Earlier studies have shown that coffee consumption may protect against the development of Parkinson’s disease in people who have no genetic risk factors for the disease. This study looked at people with a genetic mutation that increases the risk of Parkinson’s. The mutation is in a gene called LRRK2 for leucine-rich repeat kinase 2. But having the abnormal gene does not guarantee that people will develop the disease, so researchers are hoping to identify other genetic or environmental factors that affect whether people develop the disease.
The study compared 188 people who had Parkinson’s disease to 180 people who did not have the disease.
Among people carrying the LRRK2 gene mutation, those who had Parkinson’s had a 76% lower concentration of caffeine in their blood than those who did not have Parkinson’s. People with Parkinson’s with a normal copy of the gene had a 31% lower concentration of caffeine in their blood than non-carriers without Parkinson’s.
Carriers of the gene mutation who had Parkinson’s also had lower consumption of caffeine in their diet. The gene carriers with Parkinson’s consumed 41% less caffeine per day than the people who did not have Parkinson’s, both with and without the gene mutation.
“We don’t know yet whether people who are predisposed to Parkinson’s may tend to avoid drinking coffee or if some mutation carriers drink a lot of coffee and benefit from its neuroprotective effects,” [researcher Grace] Crotty said.