A Caffeinated Conundrum
Coffee drinkers beware...
Does coffee lead to increased risk of dementia and stroke?
Moderation is best!
Coffee, with over 22 billion pounds consumed annually, is without a doubt one of the most popular drinks worldwide. (1) Many of us wake up each morning and seek energy from this bitter bean as it provides a high source of caffeine. Coffee is low in calories, high in potassium, and very high in antioxidants. Is this a super drink? Perhaps a miracle elixir? Research indicates that there are key advantages and disadvantages for those who consume this brewed beverage.
Coffee’s appeal comes from the popular psychoactive stimulant caffeine, which works by antagonizing the A1 and A2A receptors in the brain.(2) This causes stimulation of the central nervous system and ultimately leads to a boost of energy.
In a study led by Ricardo Magalhaes et al, researchers examined human brain networks using functional magnetic resonance imaging (fMRI) on volunteers who consumed or did not consume coffee. After examining the neural networks of the volunteers, the researchers’ data showed decreased functional connectivity of the cerebellar, subcortical and motor cortex regions of the brain. A decreased functional connectivity demonstrated a higher overall efficiency due to a reduced inter-regional dependence. (2)
Not all data supports the health benefits of habitual coffee drinking. A study conducted by the University of South Australia demonstrated a connection between overconsumption (more than six cups per day) of coffee and increased probability of developing dementia. Researchers gathered 398,646 participants between the ages of 37-73 and grouped them by their coffee consumption frequency. Pre-existing medical conditions were screened via a background check and MRI of the brain. An MRI was repeated 4-6 years after the initial assessment in order to evaluate brain volume changes. After covariate adjustment, the data showed that people who consumed greater than six cups of coffee per day demonstrated a reduction in brain volume, a 53% increased probability of developing dementia, and a 0-37% increased association of stroke compared to participants that consumed 1-2 cups per day. (3)
Based on these studies, the evidence suggests coffee can have both positive and negative effects. Light to moderate consumption (1-5 cups) provides acceptable stimulation to the body. Low-dose caffeine usage displays a lower functional connectivity in segregated brain regions and an overall increase in efficiency.(2) New data, however, suggests a correlation between heavy consumption (more than 6 cups per day) and shrinkage of the brain with increased probability of dementia and strokes. (3) The main takeaway here is that moderation is key for anything and further data may provide definitive causal analysis on this popular morning beverage.
By Miles Amby
Research Microbiologist, Hardy Diagnostics
