Caffeine and Parkinson’s disease: what’s the connection and what you should know

Over the past three decades (and more), several epidemiological studies have observed an interesting association: people who consume caffeine regularly appear to have a lower risk of developing Parkinson’s disease compared to those who do not, with some large studies suggesting a 30–40% risk reduction.

This effect is specific to caffeine, it has also been observed with tea, cola, and other caffeinated beverages, and appears to be dose-dependent (within certain limits). The effect, however, is absent in decaffeinated coffee.

Moreover, the protective effect seems to be more pronounced in men, while in women it may vary depending on hormonal factors, such as estrogen use.

The mechanism behind this protective association is not yet fully understood. One of the most supported hypotheses involves caffeine’s antagonistic action on adenosine A2A receptors. By blocking these receptors, caffeine may modulate dopaminergic pathways the very circuits primarily affected by Parkinson’s disease.

In addition, caffeine may influence other mechanisms related to the disease through its antioxidant and anti-inflammatory properties. It may reduce alpha-synuclein accumulation (a protein involved in Parkinson’s pathology) and enhance the neurons’ ability to “clean up” damaged components through autophagy.

Finally, caffeine may exert a neuroprotective effect by stimulating the release of neurotrophic factors, proteins essential for neuron survival and function.

To date, there is no solid scientific evidence that caffeine can slow the progression of Parkinson’s disease. Research remains preliminary, and current data are insufficient to draw firm conclusions.

Some clinical studies have reported modest improvements in certain motor and non-motor symptoms, but findings are inconsistent and often non-replicable not enough to recommend caffeine as a treatment.

An interesting area of investigation concerns caffeine’s possible role in managing non-motor symptoms, which are often difficult to treat. Caffeine and similar molecules may represent a new therapeutic approach.

There are already drugs that act on the same target receptors as caffeine the adenosine A2A receptors. One example is istradefylline, approved in Japan and the United States as an add-on therapy to levodopa for advanced Parkinson’s disease to help reduce motor fluctuations.

Other similar compounds are currently undergoing clinical trials. This is therefore a promising field of research, which in the future could lead to new treatment options, especially for symptoms that current therapies struggle to address.

Although caffeine is a natural and widely used substance, it is not free from side effects. High doses may cause:

• anxiety;
• irritability;
• sleep disturbances;
• tremors;
• increased heart rate;
• digestive issues.

In Parkinson’s disease, where symptoms such as insomnia, anxiety, or orthostatic hypotension are already common, excessive caffeine consumption may worsen some symptoms. Furthermore, since caffeine also affects the cardiovascular system, it may be contraindicated in individuals with heart disease.

According to the European Food Safety Authority (EFSA), up to 400 mg of caffeine per day (roughly equivalent to 3–5 cups of coffee) is considered safe for healthy adults (excluding pregnant women).

However, individuals with chronic medical conditions should always consult their physician to assess personal tolerance and potential drug interactions.

Caffeine is an intriguing substance widely studied for its potential protective effect against Parkinson’s disease. However, at present, there are no formal recommendations for its therapeutic use.

Several ongoing studies aim to explore the potential of this everyday compound more deeply, one that we consume almost daily but may still hold untapped therapeutic potential. These investigations may pave the way for new preventive or therapeutic strategies, based on biological mechanisms that science is only beginning to understand.

For now, moderation remains key: a balanced intake of caffeine, within a healthy lifestyle, may be beneficial but it cannot replace medical treatment or specialist monitoring.