Researchers from the Erasmus Medical Center in Rotterdam analysed more than 5,000 people and found that those who took most vitamin B6 were half as likely to develop Parkinson's disease as compared to those who consumed the least.
There is evidence that high levels of the amino acid homocysteine could cause damage to brain cells. The researchers followed 5,289 men and women aged 55 and older who were free of the disease at the beginning of the study to see whether higher intake of folate and vitamins B6 and B12, which can reduce homocysteine levels, would also reduce Parkinson's risk.
After nearly 10 years of follow up, 72 people developed Parkinson's disease. The researchers found no association between consumption of B12 or folic acid and risk of developing the disease. However, the more the consumption of vitamin B6, the lower was the risk of developing the disease.
Those in the highest third intake of vitamin B6 were 54 percent less likely to develop the disease as 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. 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. To provide a more definitive answer, studies must be conducted that look at levels of the nutrients in the blood, which is a more sensitive indicator of their effects.
