Often touted for its many health benefits, new research suggests you might not even need to drink coffee to reap some of its rewards, with a US study finding that just the scent of a cup of joe could help give people a cognitive boost that improves performance on certain tasks.

Led by the Stevens School of Business along with researchers at Temple University and Baruch College, the team carried out two studies to investigate whether the scent of coffee alone, which has no caffeine, could be strong enough to boost cognitive performance.

In the first study, the researchers looked at performance Graduate Management Aptitude Test, or GMAT, a computer adaptive test required by many business schools.

They gave a 10-question GMAT algebra test to around 100 undergraduate business students in a computer lab setting, and divided the participants into two groups.

One group took the test in the presence of an ambient coffee-like scent, while a control group took the same test in an unscented room.

The researchers found that the group in the coffee-smelling room scored significantly higher on the test.

To investigate further, and find out whether it was the coffee scent which increase alertness and subsequently improved performance, the team designed a follow-up survey which they gave to more than 200 new participants.

The group were surveyed on their beliefs about various scents and their perceived effects on human performance, with the participants reporting that they they believed they would feel more alert and energetic when smelling a coffee scent, compared to a flower scent or no scent.

They also said that exposure to coffee scent would increase their performance on mental tasks.

The results suggest that smelling a coffee-like scent, despite having no caffeine in it, has a effect similar to drinking coffee in part due to the participants' expectations, suggesting a placebo effect of coffee scent.

"It's not just that the coffee-like scent helped people perform better on analytical tasks, which was already interesting," commented lead researcher Professor Adriana Madzharov. "But they also thought they would do better, and we demonstrated that this expectation was at least partly responsible for their improved performance."

Madzharov is now looking to explore whether coffee scents could have a similar placebo effect on other types of performance, such as verbal reasoning.

Coffee has previously been found to also have many physical health benefits, including a reduced risk of heart disease, diabetes and dementia, with some also suggesting that it may even help us live longer.

The results can be found published online in the Journal of Environmental Psychology.