Fava Beans, A Natural Source of Levodopa -

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Fava Beans, A Natural Source of Levodopa -

 

Prolongs " On " Periods in Patients with Parkinson Disease

http://www.parkinson.org/favabeans.htm

 

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.

 

We welcome comments.

http://www.parkinson.org/favabeans.htm

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