A newly published scientific review brings together a growing body of research on how wild blueberries may influence cardiometabolic health. This area of health includes measures such as blood vessel function, blood pressure, blood lipids (cholesterol and triglycerides), and blood sugar (glucose).

The review was published in Critical Reviews in Food Science and Nutrition and was developed following an expert symposium hosted by the Wild Blueberry Association of North America (WBANA) in Bar Harbor, Maine.1 Twelve specialists took part, representing fields that included nutrition, food science, dietetics, nutrition metabolism and physiology, cardiovascular and cognitive health, gut health and microbiology, and preclinical and clinical research models. While travel to the symposium was reimbursed, no funding was provided for writing or producing the manuscript.

Decades of studies reviewed

The paper evaluates findings from 12 human clinical trials conducted over 24 years across four countries that examined the cardiometabolic effects of wild blueberries. In addition, the authors reviewed dozens of other clinical, translational, and mechanistic studies involving wild blueberries, cultivated blueberries, and a range of cardiometabolic outcomes.

According to the authors, results are most consistent when it comes to vascular function. Evidence related to blood pressure, blood lipids, and blood sugar control is described as promising, but the review emphasizes the need for larger, well-controlled clinical studies to confirm and refine these findings.

The review also looks beyond traditional cardiometabolic markers to consider related outcomes influenced by overall cardiometabolic health, including gut health and cognitive function.

Strong evidence for improved blood vessel function

Across the clinical research examined, improvements in blood vessel function stand out as one of the most reliable findings. Studies included in the review suggest that wild blueberries may support endothelial function (or how well blood vessels relax and respond to stimuli). Some trials reported effects within hours of a single serving, while others observed benefits after consistent intake over weeks or months.

Gut microbiome changes linked to blueberry intake

The authors explain that wild blueberries contain fiber and polyphenols that largely reach the colon intact (only about ~5–10% of these compounds are metabolized/absorbed in the small intestine). Once in the colon, gut microbes convert these compounds into metabolites that can be absorbed into the bloodstream. These microbial metabolites may account for up to 40% of the active compounds detected in blood after consuming polyphenol-rich foods like wild blueberries.

In one six-week clinical study highlighted in the review, adults who consumed 25 grams of freeze-dried wild blueberry powder each day showed increases in beneficial Bifidobacterium species. The authors identify the gut microbiome as a likely contributor to the cardiometabolic effects linked to wild blueberries, while noting that more research is needed to better define its role.

Cognitive performance and brain health

The review also summarizes intervention studies conducted in older adults that suggest wild blueberry intake may support certain aspects of cognitive performance. Improvements were observed in measures such as thinking speed and memory. These effects may be related to improvements in whole-body circulation and other cardiometabolic factors, and were seen in both single-serving and longer-term interventions.

Effects on blood pressure, cholesterol, and blood sugar

Among people with elevated cardiometabolic risk, several of the reviewed studies reported clinically meaningful improvements in blood pressure, blood sugar regulation, and lipid markers, including total cholesterol, LDL cholesterol, and triglycerides, after weeks of wild blueberry consumption.

The researchers note that outcomes may vary depending on baseline health, medication use, overall diet, and individual differences in metabolism and the gut microbiome. They call for future studies designed to identify “responders,” determine optimal doses and food forms, and examine a broader range of biomarkers.

Multiple biological pathways may be involved

“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,” explains Sarah A. Johnson, PhD, RDN, Associate Professor at Florida State University, registered dietitian nutritionist, and lead author of the review. “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.”

The review outlines several pathways that may help explain these effects, including nitric oxide signaling that supports healthy circulation, inflammation and oxidative stress processes, lipid and glucose metabolism, and interactions with the gut microbiome.

How much wild blueberry intake was studied

Across the studies reviewed, wild blueberries were tested in several different forms. Health benefits were observed with regular consumption over weeks or months using practical serving sizes. In everyday terms, this means aiming to eat about one cup of wild blueberries per day.

Because most wild blueberries are sold frozen, they are easy to store and use throughout the year. They can be added to smoothies, oatmeal, yogurt, salads, or baked goods.

Why wild blueberries stand apart

Wild blueberries, also known as lowbush blueberries, grow in Maine and Eastern Canada under challenging environmental conditions such as harsh winters. These stresses may prompt the plants to produce a wide range of protective compounds, including polyphenols such as anthocyanins. Wild blueberries contain around 30 distinct anthocyanin forms.

“Wild blueberries have been valued by people for thousands of years,” notes Dorothy Klimis Zacas, PhD, FACN, Professor of Clinical Nutrition at the University of Maine and co-lead author on 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.”