Flashback Friday: Benefits of Blueberries for the Brain

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 search the medical literature for studies on berries, papers like this pop up: A “‘Blueberry Muffin’ Rash”, ahh… Or, pictures of “strawberry tongue[s],” or as a way to describe “stool appearance,” though “stools truly resembling currant jelly” are not very common. What is it with pathologists’ love affair with food terminology? —the grossest of which may be the way amoeba chest infections are described, where you spit up pus that looks like “anchovy sauce,” which sounds gross—even without the pus.

There are actual studies on berry supplementation, like on how they can mitigate the negative effects of a “high [saturated-] fat diet on the brain and behavior,” but that was in mice. Maybe a better way to mitigate would be to not feed your pet mouse a stick of butter in the first place.

Then, there are studies of proprietary berry-based nutraceutical supplements, purported to improve cognitive performance. See how there’s a steeper rise in the supplement group?

Old hats will instantly recognize this as the timeless trick featured in the 1950s classic, How to Lie with Statistics. See how they don’t start the Y axis at zero? That’s to inflate the appearance. Correct the graph, and you can see the effect doesn’t look quite so impressive.

There are studies of actual berries on actual humans, but when they’re funded by berry industry trade groups, you get studies like this: “An afternoon snack of berries reduces subsequent energy intake.” Great! But that’s compared to candy. Strawberries, raspberries, blackberries, blueberries—fantastic, compared, to a handful of “Jelly Babies,” which are just like coated gummy bears. Do berries offer so little that you have to compare them to candy to make them look good?

There was that famous Harvard study I did a video about, where berry-eating appeared to delay brain aging by up to two-and-a-half years. But, you don’t know if it’s cause and effect until you put it to the test. And, “[b]lueberry supplementation [was able to] improve…memory in older adults” in just 12 weeks’ time. But, that was feeding them up to six cups of wild blueberries a day. Now, this was a proof-of-concept pilot study just to see if they could get any effect. We just didn’t have any studies using more realistic doses…until, now.

How about just a cup a day of blueberries? They found that “the addition of easily achievable quantities of blueberries to the diets of older adults can improve some aspects of cognition,” like long-term memory. In terms of the number of errors, the placebo group got worse; the blueberry group got better.

You can even correlate the cognitive improvements with enhanced brain activation using fancy brain scan technology to actually visualize the improved blood flow to those same regions of the brain caused by the blueberry consumption.

Does it work in kids, too? “[B]lueberry treatments have shown positive effects on cognition in both” rats and adult humans. But, do those these “benefits transfer to children”—human children? How about a randomized, double-blind placebo-controlled study comparing about one cup of blueberries, to two cups, to zero cups. What did they find? “[C]ognitive performance improve[ments] across all measures,” and the more berries, the better. And, this wasn’t after twelve weeks of eating berries, but within hours of just a single blueberry meal. Sounds like a good breakfast any day our kids are having their exams.

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• Darby JB, Valentine G, Hillier K, et al. A 3-Week-Old With an Isolated "Blueberry Muffin" Rash. Pediatrics. 2017;140(1).
• Kole A, Chandakole D. IMAGES IN CLINICAL MEDICINE. Strawberry Tongue. N Engl J Med. 2015;373(5):467.
• Yamamoto LG, Morita SY, Boychuk RB, et al. Stool appearance in intussusception: assessing the value of the term "currant jelly". Am J Emerg Med. 1997;15(3):293-8.
• Shamsuzzaman SM, Hashiguchi Y. Thoracic amebiasis. Clin Chest Med. 2002;23(2):479-92.
• James LJ, Funnell MP, Milner S. An afternoon snack of berries reduces subsequent energy intake compared to an isoenergetic confectionary snack. Appetite. 2015;95:132-7.
• Carey AN, Galli RL. Mitigating the effects of high fat diet on the brain and behavior with berry supplementation. Food Funct. 2017;8(11):3869-3878.
• Small BJ, Rawson KS, Martin C, et al. Nutraceutical intervention improves older adults' cognitive functioning. Rejuvenation Res. 2014;17(1):27-32.
• Krikorian R, Shidler MD, Nash TA, et al. Blueberry supplementation improves memory in older adults. J Agric Food Chem. 2010;58(7):3996-4000.
• 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.
• Bowtell JL, Aboo-bakkar Z, Conway ME, Adlam AR, Fulford J. Enhanced task-related brain activation and resting perfusion in healthy older adults after chronic blueberry supplementation. Appl Physiol Nutr Metab. 2017;42(7):773-779.
• Whyte AR, Schafer G, Williams CM. Cognitive effects following acute wild blueberry supplementation in 7- to 10-year-old children. Eur J Nutr. 2016;55(6):2151-62.
• Miller MG, Hamilton DA, Joseph JA, Shukitt-hale B. Dietary blueberry improves cognition among older adults in a randomized, double-blind, placebo-controlled trial. Eur J Nutr. 2017.
• Huff D. How to lie with statistics. New York, NY: W. W. Norton & Company; 1954.

Image credit: Joanna Kosinska via Unsplash. Image has been modified.

Motion graphics by Avocado Video.