Sleep Promoting Ingredients in Walnuts

The English walnut is the most popular one in the U.S.

Walnuts are a tree nut, similar to cashews, Brazil nuts and pecans. Packed with health benefits, these nuts contain a particularly beneficial form of Vitamin E and antioxidants not common in other foods, and have been shown to provide protection against cardiovascular problems, Type 2 diabetes and some cancers. They also contain an unusual concentration of melatonin, an element used by the body to aid in regulating sleep patterns.

Melatonin

An average walnut contains a small amount -- about 3.6 nanograms per gram -- of melatonin. This hormone is usually secreted by a gland in the brain that controls sleeping and waking cycles, sometimes known as "circadian rhythms." These cycles are affected by light and dark, and by how much melatonin is produced. However, the amount of secreted melatonin decreases as we get older. Supplements are often used to as a back-up to strengthen the immune system and treat symptoms of insomnia.

Studies

Sleep patterns are regulated by melatonin levels.

Research on rats has shown that the melatonin found in walnuts can have a positive effect on reducing stress and can measurably increase melatonin levels. In 2005, A University of Texas Health Science Center study cited by the Nutra Ingredients website showed almost a three-fold increase in the melatonin levels of rats that were fed a diet enhanced with walnuts. However, as of 2010 no scientific study has concluded how many walnuts a person would have to eat to experience a direct positive effect.

Insomnia

In practice, eating a few walnuts will probably not cure insomnia or make any dramatic difference in sleep patterns. The average walnut weighs about 20 grams and contains about about .000072 milligrams of melatonin. Thus, for someone to gain the same impact from walnuts that a single 10-milligram supplement of pure melatonin would provide, she would have to eat an unfeasible 138,888 walnuts.

Supplements

Walnuts can be part of a heart-healthy diet.

If you choose to take supplements, a doctor can prescribe them typically in ranges from .2 to 20 mg, depending on the reasons for use. They can have side effects, such as sleepiness, stomach upset and headaches, and would not work for anyone with allergies to nuts.

References

• The World's Healthiest Foods: What's New and Beneficial about Walnuts
• Nutra Ingredients: Walnuts are a Source of melatonin, Shows Study; Jess Halliday; Sept. 2005
• WebMD: Sleep Disorders Health Center; Melatonin - Overview