Light Therapy Can Help to Brighten Your Health in Winter

The winter months bring shorter daylight hours and more time spent indoors, both of which restrict your exposure to light. This loss can trigger a condition called seasonal affective disorder (SAD), a type of seasonal depression caused by deficient light exposure. “Older adults need to be mindful about SAD as many can suffer from it and not even realize it,” says Michael Gitlin, MD, of the Resnick Neuropsychiatric Hospital at UCLA.

People with SAD have many of the common signs of depression, although the severity can vary. They include:

  • Withdrawal from social activities
  • Inability to concentrate
  • Extreme fatigue and lack of energy
  • Increased need for sleep
  • Sadness
  • Anxiety
  • Irritability
  • Craving for carbohydrates and accompanying weight gain
  • Loss of interest in usual activities

Common Causes of SAD

The exact cause of SAD is unknown, but evidence suggests reduced sunlight disrupts the body’s circadian rhythm, the internal 24-hour biochemical cycle that tells us when to eat, sleep, and wake up. Lack of light increases the production of melatonin, the sleep hormone secreted by the pineal gland in the brain. This makes you crave more sleep. In fact, people with SAD sleep an average of 2.5 more hours in winter than in summer, while those without SAD sleep 0.7 more hours in winter.

SAD affects women more than men. Geography is a factor, too. SAD is more common in areas above the 35th parallel, which begins in southern North Carolina and stretches across the country to Southern California. Of course, even if you live in sunnier climates, refraining from natural sunlight also can contribute to SAD.

The easiest cure for SAD is to increase light exposure. Yet, this can be difficult in winter when daylight hours are reduced and people tend to stay inside to avoid the cold or have mobility issues that limit their outside activities. The solution is to bring the sunshine inside with light therapy to reset your body clock and help correct any imbalances.

What’s in the Box?

Light therapy, also called phototherapy, is administered by a light box that contains white fluorescent light tubes covered with a plastic screen that blocks ultraviolet rays. Light boxes are usually about 2 feet long and 18 inches high, and easily fit on a table or desktop. They are sold over-the-counter at many drug stores and online. (The devices cost about $100 or more; check with your insurance company to see if it may be covered.)

Boxes that illuminate close to 10,000 lux (a measurement of intensity) are the most therapeutic. For perspective, an average lit room is about 300 to 500 lux while a bright summer day is approximately 100,000 lux.

Light therapy has been shown to directly influence many of the effects of SAD, such as weight gain, poor sleep, and depression.

For instance, a recent study in the journal PLOS ONE found that people who have most of their daily exposure to even moderately bright light in the morning—between 8 a.m. and noon for 20 to 30 minutes—had lower body mass index (BMI) than individuals who were exposed to light later in the day.

Exposure to early-in-the-day light helps to synchronize your body’s internal clock, which is known to increase metabolism and lead to weight loss, according to lead researcher Phyllis Zee, MD, PhD, a professor of neurology at Northwestern University.

Also, a 2014 study in Sleep reported that daily light treatments of at least 9,000 lux for four weeks improved sleep quality and lowered depression and agitation in people with Alzheimer’s disease and related dementia.

See the Light

With light therapy, you don’t stare at the box—just face it with open eyes from about 1 to 3 feet away. Read, eat, watch TV, or spend the time in quiet reflection. Experts suggest beginning with 15 to 30 minutes daily. Mornings tend to be better, according to some studies.

Some people notice a lift in mood and energy levels after one or two sessions, while for others it may take a week or longer. “Don’t give up if you do not notice a difference right away,” says Dr. Gitlin. The symptoms of SAD return quickly after light therapy is stopped, so treatments should continue throughout the entire season of low sunlight.

Another light therapy option is a light visor, which resembles a baseball cap or tennis visor and emits light from under the lid. They are used in the same manner as a light box. A dawn simulator can also help maintain your normal sleep routine. These devices gradually fill your bedroom with light like a sunrise to gently tell your body it’s time to wake up—even if it’s still dark outside—and promote a more natural sleep cycle rather than being jolted awake by an alarm.

Check with Your Doctor First

If you think you have symptoms of SAD, see your doctor for a thorough examination. He or she will want to determine if these symptoms indicate another psychiatric condition or major medical illness.

Light therapy generally is safe. Side effects are minimal and can include eye strain, headache, irritability, fatigue, and insomnia (if used late in the day and too near your usual bedtime). You can relieve these side effects by decreasing the amount of time you spend under the light.

You should also consult with your physician if you have diabetes or suffer from diabetic retinopathy, a complication of the disease that affects the eyes. People who have sensitive eyes or skin should not use light therapy without medical approval.

The post Light Therapy Can Help to Brighten Your Health in Winter appeared first on University Health News.

Read Original Article: Light Therapy Can Help to Brighten Your Health in Winter »

Powered by WPeMatico