Parkinson’s diseaseIntroduction

Parkinson’s disease (PD) is a chronic progressive neurological disease that is linked to decreased dopamine production in the substantia nigra and is marked by tremor of resting muscles, rigidity, slowness of movement, impaired balance, and a shuffling gait.
– The American Heritage® Dictionary of the English Language, 2007.

It impairs the motor skills, speech, and other functions1. The neurons at greatest risk in PD are substantia nigra pars compacta (SNc) dopamine (DA) neurons.

There are a number of risk-modifying factors for PD. One is low uric acid levels in the blood2. Uric acid scavenges superoxide, peroxynitrite and hydroxyl radical3. The role of uric acid in neuroprotection was outlined in Kutzing and Firestein4. Its main function seems to be to assist in the removal of superoxide by preventing the degradation of superoxide dismutase5. Doing so helps prevent its reaction with NO, blocking the formation of peroxynitrite6. Peroxynitrite plays an important role in the pathogenesis of PD78.

Milk consumption is found to increase the risk of PD, with milk protein (largely casein) indicated as the most important component9. Several studies have found lower uric acid levels associated with milk drinking1011. Uric acid acts as an antioxidant in the brain, where it could affect risk of PD12.

There is also evidence that vitamin D reduces the risk of PD.

Page last edited: 03 May 2011

References

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  2. Schlesinger, I. Schlesinger, N. Uric acid in Parkinson’s disease. Mov Disord. 2008 Sep 15; 23 (12): 1653-7.
  3. Andreadou, E. Nikolaou, C. Gournaras, F. Rentzos, M. Boufidou, F. Tsoutsou, A. Zournas, C. Zissimopoulos, V. Vassilopoulos, D. Serum uric acid levels in patients with Parkinson’s disease: their relationship to treatment and disease duration. Clin Neurol Neurosurg. 2009 Nov; 111 (9): 724-8.
  4. Kutzing, M. K. Firestein, B. L. Altered uric acid levels and disease states. J Pharmacol Exp Ther. 2008 Jan; 324 (1): 1-7.
  5. Pacher, P. Beckman, J. S. Liaudet, L. Nitric oxide and peroxynitrite in health and disease. Physiol Rev. 2007 Jan; 87 (1): 315-424.
  6. van der Veen, R. C. Hinton, D. R. Incardonna, F. Hofman, F. M. Extensive peroxynitrite activity during progressive stages of central nervous system inflammation. J Neuroimmunol. 1997 Jul; 77 (1): 1-7.
  7. Kuhn, D. M. Sakowski, S. A. Sadidi, M. Geddes, T. J. Nitrotyrosine as a marker for peroxynitrite-induced neurotoxicity: the beginning or the end of the end of dopamine neurons?. J Neurochem. 2004 May; 89 (3): 529-36.
  8. Ebadi, M. Sharma, S. K. Ghafourifar, P. Brown-Borg, H. El Refaey, H. Peroxynitrite in the pathogenesis of Parkinson’s disease and the neuroprotective role of metallothioneins. Methods Enzymol. 2005; 396276-98.
  9. Chen, H. O’Reilly, E. McCullough, M. L. Rodriguez, C. Schwarzschild, M. A. Calle, E. E. Thun, M. J. Ascherio, A. Consumption of dairy products and risk of Parkinson’s disease. Am J Epidemiol. 2007 May 1; 165 (9): 998-1006.
  10. Ghadirian, P. Shatenstein, B. Verdy, M. Hamet, P. The influence of dairy products on plasma uric acid in women. Eur J Epidemiol. 1995 Jun; 11 (3): 275-81.
  11. Choi, H. K. Liu, S. Curhan, G. Intake of purine-rich foods, protein, and dairy products and relationship to serum levels of uric acid: the Third National Health and Nutrition Examination Survey. Arthritis Rheum. 2005 Jan; 52 (1): 283-9.
  12. Anderson, R. F. Harris, T. A. Dopamine and uric acid act as antioxidants in the repair of DNA radicals: implications in Parkinson’s disease. Free Radic Res. 2003 Oct; 37 (10): 1131-6.