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Vitamin B6 may cut risk of Parkinson's disease
- Aug 01 2006
A higher dietary intake of vitamin B6 may decrease the risk of Parkinson's disease, a study suggests.
Among more than 5,000 people, Dutch researchers found those who reported taking in the most vitamin B6 were about half as likely as those who consumed the least to develop Parkinson's disease.
Vitamin B6 is essential for metabolism of protein and proper immune and nervous system function, and is found in both meat and vegetables.
There is evidence that high levels of the amino acid homocysteine could cause damage to brain cells. To see whether higher intake of folate and vitamins B6 and B12, which can reduce homocysteine levels, would also reduce Parkinson's risk, researchers followed 5,289 men and women aged 55 and older who were free of the disease at the study's outset.
During nearly 10 years of follow up, 72 people developed Parkinson's disease, Dr. Monique M. B. Breteler of Erasmus Medical Center in Rotterdam and colleagues report in the journal Neurology.
The researchers found no association between consumption of B12 or folic acid and risk of developing the disease. However, the more B6 people consumed, the lower their risk.
Those in the highest third of vitamin B6 intake were 54 percent less likely to develop the disease compared to those in the lowest third. A closer look suggested that this relationship was only statistically significant for smokers.
The findings suggest that the nutrient could lower Parkinson's disease risk not by affecting homocysteine levels but by protecting brain cells from damage caused by harmful by-products of metabolism known as free radicals, Breteler and her team propose. They note that several studies have shown that smoking actually cuts Parkinson's risk, possibly due to brain-cell-protecting properties of nicotine.
The study doesn't rule out the possibility that B12 and folate could also be protective, the researchers point out. To provide a more definitive answer, they add, studies must be conducted that look at levels of the nutrients in the blood, which is a more sensitive indicator of their effects.
SOURCE: Reuters Health News www.today.reuters.com/news/home.aspx
Commentary from the Parkinson's Disease Foundation
Vitamin B6 and the risk of Parkinsonís disease
Neurologists, nutritionists and patients share a long-standing interest in dietary factors that might alter the risk of developing Parkinsonís disease as well as dietary constituents that might alter clinical decline. Using information from a large general population study in the Netherlands, de Lau and colleagues recently published a report in Neurology (2006;67:315-318) on vitamin B6 or pyridoxine use and the subsequent development of Parkinsonís disease. They found that people who smoked and consumed higher dietary vitamin B6 had a lower risk of Parkinson's disease. This apparent protective effect against Parkinson's disease did not exist for non-smokers.
This report is of scientific interest on factors that could participate in the development of Parkinson's disease, but it does not give patients who already have Parkinson's disease direct information on the advisability of supplementing their diet with vitamin B6.
In all situations, vitamin supplementation should be discussed with a physician, because chronic, very high doses of vitamin B6 are not safe and can cause toxic neurological syndromes.
Further, the protective effect that was observed only occurred in people who smoked, and smoking carries its own serious medical risks. Most importantly, this report did not focus on the progressive course of Parkinson's disease and the effects of vitamin B6 in patients already diagnosed with Parkinson's disease.
Based on this report, PDF cannot make any recommendation for patients with Parkinson's disease to take supplemental vitamin B6 in hopes of altering their clinical course.
Christopher G. Goetz, MD: Chair, Medical Policy Subcommittee of the Scientific Advisory Committee, Parkinsonís Disease Foundation.
Source Date: Aug 01 2006
Source Publication: Reuters Health New
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