We have long been told that we are what we eat but now a study by the International Society for Stem Cell Research in Cambridge, Massachusetts in the United States suggests a compound found in apples can actually make us smarter or, at the very least, grow brain neurons in a process called neurogenesis.
A lot has already been written about the health benefits of quercetin, found most abundantly in red apple skins, but what is different about this study is that the researchers also found a pro-neurogenic, in a non-flavanoid phenolic which improved the smarts in the lab mice.
“We also identified additional pro-neurogenic compounds in apple flesh that were not related to flavonoids. We found that 3,5-dihydroxybenzoic acid significantly increased neural precursor cell proliferation and neurogenesis. This work shows that both flavonoids and 3,5-dihydroxybenzoic acid are pro-neurogenic, not only by activating precursor cell proliferation but also by promoting cell-cycle exit, cellular survival, and neuronal differentiation,” says the study’s authors, Ichwan et al.
Highlights include that quercetin promotes neuronal precursor cell survival and differentiation; it induces endogenous antioxidant activity and the MAPK signaling pathway but that apple juice supplementation has no effect on adult neurogenesis or learning. 3,5-Dihydroxybenzoic acid increases precursor cell proliferation and neurogenesis.
The authors report that as mammals evolved with exposure to particular diets, naturally abundant compounds may have become part of the set of environmental co-determinants that shaped brain structure and function. “Here we investigated whether bioactive factors found in apples directly affect hippocampal neurogenesis in the adult mouse. We found that quercetin, the most abundant flavanol in apple peel, was anti-proliferative at high concentrations but pro-neurogenic at low concentrations. This was confirmed in vivo, with intraperitoneally delivered quercetin promoting survival and neuronal differentiation, without affecting proliferation,” say the authors.
As the largest exporter and marketer of South African apples and pears, Tru-Cape is always interested in studies which might lead people to consume more apples and pears. “The good news in this study is that in addition to reducing inflammation, compounds in apples now also appear to regenerate our brains. Who doesn’t want to be smarter?” asks Henk Griessel, a horticulturist and Tru-Cape’s Quality Manager.
