- Nutrition -

Snooze Foods

What you eat (and what you don’t) can have a powerful influence on how well you sleep.

Can’t sleep? If you constantly wake up from tossing, turning or jerking, or if you lie awake for what seems like hours, trying to drift off, it may be tempting to reach for sleep aids of some sort. Sure, they’ll knock you out for the night, but at what price? Most are just short-term solutions and don’t address your overall state of slumber. Plus, in the morning they often leave you groggy, hungover and feeling far from rested.

There are more natural approaches to better sleep. Some revolve around the nutrients you are eating – or not eating. You probably know the basic no-noes when it comes to your diet and sleep: no alcohol, no caffeine, no spicy foods, no sugar. All of these can rattle your normal sleeping pattern. Yet, increasing your intake of certain foods and correcting any nutrient deficiencies could be the key to easing your sleep problems, whether they are caused by anxiety and stress, restless legs syndrome or something else. Here’s a look at how your diet can influence your sleep and what steps you need to take at mealtime to ensure more peaceful slumber.

Tryptophan Talk

Ever notice how drowsy you get after a big Thanksgiving meal? It could be that you just plain overate, of course. But if there is a magic sleep aid here, it’s probably the turkey, or more specifically it’s tryptophan, the raw material that the brain uses to build the sleep-inducing substances serotonin and melatonin. Tryptophan is one of nine essential amino acids that the body cannot manufacture on its own. The only way to obtain it is through protein, such as meat, milk, eggs and cheese. Once tryptophan enters your system, it gets together with vitamin B6 and is converted into 5-hydroxytryptophan (5-HTP), which is then converted into the neurotransmitter serotonin. Serotonin, one of hundreds of neurotransmitters that carry messages between nerve cells in the brain, has a calming effect that creates a feeling of contentment. Another way serotonin aids sleep is through its conversion by the pineal gland into melatonin, the hormone that governs the workings of your sleep/wake cycle.

How much tryptophan do you need? Unfortunately, that’s not easy to measure. Your diet likely contains enough vitamin B6, which has a DRI (dietary reference intake) of just 1.3 to 2 mg per day, but gauging your tryptophan intake is trickier: There’s no DRI and food labels don’t list amino acids. In its effort to prevent pellagra, a disease caused by tryptophan deficiency, the World Health Organization suggests a daily tryptophan intake of 3.5 mg per kilogram of weight, which works out to around 225 mg for a 140-pound woman and 320 mg for a 200-pound man. You don’t have to eat turkey every day to satisfy this requirement either. Each of the following protein sources contains more than 300 mg of tryptophan per serving:

  • Chicken breast, roasted (4 oz.): 390 mg
  • Yellowfin tuna, baked or broiled (4 oz.): 380 mg
  • Soybeans, cooked (1 cup): 370 mg
  • Lean beef tenderloin, broiled (4 oz.): 360 mg
  • Turkey breast, roasted (4 oz.): 350 mg
  • Halibut, baked or broiled (4 oz.): 340 mg
  • Shrimp, steamed or boiled (4 oz.): 330 mg

Just loading up on protein doesn’t mean you’ll sleep better or longer, though. In fact, if you do that you’ll actually get less tryptophan into your brain. The reason is that tryptophan is the least abundant amino acid in any protein and it has to fight its way through the overwhelming amounts of other amino acids. (Think of it as trying to squeeze through a crowd going in the opposite direction as you.) So the more protein you eat, the more obstacles tryptophan has to endure and the less of it is able to reach the brain.

For tryptophan to reach its ultimate destination, it needs help in the form of carbohydrates. In fact, eating a high-protein meal without the accompanying carbohydrates may keep you awake, since many protein-rich foods also contain the amino acid tyrosine, which perks up the brain.

Helpful Carbohydrates

Here’s how carbohydrates lend tryptophan a hand. When your body processes carbs, blood-sugar levels rise, which prompts the pancreas to release more insulin, explains Ray Sahelian, MD, author of Mind Boosters: A Guide to Natural Supplements That Enhance Your Mind, Memory, and Mood (St. Martin’s Press, 2000). More insulin in the blood helps clear a path through the bloodstream for those amino acids that compete with tryptophan. “With less competition, you’ll actually have more tryptophan entering the brain,” says Sahelian.

But not just any carb will do. While you can get more insulin in the blood quickly by consuming simple carbs, such as cookies and fruit juice, this may disrupt your sleep in another way. “For some people, if their blood sugar drops in the middle of the night, they’ll wake up,” says Cynthia Collins, DACBN, CCN, a nutritionist in Montrose, Calif. This is why experts recommend staying away from simple sugars close to bedtime. Instead focus on pairing complex carbohydrates (such as legumes, whole grain bread and cereals and vegetables) along with your tryptophan. (See “Sleepy Eats,” next page.) This can help get more tryptophan into your brain, but without the risk of blood-sugar fallout.

Restful Minerals

Ever wonder why milk makes the eyelids so heavy? In addition to 100 mg of tryptophan, a 1-cup serving of milk contains the one-two punch of the potentially sleep-inducing minerals calcium and magnesium, according to Paul Lachance, PhD, executive director of the Nutraceuticals Institute at Cook College in New Brunswick, N.J.

When it comes to magnesium and calcium, though, it’s not getting extra that’s critical for sleep, but rather making sure you get enough in the first place. A deficiency in both has been linked to insomnia and restless legs syndrome (RLS), a neurological condition that causes uncontrollable leg jerking in sufferers. A calcium deficiency can also cause muscle spasms and cramps while you sleep, says Cathy Wong, ND, a naturopathic doctor in New York. People with magnesium deficiency sometimes suffer from type 2 insomnia, where they fall asleep easily but only experience a short period of deep, restful sleep. (Stress also contributes to this kind of insomnia as it tends to soak up magnesium in the body.)

Individuals who suffer from RLS can also benefit from more magnesium. A recent study from Albert-Ludwigs University in Germany found that magnesium supplements improved sleep efficiency by 10 percent in RLS patients who took doses prior to bedtime for four to six weeks.

Calcium and magnesium work best when paired together. Interestingly, they both compete for absorption in the body, and too much calcium in your diet may actually block magnesium absorption. This is why many experts recommend keeping both in check and suggest a 2:1 ratio of calcium and magnesium (500 mg of calcium and 250 mg of magnesium has been shown to be effective) about 45 minutes to an hour before bedtime.

There are supplements available with this ratio, but you can also get what you need from food. Good sources for calcium include yogurt, milk and most cheeses. Magnesium is also found in green leafy vegetables, nuts, seeds, meat and unpolished grains. (Note that the magnesium content of refined foods is usually low. For instance, whole-wheat bread contains twice as much magnesium as white bread.)

Iron and Copper
Both iron and copper deficiencies are also linked to common sleep problems, especially RLS. A study led by James R. Connor, PhD, at Penn State University College of Medicine, discovered that low iron concentrations in the brain likely play a role in causing RLS and that many RLS sufferers can benefit from iron supplementation.

Even if you’re getting your iron, you need copper to put it into action. Without enough copper in your diet, the majority of your iron intake remains in your liver instead of being used to produce hemoglobin. Over time, this lack of copper can cause iron-deficiency anemia (even if you are consuming adequate iron) and lead to a low brain iron concentration, which again can lead to RLS. You can have your doctor check for an iron and copper deficiency. If you aren’t getting the DRI for iron (8 mg/day for nonvegetarian men and postmenopausal women; 18 mg/day for premenopausal women) and copper (1 to 2 mg daily for both men and women), your doctor may suggest short-term supplementation or just advise you to increase your intake of certain iron and copper-rich foods like beef, liver, pork, kidney beans and cooked spinach (iron) and various seafood, such as clams, oysters and shrimp (copper).

Herbs for Sleep
Natural sleep solutions are not restricted to amino acids and minerals. Certain herbs have also gained attention for their ability to ease sleep blockers like stress and anxiety. Two of the more coveted ones are valerian and kava kava.

Valerian is sold as a dietary supplement in the United States and is a common ingredient in products promoted as mild sedatives and sleep aids for nervous tension, anxiety and insomnia. Its “secret” ingredient is believed to be valerenic acid, which inhibits the enzyme-induced breakdown of GABA (a major inhibitory neurotransmitter) in the brain and can result in a sedative effect. But studies on using valerian to specifically treat insomnia have had conflicting results. Recent research at the Centre for Addiction and Mental Health in Toronto, for example, reported that valerian and placebos were equally effective in treating insomniacs. Other studies have suggested that valerian can help people fall asleep more quickly and promote deeper sleep. Side effects appear to be rare and minor (headache or mild morning grogginess are the most frequent complaints) and these are very well tolerated for up to six weeks, according to Nikos M. Linardakis, MD.

Kava kava is also popular for its ability to treat anxiety, stress, muscle fatigue and insomnia. Kava kava works like manmade pharmaceutical agents in that it facilitates the transmission of certain neurotransmitters in the brain. Kava seems to especially benefit people who suffer from sleep disorders associated with anxiety, according to researchers from the University of Erlangen-Nuremberg in Germany. If kava kava has a downside it’s that it has recently been linked to at least 25 cases of liver toxicity, including hepatitis, cirrhosis and liver failure. But this may be explained by the fact that some kava-root products include kava-stem peelings and leaves, which may contain a toxic chemical called pipermethystine. Again, consult your physician to determine whether either of these herbs would be beneficial for your sleep ailments.

Keep in mind that no single food or herb works equally well for all people. “Everybody’s chemistry is different, so a food that affects some positively may have the opposite effect in others,” says Collins. Still, a more natural approach to sleep aids might get you what you really crave: a good night’s rest, naturally.

Linda Formichelli sleeps in Massachusetts.

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