Regular consumption of coffee ‘significantly’ boosts mood and reduces anxiety

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Benefits were also recorded in non-caffeinated coffee, found to improve learning and memory
Regular consumption of coffee “significantly” boosts mood and improves concentration, while non-caffeinated coffee also has health benefits, according to a major new study that sheds new light on how the drink interacts with our minds and bodies.

Researchers at APC Microbiome Ireland, a world‑leading centre at University College Cork, found that both caffeinated and decaffeinated coffee altered the gut microbiome in ways that improved perceived mood and stress levels – and, in some cases, sharpened cognitive performance.

The team said the research builds on previous breakthroughs in understanding the numerous positive effects coffee drinking is now associated with.

They said these include reduced risks of type 2 diabetes, liver disease, cardiovascular diseases and cancer.

Meanwhile, meta-analysis has shown that light-to-moderate coffee consumption is linked to lower rates of all-cause mortality, cardiovascular mortality, and stroke incidence.

It is also associated with a reduced risk of Parkinson’s disease, is linked to a lower risk of depression and a reduction in the incidence of Alzheimer’s disease.

Their findings, published in the Nature Communications journal, were the results of a "first of its kind research" into how coffee affects the bidirectional communication system linking the gut and the brain, known as the microbiota–gut–brain axis.

The study followed 31 regular coffee drinkers – defined by the European Food Safety Authority as those consuming three to five cups a day – and 31 non‑coffee drinkers through psychological assessments, food and caffeine diaries, and stool and urine sampling.

After two weeks of abstaining from coffee, the regular coffee drinkers showed significant shifts in their metabolite profiles – the substances made or used when the body breaks down food – in the gut microbiome, compared with non‑drinkers.

When coffee was then reintroduced to both groups on a blinded basis, with half receiving caffeinated and half decaffeinated coffee, both groups reported lower perceived stress, depression and impulsivity.

Researchers also observed increases in bacteria such as Eggertella sp and Cryptobacterium curtum , linked to digestive processes that may help eliminate harmful microbes, as well as rises in Firmicutes , a group associated with positive emotions in women.

Notably, improvements in learning and memory were seen only in those drinking decaffeinated coffee, suggesting that compounds such as polyphenols – not caffeine – may drive certain cognitive benefits.

Caffeinated coffee, meanwhile, was associated with reduced anxiety, heightened vigilance and attention, and lower inflammation risk.

“Public interest in gut health has risen hugely,” said Professor John Cryan, principal investigator at APC Microbiome Ireland, and co-author of the study.

"The relationship between digestive and mental health is also increasingly being better understood, but the mechanisms behind coffee’s effects on this gut-brain axis have remained unclear.

“Our findings reveal the microbiome and neurological responses to coffee, as well as their potential long-term benefits for a healthier microbiome.

Coffee may modify what microbes do collectively, and what metabolites they use.

As the public continues to think about dietary changes for the right digestive balance, coffee has the potential to also be harnessed as a further intervention as part of a healthy, balanced diet.”
He added: “Coffee is more than just caffeine – it’s a complex dietary factor that interacts with our gut microbes, our metabolism, and even our emotional wellbeing.

Our findings suggest that coffee, whether caffeinated or decaffeinated, can influence health in distinct but complementary ways.”
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