Drinking orange juice can boost brain function to speed your reasoning skills, with researchers noting beneficial effects in as little as eight weeks – at least in people aged 60 and over.
Oranges are a rich source of a type of antioxidant polyphenol known as flavanones, which are known to cross the blood-brain barrier to have a protective effect on brain cells. Researchers from the University of Reading tested the effects of drinking orange juice on 37 healthy, older volunteers (average age 66 years) who were asked to drink either 250ml of a high-flavanone orange juice or a low-flavanone orange juice, twice a day for eight weeks.
The ‘high’ juice was prepared by diluting 100% orange juice and provided 305mg flavanones per day, while the ‘low’ juice was made from diluted orange squash and provided just 37mg flavanones per day.
The study was designed as a double-blind, randomised, cross-over trial so, after taking one of the juices for eight weeks, volunteers had a 4 week break and then took the other juice for the next 8 weeks. The drinks were coded so no-one knew which juice they were taking. Although you might think you could tell the ‘real’ juice from the squash, the volunteers were asked at the final visit which was the ‘high’ drink, and 17 said ‘don’t know’, 16 got it right and 4 got it wrong. This was probably because the 100% orange juice was prepared from frozen which, in my experience, does give orange juice a squash-like flavour.
Orange juice improves memory
The volunteers performed a series of validated tests to assess their immediate and delayed verbal recall, letter fluency and memory, ability to spot digit-symbol substitution and more besides.
Their global cognitive function was significantly better after 8 weeks of drinking the high flavanone orange juice than when drinking the squash. The researchers therefore concluded that drinking flavanone-rich orange juice for 8 weeks was associated with cognitive benefits for healthy older adults, but interestingly, they ‘diluted’ this claim by saying the orange juice halted a general decline in performance seen after 8 weeks of consuming the squash.
I did wonder if these effects were due to the natural fruit sugars present, rather than the flavanones, but on checking found the orange juice drink provided just under 45 g total sugars per day, compared with 41g for the squash, which is unlikely to account for the difference.
The only down-side seems to be the associated weight gain from adding an additional 500ml juice or squash per day for 8 weeks each – average weight gain when drinking the squash was 337g plus another 496g when drinking the orange juice.
I will continue to eat my one orange per day (especially blood oranges when I can get hold of them) for the additional fibre they provide. Juicing your own oranges provides the highest level of antioxidant polyphenols and the highest level of vitamin C. I drink freshly-squeezed (rather than frozen) orange juice as a regular (not daily) treat and leave squash well alone. Perhaps by the time I’m 66 I’ll notice the brain-boosting memory benefits – assuming I still remember this research!
Recent memory-boosting benefits were also found from drinking cocoa.
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