Is it enough to say, "Avoid Proteins"?

Greetings. I'd been wondering how to get the most out of my CD/LD and was curious about which protein-rich foods - chicken or chickpeas? - interfered most with levodopa absorption.

It's 3 particular animo acids in protein that are the culprits - branched-chain amino acids (or BCAAs) named leucine, isoleucine and valine.

Learning what foods had high levels of any or all of them seemed important. What I ran across only gave more pause.

I’ve avoided eating tuna sandwiches or fish-n-chips within that hour or two of taking the CD/LD. But having a spinach salad with alfalfa sprouts and raw mushrooms, instead? That may not give the levodopa as much of a chance as you'd think.

Per 200 calories, here are the amounts of those 3 amino acids in these particular foods:

Tuna fish, canned, in water:

Leucine: 3574mg Valine: 2266mg Isoleucine: 2026mg


Leucine: 3519mg Valine: 2230mg Isoleucine: 1994mg

Raw spinach:

Leucine: 1939mg Valine: 1400mg Isoleucine: 1278mg

Alfalfa seeds sprouted:

Leucine: 2322mg Valine: 1261mg Isoleucine: 1243mg


Valine: 2110mg

Source: "SELF Nutrition Data: Know what you eat” a chart listing the foods w the hghest amounts of leucine, isoleucine and valine and this chart listing the valine content only:

These are the mg counts per 200 calories and granted, you'd have to eat a big pile of spinach, Popeye, to take in 200 cal. But even at half that or a quarter, that still means amino acids competing with the levodopa for absorption through the gut, aminos that before seeing this, I wouldn’t have suspected were there.

This suggests it’s not enough to follow the simplistic instructions to "avoid protein" but that I have to be vigilant and learn in what foods these particular amino acids lurk. That, or just don’t eat, period, around med time.

I’m not a dietician, nor a nutritionist. Just a PWP trying to eke out every last bit of l-dopa, so that I don’t have to increase my dosage beyond the current 25/100 3xa da. I hope someone better versed in how the body absorbs amino acids can shed some more light on all of this.

18 Replies

  • I wrote a detailed response to your question but this website is haunted at times. I could not post it so here is a shorter version.

    The "on-off" phenomenon in Parkinson's disease. Relation to levodopa absorption and transport.

    "To determine whether the oscillating clinical response to levodopa in Parkinson's disease (the "on-off" phenomenon) reflects fluctuations in absorption and transport of the drug, we investigated this phenomenon in nine patients with an oscillating motor state. We studied the response to continuous infusion of levodopa and the effects of meals on the plasma levodopa concentrations and on the clinical response during oral and intravenous administration of the drug. Meals reduced peak plasma levodopa concentrations by 29 per cent and delayed absorption by 34 minutes. Bypassing absorption by constant infusion of the drug produced a stable clinical state lasting for 12 hours in all of six patients and for up to 36 hours in some. High-protein meals or oral phenylalanine, leucine, or isoleucine (100 mg per kilogram of body weight) reversed the therapeutic effect of infused levodopa without reducing plasma levodopa concentrations. Glycine and lysine at identical doses had no effect. We conclude that interference with absorption of levodopa by food and by competition between large neutral amino acids and levodopa for transport from plasma to the brain may be partly responsible for the fluctuating clinical response in patients with Parkinson's disease."


    How to maximize L-dopa therapy?

    Stalevo is a combination of carbidopa, levodopa, and entacapone and quercetin, a component of green and oolong teas, is also a COMT inhibitor like entacapone.

    Quercetin potentiates L-Dopa reversal of drug-induced catalepsy in rats: possible COMT/MAO inhibition.

    "When quercetin was combined with a subthreshold dose of L-dopa plus carbidopa, the anticatatonic effect was potentiated."

    " The results of the present study strongly suggest that quercetin could serve as an effective adjunct to L-dopa therapy in Parkinson's disease."

    Quercetin is not well absorbed in the gut and when it is coupled with bromelain, an enzyme from pineapples, it is better absorbed in the gut.

    Adding quercetin/bromelain to C/L sounds like a good idea for PD therapy.


    Recently it was discovered why L-dopa stops working:

    Researchers Discover Why L-DOPA Stops Working in Parkinson’s, Seek Prolonged Treatment

    "In a discovery that might turn out to be a game changer in Parkinson’s research, University of Alabama at Birmingham researchers discovered that DNA methylation causes L-DOPA to stop being effective after a few years, instead giving rise to dyskinesia — involuntary jerky movements making life even harder for patients."

    "The team also treated animals with a compound called RG-108, or with methionine supplementation, and saw that they could change the dyskinetic behavior of the animals."

    Methionine is a methyl donor and has been tested with L-dopa as long ago as 1984, if not longer:

    "The most impressive research on non orthodox treatment of Parkinson's concerns the use of L-methionine. WDDTY panel list Melvyn Werbach knows of several studies showing that L-methionine is as effective as L-Dopa after three weeks in people with previously untreated Parkinson's disease (Rev Neurol [Paris],1982; 138 (4): 297-303). It also brought about further improvement in Parkinsonian patients who'd reached a plateau in their orthodox treatment (South Med J, 1984; 77: 1577)."

    Betaine hydrochloride is also a methyl donor and is currently being tested with L-dopa in Iran:

    Betaine acts as an antioxidant and methyl donor agent versus levodopa-induced oxidative stress and hyperhomocysteinemia in the rat kidney

    "In contrast, betaine acts as apromising antioxidant and methyl donor agent versus LD-induced complications."

    There are other betaine hcl/PD studies. Given you are taking Sinemet taking betaine hcl seems like a good idea and methionine is also a possible therapy too. It is good to have options.

    I hope this helps.


  • Rich - Many thanks for the detailed response. In addition to being more wary of a wider range of food that could keep my Ldopa from being fully absorbed, I'm interested to hear what can enhance that absorption.

    About the Quercetin: How many cups of black oolong or green tea would a PWP have to drink to get the benefit?

  • I understand the desire to consume vitamns, etc.. from food sources but I prefer to take supplements in standardized doses that are purified and have potential toxins removed. This way you can take quercetin/bromelain with your sinemet and better gauge the response. Antioxidants in tea have variable dosage and depending on the tea, you may or may not get the correct therapeutic dose to make it an effective adjuvant therapy. This statement is from a tea drinker.

    Plus, quercetin is in oolong and green tea(s). The catechins from these teas are oxidized thru fermentation and become theaflavins, theabrownins and thearubigins in black tea. Black tea has only trace amounts of quercetin in it. It truly is a different 'animal' and just as a FYI there was a Singapore study and they found drinking 6 cups of black tea a week had a inverse relationship with Parkinson's disease to the tune of 71%. I take black tea, egcg and quercetin supplements.


    Differential Effects of Black versus Green Tea on Risk of Parkinson's Disease in the Singapore Chinese Health Study

    I take the following brand of quercetin/bromelain I take with levodopa:

    An additional factor to L-dopa is to add 200 mg of vitamin C with every dose of sinemet or levodopa (without carbidopa):

    The effect of ascorbic acid on the pharmacokinetics of levodopa in elderly patients with Parkinson disease.

    "Levodopa (LD) is one of the most effective drugs for clinical symptoms in patients with Parkinson disease (PD). Most PD patients are advanced in age and may have trouble with LD absorption because aging influences drug absorption processes. Previous reports have indicated that ascorbic acid (AsA) can reduce LD dosage without losing its effectiveness. The current study sought to determine whether AsA affects LD absorption in elderly PD patients. Sixty-seven elderly PD patients took a tablet orally containing 100 mg LD and 10 mg carbidopa following an overnight fast. Plasma LD concentrations were determined at 6 points up to 3 hours, using high-performance liquid chromatography with electrochemical detection. The area under the curve (AUC), peak drug concentration (Cmax), and time to peak drug concentration (Tmax) were calculated. The pharmacokinetic evaluation was repeatedly performed 1 week later in the same way except for adding 200 mg AsA to the tablet. The changes in AUC, Cmax, and Tmax between the tests were evaluated. Significant changes in these parameters were not observed when analyzed using data from all patients. However, significant increases in AUC and Cmax, and a significant reduction in Tmax by adding AsA were observed in 25 patients with baseline AUC < or =2500 ng.hour/mL. In conclusion, AsA can improve LD absorption in elderly PD patients with poor LD bioavailability. LD therapy in combination with AsA may be one of the strategies for PD treatment."

    200 mg doses of vitamin C are hard to find so I use 2 x 100 mg children's chewables every time I take levodopa.

    I do not chew them but swallow them whole so the dose reaches the stomach.

    Off to bed here and have a good Sunday.


  • Thank you so much for the information. I was about to ask a question as to which of the multivitamins/minerals for the over 70's, the soya isoflavones or the eve.primrose oil combined with cod liver oil might relate to occasional runs of several days of worsening symptoms. I had just realised these may be associated with the 3/4 days when I do not get round to filling up my pill boxes for the three weeks at a time I usually dole out. Obviously on those days I extract the PD meds daily but am not taking in any supplements. The m-v gives 160 mg Vit.C(200 rda) and the next thing would be to take the m-v at the same time as one of the four sinemet I take each day and see if there is a difference compared with the sinemet without the combined multivitamin + mineral tablets . Also are the isoflavones or the evening primrose/cod liver oil tabs. significant. I suppose such tweaking of the meds etc. is a far distant dream as far as being the norm given that many medics don't even mention the protein interference to their patients.

  • Soya isoflavones are phytoestrogens and not proteins. If anything, they should help with PD because estrogens are protective against PD.

    "In general, phytoestrogens are weaker than the natural estrogen hormones (such as estradiol) found in humans and animals or the very potent synthetic estrogens used in birth control pills and other drugs."

    Neurotrophic and Neuroprotective Actions of Estrogen: Basic Mechanisms and Clinical Implications

    Here is a PD study which shows a specific soy isoflavone is protective against PD:

    Anti-Inflammatory Role of the Isoflavone Diadzein in Lipopolysaccharide-Stimulated Microglia: Implications for Parkinson’s Disease

    +The major question is do you have thyroid dysfunction? ++

    Effects of soy protein and soybean isoflavones on thyroid function in healthy adults and hypothyroid patients: a review of the relevant literature.

    "One concern is that soy may adversely affect thyroid function and interfere with the absorption of synthetic thyroid hormone."

    [Hypothyroidism concealed by Parkinson's disease].

    Thyroid-Induced Worsening of Parkinsonian Tremor Resistant to Drugs and Subthalamic Nucleus Deep Brain Stimulation

    The Health Dangers of Soy

    I have osteoarthritis and take soy and soybean unsaponifiables:


    As for cod liver oil I cannot think of any negative consequence for PWP. The only issue with CLO is it has to be distilled at a molecular level to remove impurities. I take CLO and the DHA omega threes help with dyskinesia and are being tested for this problem:


    Long-term omega-3 fatty acid supplementation prevents expression changes in cochlear homocysteine metabolism and ameliorates progressive hearing loss in C57BL/6J mice

    "Omega-3 polyunsaturated fatty acids (PUFAs) are essential nutrients well known ... which, in turn, would be oxidized to betaine, the methyl donor for BHMT [27]."

    I did not read the above article but just found the information I needed to continue this response.

    Study #27 reference

    M.A. Pajares, D. Perez-Sala

    Betaine homocysteine S-methyltransferase: just a regulator of homocysteine metabolism?

    Cell Mol Life Sci, 63 (2006), pp. 2792–2803

    So omega 3s are oxidized into betaine and which is a antidyskinetic agent. The betaine studies are listed above.

    I take about 2 grams - 2,000 mg of combined salmon and cod liver oil per day.


    I also take Evening Primrose Oil in the, well, evening because it has trace amounts of tryptophan which help with rest. There is some evidence that taking EPO is good for PD:

    "Evening primrose: (Oenothera biennis). Evening primrose oil (EPO) improved Parkinson's-induced tremors in 55 percent of those who took the equivalent of two teaspoons a day for several months. The oil contains traces of the amino acid tryptophan, which boosts the effectiveness of L-dopa. (Ground evening primrose seeds contain even more.)"

    The above statement is the only information related to EPO.

    Does tryptophan improve PD symptoms?

    L-tryptophan supplementation in Parkinson's disease.

    "Two female Parkinsonian patients with levodopa-induced "On-Off" responded dramatically to administration of L-tryptophan supplementation."


    Of all the supplements you listed I have to point out that the isoflavones might effect you negatively by depressing your thyroid gland. Like I asked before, do you have a thyroid problem?

    Have a good Sunday.

  • Thank you so much for this information. I did know isoflavones were not protein. Perhaps I should have started a new thread. I did not want to ask too ma ny questions. I felt sure you would pick up on what was relevant. Yes, I do have under-active thyroid. I

    I have taken these particular supplements for some years ago and am not inclined to add to them just now. My somewhat unscientific rule of thumb is that if it won't fit into the day pill boxes I have I can't have it . I might feel differently about fine tuning if my symptoms are not controlled and the mild dyskinesia gets worse. . However, I will print your info. out and digest it carefully links and all.

  • cabbage (raw) has a phytochemical that depresses my thyroid. I must avoid it during flu season, and when I was nubile youth, my eyes would protrude.....I thought it had something to do with my might of factored in....but cabbage, that most healthy of foods is definitely a culprit. so is broccoli. you can test it out for yourself.

    I tried some blue cabbage the other week, after avoiding it for perhaps years, with strange effect...just an overall uck feeling. i'm usually of good cheer. I was raised on cabbage and sourcrout.

    I always tested lower normal thyroid tests.

  • i'm very curious about microglial function: they are part of immune system I gather?

    their action causes inflammation which can damage neighbour neurons?

    this is very interesting to me because I had broken teeth that I finally had removed because I suddenly developed pyreha (gum disease) .

    i was sick with something caused by my teeth (old fillings) but dentist said that was unlikely, but gave me a short course of antibiotics and that definitely helped.

    because of a leaky right eye i focused on my eye tooth as possibly leaching lead past my brain barrier or something like that.

    to boot, i had swollen glands, not under my chin but at the base of my neck. (both sides)

    i still get the occasional but slight swelling, but only on my right side. any possibility that my PD was brought on by a simple infection in my case?

  • This is an academic question. If you eat more than 45 minutes after taking medication or you take medication more than one hour after eating, the protein will not interfere with the medication. If you are taking medication as much as every 2 hours you should be able to take it within those limits.

    Have you thought of placing less reliance on medication and start doing some exercise to help reducing your reliance on the medication?

    Fast walking actually repairs the damaged brain cells and so do other forms of exercise, to a lesser extent.


  • In our personal experience, it is only the protein from animal foods (meat, eggs, dairy) that interfere with my husband's PD meds. He is mostly on when he follows a vegan diet. All plant foods contain some protein, but it isn't a problem for him.

  • I have not paid a lot of attention to the instruction that we should not consume large amounts of Protein. I also must ignore the instruction to not eat before taking medication due to nausea. An old Pharmacist told me to take the medications with a large glass of whole (3.25%) milk. He said that although Protein it was an acceptable type of Protein , but he could not illuminate further what other foods were acceptable type. I am much more concerned about regularity and which foods maintain it. The medication is taken up in the upper bowel and not in the stomach and the situation of bloated, backed up, plugged, and uncomfortable completely eliminates any good regularity taking the medication would provide. Amino acids eh. I will look into it. Thanks

  • You brainiacs are too smart for me.

  • Beckey, I feel the same way!

  • This is the kind of information we should all be seeking! Thank you!!!!

  • Info = power.

  • You get no argument from me! I'm just grateful for you smart guys who can translate all this info into Joe Average verbiage.

  • I agree Beckey. Sooo much info! My head is spinning. But keep it coming, it's amazingly informative.

  • It would be very helpful if you could condense this into what supplements you actually take - the information is fascinating and I try to regulate our diet carefully but we don't take any supplements at the moment. My husband has had PD for 12 years and takes Stalevo and pramipexole, dyskinesia is a major problem. Please don't tell him to walk fast - if he could he would, he was always a fitness fanatic and does as much as can now, but fast walking is a goal not a reality!

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