What you eat affects how you sleep. One of the keys to a restful night's
sleep is to get your brain calmed rather than revved up. Some foods
contribute to restful sleep; other foods keep you awake. We call them
sleepers and wakers. Sleepers are tryptophan-containing foods,
because tryptophan is the amino acid that the body uses to make serotonin,
the neurotransmitter that slows down nerve traffic so your brain isn't so
busy. Wakers are foods that stimulate neurochemicals that perk up the brain.
Tryptophan is a precursor of the sleep-inducing substances serotonin and
melatonin. This means tryptophan is the raw material that the brain uses to
build these relaxing neurotransmitters. Making more tryptophan available,
either by eating foods that contain this substance or by seeing to it that
more tryptophan gets to the brain, will help to make you sleepy. On the
other hand, nutrients that make tryptophan less available can disturb sleep.
Eating carbohydrates with tryptophan-containing foods makes this calming
amino acid more available to the brain. A high carbohydrate meal stimulates
the release of insulin, which helps clear from the bloodstream those amino
acids that compete with tryptophan, allowing more of this natural
sleep-inducing amino acid to enter the brain and manufacture sleep- inducing
substances, such as serotonin and melatonin. Eating a high-protein meal
without accompanying carbohydrates may keep you awake, since protein-rich
foods also contain the amino acid, tyrosine, which perks up the brain.
To understand how tryptophan and carbohydrates work together to relax
you, picture the various amino acids from protein foods as passengers on a
bus. A busload containing tryptophan and tyrosine arrives at the brain
cells. If more tyrosine "passengers" get off the bus and enter the brain
cells, neuroactivity will rev up. If more tryptophan amino acids get off the
bus, the brain will calm down. Along comes some insulin which has been
stalking carbohydrates in the bloodstream. Insulin keeps the tyrosine amino
acids on the bus, allowing the brain-calming tryptophan effect to be higher
than the effect of the brain-revving tyrosine.
You can take advantage of this biochemical quirk by choosing protein or
carbohydrate-rich meals, depending on whether you want to perk up or slow
down your brain. For students and working adults, high protein,
medium-carbohydrate meals are best eaten for breakfast and lunch. For dinner
and bedtime snacks, eat a meal or snack that is high in complex
carbohydrates, with a small amount of protein that contains just enough
tryptophan to relax the brain. An all- carbohydrate snack, especially one
high in junk sugars, is less likely to help you sleep. You'll miss out on
the sleep-inducing effects of tryptophan, and you may set off the
roller-coaster effect of plummeting blood sugar followed by the release of
stress hormones that will keep you awake. The best bedtime snack is one that
has both complex carbohydrates and protein, and perhaps some calcium.
Calcium helps the brain use the tryptophan to manufacture melatonin. This
explains why dairy products, which contain both tryptophan and calcium, are
one of the top sleep-inducing foods.
