Blueberries Show Promising Links to Hea, Gut, and Brain Health

Whether sprinkled on top of your yogurt, added to an afternoon salad, paired with peanut butter as a little snack, or enjoyed as a handful for dessert, blueberries are perfect at just about any time of day. And if you’re a blueberry fiend who likes them morning, noon, and night, researchers have some deliciously good news for you.

In January, researchers published the findings of a massive scientific review that synthesized decades of research from across specialties, all of which examined how wild blueberries influence cardiometabolic health. Wild blueberries differ from ordinary berries because they are smaller and pack more anthocyanin antioxidants per serving.

The review, published in the journal Critical Reviews in Food Science and Nutritionbegan as a symposium organized by the Wild Blueberry Association of North America in Bar Harbor, Maine, an appropriate place for such an event, since the state grows about 99% of the nation’s wild blueberries. While the association helped convene the event, the researchers conducted an independent review of decades of clinical data.

At the symposium, 12 specialists from fields such as nutrition and food science met and decided to collaborate on a paper evaluating 12 human clinical trials conducted over 24 years across four nations. The researchers also reviewed dozens of related clinical, translational, and mechanistic studies on wild and cultivated blueberries, all looking into the fruit’s cardiometabolic effects.

“Wild blueberries have been valued by people for thousands of years,” said Dorothy Klimis-Zacas, PhD, professor of clinical nutrition at the University of Maine and co-lead author of the study. “Traditional knowledge recognized their value, and today’s research continues to explore how the unique composition of wild blueberries may support health when eaten as part of an overall balanced diet.”

In their review, the researchers found that the strongest link to health outcomes was between blueberries and improved vascular function, specifically supporting “endothelial function,” which they explained is “how well blood vessels relax and respond to stimuli.” Some studies even observed this effect within hours of a single serving (about one cup a day).

But that’s not all. The researchers also note that thanks to the fruit’s fiber and polyphenol content, blueberries can positively affect the gut microbiome. They cited a six-week clinical study that found that adults who ate 25 grams of freeze-dried wild blueberry powder daily had an increase in Bifidobacterium, a beneficial probiotic, in their gut.

The review also found that wild blueberries can be beneficial for those with “elevated cardiometabolic risk,” as some of the studies they reviewed showed “meaningful improvements” in blood pressure and blood sugar control. And lastly, the researchers noted that wild blueberries may helpg supportcognitive performance, including improvements in thinking speed and memory, showing that wild blueberries really do earn the distinction of being a superfood.

“What makes wild blueberries remarkable is that they contain numerous polyphenols and nutrients and don’t appear to exert their health benefits through just one mechanism,” Sarah A. Johnson, PhD, associate professor at Florida State University, and lead author of the review, added. “The evidence suggests these berries may support multiple biological pathways relevant to cardiometabolic health, from blood vessel function to inflammation and oxidative stress, with effects that can vary from person to person. Recent research on the role of the gut microbiome in determining their health benefits is exciting and may help researchers determine ways to support the gut microbiome to enhance their health benefits.”