Fruits, vegetables and their 100% juices may play a role in supporting brain and cognitive health.(Lamport) The plant nutrients found in citrus, particularly the flavonoids hesperidin in oranges and naringin in grapefruit, may help maintain cell health in brain tissue. These flavonoids are able to cross the blood-brain barrier, which the body uses to protect the brain from harmful or damaging agents.  Research suggests that these flavonoids may help reduce inflammation or help maintain blood flow which could have positive effects on cognition. Positive effects on memory have been observed with the consumption of a polyphenol-rich blueberry beverage(Whyte), supporting the premise that polyphenolic compounds may play a key role in cognitive health.

A clinical study investigated whether the daily intake of flavanone-rich orange juice was beneficial to cognitive function in healthy older adults and reported that compared to the control drink, adults who consumed 100% orange juice scored better on some cognitive function tests and the benefits appeared to persist over time.(Kean)  Orange juice with orange pomace added (to increase the fiber and flavonoid content of the juice) was associated with beneficial effects on psychomotor speed, attention/executive function, and subjective alertness in healthy overweight or obese men.(Alharbi) The consumption of citrus fruit and orange juice was significantly associated with better performance on some cognitive tests in older Norwegian adults.(Nurk) Benefits to cognitive function may result from the potential ability of orange juice to support healthy blood vessels and blood flow.

References
Alharbi MH et al. Eur J Nutr. 2016;55(6):2021-2029.
Kean RJ et al. Am J Clin Nutr. 2015;101:506-514.
Lamport DJ et al. Nutr Rev. 2014;72:774-789.
Nurk E et al. Br J Nutr. 2010;104:1190-1201.
Whyte AR et al. Nutrition. 2015;31:531-534.