Can daily blueberry consumption actually improve your brain health?
A new study finds that daily blueberry consumption may help improve your cognitive abilities. But the researchers left one important question unanswered.
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Hello and welcome to the Nutrition Diva podcast. I’m your host Monica Reinagel and today I want to talk about a new research study suggesting that eating more blueberries could help you hang on to the old gray matter as you age.
There is a limited amount of prior research—some rodent studies and one very small human trial—suggesting that blueberry juice or extracts could help improve memory and prevent cognitive decline in elderly subjects.
The 30 or so subjects in this study were all between 50 and 65 years old and were at increased risk of experiencing dementia later in life. They did a battery of cognitive tests on them and then divided them into two groups. One group consumed a daily packet of powdered blueberries, equivalent to eating about ½ cup of blueberries every day.
The other group got a placebo powder that had the same color and flavor but did not contain the anthocyanins that are thought to be responsible for the positive health effects of blueberries.
Although taking blueberry powder doesn’t seem nearly as pleasant as actually eating fresh blueberries, it would have been nearly impossible to provide anthocyanin-free blueberries as a control–and perhaps that’s why they went with a powder instead of whole fruit.
The study ran for 12 weeks, at which point they repeated all of the cognitive tests and they found that those who consumed the blueberry powder performed better on some tasks than those who got the placebo. The conclusion was that “ongoing blueberry supplementation may contribute to protection against cognitive decline when implemented early in at-risk individuals.”
The study was funded by the US Highbush Blueberry Council, which also provided blueberry products that were used in the study. However, the researchers have no connection to or financial interest in the blueberry industry and certify that the funding organization had no role in the design of the study, the interpretation of data, or the writing of the manuscript. And all the studies published in this journal go through a rigorous peer-review process.
So I have no reason to question that the study was properly conducted and reported and that these results are legit. But it does make me wonder if blueberries provide a unique benefit for brain health or whether anthocyanins from any source would be just as effective.
Anthocyanins are found in all the different types of berries, as well as red cabbage, plums, onions, black and red rice, eggplant, grapes, and, famously, red wine. And these plant-based antioxidants have been linked with a wide range of health benefits—everything from improved lung and brain function to reduced risk of heart disease and cancer.
If they’d wanted to test whether there was something special about blueberries above and beyond their anthocyanin content, they could have had some of the people in the study take a placebo, others take blueberry powder, and still others take a powdered supplement made from another anthocyanin-rich fruit.
But the funders (blueberry growers) were obviously not as interested in asking (or answering) that question. In that way, this study reminds me of some of the research funded by cherry growers. Those studies found that people who consumed tart cherry juice or concentrate on a daily basis had reduced inflammation. Again, this was thought to be due to the anthocyanin content of the cherries. But, as with the blueberry study, virtually all of the cherry studies compared the cherry juice or concentrate to an inactive placebo. They didn’t compare cherry juice to other fruit and vegetable juices.
And I had the same question about that research, namely: Would another anthocyanin-rich food have worked just as well?
Commodity groups often invest a lot of money into scientific research on their particular crop’s health benefits. And while that research is scientifically valid and does advance our understanding of the ways in which foods and nutrients interact with the body, it also has the effect of suggesting to consumers that a given food offers superior protection against a certain condition or specific protection for a certain organ.
And I suspect that’s not a completely unintended effect.
I can almost imagine a smoke-filled back room where the fruit barons divided up their fiefdoms. “OK, cherries, you guys get joints. Grapes, you get heart health. Blueberries, we’re going to give you the brain.”
The average American takes in about 12 mg of anthocyanins per day—and that low number is due in part to the fact that only 1 in 10 Americans gets the recommended amount of fruits and vegetables. I bet we would be healthier if our anthocyanin intake were higher—because this would mean we were eating more produce. But eating a variety of fruits and vegetables, rather than eating the same “superfruit” every day, is going to give you a much wider array of nutrients, phytochemicals… and health benefits. It’s also a lot more interesting.
So, if you needed an excuse to eat more blueberries, you’ve got it. They’re good for your brain. Or, to be more accurate, the anthocyanins they contain appear to be good for your brain. So, if you can’t find blueberries (or you get tired of blueberries), keep in mind that there are lots of other sources of anthocyanins you can enjoy instead.
I’d also much prefer that you get your anthocyanins from whole foods rather than a pill, powder, or even a juice. Whole fruits and vegetables are much more filling, in part because of the fiber but also due to the physical action of chewing them and the time it takes to consume them. In my experience, when people start eating more whole fruits and vegetables, they tend to have less room on their plates and in their stomachs for junk food and empty calories. And when it comes to the health of your heart, brain, joints, and everything else, reducing your intake of unhealthy foods can be just as important as increasing your intake of healthy ones.
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