Researchers found that both caffeinated and decaffeinated coffee were linked to reduced depression, lower impulsivity, and measurable changes in gut health associated with mental well-being.
By yourNEWS Media Newsroom
New findings from researchers at APC Microbiome Ireland suggest that regular coffee consumption may positively influence mental health through changes in the gut microbiome, with both caffeinated and decaffeinated coffee linked to lower stress levels, reduced symptoms of depression, and improved emotional regulation.
The study, published in a peer-reviewed scientific journal, examined 62 adults and explored how coffee consumption affects the gut-brain axis, a communication network connecting intestinal microbes with the central nervous system. Researchers analyzed psychological assessments alongside stool and urine samples to evaluate changes in microbial activity and metabolites associated with mood and cognition.
Participants included 31 regular coffee drinkers and 31 non-drinkers. Individuals classified as habitual coffee consumers typically drank between three and five cups daily. During the study, coffee drinkers abstained from coffee for two weeks before reintroducing it in a blinded trial where half consumed caffeinated coffee and the other half consumed decaffeinated coffee.
Researchers reported that both groups experienced reductions in stress, depression, and impulsivity after coffee was reintroduced, indicating that coffee’s effects extend beyond caffeine alone. Scientists also documented shifts in gut bacteria associated with digestion, immune regulation, and neurological signaling.
Dr. John Cryan, a principal investigator at APC Microbiome Ireland and lead researcher on the project, said the results point toward a broader role for coffee in influencing health through microbial pathways. Nutrition specialists reviewing the findings said the study reinforces growing scientific interest in the relationship between diet, gut health, and emotional well-being.
“This study is the first to confirm what gut health specialists have seen in clinical practice for years: that coffee is a functional beverage,” said certified integrative nutritionist Coco Pierrel, who was not involved in the research, in comments quoted by Healthline.
Researchers found notable differences between caffeinated and decaffeinated coffee. Participants consuming caffeinated coffee demonstrated lower anxiety levels, improved vigilance and attention, and reduced inflammatory markers. Decaffeinated coffee, meanwhile, was linked to improvements in learning and memory performance.
According to the study, the findings suggest that coffee’s naturally occurring polyphenols and melanoidins may contribute significantly to these effects. Pierrel explained that these compounds nourish gut bacteria, which then produce short-chain fatty acids capable of communicating with the brain through the vagus nerve.
“Your gut bacteria ferment these into short-chain fatty acids, which send signals directly to the brain through the vagus nerve,” Pierrel said in comments cited by Healthline.
The study adds to expanding research surrounding the gut-brain axis, a bidirectional communication system increasingly associated with mood regulation, cognition, inflammation, and stress responses. Researchers noted that caffeine itself also plays a separate neurological role by blocking adenosine receptors in the brain while stimulating digestive activity and metabolic signaling.
Pierrel said habitual coffee drinkers may gradually develop a reduced cortisol response, potentially making the nervous system less reactive to stress over time.
“What most people miss is that habitual coffee drinkers develop a blunted cortisol response over time, meaning daily coffee may actually train your nervous system to handle pressure with less reactivity,” she said.
The researchers said caffeine also appeared to contribute to lower inflammation levels, while anti-inflammatory compounds present in decaffeinated coffee likely explained its cognitive benefits despite the absence of caffeine.
The findings align with broader scientific literature examining the connection between nutrition and mental health. Researchers referenced earlier work showing that certain foods influence neurotransmitters such as serotonin, dopamine, and GABA, which are involved in mood regulation and emotional processing.
Experts involved in reviewing the study cautioned that coffee’s benefits may depend heavily on how it is consumed. Pierrel recommended limiting intake to two or three cups daily and avoiding coffee late in the afternoon due to potential sleep disruption.
She also warned that processed additives frequently used in commercial coffee drinks—including flavored syrups, artificial sweeteners, seed oil-based creamers, and stabilizing gums—may counteract some of coffee’s anti-inflammatory properties.
“The real problem is rarely the coffee itself; it is what most people pour into it,” Pierrel said in comments quoted by Healthline.
She recommended consuming black coffee when possible, or pairing it with simple plant-based milk alternatives and minimally processed sweeteners such as raw honey, maple syrup, or stevia.
Researchers emphasized that individual responses to coffee may vary based on genetics, metabolism, caffeine sensitivity, and existing health conditions. They said additional long-term studies are needed to better understand how coffee affects different populations and whether gut microbiome differences influence mental health outcomes over time.
The study’s findings contribute to growing scientific interest in dietary interventions targeting emotional well-being and neurological health through the microbiome. Researchers said the results suggest coffee may increasingly be viewed not solely as a stimulant, but as a dietary component capable of influencing mood, cognition, and stress regulation through biological pathways involving gut bacteria and inflammation.
Source: Natural News
Original article
Comments