Updated: Oct 1, 2020
In the minds of many cynics, anything that you love must be bad for you. Thus it is that many people feel that their daily coffee habit is quite possibly doing them no good. However, coffee has a number of quite appealing benefits. One that has interested me this week is the protective effect of coffee on the brain, and in particular on reducing the risk of both Alzheimer's and Parkinson's diseases (by perhaps about 25-30% it is suggested).
Parkinson's disease is a progressive neurodegenerative condition which manifests as stiffness in joints and difficulties in balance and coordination as well as tremors. There is currently no cure, medications can only manage the symptoms.
It is not known why some people develop Parkinson's and others do not. However, what has been observed are the nature of some of the changes which take place in the brain. One of the most important ones seems to be a buildup of a certain type of protein in the brain which is 'misfolded' - ie isn't in its normal functioning shape. This is known to trigger cells dying, which eventuates in Parkinson's becoming apparent.
This protein is alpha-synuclein, which sticks together and joins up with other compounds to create deposits in the brain called Lewy bodies. The Lewy bodies cause chemical changes. Alpha-synuclein can pass from one neuron to another, causing damage to spread.
Studies over the years have suggested that drinking coffee can reduce your chances of developing Parkinson's. This was attributed in part to the caffeine, however some studies showed similar protective effects from decaffeinated coffee. So, which of the hundreds of compounds in coffee are beneficial, and how?
A 2010 study has identified a compound called eicosanoyl-5-hydroxytryptamide (EHT). EHT both protects neurons and is also anti-inflammatory. Experiments on mice found that the best anti-Parkinson's effects were seen when caffeine and EHT worked together, however, each does have some effect in isolation.
Another beneficial group of compounds are phenylindanes which are formed in the roasting process and which contribute to coffee's bitter taste. These seem to interact with the proteins responsible for Parkinson's and Alzheimer's and prevent plaques or Lewy bodies from forming. The darker the roast, the greater the phenylindanes produced and the more protective the effect. This is independant of caffeine, so degree of roasting is more important than the 'hit' you're getting!
Experts agree that there are so many compounds in coffee that it is probable that others are involved too. Many of these experiments have only been carried out in animals too, so the translation to demonstrated results in humans is still a way off. Nevertheless, it is still the case that fewer coffee drinkers as opposed to non coffee drinkers do develop Alzheimer's and Parkinson's diseases.
Good to know that your daily latte or espresso is keeping your brain healthy, so drink up and enjoy!