Nestlé Research Center and EPFL uncover the medicinal power of spices

In addition to making food taste better, spices are also used in several traditional medicines to improve health and prevent physical and mental illness. Yet, our understanding of the mechanisms underlying these benefits is limited, and evidence for the medicinal effects of spices has been anecdotal. In two groundbreaking studies, scientists from the Nestlé Research Center (NRC) and from the Laboratory of Neural Microcircuitry (Brain Mind Institute, EPFL Dept/School of Life Sciences) show that some active ingredients in spices such as cinnamon and mint could fight against conditions like obesity, diabetes, and even epilepsy. The two studies are published in Scientific Reports.

It is known that the burning sensations from chili peppers and the cooling notes from mint follow the activation of Transient Receptor Potential Channels (TRP channels) in free nerve endings on skin and tongue. The joint projects, led by Johannes le Coutre (NRC) and Henry Markram (EPFL Brain Mind Institute), aimed to find TRP channels in other organs of the body such as the gut and the brain, and also to investigate the effects of certain spices on the brain and on general metabolism.

The researchers consecutively identified several TRP channels in both the brain and the stomach. Surprisingly in the brain, they found that active ingredients from nutmeg (eugenol), chili (capsaicin) and mint (menthol) are able to decrease some neuronal signals in the brain that are associated with epileptic seizures but through a non TRP related mechanism. These findings suggest that some spices could play a beneficial role in the treatment of epilepsy and neurodegenerative diseases such as Alzheimer’s disease or Huntington’s disease, to name a few.

In cells of the stomach and the gastrointestinal tract in general, the researchers discovered a TRP channel receptor that responds to cinnamaldehyde, the ingredient that gives cinnamon its flavor and odor. Interestingly, the cells with this receptor on their surface also produce the hormone ghrelin, which stimulates our perception of hunger. The researchers found that just a single dose of cinnamaldehyde can reduce ghrelin secretion and, as a result, slow down gastric emptying and overall food intake. In addition, a daily dose of cinnamaldehyde can significantly reduce hyperglycemia and weight gain. Consequently, the TRPA1 pathway can potentially improve cellular metabolism, insulin sensitivity, and even reduce fat mass.

“We are only now beginning to fully understand the health benefits of spices and the science behind their advantageous properties,” says Johannes le Coutre. “This collaborative research opens new and exciting avenues to explore in order to fully exploit the true potential of spices.”

References

Camacho S, Michlig S, de Senarclens-Bezençon C, Meylan J, Meystre J, Pezzoli M, Markram H, le Coutre J. Anti-obesity and anti-hyperglycemic effects of cinnamaldehyde via altered ghrelin secretion and functional impact on food intake and gastric emptying. Sci. Rep. 5, 7919; DOI:10.1038/srep07919 (2015).

Pezzoli M, Elhamdani A, Camacho S, Meystre J, Michlig González S, le Coutre J, Markram H. Dampened neural activity and abolition of epileptic-like activity in cortical slices by active ingredients of spices.Sci. Rep. 4, 6825; DOI:10.1038/srep06825 (2014).

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