Blueberries, nature’s candy that enhances brains

It’s blueberry season. Nature’s candy is ripe and ready to enhance brains. You might have thought it was just a tasty fruit, or even knew it was full of antioxidants, but while you were debating to spring for the organic berries, researchers were examining what blueberry does to cognitions.

Before we get into details, it’s important to note that there are wild blueberries and ordinary blueberries. Wild blueberries are smaller and said to have a more intense blueberry taste compared to the plumper, water-engorged ordinary variety.  Wild blueberries are noted to have more antioxidants and anthocyanins (a specific antioxidant flavonoid that gives blueberries their color) than the ordinary variety. And there has been a load of research into the relationship between the roots of wild blueberries and specialized fungus that is believed to be a commensal relationship that allows the wild variety to grow in harsher environments.

Maine is a major producer of wild blueberries (they are one of the few grocery-store fruits native to North America — talk about going local).

Anyway, not all blueberries are created equal and many studies use wild blueberries or wild blueberry extracts. Minimal processing preserves the beneficial compounds; stay away from homogenized products and jams if you want to maximize the benefits of blueberries.

The blossoming field of nutritional psychology examines how the foods we eat influence our well-being. This isn’t just about the dopamine hit you get from biting into a sea-salt-sprinkled, chocolate-covered caramel. It’s about that we are what we eat both physically and mentally. In the case of blueberries, they seem to improve cognitive performance.

Granted the studies are small, but one randomized, double-blind, crossover study (meaning the researchers and test subjects didn’t know who got the blueberry drink or a lookalike placebo and then in the second half of the study the subjects got the “other” drink) looks promising.

After drinking the wild blueberry drink equivalent to eating one cup of wild blueberries, or placebo, the subject did a series of computer games that included learning, recall, recognition and response inhibition. They also had blood glucose, insulin and glucagon levels checked. As a whole, the wild blueberry drinkers performed better on the higher demand cognitive tasks than the placebo consumers.  Furthermore, the study also demonstrated the previously studied and known association between body-mass index (BMI) and cognitive function in that the higher BMI individuals do not perform as well as the lower BMI individuals.

The wild blueberry drink appears to reduce blood glucose levels when consumed with a meal compared to placebo. The blood sugar benefit of eating fruits compared to processed fruity foods of similar calorie load has been studied extensively and the take-home message is always the same — stick with your fruit the way Mother Nature packaged it.

A similar cognitive study was done in children aged 7 to 10. They found that the wild blueberry drink consumers performed significantly faster on cognitively demanding tests. Another study used functional MRI to look at the brains of people who drank a juice high in flavonoids versus a similar juice without. The flavonoid (of which blueberries are rich in) found that some parts of the brain had an acute enhancement of blood flow to the brain.

The anthocyanins (the pigment molecules) have also been shown to reduce markers of inflammation. A randomized study of 49 adults with mild to moderate dementia drank anthocyanin-rich cherry juice or placebo for 12 weeks. The cherry juice drinkers had significant improvement of short-term memory, verbal fluency and blood pressure.

Blueberries were originally called a “super fruit” due to their high concentration antioxidants. We’ve since discovered that not all antioxidants are equal, some don’t even get absorbed when we eat them. However, the anthocyanins of berries is linked with heart and brain health. It appears that fish do not have a monopoly on the claim to being brain food, and like fish, blueberries are best fresh but a lot easier to catch.

Dr. Sal Iaquinta is the author of “The Year They Tried To Kill Me.” He takes you on the Highway to Health every fourth Monday.