This may sound simple—eat and drink less caffeine-containing foods and you’ll sleep better. Caffeine does stimulate the central nervous system. While one or two cups of coffee in the morning can give you that gentle lift you were hoping for, the fourth or fifth cup can overstimulate your body and cause insomnia. My first recommendation is to avoid caffeine in the afternoon. Replace caffeinated beverages with caffeine-free or decaffeinated beverages, like herbal tea, mineral water, fruit and vegetable juice or decaf coffee.
The daily upper limit for caffeine is 400 to 450 milligrams per day. This recommendation is based on studies that have investigated the effect of caffeine on blood pressure and other health conditions, not your ability to sleep soundly. It turns out that even less caffeine may keep you up at night. Studies have shown that one or two small cups of coffee in the morning can affect the quality of sleep that night.1 Caffeine blocks the action of adenosine, a natural sleep-inducing brain chemical. If you’re suffering from insomnia, aim for no more than 200 milligrams of caffeine a day, and preferably none. To see where you’re getting your caffeine, see the table on page 38 in chapter 1.
Alcohol for Insomnia
The effects of alcohol are detrimental to sleep. Alcohol worsens insomnia and can rob you of a good night’s sleep even if you don’t have a sleep disorder. Once absorbed into the bloodstream, alcohol is metabolized at a set rate by your liver. If you drink more alcohol than your liver can keep up with (i.e., more than one drink an hour), alcohol arrives in your brain, where it interferes with brain chemicals called neurotransmitters. Alcohol has been shown to impair the REM portion of sleep, the time when your body is in its restorative phase.
Alcohol also dehydrates you, which can make you feel fatigued the next day. It does so by depressing the brain’s ability to produce a hormone called antidiuretic
hormone. This causes your body to lose water through your kidneys. Water makes it possible for your body to generate energy. You need water to digest, absorb and transport nutrients in your body and to regulate your body temperature. So when you’re dehydrated after an evening of drinking alcohol (even a few drinks), your cells and tissues receive nutrients less efficiently and your body can’t properly regulate its temperature. Both lead to fatigue.
When it comes to reducing your risk for cancer, women should consume no more than seven drinks per week. But if you’re suffering from insomnia, I recommend that you eliminate it from your diet altogether. Instead of having a glass of wine, pour yourself a glass of sparkling mineral water with a slice of lime. Or try some of the non-alcoholic wines or beers available in the supermarket. If you’re looking for a cocktail, order a virgin Caesar, a tomato juice or a glass of cranberry and soda.
To lessen alcohol’s effect on your ability to sleep, drink alcohol with a meal or snack. If you drink alcohol on an empty stomach, about 20 percent is absorbed directly across the walls of your stomach and reaches the brain within a minute. But when the stomach is full of food, alcohol has a lesser chance of touching the walls and passing through, so the effect on your brain is delayed.
If you’re out socially or you are entertaining at home, don’t drink more than one alcoholic beverage per hour. Since the liver can’t metabolize alcohol any faster than this, drinking slowly will ensure your blood alcohol concentration doesn’t rise. To slow your pace, alternate one alcoholic drink with a non-alcoholic drink or a glass of water. One drink is equivalent to 5 ounces of wine, 12 ounces of beer, 10 ounces of wine cooler or 1.5 ounces of liquor.
Carbohydrate before Bed for Insomnia
If you’ve ever heard that a glass of warm milk can help you sleep, you might give this a try—there is some science to back this claim. A carbohydrate-rich snack like milk, a small bowl of cereal or a slice of toast provides the brain with an amino acid called tryptophan. The brain uses tryptophan as a building block to manufacture a neurotransmitter called serotonin. Serotonin has been shown to facilitate sleep, improve mood, diminish pain and even reduce appetite.
If you want to see if eating a little bit of carbohydrate helps you fall asleep, eat something small or drink a glass of low-fat milk or soy beverage. Try it for a week. If your insomnia has not improved, look at other factors that may be disrupting sleep.