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For years studies have suggested that eating blueberries and other berries is good for our health (here, here, and here). Now another study suggests that eating wild blueberries benefits children's thinking, specifically attention and "executive function" (mental processes which lets people plan, organize, and complete tasks). What was nice in this study was that it was "double-blind"- which meant that biases couldn't influence the results. 

Flavonoids are a diverse group of phytonutrients (plant chemicals) found in almost all fruits and vegetables. They are powerful antioxidants with anti-inflammatory and immune system benefits. And yes, other studies have also found various benefits to mental processes with an increase of flavonoids in the diet - in both children and adults.

What foods contain flavonoids? There are 6 main classes of flavonoids, and each is found in different foods: - Anthocyanidins – found in red, purple,and blue berries, red wine, and red and purple grapes. - Flavonols - found in onions, leeks, broccoli, Brussels sprouts, kale, tea, berries, beans, and apples. - Flavones - found in parsley, celery, and hot peppers. - Isoflavones - found in soybeans, soy products, and legumes. - Flavanones - found in citrus fruit and tomatoes. - Flavanols - found in tea, red wine, grapes, apples, fava beans, and cocoa. From Medical Xpress:

Primary school children could show better attention by consuming flavonoid-rich blueberries, following a study conducted by the University of Reading. In a paper published in Food & Function, a group of 7-10 year olds who consumed a drink containing wild blueberries or a matched placebo and were tested on their speed and accuracy in completing an executive task function on a computer.The double blind trial found that the children who consumed the flavonoid-rich blueberry drink had 9% quicker reaction times on the test without any sacrifice of accuracy. In particular, the effect was more noticeable as the tests got harder.

Previous [Univ. of] Reading research has shown that consuming wild blueberries can improve mood in children and young people, simple memory recall in primary school children, and that other flavonoid rich drinks such as orange juice, can also improve memory and concentration.

Wild blueberries are grown and harvested in North America, and are smaller than regular blueberries, and are higher in flavonoids compared to regular varieties. The double-blind trial used a flavonoid-rich wild blueberry drink, with a matched placebo contained 8.9 g of fructose, 7.99 g of glucose and 4 mg of vitamin C matching the levels of nutrients found in the blueberry drink. [Original study.] 

A new study was published that supports eating lots of blueberries (or drinking blueberry juice) for health - this time better brain functioning in people aged 65 to 77 who drank concentrated blueberry juice daily for 12 weeks. The people randomly assigned to the group drinking blueberry juice daily showed improvements in cognitive function, blood flow to the brain, and activation of the brain while carrying out cognitive tests. The people received MRIs (magnetic resonance imaging), as well as various blood tests and cognitive tests.

And how much did they drink of the juice daily? Thirty ml or 1 ounce of blueberry concentrate (which provided 387 mg anthocyanins) which was diluted with tap water. Anthocyanins are anti-oxidants that belong to a class of compounds called flavonoids, and are found in high concentrations in blueberries, cherries, and plums. The blueberry concentrate amount was equivalent to about 230 grams of blueberries - about 1 1/3 cups blueberries.

What was good about the study was that to eliminate bias people were both randomly assigned to the blueberry juice group or a placebo group (they drank a synthetic fruit cordial) - and it was "double-blind" so that no one knew who was in which group. Interestingly, people who were already eating more than 5 portions of fruits daily were excluded from the study - because so many other studies have already found all sorts of brain benefits from a diet with lots of fruits and berries. But the main conclusion from this and other related research is: eating lots of berries is good for you and has health benefits. From Medical Xpress:

Blueberry concentrate improves brain function in older people

Drinking concentrated blueberry juice improves brain function in older people, according to research by the University of Exeter. In the study, healthy people aged 65-77 who drank concentrated blueberry juice every day showed improvements in cognitive function, blood flow to the brain and activation of the brain while carrying out cognitive tests. There was also evidence suggesting improvement in working memory. Blueberries are rich in flavonoids, which possess antioxidant and anti-inflammatory properties.

Of the 26 healthy adults in the study, 12 were given concentrated blueberry juice - providing the equivalent of 230 g of blueberries - once a day, while 14 received a placebo. Before and after the 12-week period, participants took a range of cognitive tests while an MRI scanner monitored their brain function and resting brain blood flow was measured. Compared to the placebo group, those who took the blueberry supplement showed significant increases in brain activity in brain areas related to the tests. The study excluded anyone who said they consumed more than five portions of fruit and vegetables per day, and all participants were told to stick to their normal diet throughout. [Original study.]

The following is a list of nutrients that some researchers (from the Institute of Food Technology) think of as especially beneficial to the brain. Other researchers may (or probably will) focus on other nutrients. I am posting it even though I generally dislike articles that talk about "superfoods" or an itemized list of foods that one should eat to the exclusion of others. Because, of course, focusing on some nutrients may leave out many just as important nutrients.

Also, medical thinking changes over time and what was once considered "unhealthy" may later be considered a wonderful food (remember when eggs, nuts, and coconuts were almost considered evil?). And vice versa (remember when margarine with partially hydrogeneated oils and trans-fats was considered healthier than butter?) And study after study says it is better to eat the foods, rather than take supplements. So keep in mind that the following nutrients are found in whole foods and in a varied diet. And when they mention a specific food such as blueberries, remember that ALL berries have benefits (though they vary), so eat a variety of berries. Same with nuts - eat a variety and not just walnuts. From Science Daily:

Eight nutrients to protect the aging brain

Brain health is the second most important component in maintaining a healthy lifestyle according to a 2014 AARP study. As people age they can experience a range of cognitive issues from decreased critical thinking to dementia and Alzheimer's disease. In the March issue of Food Technology published by the Institute of Food Technologists (IFT), contributing editor Linda Milo Ohr writes about eight nutrients that may help keep your brain in good shape.

1. Cocoa Flavanols: Cocoa flavanols have been linked to improved circulation and heart health, and preliminary research shows a possible connection to memory improvement as well. A study showed cocoa flavanols may improve the function of a specific part of the brain called the dentate gyrus, which is associated with age-related memory (Brickman, 2014). {NOTE: good sources are cocoa and dark chocolate}

2. Omega-3 Fatty Acids: Omega-3 fatty acids have long been shown to contribute to good heart health are now playing a role in cognitive health as well....Foods rich in omega-3s include salmon, flaxseed oil, and chia seeds.

3. Phosphatidylserine and Phosphatidic Acid: Two pilot studies showed that a combination of phosphatidylserine and phosphatidic acid can help benefit memory, mood, and cognitive function in the elderly (Lonza, 2014). {NOTE: good sources are fish and meat}

4. Walnuts: A diet supplemented with walnuts may have a beneficial effect in reducing the risk, delaying the onset, or slowing the progression of Alzheimer's disease in mice (Muthaiyah, 2014).

5. Citicoline: Citicoline is a natural substance found in the body's cells and helps in the development of brain tissue, which helps regulate memory and cognitive function, enhances communication between neurons, and protects neural structures from free radical damage.... {NOTE: Citocoline is synthesized in the body from choline, so see foods high in choline}

6. Choline: Choline, which is associated with liver health and women's health, also helps with the communication systems for cells within the brain and the rest of the body. Choline may also support the brain during aging and help prevent changes in brain chemistry that result in cognitive decline and failure. A major source of choline in the diet are eggs. { NOTE: Good sources of choline are eggs, meat, fish, beans, and cruciferous vegetables.}

7. Magnesium: Magnesium supplements are often recommended for those who experienced serious concussions. Magnesium-rich foods include avocado, soy beans, bananas and dark chocolate.

8. Blueberries: Blueberries are known to have antioxidant and anti-inflammatory activity because they boast a high concentration of anthocyanins, a flavonoid that enhances the health-promoting quality of foods. Moderate blueberry consumption could offer neurocognitive benefits such as increased neural signaling in the brain centers.

I bet eating fresh blueberries daily instead of blueberry powder would not only be more delicious, but also have even more health benefits. From Science Daily:

Blueberries may help reduce blood pressure and arterial stiffness

Just one cup of blueberries per day could be the key to reducing blood pressure and arterial stiffness, both of which are associated with cardiovascular disease. .... Johnson said she is interested in looking at how functional foods -- foods that have a positive impact on health beyond basic nutrition -- can prevent and reverse negative health outcomes, particularly for postmenopausal women.

Over an eight-week period, 48 postmenopausal women with pre- and stage-1 hypertension were randomly assigned to receive either 22 grams of freeze-dried blueberry powder -- the equivalent to one cup of fresh blueberries -- or 22 grams of a placebo powder. Participants, meanwhile, continued their normal diet and exercise routines.

At the end of the eight weeks, participants receiving the blueberry powder on average had a 7 mmHg (5.1 percent) decrease in systolic blood pressure, which is the top number in the blood pressure reading that measures the pressure in the arteries when the heart beats. They also saw a 5 mmHg (6.3 percent) reduction in diastolic blood pressure, or the bottom number measuring the pressure in the arteries between heartbeats.

Additionally, participants in the blueberry-treated group had an average reduction of 97 cm/second (6.5 percent) in arterial stiffness.They also found that nitric oxide, a blood biomarker known to be involved in the widening of blood vessels, increased by 68.5 percent. That is important, Johnson said, because arterial stiffness and the narrowing of blood vessels are both a part of hypertension. This rise in nitric oxide helps explain the reductions in blood pressure.

 Well, it looks like the researchers devised a nutritional supplement, which they then tested and found beneficial effects on the thinking processes of older adults - so some bias there, but still interesting. What was in the supplement they called NT-020? Extracts of blueberries, green tea, vitamin D3, and amino acids such as carnosine. Science Daily:

Nutritional supplement improves cognitive performance in older adults, study finds

Now a University of South Florida (USF) study reports that a formula of nutrients high in antioxidants and other natural components helped boost the speed at which the brains of older adults processed information.

The USF-developed nutritional supplement, containing extracts from blueberries and green tea combined with vitamin D3 and amino acids, including carnosine, was tested by the USF researchers in a clinical trial enrolling 105 healthy adults, ages 65 to 85. The two-month study evaluated the effects of the formula, called NT-020, on the cognitive performance of these older adults, who had no diagnosed memory disorders.

Those randomized to the group of 52 volunteers receiving NT-020 demonstrated improvements in cognitive processing speed, while the 53 volunteers randomized to receive a placebo did not. Reduced cognitive processing speed, which can slow thinking and learning, has been associated with advancing age, the researchers said. Blueberries, a major ingredient in the NT-020 formula, are rich in polyphenols, a type of antioxidant containing a polyphenolic, or natural phenol substructure.

In several preclinical trials, researchers gave aging laboratory rats NT-020 to see if it boosted memory and other cognitive performance by promoting the health of neurons in the aging brain. Those studies demonstrated that NT-020 promoted the growth of stem cells in the brain, produced an overall rejuvenating effect, benefited animals with simulated stroke, and led to better cognitive performance.