Dear Listfriends,
The message below is from the National Parkinson Foundation's "Ask Dr.
Lieberman" list, and may be of interest to some of you.
=======================================================

we have had numberous questions about fava beans.  The following was
adapted from an article that appeared in the Journal Movement Disorders,
the official journal of the Movement Disorders Society
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.
     We welcome comments.
--
Kathrynne Holden, MS, RD
Author: "Eat well, stay well with Parkinson's disease"
"Constipation and Parkinson's" --  audiocassette & guidebook
"Guidelines for Medical Nutrition Therapy for Parkinson's
disease" & Risk Assessment Tools
"Risk for malnutrition and bone fracture in Parkinson's
disease," J Nutr Elderly. V18:3;1999.
http://www.nutritionucanlivewith.com/

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