15 October 2010
Cereda
E, Barichella M, Pedrolli C, Pezzoli G
The American Academy of Neurology suggests advising the redistribution
of daily protein meal content to every Parkinson's disease (PD) patient
with motor fluctuations during levodopa treatment. However, no
comprehensive evaluation of this complementary therapy has been
performed.
A systematic review of intervention studies investigating the
neurologic outcome of low-protein (<0.8 g/kg of ideal weight/day)
and protein-redistribution diets in patients with PD experiencing motor
fluctuations during levodopa treatment. All studies (uncontrolled or
randomized) investigating a low-protein and/or a protein-redistribution
diet (LPD and PRD) and involving patients with PD with motor
fluctuations were included, provided that sufficient information on
dietary protein content and neurologic outcome measures was available.
We identified 16 eligible studies, but they were markedly heterogeneous.
There was not enough evidence to support the use of LPD. Response to
PRD seemed very good. Acceptability appeared high upon introduction, but
it seemed to progressively decrease over time. On average, PRD resulted
in improved motor function, but also complications occurred.
At the
beginning, drop-outs were due to levodopa side effects rather than
unsatisfactory benefits. Long-term adherence was more affected by
changes in dietary habits than by diet-related side effects. Efficacy
and benefits appeared to be higher when the intervention was proposed to
subjects in the early stages of PD.
PRD can be safely advised to
fluctuating patients with PD, but those in whom benefits override the
possible inconveniences still need to be identified. The long-term
effects of PRD on nutritional status should be evaluated and true
effectiveness in clinical practice should be reassessed, given the
changes in levodopa formulations and the introduction of several
adjuvants (levodopa degradation inhibitors and/or dopamine agonists)
