Lower levels of caffeine were found in the blood of people with Parkinson’s disease in a recent study. The research compared individuals with Parkinson’s who carry a specific genetic mutation known to increase the risk of Parkinson’s with individuals who carry the same mutation but do not have the disease.
Parkinson’s disease is a progressive disorder of the brain characterized by tremors, limb and torso rigidity, and problems with movement and balance. There is an increased risk of depression and dementia in people with the condition as well.
According to the U.S. National Library of Medicine, more than 1 million people in North America and more than 4 million people worldwide have Parkinson’s disease. Every year, approximately 60,000 individuals undergo a diagnosis in the United States.
Around 15 percent of people with the disorder have a Parkinson’s family history, which means that they have inherited genes that raise their likelihood of developing the condition. Most events, however, arise from a complex combination of genetic and environmental factors, which is poorly understood.
Several environmental variables have associations with increased risk, such as head trauma, chemicals, and medications, while exercise has associations with decreased risk.
A 2010 analysis of previous studies showed that the more people frequently drink caffeine, the lower their risk of Parkinson ‘s development.
Another research found that individuals with Parkinson’s who do not have genetic risk factors for the disease have lower blood levels of caffeine than individuals without the disease.
A team led by scientists at the Massachusetts General Hospital in Boston, MA, set out to find out if coffee could also protect individuals with an LRRK2 gene mutation. Getting this gene raises, but does not guarantee, the chance of developing the disease.
The authors compared individuals with and without Parkinson’s disease. Both groups contained individuals with and without the LRRK2 gene mutation.
The researchers observed that among individuals with this genetic disorder, the variations in the levels of blood caffeine between individuals with Parkinson’s and those without were greater.
Dr. Grace Crotty, who led the research, says:
“These results are promising and encourage future research exploring caffeine and caffeine-related therapies to lessen the chance that people with this gene develop Parkinson’s … It’s also possible that caffeine levels in the blood could be used as a biomarker to help identify which people with this gene will develop the disease, assuming caffeine levels remain relatively stable.”
The authors published the study in the journal Neurology.
Five coffee-related chemicals
The researchers analyzed blood plasma samples from 368 people participating in the LRRK2 Cohort Consortium, a 2009 research project organized and sponsored by the Michael J. Fox Parkinson’s Research Foundation.
One group comprised 188 people with Parkinson’s, and 180 people without the disorder were in the control group. There was a mutation in the LRRK2 gene in about the same proportion of each group.
When the researchers compared the plasma chemical profile of the two groups, they found that the levels of five unique chemicals varied the most, all of them linked to caffeine.
For people with Parkinson’s disease, the concentrations of all five chemicals were substantially lower than among those without the disorder.
For people with a non-mutated LRRK2 gene, the concentration of caffeine in the plasma of those with Parkinson’s was, on average, 31 percent lower than those without the disorder.
Compared with controls, caffeine levels were 76 percent lower in individuals with Parkinson’s and a mutated LRRK2 gene.
The researchers also looked at questionnaires filled out by 212 of the participants to cross-check their results, detailing how much caffeine they consumed.
This showed that individuals with Parkinson’s and a mutated LRRK2 gene received 41 percent less caffeine per day than individuals without Parkinson’s regardless of whether the mutated gene was carried in them.
Alternative explanation
The researchers are careful to point out that their analysis revealed a correlation between Parkinson’s disease and caffeine. It did not demonstrate that the intake of caffeine protects individuals against the disease.
For instance, the possibility remains that having a mutation in the LRRK2 gene not only raises the risk of Parkinson’s in an individual, but also makes them less likely to consume caffeinated drinks.
“We do not yet know whether people who are predisposed to Parkinson’s can prefer to avoid drinking coffee or whether a lot of coffee is drink by some mutation carriers and benefit from its neuroprotective effects,” Crotty says.
In addition, Crotty states that at one point in time , the research looked at adults, so it doesn’t say anything about when there is a protective effect or how caffeine could affect the progression of the disease.
