字幕列表 影片播放 列印英文字幕 You know the feeling you get when you learn something new about a health problem you've been trying to reverse? Maybe high blood pressure, diabetes, or heart disease. Well, there's nothing I like better than bringing you the information that will help you do just that. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. Today we begin a fascinating new series on treating Parkinson's with diet. And we begin with a question: since Parkinson's is caused by a dopamine deficiency in the brain, what if you ate foods rich in the dopamine precursor—levodopa? Two centuries have passed since James Parkinson's Essay on the Shaking Palsy described a disease characterized by tremor and problems with movement. Today, treatment options include surgically implanting electrodes into the brain. There has to be a better way. We've known since the 1950's that Parkinson's disease is manifested by a dopamine deficiency in the brain. Well then why not eat a dopamine diet? A variety of fruits and vegetables contain the same dopamine made by our brain. Unfortunately, dopamine can't cross the blood-brain barrier and hence is ineffective as therapy, however the dopamine precursor, known as l-dopa or levodopa can get from the blood up into the brain where it can then be converted to dopamine within the brain by an enzyme called decarboxylase. We don't want the levodopa to be converted to dopamine outside the brain because then it can't get in, so we give people a decarboxylase inhibitor which itself can't get into the brain, so that keeps levodopa from prematurely turning into dopamine before it gets into the brain where we need it. So eating dopamine- rich foods doesn't help, but what if we ate levodopa-rich foods? More than 1500 years before Dr. Parkinson came on the scene, an Indian physician seems to have nailed it and even suggested a treatment, velvet beans, the plant with the highest amount of L-DOPA. Hmm, so might there be a way to forestall the epidemic of Parkinson's Disease through plant-based remedies after all? Levodopa is the gold standard therapy for Parkinson's patients, but most Parkinson's patients in low-income areas cannot afford long-term daily Levodopa therapy. In rural Africa, for example, it is estimated that only 15% of patients are treated with levodopa, because the daily cost of Levodopa treatment is about a dollar day, which may be half of what people make in a day. Same with other regions in the Global South. L-DOPA is mostly unavailable or unaffordable. So patients frequently use powdered velvet beans as a replacement or supplement to the drug. But does it work? You never know... until you put it to the test. Velvet beans in Parkinson's Disease a randomized, double blind, clinical study, and, a dose of 30g, which is about three tablespoons led to a reliable and sustained antiparkinsonian effect in all patients, working significantly quicker than the drug, working significantly longer than the drug, and working significantly better than the drug, in another double-blind, randomized, head-to-head crossover study. The levodopa in velvet beans appears to be 2–3 times more potent as compared to the same dose of pill-form Levodopa, suspected to be because there may be some intrinsic decarboxylase inhibitor compound in the plant as well. OK, but those were single dose studies. What about the chronic use of velvet beans for Parkinson's. Fourteen patients with advanced Parkinson's received roasted velvet bean powder or the standard drug, switching back and forth for months, looking at changes in quality of life, activities of daily living, movement and non-movement symptoms, and time with good mobility without troublesome involuntary writhing movements and the velvet beans seemed to work as well as the drug in all measures of efficacy, including quality of life. Despite the efficacy, the chances of this cheap herbal remedy ever being licensed seems unlikely—and for good reason. First of all, the stuff evidently tastes nasty. And we don't really have good data going out more than a few months. While velvet beans may potentially be part of the answer to Parkinson's disease management in low-income countries, in high-income countries, one may be tempted to prefer them to drugs just because it's a "more natural therapy," but researchers discourage patients and physicians to consider its use when the drugs are available. So levodopa in pill form should remain the first-line treatment for Parkinson's. However, velvet bean powder may be better tolerated in certain patients. Psychologically, some patients just have a thing against taking pills and so if they refuse, then certainly the beans can step in. But otherwise, velvet bean supplements suffer from the issues common to all supplements, specifically lack of sufficient regulation and quality control. There's all sorts of brands out there, but there's no head-to-head comparisons as to which is best, and the quality of the products likely vary, but you don't know... until you put it to the test. Six brands of velvet bean product were ordered through the internet and most of them four out of six showed a large discrepancy between the claim on their label and the actual L-Dopa content, and only two even came close. The remaining products contained considerably less, less than 10% in two cases. Too bad there isn't a food source of L-dopa that you could just eat instead of taking in a supplement. Well, wait a second. L-dopa was originally discovered, more than a century ago, in faba beans. Might eating faba beans help with Parkinson's? I'll explore just that question, next. Increased risk of Parkinson's disease has been associated with exposure to pesticides, consumption of dairy products, a history of melanoma, and traumatic brain injury. Why is the risk of Parkinson's disease increased among individuals with high milk and dairy consumption? It could be the animal fat. Maybe the animal protein. So why not a plant-food diet for the risk and management of Parkinson's Disease? There are phytochemicals that may target the underlying cause, but in terms of treatment, ancient sacred texts from thousands of years ago refer to trembling individuals who were prescribed a plant from the bean family to treat the condition. In my last video I talked about the use of velvet beans, but in 1913 the miracle drug L-dopa was discovered for the first time, in faba beans, also known as fava beans or broad beans, as a natural source of L-dopa to consider. The amount varies considerably based on a number of factors, but typically it looks like they have about 10 times less than velvet beans, but that's okay since you can eat larger quantities since fava beans are an actual food instead of a powdered supplement. The important thing is that amount of L-dopa in fava beans is enough to be pharmacologically active in Parkinson's disease. In fact, there are some reports indicating that Parkinson's patients might respond better to the beans than to standard L-dopa preparations in pill form. But anecdotal reports that patients may gain benefit from a broad bean rich diet don't cut it. What you have to do... is put it to the test. Parkinson's patients were fed about one and a third cups of cooked fava beans, and during the next four hours a substantial clinical improvement was noted. In fact similar to the improvement seen after receiving the standard pharmacological combination of L-dopa plus carbidopa, the decarboxylase inhibitor drug I talked about in the last video that boosts L-dopa levels in the brain. No surprise that there was a similar effect since they had very similar L-dopa levels in the blood. In fact, half the time you could hardly tell the beans from the drugs. How could there be the same levels if the bean L-dopa lacked the carbidopa booster drug. Because fava beans may not only be a natural source of L-dopa, but a natural source of the carbidopa booster too. So the consumption of fava beans has the potential to increase the levels of L-dopa and carbidopa in the blood, with a marked improvement in the muscle movement performance of the patients with Parkinson disease, without any side effects. In fact they work so well you have to be careful about abruptly stopping them. There's a condition called neuroleptic malignant-like syndrome characterized by fever, rigidity, all sorts of neurological problems, muscle breakdown, altered levels of consciousness, which is usually precipitated by an abrupt withdrawal of the L-dopa drug, caused by an acute dopamine-deficient state. Well, you can see the same thing if you're treating your Parkinson's with fava beans and then all of a sudden you stop them. Alternative therapies carry similar risks to traditional agents, because in this case they really are the ultimate traditional agent. There are some downsides you don't see with the drug, though. Like fava-induced flatulence. You also have to be careful with fava consumption if you're on MAO inhibitor drugs often used as anti-depressants, since there can be drug interactions. And then there's the risk of a condition known as favism. There's a genetic mutation that occurs in about 1 in 20 people, and at even higher rates in those of African, Asian, and Mediterranean descent, in which people lack an enzyme that's necessary to detoxify certain compounds found in fava beans, and without the enzyme fava bean consumption can cause your red blood cells to rupture. Thankfully, genetic testing for this mutation is widely available and affordable, and so it seems prudent to screen patients with Parkinson's for this favism, what's called G6PD deficiency mutation, prior to putting them on daily fava bean consumption. If you want to give fava beans a try. fresh green fava beans have significantly more L-dopa than dried, so much so that dried fava beans may not provide any clinical benefits. Roasting and boiling removes some or even all of the L-dopa, though other studies have found that about a half cup of cooked favas contain approximately 250 mg. Sprouted favas may have the most, increasing up until day 9, by which time the indigestible flatulence sugars may be eliminated, offering another advantage of fava bean sprouting. But you don't know if fava bean sprouts help... until you put them to the test. Researchers fed Parkinson's patients a salad with about a half cup of freshly chopped fava sprouts and observed substantial clinical improvement. Other beans, just like regular beans also naturally have L-DOPA, though at lower amounts. Soybeans have a bonus compound that may act as an L-dopa boosting carbidopa compound. What if you fed people soybeans on top of their regular Parkinson's meds? Given people just one and a half spoonful's worth of roasted soybeans led to a significant improvement over the drugs alone with significantly fewer involuntary movements hours later. Until more information is available, Parkinson's combo drugs like Sinemet should remain the first-line therapy, but adding beans to one's diet may only help. 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