Does Caffeine Prevent Depression?
We’re a nation that loves our caffeine. From tea and energy drinks to our morning cup of joe. Caffeine is the world’s number 1 stimulant world wide, so it’s safe to say we’re a bit obsessed.
This isn’t a big surprise, there’s a lot of great benefits to caffeine. It gives you a burst of energy, helps you focus, and…..fights depression?
It might sound too good to be true. But let’s take a look at the science.
Stressing About Caffeine
A recent study published in the Proceedings of the National Academy of Sciences recently found that caffeine could helps us guard against the effects of stress, memory loss, and possibly depression.
This might seem counter-intuitive, since caffeine has been shown to raise the stress hormone, cortisol, in the bloodstream. If the body responds to caffeine as if stressed, how can it actually help manage stress? And how does that relate to depression?
Scientists from the US, Brazil, and Portugal used mice to test the interaction of caffeine on stress. They used two groups of mice for the experiment. Over three weeks they gave the first group caffeine through their water supply, and the second group they gave regular water. They then exposed each group to stressful situations. Cold baths, food deprivation, and tilted cages.
When they compared the two groups after the tests, the mice that had caffeine were behaving normally. The group without caffeine, though, scored worse on memory tests and displayed depression like behavior.
They authors of the study found that caffeine blocked a stress related chemical, allowing the mice to better cope under stressful situations.
In the past, researchers weren’t able to determine if caffeine was the cause of the stress reduction or something else. Activities associated with caffeine, like socializing at a coffee shop, being with friends, or relaxing, may have been a factor. This is the first study to help establish a casual link between the intake of caffeine and depression.
While the study was done on mice, it helps identify the specific mechanisms related to stress and mood. In the past, studies on mice have been a reliable model for humans.
Clues From the Past
The case between caffeine and depression has been building for some time. For instance, a study in 2005 noticed that caffeine could help blunt the effects of cortisol on the body.
The effects of caffeine have been studied in cases of suicide. While a grim topic, scientists have found clues here as well.
A team from Harvard looked at 3 separate studies to see if there was a link between suicide and caffeine intake. Data on more than 200,000 people, some followed for 16 years, were analyzed. They found that compared to non-coffee drinkers, people who consumed 2 to 4 cups a day had over a 50% reduced risk of suicide.
They also noticed that this association disappeared when they looked at data of people who consumed non-caffeinated beverages. This ruled out other factors, like antioxidants, in coffee or other drinks.
This agrees with earlier evidence from a study on suicide of over 50,000 women. Over 10 years researchers tracked caffeine intake and cases of suicide. They also found that increased consumption of coffee and caffeine reduced the risk of suicide, even when controlling for factors like smoking, alcohol, drug use, and self-reported stress.
What About Coffee or Green Tea?
About 80% of the caffeine in the world is consumed in the form of coffee. So it makes sense to see if there are clues from the study of coffee and green tea consumption.
A study of caffeine, green tea, and coffee consumption in Japan workplaces was published in 2014. The results found that people who consumed 4 or more cups of green tea had 51% lower odds of having depressive symptoms. They found similar results for a higher intake of coffee and caffeine
The caffeine habits of over 50,000 US women was done in a similar study. Covering a span of 10 years, levels of consumption were recorded at regular intervals. The scientists then looked at cases of depression in the group.
They found that increasing levels of coffee consumption was linked with decreasing risk of depression. Women who drank two to three cups had a 15% reduced risk of depression. If they drank 4 or more cups, it increased to 20%. It was also found that decaffeinated coffee was not associated with depression risk.
Always in Moderation
The combined results of recent and past studies points to an interesting relationship that consuming caffeine can do more than make you alert. Our favorite psychoactive drug could very well help people from falling into a depressed state.
This isn’t to say that you can slam 3 energy drinks and go on your merry way. The adverse side effects of caffeine – such as sleep disturbances and anxiety – are very real. There can be too much of a good thing. People also have different levels of sensitivity to caffeine.
Consumed in moderation, though, it seems that a daily shot of caffeine can be largely beneficial to your health. Which is excellent news, because I’m not sure I could quit on my love of coffee.
Image: Logan Brumm