Writing in the Journal of the Neurological Sciences, the research team investigated the biochemical and clinical effects of whey protein in people with Parkinson’s disease (PD) – finding that supplementation at a level of 20 grams per day for six months has a significant beneficial effect on biomarkers of the disease, including higher levels of blood plasma reduced glutathione and lower homocysteine levels.
However, the team led by Piyaratana Tosukhowong from Chulalongkorn University, Thailand, also reported that no significant improvements in clinical outcome measures were seen in the pilot study.
“These biochemical changes may be beneficial for improving oxidative stress status, stimulating muscle protein synthesis, and reducing the risk for cognitive impairment and dementia,” wrote Tosukhowong and colleagues.
“The clinically meaningful effect of the reduction of Hcy following the supplementation with whey protein should be evaluated in clinical trials with objective outcomes before adopting this approach in daily clinical practice,” they added.
“Large-scale prospective randomized, double-blind clinical trials are needed to evaluate further the potential of whey protein supplementation as part of the holistic management of PD patients.”
The pilot-scale placebo-controlled, double-blind study (registered as NCT01662414) aimed to investigate the effects of whey protein isolate supplementation for six months on plasma glutathione, plasma amino acids, and plasma homocysteine (Hcy) in PD patients.
Measures of clinical outcome assessments including the unified Parkinson's disease rating scale (UPDRS) and striatal L-3,4-dihydroxy-6-(18)F-fluorophenylalanine (FDOPA) uptake were also measured before and after supplementation, said the team.
In total, 15 patients received the whey protein and 17 received a soy protein supplement that served as a control.
According to Tosukhowong et al, supplementation with whey protein at 20 grams per day for six months resulted in significant increases in plasma concentration of reduced glutathione.
“This was associated with a significant decrease of plasma levels of homocysteine,” said the team – noting that the plasma levels of total glutathione were not significantly changed in either group.
Plasma levels of branched-chain amino acids (BCAA) and essential amino acids (EAA) were also found to be significantly increased only in the whey-supplemented group, the Thai team noted.
Furthermore, measures of clinical outcomes as defined by the UPDRS and striatal FDOPA uptake were not significantly improved in either group, they noted.
“However, significant negative correlation was observed between the UPDRS and plasma BCAA and EAA in the pre-supplemented PD patients,” said Tosukhowong and colleagues.
Source: Journal of the Neurological Sciences
Volume 367, 15 August 2016, Pages 162–170, doi: 10.1016/j.jns.2016.05.056
“Biochemical and clinical effects of Whey protein supplementation in Parkinson's disease: A pilot study”
Authors: Piyaratana Tosukhowong, et al