequate sleep precedes the onset of Alzheimer’s disease, cancer and various psychiatric illnesses; it is also associated with heart disease, obesity and diabetes.” Geddes investigates a variety of topics related to light and sleep, including artificial lighting, vitamin D supplements, seasonal affective disorder, light therapy, and the cardiovascular system’s circadian variations. The author is a sure hand when it comes to explaining the various biological interactions and a steady voice in calling for lifestyles more in sync with our master clocks and less hidebound by work or tradition. “It doesn’t matter when you start work, so long as you get the job done. It’s about internal time, not what the clock on the wall says.”

A sparkling story about how we can forge a healthier relationship with light.