Cinnamaldehyde is an essential oil that not only gives cinnamon its distinct flavor, but has also been shown to protect mice against obesity. Now, University of Michigan scientists led by Prof. Jun Wu have gained a better understanding of how it does so, and how it could help keep humans from getting fat, too.

Fat cells, also called adipocytes, store energy in the form of fatty acids known as lipids. While that wasn't a problem back when our early ancestors needed (and used) all the stored energy they could get, today it can cause obesity.

In the study, the researchers collected adipocytes from human volunteers of various ages, ethnicities and body mass indices. After the cells were treated with cinnamaldehyde, they started expressing increased amounts of genes and enzymes that enhance lipid metabolism. This means that the adipocytes were burning energy instead of storing it as fat, in a process called thermogenesis.

Additionally, the cinnamaldehyde caused an increase in metabolic regulatory proteins involved in thermogenesis, within the fat cells.

"Cinnamon has been part of our diets for thousands of years, and people generally enjoy it," says Wu. "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."

Wu does add that further studies are necessary, in order to determine how to reap the benefits of cinnamaldehyde while avoiding unwanted side effects.

A paper on the research was recently published in the journal Metabolism.

And cinnamon, incidentally, has also recently been shown to boost learning capabilities in mice.