Sunlight and vitamin D protect against Parkinson's disease
People who spend two hours a day outside are two times less likely to develop Parkinson's disease than people who only spend an hour or less outside, Chinese neurologists at Chongqing Medical University write in Nutrients. Sunlight stimulates the skin to manufacture vitamin D, and this is probably the vitamin that protects against Parkinson's.
The researchers studied two hundred adults who had just been diagnosed by doctors as having Parkinson's disease. They measured the concentration of vitamin D3 in the subjects' blood and recorded how many hours a week the participants' skin was exposed to sunlight. The researchers also studied two hundred comparable adults who did not have Parkinson's.
The researchers divided the participants into four equal sized groups according to the amount of vitamin D3 they had in their blood. These groups are called quartiles.
Quartile 1 = 0-18 nanograms vitamin D3/mL, Quartile 2 = 18-22 nanograms vitamin D3/mL, Quartile 3 = 22-25 nanograms vitamin D3, Quartile 4 = over 25 nanograms vitamin D3/mL.
The researchers did the same for exposure to sunlight.
Quartile 1 = 0-7 hours sunlight per week, Quartile 2 = 7-10 hours sunlight per week, Quartile 3 = 10-14 hours sunlight per week, Quartile 4 = over 14 hours sunlight per week.
The figure below shows that both sunlight and the amount of vitamin D3 in the blood reduced the risk of contracting Parkinson's.
The researchers also found a clear correlation between sunlight and the concentration of vitamin D3 in the blood. Consuming vitamin D through food had far less effect. That was probably because the participants' diets did not contain high levels of vitamin D3.
"In sum, our study found that lower levels of serum vitamin D3 and sunlight exposure are significantly associated with a higher risk for Parkinson's disease", the researchers summarised the results of their study. "Further cohort and vitamin D supplementation studies are needed to confirm this finding."
Nutrients. 2016 Mar 4;8(3):142.
Vitamin B6 protects against Parkinson's 13.11.2015
Paprika protects against Parkinson's 05.02.2015
Athletes less likely to develop Parkinson's 04.02.2015