What if enjoying a cup of coffee everyday could preserve your cognitive functioning when aging?
In the last decades, the number of individuals that suffer from cognitive decline has increased exponentially. In parallel with an aging population this is a major public health issue. Neurological diseases such as Alzheimer’s disease and other types of dementia have a multifactorial background, which means that they are caused by many different factors, both genetic and environmental. One of these environmental factors is diet, which has a potential beneficial effect on preventing dementia onset and progression.
Coffee is one the most consumed beverages worldwide. It is a seed rich in vitamins, minerals, bioactive phytochemicals such as polyphenols (with antioxidant properties), caffeine, diterpenes, melanoidins and trigonelline. Due to its complex compound matrix, its association with health has been object of especial research interest.
Motivated by these major issues, we conducted an analysis in the framework of the PREDIMED-Plus study (with more than 6000 participants). We investigated the association between coffee consumption and cognitive functioning status. Using a collection of many different neuropsychological tests, we evaluated several cognitive functions such as memory, orientation, registration, concentration, processing speed, visual search, and attention. We observed that people who consumed coffee (either caffeinated or decaffeinated) on average showed better cognitive functioning than non-coffee consumers [1]. Moreover, this protective effect of coffee was stronger in participants who consumed caffeinated coffee compared to the decaffeinated drink.
How does coffee protect us from cognitive decline? One potential explanation is the synergic effect between the different compounds in coffee. Caffeine is structurally similar to adenosine, a neurotransmitter with mostly inhibitory effects on the central nervous system. Caffeine blocks the adenosine A1 and A2A receptors in the brain, which disables the capacity of adenosine to bind to these receptors. By blocking the action of adenosine, caffeine improves behavioral functions, such as vigilance, attention, mood and arousal. In addition, caffeine can increase alertness, improve sustained attention and working memory and reduce reaction time and fatigue.
A second important compound in coffee are chlorogenic acids (polyphenols). These may help to reduce oxidative stress and neuroinflammation. The antioxidant capacity of coffee depends on its ability to increase the concentration of a third compound, called glutathione, that is present in blood plasma. This is important because levels of glutathione in the brain tend to decrease with aging, as well as in Parkinson’s disease and Alzheimer’s disease. Furthermore, coffee components such as quinic acid, caffeic acid, quercetin, and phenylindane have been associated with anti-inflammatory properties and protection against amyloid toxicity, tau aggregation, and amyloid-beta inhibition. These amyloid and tau peptides are increased in Alzheimer’s disease.
As mentioned, there are many factors that influence cognitive functioning. However, the results from our study reinforce the role of dietary factors, in this case, coffee, in the prevention of cognitive decline when aging. Clearly further studies are needed to clarify the mechanism by which coffee consumption can boost cognitive functioning. However, to date, the evidence shows that to have a daily moderate coffee consumption (up to 2 cups/day), especially in form of caffeinated coffee, might reduce the risk of cognitive decline when you get older.
References
- Indira Paz-Graniel et al. (2020) “Association between coffee consumption and total dietary caffeine intake with cognitive functioning: cross-sectional assessment in an elderly Mediterranean population”. European Journal of Nutrition, https://doi.org/10.1007/s00394-020-02415-w
