Nutritional Influences on Illness

by Melvyn R. Werbach, MD

Restless Legs Syndrome

This syndrome is marked by an unpleasant crawling or aching sensation in the lower legs, between the knee and the ankle, often accompanied by restlessness in other parts of the body, especially in the flexor muscles of the arms and legs. The discomfort appears only at rest and elicits an irresistible need to move the limbs. It generally appears in the evening and early night and may be associated with severe insomnia.1

While, as usual, most of the research is preliminary, the results of studies investigating the effects of nutrients on restless legs syndrome (RLS) suggest that it has several causes, and that patient-specific dietary changes, nutrient repletion and nutrient pharmacotherapy are often effective treatments.

Dietary Factors

Based on afternoon glucose tolerance testing, many patients with RLS, particularly if they also have spontaneous leg cramps, appear to have hyperinsulinism causing functional "hypoglycemia" during testing, in fact, occasional patients may have an attack of muscle cramps concomitantly with their lowest level of plasma glucose. In an open trial, a group of 350 patients with this type of glucose tolerance curve were placed on a sugar-free, high protein diet along with frequent nibbling and at least one night feeding. The vast majority experienced a prompt remission or, at least, a striking reduction in symptoms.2

Caffeine has been shown to increase subjects' proneness to develop symptoms at lower levels of blood glucose.3 It is therefore no surprise that a xanthine-free diet (no coffee, tea, cola beverages, cocoa) has been reported to be another effective dietary measure - sometimes following a short period of caffeine withdrawal.1

Vitamins

RLS may also be an early neurologic manifestation of folate deficiency, the most common of all the vitamin deficiencies. Often the deficiency is not due to a poor diet, but to a genetic factor causing a folate dependency. While not all RLS patients complain of uncomfortable sensations, folate-deficient patients always suffer from them.4 Since high doses of folic acid (5-30 mg daily) appear to be needed to normalize folate nutriture and induce a recovery, baseline lab testing and follow-up along with medical supervision is advisable.

Vitamin E supplementation has been reported to be effective in several case reports. For example, in a group of 9 patients, 7 had complete relief following supplementation, one had almost 75% relief and one had 50% relief.5 About 300 IU daily appears to be effective, although it may take up to three months for the full benefit to become apparent.6

Minerals

Iron deficiency, which is known to cause akathisia (restlessness) may theoretically cause restless legs syndrome by reducing dopaminergic and opiate neurotransmission.7 Indeed, in one study, 25% of a group of RLS patients had a low serum iron, while 24% of a group of patients with iron-deficiency anemia had RLs.8 Iron-deficient patients respond well to supplementation. Two months after 15 such patients had begun to take ferrous sulphate 200 mg. 3 times daily, the patients whose serum ferritins were lowest initially improved the most.9

Magnesium deficiency, which is known to increase neuromuscular excitability, can also cause the syndrome.10 Once again, repletion should be effective.

Other Nutrients

The primary role of the neurotransmitter serotonin in the central nervous system is said to be the modulation and facilitation of skeletal muscle function.11 If serotonin regulation plays a role in RLS, supplementation with L- tryptophan, serotonin's nutritional precursor, could therefore be of value. While tryptophan supplement needs to be studied further, it did appear to be effective in the treatment of two RLS patients even though they had failed to respond to numerous medications.12

Summary

Evaluate your patient for functional "hypoglycemia," and deficiencies of folic acid, iron or magnesium, and treat as indicated. If these specific abnormalities are not found, consider trials of vitamin E and L-tryptophan.

Doctor Werbach cautions that the nutritional treatment of illness should be supervised by physicians or practitioners whose training prepares then to recognize serious illness and to integrate nutritional interventions safely into the treatment plan.

Next Month: Nutritional Treatments for Autism

References

1. Lutz EG. Restless legs, anxiety and caffeinism. J Clin Psychiatry 39:693-8, 1978.

2. Roberts HJ, Spontaneous leg cramps and "restless legs" due to diabetogenic (functional) hyperinsulinism: A basis for rational therapy. J Med Assoc 60(5):29-31, 1973.

3. Kerr D, Sherwin RS, Pavalkis F, et al. Effect of caffeine on the recognition of and responses to hypoglycemia in humans. Ann Intern Med 119:799-804, 1993.

4. 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

5. Ayres S, Mihan R. “Restless legs” syndrome: response to vitamin E. J Appl Nutr 25:8-15, 1973.

6. Ayres S, Mihan R. Leg cramps and “restless leg” syndrome responsive to vitamin E. Calif Med 111:87-91, 1969.

7. Pall HS, Williams AC, Fonseca A, et al. Restless legs syndrome. Neurology 37: 1436, 1987.

8. Ekborn KA. Restless legs syndrome. Neurology 10:868-73, 1960.

9. O'Keeffe ST, Gavin K, Lavan JN. Iron status and restless leg syndrome in the elderly. Age Ageing 23(3):200-3, 1994.

10. Popoviciu L, Asgian B, Delast-Popoviciu D, et al. Clinical, EEG, electromyographic and polysomnographic studies in restless legs syndrome caused by magnesium deficiency. Rom J Neurol Psychiatry 31(1):55-61, 1993.

11. Jacobs BL. Serotonin and behavior; emphasis on motor control. S Clin Psychiatry 52: 12 (suppl);17-23, 1991.

12. Sandyk R. L-tryptophan in the treatment of restless legs syndrome. Letter. Am J Psychiatry 143(4):554-5,1986.

Reprinted with pennission from the International Journal of Alternative and Complementary Medicine. Green Library, 9 Rickett St., Fulham, London SW6 IRU, United Kingdom.

Doctor Werbach's voluminous Nutritional Influences on Illness database, with more than 4000 pages of text and covering over 100 different illnesses, has just become available on a CD-ROM. For information, contact Third Line Press, Inc., 4751 Viviana Drive, Tarzana CA 91356. (800-916-0076; 818-996-0076; Fax 818-774-1575; Email: tlp@third-line.com).


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