Fava Beans again

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This is a reposting of an article that was posted awhile ago. Something that those new on the list may want to read.

Take Care Vera

Fava Beans, A Natural Source of Levodopa -

Prolongs "On" Periods in Patients with Parkinson Disease

Adapted from an article by Hulya Apaydin, Sibel Ertan, Sibel Ozekmekci

Istanbul University, Department of Neurology, Istanbul, Turkey

Appearing in Movement Disorders volume 15, page 164, 2000

Introduction

In 1913, Guggenheim identified the chemical levodopa in the seedlings, pods, and beans of Vicia faba, commonly known as "broad bean" or fava bean. Fava beans are a widely cultivated vegetable in the Mediterranean region. Its fresh green pods in the spring and also dry seeds throughout the year are consumed in Mediterranean cuisine. They are prepared by cooking with olive oil and traditionally eaten after the main meal. Fava beans are regarded as being delicious, especially when eaten with yogurt.

Recently, in our practice in our Movement Disorders Clinic, several patients with Parkinson disease (PD) who have fluctuations described to us the beneficial effect of ingesting cooked fava beans on their symptoms. These levodopa responsive patients reported that their "on" period was prolonged after consuming a fava bean meal and stated that its effect was similar to that of Sinemet (Merck Sharp and Dohme) or Madopar (Roche) (levodopa and benserazide).

There is precedent for this effect on Parkinson symptoms. Spengos and Cassilopoulos described the antiparkinson effect of fava beans and others have corroborated this finding. Rabey et al. documented a substantial increase in levodopa plasma levels following fava bean ingestion that correlated with substantial improvement in motor performance. In view of our patients’ observations, we elected to assess their responses to fava bean through an out patient open-label clinical trial.

Methods

The eight patients who previously had reported favorable effects from fava bean ingestion agreed to participate in our trial. They were asked to ingest one standard portion (approximately 250 grams or 9 ounces ) of cooked fava bean at least twice a day without otherwise altering their dietary habits. The medical treatment was kept constant. Their predominant problems were disabling motor fluctuations and dyskinesia, despite appropriate treatment with levodopa combined with other dopamine drugs. These patients with PD were asked to complete a daily diary recording the times and durations of "on" and "off" times during the 5-7 days of baseline assessment (without fava bean supplementation) and again corresponding to the 1-3 months during fava bean administration.

Discussion

We observed a beneficial effect of fava beans in our patients manifested by strikingly prolonged "on" time and shortened "off" time. Previously all these patients had been administered higher doses of levodopa up to 800-1000 mg per day, which failed to optimize their "on" time and resulted in dyskinesia. We were surprised by the reported magnitude of our patients’ responses given the fact that previous trials of higher doses of levodopa seemed to provide no further benefit.

These observations are not readily explained by assuming that fava beans are simply a source of levodopa. For example, one patient was able to experience a sustained response from fava bean meals ingested on alternate days. This is reminiscent of the "long-duration response" of synthetic levodopa. Also, surprisingly, another patient experienced decreased dyskinesia with the addition of fava bean supplementation and reduction of levodopa. This patient had previously failed to respond satisfactorily to levodopa adjustments which would have accomplished the same result if this was simply a levodopa effect. A placebo effect may have contributed in this trial but the magnitude of the reported responses raises the possibility of other mechanisms. For example, the amino acid milieu generated from broad bean administrations may favor the selective transport of levodopa across the blood-brain barrier. Alternatively other products derived from fava bean may complement the antiparkinson effect.

Our experience with fava beans complements that of Rabey who described the acute responses following a single administration of fava bean to six patients with PD. Rabey noted motor improvement of the same magnitude as seen following single doses of levodopa. Rabey also documented substantially increased plasma levodopa concentrations following fava bean administration and the motor response tended to mirror these plasma levodopa levels. In contrast to Rabey we assessed the effect of prolonged fava bean meal supplementation as opposed to a single administration. Elevation of plasma levodopa following fava bean administration has also been confirmed by Vered. Vered noted that 40 grams (1.5 ounces) of freshly chopped fava bean contained approximately 125 mg of levodopa.

Our patients ingested their broad bean meals garnished with yogurt, which is rich in protein. It is well known that as a large neutral amino acid, levodopa competes with dietary protein amino acid breakdown products in crossing the brain-blood barrier: this competition potentially results in reduced levodopa motor effects. Nonetheless, our patients still experienced a favorable motor response.

Some of our patients reported trying to cook and eat the dry seeds of fava beans but did not experience any benefit. Burbano . showed that only the fresh green pods of broad bean were rich in levodopa content, in contrast to that of dry matter, apparently explaining the observations of our patients.

Comment

Reports from many, but not all, people, document the beneficial effects of fava beans.

There’s a question about how much fava beans to eat. Vered documented that 40 grams of fava beans (1.5 ounces) is the equivalent of 125 mg of levodopa (approximately the same as one Sinemet 25/100 tablet). Yet the Turkish doctors advocated 250 grams of fava beans (almost 9 ounces) twice a day, the equivalent of 12 Sinemet (25/100) tablets. The reason for the difference may have to do with variations in the levodopa content of fava beans, differences in the way the fava beans are prepared, and other factors we do not yet know. Our own recommendation is to use 3 ounces of fava beans (110 grams) every other day. In addition to the levodopa content, fava beans contain fiber which helps with constipation.