Caffeine shows up in all kinds of places, from your morning cup (or three) of coffee to the pills you pop when you have the flu or the bar of chocolate you eat in the afternoon. In fact, caffeine is the most widely used psychoactive substance in the world.
It’s also no stranger to being in the news for its possible health effects — recent weeks have seen its advocates promote its apparent benefits while others criticize it for its perceived risks. But who is right? Both and neither, it turns out.
Heart health
Some studies show that caffeine can actually be good for our hearts. In an analysis of three large heart disease studies, researchers found that higher coffee intake was associated with a lower risk of heart failure. Sipping decaffeinated coffee did not have the same effect, indicating that the effect may be due to the caffeine, although further research is needed to fully confirm this theory.
That being said, researchers have identified some short-term cardiovascular effects when it comes to consuming highly caffeinated beverages. High levels of consumption – considered to be about one liter (34 oz) of liquid containing 320 milligrams of caffeine, which is the same as four 250 milliliter (8.5 oz) cans of Red Bull – have been found to cause temporary bouts of elevated blood pressure and palpitations.
It’s an effect that’s particularly noticeable when energy drinks are combined with alcohol – so maybe go easy on Jägerbombs.
Metabolic health
A study published last year found that people with higher levels of caffeine in their blood may have a lower risk of obesity and type 2 diabetes. These individuals had variants of two genes related to caffeine metabolism, meaning , that their bodies are slower to break down the molecule and thus it remains at a high level in their blood.
However, this research has limitations: half of caffeine’s effect is thought to be mediated through weight loss, for example. Another important factor to note is that the study included mostly people of European descent, meaning the findings may not apply to everyone. Further research needs to be done to determine whether increasing caffeine intake may play a role in reducing the risk of these two conditions.
Mental health
Caffeine is a stimulant – many people drink coffee or an energy drink for an early morning or afternoon boost not only to our energy levels but also to our mood. How does this happen? As part of the American Medical Association’s What Doctors Wish Patients Knew™ series, neurologist Dr. Nicole Clark explained that caffeine “stimulates dopamine, which is a chemical in your brain that plays a role in motivation for pleasure and learning.”
On the other hand, if you already have experience with conditions like panic disorder and anxiety, recent research shows that caffeine can make things worse for your mood. A 2022 meta-analysis found that consumption of approximately five cups of caffeinated coffee induced anxiety in both people with panic disorder (PD) and healthy subjects, but those with PD were at higher risk of panic attack .
Fetal health
Caffeine is able to cross the placenta, meaning it can enter the bloodstream of the growing fetus. Research in this area suggests that daily consumption of more than 300 milligrams may be associated with an increased risk of low birth weight, while more than 350 milligrams may be associated with pregnancy loss.
As such, while many health organization guidelines state that pregnant people can still consume some caffeine if they wish, they advise no more than 200 milligrams per day. However, a 2020 study concluded that growing research suggests there is no safe level of caffeine consumption during pregnancy.
Sports performance
The addition of caffeine is a well-established trend in fitness and sports performance, with the substance often added to pre-workout powders in varying amounts. Research generally suggests that it can improve athletic performance; although much of this work is based on data from male athletes, sports nutrition authorities have implemented it in their guidelines in general.
In a meta-analysis of studies in female team sports athletes, researchers found that caffeine supplementation was indeed effective in increasing some aspects of performance, such as hand grip strength and counter-movement jump, but not others (agility , squat jumps, repeat sprint ability). The conclusion is that more research is needed before current ideas about caffeine can be applied to everyone.
There is also some suggestion that coffee specifically may improve performance in a number of different activities, but how much, if any, of this effect is due to the specific action of caffeine is unclear.
The big picture
All that being said, what makes caffeine “good” or “bad” probably depends on the person: how well your body metabolizes it, the medications you may be taking that could interact with it, or how much you consume .
However, it’s worth remembering that caffeine is a drug, and caffeine toxicity or overdose is a very rare thing, but it can be fatal. Then it’s best to be careful with it, especially when it comes to caffeine supplements.
The Food and Drug Administration (FDA) has advice on what to watch out for when figuring out how much caffeine is too much for you. Symptoms may include:
- Insomnia
- Nausea/upset stomach
- Headache
- Trembling and/or anxiety
- I feel miserable
If you want to cut back on caffeine, it’s generally recommended that you do so gradually. While withdrawal may not be as dangerous as with other drugs, it can still have some pretty unpleasant side effects, such as headaches and fatigue, so it’s better not to throw all your coffee beans in the bin right away.
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The content of this article is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of qualified healthcare professionals with questions you may have about medical conditions.
