Nutritional influences on sleep - Nutritional Influences on Illness

Townsend Letter for Doctors and Patients, April, 2004 by Melvyn R. Werbach

In this month's column, we will review both how marginal nutritional deficiencies may interfere with sleep, and how supplementation (even in the absence of evidence of deficiency) may improve it.

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Vitamins

Folic acid Deficiency

A deficiency of folic acid may interfere with sleep by promoting the sensorimotor form of restless legs syndrome in which pain, numbness and lightning stabs of pain in the limbs are relieved by movement or local massage. (1)

Niacinamide

Animal studies suggest that niacinamide supplementation has effects similar to that of the benzodiazepines. These include hypnotic and muscle relaxant qualities. (2)

Thiamine Deficiency

In a double-blind study of healthy elderly who were likely to be marginally thiamine-deficient, supplementation improved sleep patterns and general well-being, while it reduced daytime sleep time and fatigue. (3)

Vitamin B12

Disturbances in the usual sleep-wake rhythm are a cause of insomnia, especially as patients with this disturbances are often only able to sleep at inappropriate times. Some respond to oral supplementation with vitamin B12 with normalization of sleeping patterns and of hormonal circadian rhythms. (4)

Vitamin E

There are several case reports that suggest that supplementation with perhaps 300 IU of vitamin E may provide relief from restless legs syndrome. (5)

Minerals

Chromium: A Warning

A group of 16 healthy volunteers (average age of 40 years) were provided

with either a commercial chromium yeast containing 50 [micro]g chromium or a brewer's yeast placebo nightly for 6 nights. They were asked to discontinue any vitamin or mineral supplements for one week prior to the study.

While, with 2 exceptions, no effects were attributed to the placebo, all chromium-supplemented volunteers noted increased and more vivid dreams, 75% noted increased sleep interruption, and half noted difficulty falling asleep. There were also complaints of unrefreshing sleep and fatigue. (6)

Iron Deficiency

A deficiency of iron has been found to be yet another cause of sleep disturbance from restless legs syndrome. (7)

Magnesium Deficiency

Insomnia is one of the central, or neurotic, symptoms of chronic magnesium deficiency. (8) A number of parasomnias (night terrors; nocturnal verbal and motor automatisms; restless legs syndrome) may be related to magnesium deficiency. (9), (10)

Sleep in magnesium deficiency is usually agitated with frequent nocturnal awakenings. Nocturnal instrument monitoring reveals major disorders of sleep organization. The deficiency may be severe enough to be diagnosed on the basis of clearly low blood magnesium levels. (10)

Conversely, a high magnesium, low aluminum diet has been found to be associated with high-quality sleep time and few nighttime awakenings, (11) and magnesium supplementation has been reported to reduce sleep latency and result in uninterrupted sleep. (12)

Potassium Deficiency

Evidence that a marginal potassium deficiency interferes with sleep comes from a double-blind crossover study of normal young men. While on a low-potassium diet, they randomly received either oral potassium chloride or placebo. Potassium supplements were found to improve sleep consolidation. (13)

Other Nutritional Factors

L-Tryptophan

The nutritional precursor to serotonin, L-tryptophan has been extensively studied and has been found to be an effective hypnotic. For younger insomniacs suffering purely from extended sleep latency, it is effective starting the first night of supplementation. For more chronic and severe insomniacs with both extended sleep latencies and problems in sleep maintenance, it may take several days or longer before improvement occurs. Sometimes, in these cases, improvement occurs only after supplementation is discontinued; for such patients, intermittent treatment may be most effective. (14)

Supplementation with L-tryptophan does not impair visuomotor performance, cognition or memory, does not elevate the threshold for arousal from sleep, and does not distort sleep stages. Tolerance does not develop and there is a negligible to low incidence of side effects. (14) It is unavailable in many countries, however, ever since a contaminant introduced by one manufacturer resulted in an epidemic of eosinophilia myalgia syndrome several years ago.

L-5-Hydroxytryptophan

While much less studied than L-tryptophan, L-5-hydroxytryptophan, the immediate precursor to the neurotransmitter serotonin, also appears to be effective in promoting sleep. Moreover, it may be more effective than L-tryptophan in improving sleep patterns as it increases the amount of time spent in REM sleep (during which dreaming occurs), (15) while L-tryptophan decreases the time spent in this important sleep stage. (16)

4751 Viviana Drive * Tarzana, California 91356 USA

Phone 818-996-0076 * Fax 818-774-1575

Modified from Werbach MR with Moss J. Textbook of Nutritional Medicine. Tarzana, California, Third Line Press, Inc., 1999.

References

(1.) Boutez MI et al. Neuropsychological correlates of folic acid deficiency: Facts and hypotheses, in MI Botez, EH Reynolds, Eds. Folic Acid in Neurology, Psychiatry, and Internal Medicine. New York, Raven Press, 1979