Almonds, walnuts and cheese are good natural sleep aids, reports Reader's Digest. Almonds are high in magnesium, a mineral that aids in the quality of sleep, while walnuts are rich in sleep-enhancing tryptophan, an amino acid that makes serotonin and melatonin. Cheese and all dairy products help to trigger the release of melatonin, the sleep-producing hormone, making warm milk another good option.
Some other foods that help bring on sleep are rice, pretzels and corn chips due to their high glycemic index. This causes a spike in blood sugar and insulin levels, which shortens the time it takes to fall asleep. Tuna, halibut and salmon are fish options rich in vitamin B-6, which promotes the body's natural production of melatonin and serotonin, states Reader's Digest.
Cherries or cherry juice, especially tart cherries, have natural melatonin-boosting abilities, notes Reader's Digest. Another option to promote sleep is kale, which is loaded with calcium. Calcium helps the brain use tryptophan to manufacture melatonin. Spinach and mustard greens are other calcium-rich options.
Lettuce is another leafy green that aids in the sleep process, according to Reader's Digest. Lettuce contains lactucarium, which has sedative properties that affect the brain similarly to opium. For sweeter sleep-inducing treats, honey boosts insulin and provides tryptophan easier access to the brain, and passionfruit tea has a sleep-inducing effect on the nervous system.