The effect of food and drink on sleep
It might sound simple: Drink caffeinated coffee to wake up, warm milk to fall asleep. But what about iced tea or a turkey sandwich? And does when you eat or drink make a difference?
Figuring out the connections between food and sleep can be tricky. Here's what you need to know to keep your daily diet from interfering with your nightly slumber.
BE LEERY OF CAFFEINE, EVEN LONG BEFORE BEDTIME
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"You've got a Starbucks or a Dunkin' Donuts at every corner," said Dr. Marta Maczaj, co-director of the Sleep Disorders Center at St. Charles Hospital and Rehabilitation Center in Port Jefferson. "America is caffeinated."
Indeed. A report commissioned by the U.S. Food and Drug Administration found that, from 2003 to 2008, the average American consumed 300 milligrams of caffeine a day. That's twice the amount in a 16-ounce Starbucks latte and up to three times the amount in an 8-ounce cup of brewed coffee.
Part of the reason Americans consume so much caffeine, Maczaj said, is that it's not just an ingredient in coffee. It's also found in soda, tea and iced tea, and even in dessert foods such as premium ice cream and cake, she said. "There may not be as much as in a cup of coffee, but it's there," she said. It's also present in some energy drinks, chocolates and certain over-the-counter painkillers.
Caffeine is known for its powers to help people feel alert, but it's those stimulating powers that make it bad for people who are trying to sleep. Caffeine accomplishes its awakening powers by blocking the brain's drowsy-making system, Maczaj said, and those effects can linger for as long as 12 hours as it's metabolized by the body.
For those who are especially susceptible to caffeine's effects, she said, "have a cup of coffee in the morning and maybe one at noon, but nothing after that."
BOOZE WON'T IMPROVE YOUR ZZZS
Because alcohol makes people drowsy, it might seem that a nightcap would be just the thing to send folks into dreamland. But that's not the case, said Dr. Mangala Narasimhan, a sleep specialist, section chair of critical-care medicine and an associate professor at Hofstra-North Shore LIJ School of Medicine in Hempstead.
"Alcohol helps you fall asleep very fast, but your sleep is very fragmented, and you wake up several times at night as the alcohol wears off," she said. "In the end, you get a worse night's sleep."
In fact, a study published this spring in an alcohol research journal found just that. Although a drink before bed might help you get to sleep, the disruptions it causes later block the deep sleep that's so crucial to rest.
WATCH WHEN AS WELL AS WHAT YOU EAT
"Meals high in fat or protein near bedtime make it difficult to stay asleep and cause people to have a bad night's sleep," Narasimhan said. "Ideally, you should eat dinner at least three hours prior to bedtime and then have a very light snack prior to sleeping, like one piece of fruit."
Maczaj suggests eating dairy products before bed because they contain a combination of tryptophan and calcium that makes people drowsy. Warm milk can do this, she said, as can yogurt or a slice of cheese on a cracker.
People usually know about tryptophan, an amino acid, because of the post-turkey-dinner snooze for which it's often blamed. But besides turkey and dairy products, tryptophan is found in chicken, eggs, fish, nuts, peanut butter, soy and tofu, according to the U.S. National Library of Medicine.
All these foods can contribute to sleep, but don't eat them too late. Otherwise, your dreams may not be sweet.
For people with blood sugar issues, such as those with diabetes or at risk for it, it's also important to be careful about carbohydrates before bed, Maczaj said. Carbs -- which are found in high amounts in sweets, fruits, breads, cereals and crackers -- may not affect a person's ability to fall asleep, but they will affect what happens during sleep. Carbs can lead to spikes and dips in blood sugar during sleep, she said, and "they'll wake up feeling anxious and sweaty with their heart racing."