Motor effects of broad beans (Vicia faba) in Parkinson's disease: single dose studies.

Broad beans (Vicia faba) are a natural source of L-dopa. To investigate a possible role for this substance in the treatment of Parkinsonian motor oscillations, we carried out single dose studies of Vicia faba pod mixture plus carbidopa in six patients. Motor responses of equivalent magnitude to those of conventional L-dopa medication occurred in five cases with mean onset of 39 min and mean duration of 104 min. Vicia faba meals produced comparable L-dopa blood levels to fasting standard tablet doses and recovery studies yielded 0.25% L-dopa per weight of bean pod mixture. Vicia faba contains sufficient L-dopa to be pharmacologically active in patients with Parkinson's disease and can potentially be incorporated into dietary strategies to manage Parkinsonian motor oscillations.