Recently I heard the story of a women who controlled her dyskinesia by eating protein.

Levodopa induced dyskinesia normally occurs when levodopa levels are at their highest (typically between 30 minutes and 90 minutes after taking a dose). It stops naturally once levels have dropped below the dyskinesia threshold. But it would be useful is you could speed up the decline, thus reducing the amount of time dyskinetic.

It is thought that dietary proteins compete with levodopa to get into the blood and through the BBB.

Guebilla and Thiele write [1]:

"[Levodopa's] bioavailability is hindered by dietary amino acids, leading to fluctuations in the motor response particularly in late-stage (stage 3 and 4 on Hoehn and Yahr scale) patients. The routine dietary intervention consists of low-protein (<0.8 g/kg) diets or the redistribution of daily protein allowance to the last meal."

Following on from this you could eat protein containing food with the intention of slowing and reducing the absorption of levodopa. It is in this sense that dietary protein can be thought of as "negative levodopa".

Where might negative levodopa be useful:
- as we have seen, reducing levodopa induced dyskinesia;
- response to mistakenly taking a double dose - as soon as you find the mistake eat protein;
- smooth out the peaks in levodopa levels.
- possibly, by offering an escape route if levodopa levels get too high, it could allow a more aggressive dosing regimen.

I suspect that there is a wide variety of the amounts of proteins that is required for PwP to exhibit this effect.

I would not recommend experimenting with negative levodopa without your doctor's consent.

Reference:

[1] "Model-based dietary optimization for late-stage, levodopa-treated, Parkinson’s disease patients"
M. Guebila, I Thiele
npj Systems Biology and Applications, 2016
Model-based dietary optimization for late-stage, levodopa-treated, Parkinson?s disease patients | npj Systems Biology and Applications

John