Randomized controlled studies put nuts, berries, and grape juice to the test for cognitive function.
Best Brain Foods: Berries and Nuts Put to the Test
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
When you read articles like this in Alzheimer’s disease journals, about how “Eating more berries may reduce cognitive decline in the elderly,” they’re talking about observational studies like this, where “berry intake appears to delay cognitive aging by up to 2.5 years” in the Harvard Nurses’ Health Study, or the “intake of nuts” appearing to delay brain aging by two years. They’re just talking about associations. Berry-eaters and nut-eaters tend to have better brain function as they age after trying to control for a bunch of other lifestyle factors, but you don’t know if it’s cause and effect…until you put it to the test. Thankfully, we now have a growing number of interventional studies that have done just that. Randomized, controlled trials where people eat berries or nuts and you can prove it—actually show improvements in cognitive performance, raising the berry nutty idea that we may be able to forestall or reverse the effects of neurodegeneration in aging with food.
For example, this study on the “effects of walnut consumption on cognitive performance.” College students split up into groups doing two months of walnuts, followed by two months of placebo or vice versa, and then they switch. How do you make a placebo nut? They baked it in. They gave people banana bread with or without nuts; same ingredients, just one with walnuts, and those on the nuts showed a significant improvement in “inference capacity,” the ability to accurately draw conclusions from a set of facts—in other words, critical thinking. And so, on a practical level, “maybe students or young professionals in…fields that involve a great deal of critical thinking or decision-making could possibly benefit and gain a slight advantage through regular consumption of walnuts.”
Or this berry study, where they randomized folks to some crazy berry smoothie with blueberries, black currants, elderberries, lingonberries, strawberries, and…a tomato. And not only did their bad cholesterol drop about 10 points, they “performed better” on short-term memory tests. So, good for heart, good for the brain. And not just better on like pencil-and-paper tests, but real-world applications. Give people Concord grape juice versus some fake grape Kool-Aid-type placebo, and you can get improved performance on everyday tasks—like quicker response times in driving tests. Why not just give people Concord grapes instead of juice? Well, then, it’s harder to create a placebo, and, of course, the study was paid for by Welch’s.
Okay, fruit and nuts; what about vegetables? “Consumers of cruciferous vegetables, (cabbage, cauliflower, kale, collards, broccoli, and Brussels sprouts) [have been found to perform] better in several cognitive tests than non-users.” And, in terms of cognitive decline with aging, “women consuming the most green leafy vegetables” did better—effectively slowing brain aging a year or two, and not just cruciferous, but other dark green leafies like spinach; so, maybe it’s the nitrates.
As we age, our cerebral blood flow drops—the amount of blood flowing through our brain, “which may be due to an age-related decrease in the production of [nitric oxide],” the open-sesame molecule that dilates our blood vessels and is boosted by the consumption of nitrate-rich vegetables. “This reduction in blood flow to the brain [may be] a major risk factor for the impairment of cognitive function and development of neurodegenerative diseases, such as dementia.”
We know nitrate-rich vegetables like leafy greens and beets can improve physiological performance, like beet juice does for athletes. But what about cognitive performance? We’ll find out…next.
Please consider volunteering to help out on the site.
- Eating more berries may reduce cognitive decline in the elderly: flavonoid-rich blueberries and strawberries offer most benefit. Am J Alzheimers Dis Other Demen. 2012;27(5):358.
- Devore EE, Kang JH, Breteler MM, Grodstein F. Dietary intakes of berries and flavonoids in relation to cognitive decline. Ann Neurol. 2012;72(1):135-43.
- O'brien J, Okereke O, Devore E, Rosner B, Breteler M, Grodstein F. Long-term intake of nuts in relation to cognitive function in older women. J Nutr Health Aging. 2014;18(5):496-502.
- Nilsson A, Salo I, Plaza M, Björck I. Effects of a mixed berry beverage on cognitive functions and cardiometabolic risk markers; A randomized cross-over study in healthy older adults. PLoS ONE. 2017;12(11):e0188173.
- Pribis P, Shukitt-hale B. Cognition: the new frontier for nuts and berries. Am J Clin Nutr. 2014;100 Suppl 1:347S-52S.
- Pribis P, Bailey RN, Russell AA, et al. Effects of walnut consumption on cognitive performance in young adults. Br J Nutr. 2012;107(9):1393-401.
- Lamport DJ, Lawton CL, Merat N, et al. Concord grape juice, cognitive function, and driving performance: a 12-wk, placebo-controlled, randomized crossover trial in mothers of preteen children. Am J Clin Nutr. 2016;103(3):775-83.
- Miller MG, Thangthaeng N, Poulose SM, Shukitt-hale B. Role of fruits, nuts, and vegetables in maintaining cognitive health. Exp Gerontol. 2017;94:24-28.
- Nurk E, Refsum H, Drevon CA, et al. Cognitive performance among the elderly in relation to the intake of plant foods. The Hordaland Health Study. Br J Nutr. 2010;104(8):1190-201.
- Kang JH, Ascherio A, Grodstein F. Fruit and vegetable consumption and cognitive decline in aging women. Ann Neurol. 2005;57(5):713-20.
- Stanaway L, Rutherfurd-markwick K, Page R, Ali A. Performance and Health Benefits of Dietary Nitrate Supplementation in Older Adults: A Systematic Review. Nutrients. 2017;9(11)
Image credit: StockSnap via Pixabay. Image has been modified.
Motion graphics by Avocado Video.
- aging
- Alzheimer’s disease
- beets
- berries
- beverages
- blueberries
- brain health
- broccoli
- Brussels sprouts
- cabbage
- cardiovascular disease
- cauliflower
- cholesterol
- cognition
- collard greens
- cruciferous vegetables
- currants
- dementia
- fruit
- fruit juice
- grape juice
- grapes
- greens
- Harvard
- Harvard Nurses' Health Study
- heart disease
- kale
- memory
- nitrates
- nitric oxide
- nuts
- smoothies
- spinach
- strawberries
- tomatoes
- vegetables
- walnuts
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
When you read articles like this in Alzheimer’s disease journals, about how “Eating more berries may reduce cognitive decline in the elderly,” they’re talking about observational studies like this, where “berry intake appears to delay cognitive aging by up to 2.5 years” in the Harvard Nurses’ Health Study, or the “intake of nuts” appearing to delay brain aging by two years. They’re just talking about associations. Berry-eaters and nut-eaters tend to have better brain function as they age after trying to control for a bunch of other lifestyle factors, but you don’t know if it’s cause and effect…until you put it to the test. Thankfully, we now have a growing number of interventional studies that have done just that. Randomized, controlled trials where people eat berries or nuts and you can prove it—actually show improvements in cognitive performance, raising the berry nutty idea that we may be able to forestall or reverse the effects of neurodegeneration in aging with food.
For example, this study on the “effects of walnut consumption on cognitive performance.” College students split up into groups doing two months of walnuts, followed by two months of placebo or vice versa, and then they switch. How do you make a placebo nut? They baked it in. They gave people banana bread with or without nuts; same ingredients, just one with walnuts, and those on the nuts showed a significant improvement in “inference capacity,” the ability to accurately draw conclusions from a set of facts—in other words, critical thinking. And so, on a practical level, “maybe students or young professionals in…fields that involve a great deal of critical thinking or decision-making could possibly benefit and gain a slight advantage through regular consumption of walnuts.”
Or this berry study, where they randomized folks to some crazy berry smoothie with blueberries, black currants, elderberries, lingonberries, strawberries, and…a tomato. And not only did their bad cholesterol drop about 10 points, they “performed better” on short-term memory tests. So, good for heart, good for the brain. And not just better on like pencil-and-paper tests, but real-world applications. Give people Concord grape juice versus some fake grape Kool-Aid-type placebo, and you can get improved performance on everyday tasks—like quicker response times in driving tests. Why not just give people Concord grapes instead of juice? Well, then, it’s harder to create a placebo, and, of course, the study was paid for by Welch’s.
Okay, fruit and nuts; what about vegetables? “Consumers of cruciferous vegetables, (cabbage, cauliflower, kale, collards, broccoli, and Brussels sprouts) [have been found to perform] better in several cognitive tests than non-users.” And, in terms of cognitive decline with aging, “women consuming the most green leafy vegetables” did better—effectively slowing brain aging a year or two, and not just cruciferous, but other dark green leafies like spinach; so, maybe it’s the nitrates.
As we age, our cerebral blood flow drops—the amount of blood flowing through our brain, “which may be due to an age-related decrease in the production of [nitric oxide],” the open-sesame molecule that dilates our blood vessels and is boosted by the consumption of nitrate-rich vegetables. “This reduction in blood flow to the brain [may be] a major risk factor for the impairment of cognitive function and development of neurodegenerative diseases, such as dementia.”
We know nitrate-rich vegetables like leafy greens and beets can improve physiological performance, like beet juice does for athletes. But what about cognitive performance? We’ll find out…next.
Please consider volunteering to help out on the site.
- Eating more berries may reduce cognitive decline in the elderly: flavonoid-rich blueberries and strawberries offer most benefit. Am J Alzheimers Dis Other Demen. 2012;27(5):358.
- Devore EE, Kang JH, Breteler MM, Grodstein F. Dietary intakes of berries and flavonoids in relation to cognitive decline. Ann Neurol. 2012;72(1):135-43.
- O'brien J, Okereke O, Devore E, Rosner B, Breteler M, Grodstein F. Long-term intake of nuts in relation to cognitive function in older women. J Nutr Health Aging. 2014;18(5):496-502.
- Nilsson A, Salo I, Plaza M, Björck I. Effects of a mixed berry beverage on cognitive functions and cardiometabolic risk markers; A randomized cross-over study in healthy older adults. PLoS ONE. 2017;12(11):e0188173.
- Pribis P, Shukitt-hale B. Cognition: the new frontier for nuts and berries. Am J Clin Nutr. 2014;100 Suppl 1:347S-52S.
- Pribis P, Bailey RN, Russell AA, et al. Effects of walnut consumption on cognitive performance in young adults. Br J Nutr. 2012;107(9):1393-401.
- Lamport DJ, Lawton CL, Merat N, et al. Concord grape juice, cognitive function, and driving performance: a 12-wk, placebo-controlled, randomized crossover trial in mothers of preteen children. Am J Clin Nutr. 2016;103(3):775-83.
- Miller MG, Thangthaeng N, Poulose SM, Shukitt-hale B. Role of fruits, nuts, and vegetables in maintaining cognitive health. Exp Gerontol. 2017;94:24-28.
- Nurk E, Refsum H, Drevon CA, et al. Cognitive performance among the elderly in relation to the intake of plant foods. The Hordaland Health Study. Br J Nutr. 2010;104(8):1190-201.
- Kang JH, Ascherio A, Grodstein F. Fruit and vegetable consumption and cognitive decline in aging women. Ann Neurol. 2005;57(5):713-20.
- Stanaway L, Rutherfurd-markwick K, Page R, Ali A. Performance and Health Benefits of Dietary Nitrate Supplementation in Older Adults: A Systematic Review. Nutrients. 2017;9(11)
Image credit: StockSnap via Pixabay. Image has been modified.
Motion graphics by Avocado Video.
- aging
- Alzheimer’s disease
- beets
- berries
- beverages
- blueberries
- brain health
- broccoli
- Brussels sprouts
- cabbage
- cardiovascular disease
- cauliflower
- cholesterol
- cognition
- collard greens
- cruciferous vegetables
- currants
- dementia
- fruit
- fruit juice
- grape juice
- grapes
- greens
- Harvard
- Harvard Nurses' Health Study
- heart disease
- kale
- memory
- nitrates
- nitric oxide
- nuts
- smoothies
- spinach
- strawberries
- tomatoes
- vegetables
- walnuts
Republishing "Best Brain Foods: Berries and Nuts Put to the Test"
You may republish this material online or in print under our Creative Commons licence. You must attribute the article to NutritionFacts.org with a link back to our website in your republication.
If any changes are made to the original text or video, you must indicate, reasonably, what has changed about the article or video.
You may not use our material for commercial purposes.
You may not apply legal terms or technological measures that restrict others from doing anything permitted here.
If you have any questions, please Contact Us
Best Brain Foods: Berries and Nuts Put to the Test
LicenseCreative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Content URLDoctor's Note
Stay tuned for the next video Best Brain Foods: Greens & Beets Put to the Test
What else can nuts do?
- Four Nuts Once a Month
- Which Nut Fights Cancer Better?
- Walnuts & Artery Function
- Nuts May Help Prevent Death
- Pistachio Nuts for Erectile Dysfunction
- Nuts & Obesity: The Weight of Evidence
- PREDIMED: Does Eating Nuts Prevent Strokes?
- Do the Health Benefits of Peanut Butter Include Longevity?
-
Are the Health Benefits of Nuts Limited to Those Eating Bad Diets?
What else can berries do?
- Can Cranberry Juice Treat Bladder Infections?
- Reducing Muscle Soreness with Berries
- Boosting Natural Killer Cell Activity
- How to Slow Brain Aging by Two Years
- Inhibiting Platelet Aggregation with Berries
- How Much Fruit Is Too Much?
- The Effects of Avocados & Red Wine on Meal-Induced Inflammation
- The Benefits of Açai vs. Blueberries for Artery Function
- The Antioxidant Effects of Açai vs. Apples
- Benefits of Blueberries for Artery Function
- Benefits of Blueberries for Blood Pressure May Be Blocked by Yogurt
For all our videos on the latest research on berries, visit our Berries topic page.
If you haven’t yet, you can subscribe to my videos for free by clicking here. Read our important information about translations here.