Mucuna pruriens, also known as ‘Velvet bean’, is a wild legume originally from southern China and eastern India that now grows throughout many tropical and subtropical regions of the world, where its pods are commonly used for food. In particular, its seeds are considered a rich source of dietary protein at about 23–35% protein and are rich in minerals.
Mucuna is a powerful and popular Indian medicinal plant with a long history of use in traditional Ayurvedic medicine, including as an aphrodisiac and to treat to treat arthritis, nervous disorders and Parkinson’s disease. In fact, its traditional use in degenerative nervous system disorders such as Parkinson’s is clinically supported (see “Neuroprotective” below).
All parts of the mucuna plant possess medicinal properties that have been the subject of clinical studies, including its anti-diabetic, antioxidant, anti-epileptic, anti-microbial, neuroprotective and anti-inflammatory activity.
One of the main areas of research of mucuna is as a potential treatment for Parkinson’s disease. Mucuna is most commonly known for its high natural concentration (4–7%) of L-dopa, the precursor to dopamine, a key neurotransmitter involved in motivation, mood, learning, memory, attention and even regulating body movements.
Parkinson’s disease is a degenerative disease in which dopamine-producing nerve cells in the brain gradually break down or die, including nerve cells that produce dopamine. Low dopamine levels lead to abnormal brain activity, resulting in symptoms of Parkinson's. In western medicine, doctors use either commercial drugs made with L-dopa extracted from mucuna seeds or synthetic forms of L-dopa in order to boost dopamine levels in Parkinson’s patients. On the other hand, in traditional Ayurvedic medicine, whole mucuna seed or extracts of the entire seed are used.
One study comparing commercial L-dopa medications with traditional mucuna preparations found that the quality of motor improvement was the same, but mucuna resulted in faster motor onset and longer duration of effect, suggesting that mucuna may have a higher bioavailability than standard L-dopa preparations. Further research is needed to explain the mechanism of the mucuna seed and determine whether mucuna is a viable, or even preferred alternative to standard L-dopa.
Dopamine, Serotonin (aka the ‘feel good chemical’) and Noradrenaline are neurotransmitters (chemical messengers in the brain) that are thought to play a role in regulating mood. Due to mucuna’s role in dopamine creation, studies have examined whether mucuna might also impact mood. In one animal model study, mucuna seed extract was found to have an antidepressant effect, leading researchers to believe that this may be due to mucuna’s ability to increase dopamine levels.
Two other similarly structured animal model studies also found antidepressant activity, together with increased levels of noradrenaline and serotonin neurotransmitters. This demonstrates that mucuna’s effect is likely not limited to dopamine, and leading researchers to suggest that its antidepressant-like property may be mediated via interaction with these neurotransmitters that affect mood. (1, 2)
A third animal model study found similar antidepressant results, and the presence of precursors to both dopamine and serotonin in the subjects’ brains led researchers to suspect these neurotransmitters' involvement in mucuna’s antidepressant-like action.
These findings are significant and call for further research in this area, as clinical studies suggest that disruption in dopamine, serotonin, noradrenaline neurotransmission in the central nervous system is implicated in depression.
Mucuna is often touted for its adaptogenic-like qualities (and even referred to as a known adaptogen), however clinical studies supporting its adaptogenic properties are sparse. One study on infertile men who were under psychological stress and suffering from elevated cortisol (stress hormone) levels found that 30 days of treatment with mucuna powder significantly reversed cortisol levels.
The study notes that fertility is known to be affected by various kinds of stressful conditions, including psychological stress, and that stress can also decrease levels of neurotransmitters (including dopamine and noradrenaline) in the brain, which are also known to affect fertility. The researchers therefore suggested that the reduction in stress following use of mucuna may be linked to the high L-dopa concentration of this powerful herb.