Feeling Irritable? Blame it on the time change.

Brian A. Jackson / iStock

Brian A. Jackson / iStock

THE END OF daylight saving time in the fall always sounds luxurious: an extra hour of sleep on a crisp fall morning.  But the days afterwards (although not as bad as the springtime change) can feel groggy and off-kilter, especially if you kept late-night weekend hours.

The best remedy, according to Dr. Kelly Brown at Vanderbilt Sleep Disorders Center, is  a morning walk: “Light is the most powerful way to control the internal clock,” she says: both getting sun exposure in the morning and avoiding bright light–especially blue light from electronic devices–at night.

Exposure to the first light of day stimulates a nerve pathway from the retina to the hypothalamus, which signals the brain to raise body temperature, release stimulating hormones like cortisol, and delay the release of the hormone melatonin until later.  Around 9 p.m., melatonin levels in the blood rise sharply and stay elevated for about 12 hours until they fall back to daytime levels at about 9 a.m.  Even when the body’s clock says 9 p.m., melatonin levels won’t rise until the lights dim.  Dubbed the “Dracula of hormones,” melatonin only comes out in the dark.

As a supplement, melatonin works best to make adjustments for jet lag and shift work.  While some studies suggest melatonin tablets can also shorten the time it takes to fall asleep and reduce the number of awakenings under normal circumstances, other research shows no benefit at all.

Melatonin is present in some foods, especially walnuts–which also contain  the amino acid tryptophan, which helps the body make melatonin.  Dairy products contain both tryptophan and the calcium needed by the brain to produce melatonin.  Melatonin occurs in milk–with higher concentrations in milk produced at night, whether from cows or breastfeeding women.

(Among 36 possible interventions used in the first research showing the possibility of reversing memory loss, .5 mg of melatonin every night was given to help flush potentially destructive amyloid beta proteins from the brain; along with 500 mg of tryptophan three times/week for waking at night.)

Other melatonin-containing foods: almonds, raspberries, orange bell peppers, tomatoes, cherries, olives, barley and rice.   Foods that increase the presence of melatonin include pineapples, bananas and oranges–in declining order, with pineapples producing the highest levels.   While diets rich in vegetables, fruits, grains and dairy products contain healthy levels of dietary melatonin, experts say their influence is “minor if compared with the power of the light-dark cycle.”

Because melatonin occurs naturally in foods, it is sold as a dietary supplement along with vitamins, thus not regulated by the FDA.  As a result, the labeled dosage is not completely trustworthy.   While there have been no reported cases of toxicity, too much melatonin can make you irritable, dizzy and sleepy during the day and can cause nighttime confusion and nightmares.  So start with a low dosage: some experts suggest .3 mg.

At night, the darker your bedroom, the more melatonin your body will produce.  And because bright light suppresses melatonin production, turning on a light or electronic device during the night can disrupt your sleep cycle. Use as dim a light as possible.

If you prefer not to take supplements, research also supports the soporific effects of chamomile tea–the stronger, the better.  And when the weather is bad or morning walks don’t appeal, turn on electronic devices ASAP and gaze into the blue light.  Don’t forget caffeine.

–Mary Carpenter

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