Holiday spice has fat-burning properties

Christmas treats such as German cinnamon biscuits, cinnamon rolls and cinnamon eggnog may be slightly more guilt-free this year in light of new research which suggests the common holiday spice may help prevent obesity.

Previous research on mice suggests cinnamon could increase metabolism, prevent obesity and protect against hypoglycaemia. This is all due to the essential oil cinnamaldehyde, which is responsible for giving cinnamon its flavour. However, further research was needed to understand the fundamental mechanisms behind this.

University of Michigan Life Sciences Institute researchers, led by Research Assistant Professor Jun Wu, aimed to use this research as a foundation to better understand cinnamaldehyde and whether these positive effects could be translated to humans.

"Scientists were finding that this compound affected metabolism. So we wanted to figure out how — what pathway might be involved, what it looked like in mice and what it looked like in human cells," said Wu.

Published in the journal Metabolism, Wu and her colleagues found cinnamaldehyde can improve metabolic health. The team collected fat cells, called adipocytes, from human volunteers of various ages, ethnicities and body mass indices and treated them with cinnamaldehyde. They found it increased expression of several genes and enzymes that enhance lipid metabolism. Therefore, instead of storing fat, the cinnamon substance induced adipocytes to start burning energy in a process called thermogenesis.

Researchers also noted an increase in important metabolic regulatory proteins Ucp1 and Fgf21, which are involved in thermogenesis.

Adipocytes store energy in the form of lipids which are used when food is scarce and temperatures are cold. While this was useful to our ancestors who consumed less high-fat foods and needed to store energy, this is essentially what is causing an unhealthy excess of fat.

"It's only been relatively recently that energy surplus has become a problem," Wu said. "Throughout evolution, the opposite — energy deficiency — has been the problem. So any energy-consuming process usually turns off the moment the body doesn't need it."

With obesity becoming an increasingly problematic issue worldwide, researchers have been looking at improving fat-burning processes in humans, and cinnamaldehyde could be the first step towards achieving this.

Cinnamon is already a common ingredient in the food industry, meaning it could be an easier (not to mention more delicious) treatment for those struggling with weight problems, as opposed to traditional drugs.

"Cinnamon has been part of our diets for thousands of years, and people generally enjoy it. So if it can help protect against obesity, too, it may offer an approach to metabolic health that is easier for patients to adhere to,” explained Wu.

However, the researchers warned against using the results as an excuse to gorge on cinnamon in the hope of keeping the holiday weight off. After all, cinnamon is a spice that features in a lot of sugary and unhealthy treats.

Since the studies so far have focused on mice and human cells, Wu suggests further investigation is needed to understand how to achieve the metabolic benefits of cinnamaldehyde without any adverse side effects. But ultimately, the findings are promising and could lead to more effective metabolic treatments in the future.

In the meantime, cinnamon anyone?