A coffee hit might be more commonly associated with increased alertness, but a new study shows that it could also help lower the risks of developing anxiety and depression – and there’s actually a sweet spot when it comes to how much to drink to get the best effect.
Researchers from Fudan University in China wanted to build on inconclusive findings from past studies to investigate whether or not coffee consumption could be protective against developing mood and stress disorders.
They tapped into a huge amount of data: records of 461,586 individuals, all in good mental health at the start of the study period, who were followed for a median of 13.4 years. Self-reported coffee intake was charted against future health diagnoses.
The statistical number-crunching showed that those who drank two to three cups of coffee a day were the least likely to develop mental health problems, compared to people who didn’t drink coffee at all or who drank more than three cups.
At the top end of the scale, drinking five cups or more each day was associated with a higher risk of mood disorders – so it seems it is possible to overdo the buzz.
“J-shaped associations were identified between coffee consumption and mental disorders, suggesting that a moderate intake of coffee might be beneficial for mental health,” write the researchers in their published paper.
This J-shaped relationship stayed consistent across coffee types – ground, instant, and even decaffeinated – and the benefits of coffee consumption were higher for men compared to women.
The researchers were careful to allow for multiple contributing factors, including age, education, exercise habits, and relevant underlying health conditions – increasing the likelihood that it was the coffee consumption making the difference.
However, the study stops short of proving cause and effect. The participants were only asked about their coffee drinking habits once, at the start of the study period, and this wasn’t monitored over time.
The researchers ran a genetic analysis too, identifying individuals in the study whose genes suggested they would be better or worse at metabolizing caffeine (processing it through the body). However, these genetic subtypes didn’t really move the needle on the associations.
We know that coffee contains many different bioactive compounds, and the researchers think that some of these may be having a calming and anti-inflammatory effect on brain circuits linked to mood and stress. Similar processes could be protecting the brain from disease, past studies suggest.
While the researchers didn’t measure any brain effects directly, the findings provide some useful new clues about the effects of coffee on the brain – and some much-needed clarity.
“Previous studies examining the association between coffee consumption and mental health, specifically depression and anxiety, have yielded inconsistent results regarding the direction of associations or the optimal daily intake,” write the researchers.
“These discrepancies may be partially explained by methodological heterogeneity, including differences in study design, sample size, and population characteristics.”
Previous research has linked coffee to a longer life, protection against heart disease, and improved body weight regulation, so it’s already associated with multiple physical health benefits – and now we may be able to add mental ones to the list.
With mental health conditions becoming more and more prevalent, there’s a real urgency behind the search for treatments and preventative measures to combat stress and anxiety. Simple solutions, like a daily cup of coffee or three, could benefit millions.
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“Over the past decade, mental disorders have increasingly gained recognition as one of the most important disease burdens to global public health,” write the researchers.
“Therefore, potential preventative strategies are needed to develop for curbing the pandemic of mental health disorders.”
The research has been published in the Journal of Affective Disorders.