Post: What happens when you take too much caffeine

Getty Images Woman looking tired (Credit: Getty Images) Caffeine is an active ingredient in some of the world’s favourite drinks and has a powerful effect on humans. What happens if you take too much?

It is there naturally in your morning coffee and cup of tea or added to your favourite energy drink and many popular soft drinks. For many of us, a slug of caffeine can give our bodies and brains a much needed boost if we are feeling a little sluggish.

But recently, a brand of lemonade on sale in the US was discontinued amid accusations its caffeine content was dangerously high , despite reportedly being within the country’s recommended daily intake of caffeine for adults. It has raised questions about just how much caffeine is too much, and does it matter where we get it from?

While there’s a vast number of studies showing that some caffeinated drinks have health benefits, there’s still some uncertainty around how we should be consuming it. How caffeine affects the body

There are many crucial functions at play in our bodies all the time, including heart rate, blood flow and sleep-wake cycles. Many of these affected by adenosine – a chemical that occurs naturally in your body, and whose job it is to make us tired at the end of the day.

"Adenosine is one of the naturally produced substances in the body to cause a quieting of activity in various organs that are under stress or in need of lowering energy demand," says Kenneth Jacobson, chief of the molecular recognition section at the National Institute of Diabetes and Digestive and Kidney Diseases in the US.

Adenosine receptors are found on the outer surface of many cells in the body, he says, and they react to variable levels of adenosine near the cell to send a command inside the cell to lower its level of activity. This promotes sleep in the heart, kidneys, immune system and other tissues.

When we consume caffeine, it’s quickly absorbed into our bloodstream, where it out-competes adenosine by preventing it from connecting to these receptors and doing its job. […]

What happens when you take too much caffeine