I would venture a guess that most people enjoy some form of caffeine on a daily basis. Whether it’s coffee, tea, soda, or chocolate, it can sometimes feel like the crutch we need to get through the day.

Over the years, we’ve read that caffeine is bad, or that it’s good, or maybe it’s neither – but what is the real truth?

Caffeine is a natural stimulant that can help us focus and improve our mood, and because a majority of people get it through coffee, cardiologist Dr. Greg Marcus says most of the research centers around coffee, not caffeine.

“The literature on the whole shows that coffee consumption is generally not a detriment to health. But I am very reluctant to recommend anyone begin drinking coffee if they aren’t otherwise doing so, or to increase consumption for any health benefit.”

Studies that focus on all caffeine consumption are mixed, finding it can do both good and harm in a human body. People who drink coffee might be less likely to develop chronic diseases like cardiovascular disease, diabetes, and Parkinson’s, but as with everything on this big blue planet, moderation is definitely the key.

400 milligrams of caffeine is considered “safe” as a daily amount consumed by healthy adults. That’s actually a lot – 4 to 5 cups of coffee, 8 cups of tea, two energy drinks, and around 10 sodas.

Of course, those drinks contain other issues besides caffeine, so buyer beware and all of that.

Moderate doses of caffeine make people less tired and more alert, can reduce their appetite and also lower their risk for depression. Higher doses, however, cause anxiety, high blood pressure, heart palpitations, and insomnia. Stopping your caffeine consumption cold turkey can lead to withdrawal symptoms like headaches, fatigue, and depression.

The tough part is, the question of “how much is too much” can only be answered by an individual. People metabolize caffeine at different rates, they have differing weights, and take different medications that may or may not influence how caffeine affects them.

Marcus and his colleagues completed a few studies on caffeine consumption, asking participants to either drink, or refrain from drinking, caffeine for two consecutive days for two weeks.

They found that people were more active and slept less on the days they consumed, but also had more irregular heartbeats from the lower chambers of the heart. Conversely, they experienced fewer episodes of abnormally rapid heartbeats from the upper chambers of the heart.

People who metabolized caffeine faster had fewer issues sleeping, which is probably to be expected.

“I generally advise that it is reasonable for patients bothered by trouble sleeping or with palpitations to experiment with their caffeine consumption. Take some time off of caffeine to se if it makes a difference.

Even so, Marcus doesn’t blanket recommend avoiding it to his cardio patients, either, and says health differences between consuming say, tea and coffee, have not been adequately studied.

He’s less neutral about energy drink consumption, since they tend to contain a large amount of caffeine in one go, in addition to tons of sweeteners, carbs, and other additives. Energy drinks are known to cause abnormal electrical activity in the heart and higher blood pressure that lasts for hours.

And honestly, he thinks there are other ways to stay alert.

“The best strategies and overall most healthy strategies to boost alertness are long-term healthy habits.”

If you’re having heart issues or sleep issues, you should always contact your doctor.

Until then, enjoy your coffee (or tea or chocolate or soda) – in moderation.

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