Best Brain Foods: Greens and Beets Put to the Test

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The production in our brain of nitric oxide—the open-sesame molecule that dilates our blood vessels and is boosted by the consumption of nitrate-rich vegetables—and the role of nitric oxide in the control of nerve functioning “has been comprehensively investigated in [lab animals]. However, little evidence on [its] role” in human brain function existed…until it was put to the test.

Feed people lots of green leafy vegetables with some beet juice to boot, and then measure cerebral blood flow. See that spot there with improved flow? That’s a critical brain area known to be involved in executive functioning. Okay, but improved blood flow doesn’t necessarily translate into improved cognitive function. For example, feed people tart cherries, and “despite some indication of improved blood flow,” this didn’t appear to manifest as improved cognitive performance.

And indeed, some of the initial studies were disappointing. Give people over a cup of cooked spinach, and no immediate boost in the ability to carry out simple tasks. But, that may be because the tests weren’t hard enough. Give people a similar battery of simple tasks after consuming cocoa and no significant effect. But put people through a more demanding set of tasks, and you can see “acute improvements” in cognitive performance after cocoa consumption. The tasks they’re talking about are like counting “backwards in threes” for minutes at a time. What if you tried doing that same thing after drinking two cups of organic beet juice, which has about the same amount of nitrate as two cups of cooked arugula?

Significantly improved performance, in terms of more correct answers on the sustained subtraction task. “These results suggest that a single dose of [nitrate-rich vegetables] can modify brain function, and that this is likely to be as a result of increased [nitric oxide] synthesis.” Okay, but how do we know it’s the nitrate? Beets are packed with all sorts of phytonutrients, like the betalain red pigment. One way to tease it out would be to come up with some kind of nitrate-depleted beet juice—has all the other stuff in beets, but just missing the nitrate—to see if that works just as well, and that’s exactly what researchers did.

They developed a nitrate-depleted beetroot juice placebo. And, compared to that, within two weeks of supplementation with the real stuff, this group of diabetics got a “significant improvement in…reaction time.” Now we’re just talking 13 milliseconds here, but other interventions, like balance training, that only increased reaction time like seven milliseconds, were associated with significantly lower fall risk. And, of course, in athletes, those fractions of a second can sometimes make a difference.

“At very high exercise intensities…, cognitive task performance deteriorates, with a pronounced detrimental effect on reaction time.” And, that may be just when you need it the most. You’re like playing football or something, and need to make rapid appropriate decisions while simultaneously going all out. And, once again, beets to the rescue: significantly reducing reaction time. So, not only improving physical performance, but mental performance as well.

Yeah, but can it improve the structure of your brain? Things like cognitive training and aerobic exercise can actually affect the structure of the human brain. There’s something called neuroplasticity, where your brain can adapt, changing its configuration as you like learn to play piano or something.

We used to think only younger brains could do this, but now we know it can occur in the aging brain as well. Can’t “beet” that—or can you? We didn’t know…until now. Here’s your brain before and after a six-week exercise program, measuring connectivity between various parts of your brain that control movement. No big change.  But, what about the same amount of exercise before… and after drinking some beet juice, too? Big difference. “The exercise plus [beetroot juice] group developed brain networks that more closely resembled those of younger adults, showing the potential enhanced neuroplasticity conferred by combining exercise and [nitrate-rich vegetables].”

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• Pase MP, Scholey AB, Pipingas A, et al. Cocoa polyphenols enhance positive mood states but not cognitive performance: a randomized, placebo-controlled trial. J Psychopharmacol (Oxford). 2013;27(5):451-8.
• Scholey AB, French SJ, Morris PJ, Kennedy DO, Milne AL, Haskell CF. Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort. J Psychopharmacol (Oxford). 2010;24(10):1505-14.
• Morrison S, Colberg SR, Mariano M, Parson HK, Vinik AI. Balance training reduces falls risk in older individuals with type 2 diabetes. Diabetes Care. 2010;33(4):748-50.
• Wightman EL, Haskell-ramsay CF, Thompson KG, et al. Dietary nitrate modulates cerebral blood flow parameters and cognitive performance in humans: A double-blind, placebo-controlled, crossover investigation. Physiol Behav. 2015;149:149-58.
• Gilchrist M, Winyard PG, Fulford J, Anning C, Shore AC, Benjamin N. Dietary nitrate supplementation improves reaction time in type 2 diabetes: development and application of a novel nitrate-depleted beetroot juice placebo. Nitric Oxide. 2014;40:67-74.
• Thompson C, Wylie LJ, Fulford J, et al. Dietary nitrate improves sprint performance and cognitive function during prolonged intermittent exercise. Eur J Appl Physiol. 2015;115(9):1825-34.
• Petrie M, Rejeski WJ, Basu S, et al. Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain. J Gerontol A Biol Sci Med Sci. 2017;72(9):1284-1289.
• Stephan BCM, Harrison SL, Keage HAD, Babateen A, Robinson L, Siervo M. Cardiovascular Disease, the Nitric Oxide Pathway and Risk of Cognitive Impairment and Dementia. Curr Cardiol Rep. 2017;19(9):87.
• Presley TD, Morgan AR, Bechtold E, et al. Acute effect of a high nitrate diet on brain perfusion in older adults. Nitric Oxide. 2011;24(1):34-42.
• Keane KM, Haskell-ramsay CF, Veasey RC, Howatson G. Montmorency Tart cherries (Prunus cerasus L.) modulate vascular function acutely, in the absence of improvement in cognitive performance. Br J Nutr. 2016;116(11):1935-1944.
• Bondonno CP, Downey LA, Croft KD, et al. The acute effect of flavonoid-rich apples and nitrate-rich spinach on cognitive performance and mood in healthy men and women. Food Funct. 2014;5(5):849-58.

Image credit: vrozhko via Adobe Stock images. Image has been modified.

Motion graphics by Avocado Video.

• aging
• Alzheimer’s disease
• athletes
• beets
• brain health
• cocoa
• cognition
• diabetes
• exercise
• fruit
• greens
• memory
• nitrates
• nitric oxide
• phytonutrients
• spinach
• tart cherries
• vegetables