To the Editor.
—Pincus and Barry's article1 describing the effects of a low-protein day diet on the control of motor fluctuations in Parkinson's disease certainly offers food for thought. However, the diet component of the study was designed, controlled, and applied in a manner that makes it difficult to accept the conclusions as valid enough to warrant clinical application of the diet regimen described.The range in protein content of the test diets, 7 g vs 160 g, was quite dramatic. Both are unrealistic levels of intake. Why study such extremes without including a test and/or control diet that provides the adult recommended daily dietary allowance for protein, 0.8 g/kg of body weight?2 It is possible that an applicable diet regimen equally distributing 50 to 80 g of dietary protein daily would offer similar or superior benefits than the low-protein diet regimen described in this study. What was
Goldstein DJ. Parkinson's Disease. Arch Neurol. 1988;45(7):715–716. doi:10.1001/archneur.1988.00520310017009