Coffee is a daily ritual for many, but did you know that this popular beverage is more than just a pleasant drink to wake up to? Increasing evidence suggests that caffeine in coffee has significant effects on mood, and the effects vary from individual to individual.
For decades, researchers have delved into the effects of caffeine on stress and anxiety. While some studies show that drinking coffee reduces stress, other studies show drinking coffee doesn’t and it increases anxiety. The latter isn’t hard to believe, as caffeine is a stimulant that activates your sympathetic or fight or flight nervous system and causes you to feel “pumped” and anxious.
But it’s more complicated than that. Your brain develops tolerance to caffeine if you drink it regularly. So. The jolt of energy and jitteriness you get after drinking a cup of coffee lessens over time as your brain adapts to its effects. This adaptation has to do with receptors in the brain, known as adenosine receptors.
Adenosine receptors explain some of the effects caffeine has on mood. Adenosine, a chemical in your brain has a relaxing effect on the body, giving you a feeling of calm, but caffeine blocks adenosine receptors. With adenosine receptors blocked by caffeine, you feel less relaxed, more energized, and a bit jittery.
But if you continue to consume caffeine, your brain builds more adenosine receptors that can bind to adenosine and relax your body. So, you don’t feel as hyped up when you drink your usual quantity of coffee. This is how your brain adapts to caffeine. You feel more alert and hyped up when you first start consuming caffeine and the effect diminishes over time.
Once caffeine adaptation takes place, you must drink even more coffee to block the extra adenosine receptors your brain built to get the same boost in energy and alertness. If you stop drinking coffee suddenly, you might get caffeine withdrawal and feel tired because there’s no caffeine to block your adenosine receptors.
The Effect of Coffee on Mood Varies with the Dose and Individual
The effects of caffeine are dose-dependent, meaning the amount of caffeine you consume affects the response you get and your mood. It also depends on whether you’re a regular coffee drinker or not. One study found that drinking one cup of coffee every four hours led to significant improvements in mood. It also found that drinking 2-5 cups of coffee daily reduced anxiety and enhanced feelings of relaxation. However, consuming large quantities of caffeine, more than 4 or 5 cups per day, increases tension and worsens anxiety. So, the dose matters, and individual tolerances to caffeine vary.
There are many other factors that may influence how caffeine affects your anxiety. For example, if you’re a naturally anxious person or have a family history of anxiety disorders, coffee may not decrease your stress levels. Instead, you should be aware of and monitor any increase in your anxiety symptoms when consuming caffeine.
The effect coffee has on mood depends on how you metabolize caffeine and your individual tolerance to this common stimulant. Studies show that some people are also slow metabolizers of caffeine and are more likely to experience caffeine side effects, including anxiety and an increased heart rate.
Therefore, if you break down caffeine slowly, you may have a different experience when you drink too much coffee. You may feel more anxious than a slow metabolizer and be more prone to adverse effects like heart palpitations. Studies also show that people who break down caffeine slowly are at a higher risk of a heart attack when they drink more than 2 cups of caffeinated coffee daily.
What about Caffeine and Depression?
Some studies show a link between a lower risk of depression as caffeine consumption increases. Although both coffee and tea contain caffeine, coffee is more strongly linked to lowering the risk of depression. It’s unclear why and it may have nothing to do with the caffeine. Coffee contains more than caffeine: it’s a source of hundreds of natural chemicals with bioactive properties. Some of these, including ferulic acid, caffeic acid, and chlorogenic acid, reduce nerve cell inflammation in the brain.
If Coffee Causes Anxiety
If coffee causes anxiety, mix decaffeinated coffee with caffeinated and don’t go overboard with the caffeine. Research shows moderate amounts of caffeine (about 300 mg a day) are beneficial to relaxation and mood enhancement, while excessive amounts (about 600 mg a day for adults) can increase feelings of stress. Plus, as Mayo Clinic points out, up to 400 milligrams daily, equivalent to 3 to 4 cups of brewed coffee, appears safe for healthy adults. Beyond that, the risk of side effects goes up, especially if you’re a slow metabolizer.
The Bottom Line
Coffee has mood-enhancing benefits for some people, but it varies with the individual, how much they consume, and how they metabolize caffeine. If you’re curious whether caffeinated coffee lifts your spirits or reduces stress, try consuming small amounts while keeping a symptom diary. As you increase your caffeine consumption, write down how it impacts your mood. But don’t consume more than a cup or two of caffeinated coffee per day without talking to your doctor if you have medical problems.
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