Caffeine induces cravings for sweet foods Picture: Instagram (raymond_uyehara)
They're a classic combo, munched across the world. A cup of coffee and a sweet glazed doughnut are a breakfast staple - particularly in America.

Now new research has provided evidence that there's a strong reason why they work so well together.

Caffeine may alter your perceived sense of sweetness, making you crave more sugary treats than you normally would after a cup of coffee, a study published in the Journal of Food Science suggests.

Researchers distributed both caffeinated and decaf coffees to two sets of volunteers – none of whom knew which type of coffee they had been given.

Both groups were asked to add sugar to their drinks and subsequently rate its sweetness.
Coffee and a sweet glazed doughnut, a breakfast staple. Picture: Instagram (mindingmyowncoffee)
Those who drank the caffeinated coffee rated it as less sweet than the decaf drinkers.

Participants were then asked to rate their mental alertness and estimate how much caffeine was in their drinks.

Regardless of whether they drank the caffeine or not, the volunteers all said they experienced the same boost in alertness and few were able to accurately determine the level of caffeine in their drinks.

Thus, the study also proves that drinking coffee provides a placebo effect whereby drinking it gives us that same jump in energy, whether it contains caffeine or not.

The relation between our taste buds and our sense of alertness comes from a chemical in our brains known as adenosine, which allows us to calm our nerves and drift off to sleep at night.

Caffeine blocks the receptors in the brain that adenosine binds to and therefore makes us feel like we are more alert – even if we aren’t.

The effect doesn’t last long, nor does the impact it has on our taste buds.

But that won't stop us using science as an excuse to reach for another bite of glazed goodness...

UK Independent