A team of researchers at Birjand University of Medical Sciences in Iran recently reviewed several past studies exploring the effects of cinnamon on cognitive functions. Their analysis, outlined in Nutritional Neuroscience, highlights the potential value of cinnamon for preventing or reducing memory or learning impairments.
Nakhaee, Kooshki and their colleagues reviewed hundreds of studies stored in several online research databases, including PubMed, Scopus, Google Scholar and Web of Science. They then narrowed down their analysis to 40 of these studies, those that were most pertinent to their topic of interest.
Among these 40 studies, 33 were carried out in vivo (i.e., examining real living organisms, such as humans, rodents, or other animals). Five of them were conducted in vitro (i.e., outside of living organisms, for instance by analyzing cells or post-mortem tissue), and two were clinical studies (i.e., with medical patients).
The researchers extracted data relevant to all these studies, including their author, year of publication, compound or type of cinnamon used, the study population and sample sizes, doses of cinnamon or its bioactive components used, gender and age of participants, duration and method of consumption, and the results obtained. They then assessed the quality and reliability of the studies looking at their design, sample size, inclusion criteria, and other methodological aspects.
"In vivo studies showed that using cinnamon or its components, such as eugenol, cinnamaldehyde, and cinnamic acid, could positively alter cognitive function," Nakhaee, Kooshki and their colleagues wrote in their paper. "In vitro studies also showed that adding cinnamon or cinnamaldehyde to a cell medium can reduce tau aggregation, Amyloid β and increase cell viability."
Out of the two clinical studies analyzed by the researchers, one was conducted on adolescents and the other on pre-diabetic adults who were 60 years old or younger. The first study asked the adolescents to chew cinnamon gum, while the latter asked participants to eat 2g of cinnamon on white bread.
The study on adolescents yielded positive results, suggesting that chewing cinnamon gum improved memory function and reduced anxiety. In contrast, the clinical study on pre-diabetic adults found no significant changes in cognitive function following the consumption of cinnamon.
"Most studies reported that cinnamon might be useful for preventing and reducing cognitive function impairment," the researchers wrote in their paper. "It can be used as an adjuvant in the treatment of related diseases. However, more studies need to be done on this subject."
Overall, the systematic review paper by Nakhaee, Kooshki and their colleagues suggests that cinnamon and some of its active components could have positive effects on the functioning of the human brain, boosting memory and learning.
