The Ghana trial [1] compared data from a group of Ghanaian PwPs, with data from a group of Italian PwPs. The trial demonstrated that the time from diagnosis to the onset of dyskinesia was similar in the two groups, even though the Ghanaian PwPs started levodopa therapy a few years later than the Italian PwPs. The major recommendation from the trial was that the common practice of delaying the start of levodopa therapy (in order to delay the time-of-onset-of-dyskinesia) was not justified.

The research paper titled "The impact of early versus late levodopa administration" [2] currently has 3 "cites" in Google Scholar (i.e. 3 later-publication-date papers make reference to it). In one of them [3] the following text appears: " ... protein-restricted diets may also contribute to several side effects, including dyskinesia ...". Assuming that this is correct, and assuming that Ghanaians have a protein-restricted diet (at least compared to Italians) then this seems to me to invalidate the major result of the Ghana trial (i.e. a protein-restricted diet might have caused the Ghanaian PwPs to get dyskinesia "artificially" early, in a timeframe similar to the Italian PwPs).

Here is a quote from [2]: " ... [the Ghana trial] compared two different populations with very different ethnic, genetic and environmental characteristics ... ". To that list perhaps could be added the word "diet" (i.e. pull it out from the general area of "environment").

When I had my first visit to my MDS neurologist (almost 3 years ago) I told him that I had read about the common practice of delaying the start of levodopa therapy (in order to delay the time-of-onset-of-dyskinesia). He assured me that this had now been disproven, and gave me a reference to the Ghana trial. I Googled it and was duly convinced by its clarity and simplicity.

Today I am no longer so sure.

[1] Cilia R, et al. (2014) The modern prelevodopa era of Parkinson's disease: insights into motor complications from sub-Saharan Africa. Brain 137(Pt 10):2731-2742

The modern pre-levodopa era of Parkinson’s disease: insights into motor complications from sub-Saharan Africa

[2] Yahalom G, et al. (2016) The impact of early versus late levodopa administration. J.Neural Transm. 24, 471-476. doi: 10.1007/s00702-016-1669-4

The impact of early versus late levodopa administration (PDF Download Available)

[3] Wang L, et al. (2017) Protein-Restricted Diets for Ameliorating Motor Fluctuations in Parkinson's Disease. Front. Aging Neurosci. 9:206. doi: 10.3389/fnagi.2017.00206

Protein-Restricted Diets for Ameliorating Motor Fluctuations in Parkinson's Disease