The amount of caffeine was even lower in the blood of people with a genetic mutation that predisposes them to suffer from Parkinson’s, writes Dr. Grace Crotty of Massachusetts General Hospital in Boston in the medical journal Neurology.
“It has been many years since epidemiological studies have shown that, overall, coffee consumption is associated with a reduced risk of having Parkinson’s disease, commented Professor Louis-Éric Trudeau, of the department of pharmacology and physiology of the University of Montreal
“The difference here is that they measured markers for caffeine and other related markers in plasma. They weren’t satisfied with patient-reported measurements of their coffee consumption. ”
Such a direct measurement of plasma caffeine levels reduces the risk of error, he continues, since one does not rely solely on the subjects’ memories of their caffeine consumption in the past few days or weeks.
American researchers compared 188 patients with Parkinson’s disease to 180 healthy people.
Plasma caffeine levels were lower in sick participants than in others. The difference was even more pronounced in subjects who had mutations in the LRRK2 gene, and who may predispose to Parkinson’s.
“People who are carriers of these mutations (…) also had even lower levels of coffee in their blood than people with the sporadic form of the disease, that is to say the majority of the people, Trudeau said.
“It was even half as much as the other people who had the disease and who were carriers of the disease, so it’s still a good increase.”
However, we must resist the temptation, which can be strong, to conclude that the consumption of caffeine will protect against this neurodegenerative disease.
First, it is not known whether people with mutations in the LRRK2 gene simply consume less caffeine than others or if they consume just as much, but metabolize it more quickly.
In addition, although studies carried out in the laboratory have shown that caffeine can have a neuroprotective effect, no studies conducted in humans yet allow us to conclude that an increase in caffeine consumption will reduce the extent of the effects. symptoms or slow the progression of the disease.
But giving caffeine to a subject who already suffers from the symptoms of Parkinson’s is not comparable to consuming a potentially protective product for 20 or 30 years, underlines Louis-Éric Trudeau.
“It would be an undeniable advantage to delay the disease since in many cases, people who develop the disease still have an acceptable quality of life for several years with existing treatments, and if we could postpone even ten n the onset or progression of symptoms, that would have a huge impact, ”he concluded.