Cup of coffee being poured
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I am a regular coffee drinker. I have also been interested in stories about beneficial health effects of coffee, such as recent articles documenting a decreased risk of cardiovascular disease and of dementia.
Another recent paper highlights beneficial effects of coffee on gut health and mood. Researchers at University College Cork, Ireland, found that regular moderate coffee consumption (defined as 3 to 5 cups per day) helped promote some of the “good” bacteria within the microbiome of the human gastrointestinal tract that aid in digestion. These in turn may play a role “in eliminating unhealthy gut bacteria and stomach infections.”
Another effect they found was improvements in mood, with some interesting differences in responses to caffeinated vs. decaffeinated coffee: “caffeinated coffee reduced anxiety, psychological distress, blood pressure, and improved attention and stress coping, while decaffeinated coffee enhanced sleep, physical activity, and memory.” However, both types of coffee lowered levels of stress and depression, while improving overall mood and cognition.
Intriguingly, these effects seem to be related, working through what is called the “microbiota-gut-brain axis.” Although the exact linkages are not fully understood, the researchers noticed potentially intriguing correlations between coffee’s effects on gut bacteria and on the brain. For example, “both Velonella species are strongly associated with theophylline that in turn is strongly associated with several cognitive scores.”
Coffee consumption also was associated with a reduction in inflammatory markers and “higher levels of the anti-inflammatory cytokine IL-10.” The authors note, “These findings suggest that coffee or its components may have specific effects on immune function, potentially mediated by phenolic compounds with anti-inflammatory properties.” Nutritionist Nicola Shubrook explains that these anti-inflammatory compounds “can help reduce the risk of cancer by neutralising harmful free radicals, the chemicals that damage cells.”
Another interesting finding was that, “Mood benefits of coffee occur without changes in cortisol physiology.” This suggests that the beneficial effects of coffee on mood can occur independently of other forms of stress-reduction.
Other studies suggest that although drinking coffee might temporarily raise one’s blood pressure, it does not increase the risk of developing long-term hypertension for people with otherwise normal blood pressure. (People with severe hypertension should consult with their physicians before drinking large quantities of coffee.)
These researchers did not specifically indicate what times of day one should drink coffee, although earlier studies indicate that other health benefits occur predominantly in those who confine their coffee consumption to the mornings, as opposed to throughout the day.
Coffee is a complex beverage with multiple bioactive components including (but not limited to) caffeine. Humans are complex biological systems, with multiple interactions between the GI system, cardiovascular system, and nervous system that are still only partially understood.
The research from University College Cork is notable for looking at these complexities in detail, trying to tease out some of the underlying mechanisms. I like how they summarized their multiple discoveries: “Coffee influenced the gut microbiome, increased beneficial (poly)phenols and metabolites, and provided anti-inflammatory effects, suggesting that coffee, regardless of caffeine content, supports cognitive, psychological, immune, and metabolic health in distinct but complementary ways.”