Springing Forward May be Bad For You

Blogged by Nahk.

This Sunday most U.S. residents will gain an hour of daylight as it's time to spring forward.

Few people will wake up exactly at 2:00 a.m. local time to move the clock hand, or dial, forward an hour. But that's when daylight saving time officially begins on the second Sunday in March this year. It ends on the first Sunday in November, when clocks are turned back at 2:00 a.m. local time to read 1:00 a.m. That is, for everyone except those who live in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands, and by most of Arizona, with the exception of the Navajo Nation.

As far back as the 1700s, people recognized the potential to save energy by jumping clocks ahead one hour in the summer although the idea was not put into practice until the 20th century.

During both World Wars, the United States and Great Britain began observing Daylight Saving Time. After the war, U.S. states were free to choose whether to observe Daylight Saving Time and the calendar start dates of the time change. The result was time confusion for travelers and newscasters. In 1966, Congress enacted the Uniform Time Act, which stated that if any state observed Daylight Saving, it had to follow a uniform protocol, beginning and ending on the same dates throughout the country.

Now it is normal course of life. But the time switch can shake up your biological clock, rattle your mood and give your bones and teeth an extra dose of vitamin D.

Changing household clocks can be a small chore. Changing your body's internal clock will be trickier.

A cluster of brain cells located in the hypothalamus acts as your body's timekeeper. The neural ticker, also called a circadian rhythm, tells your body when to eat, sleep, wake up and perform many other body functions over the course of a day.

Light is the key to cuing up the internal clock. For instance, sunrise directs the body to release various "wakeful" hormones, which boost metabolism, blood pressure and body temperature.Sunset tells the body it's time to wind down and sleep. To keep your body systems in sync with local time, your body's internal clock relies on cues from sunlight, particularly early morning light.

Daylight Saving Time effectively snatches a morning hour and adds it to your evenings. That means 7 a.m. Daylight Saving Time is equivalent to 6 a.m. standard time, so your typically sunlit morning walks will be dark. The morning darkness could keep your biological clock in winter mode.

We all know that depressive symptoms become worse during the winter months. Winter blues, affecting about 35 million Americans, are a mild form of seasonal affective disorder (SAD), which affects as many as 12 million Americans. Symptoms of SAD include depression, sleep problems, cravings for sweets and other carbohydrates, sluggishness andheadaches. The doldrums begin to ramp up some time in the fall and typically remit by the second week of May.

"We are making the sun rise even an hour later than it otherwise would during a period when these symptoms should be beginning to improve," said Michael Terman, director of the Center for Light Treatment and Biological Rhythms at Columbia University Medical Center.

"We are placing these people back into February," Terman said. "We are dealing with a public health issue and the extension of Daylight Saving Time at both ends is extending the period of year in which people are most vulnerable to depression."

So whether you are ready or not, we are going to spring forward tonight!