A new scientific review summarizes the growing body of research on wild blueberries and cardiometabolic health, which includes factors like 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 developed from an expert symposium hosted by the Wild Blueberry Association of North America (WBANA) in Bar Harbor, Maine.
Twelve experts participated in the symposium from the fields of nutrition, food science, dietetics, nutrition metabolism and physiology, cardiovascular and cognitive function and health, gut health and microbiology, and preclinical and clinical models. Financial support was provided in the form of travel reimbursement to the symposium, but no funding was received to support the development of this manuscript.
The paper summarizes 12 human clinical trials on the cardiometabolic effects of wild blueberries spanning 24 years and four countries, as well as dozens of other clinical, translational, and mechanistic studies on wild blueberries, cultivated blueberries, and cardiometabolic outcomes.
The authors report that findings are most consistent for vascular function, while results for blood pressure, blood lipids and glycemic control are promising but underscore the need for larger, well-controlled clinical research studies.
The paper also explores related health outcomes impacted by overall cardiometabolic wellness, such as gut health and cognitive function.
A deeper look at the findings
Improved blood vessel function: Across the clinical literature, improvements in blood vessel function are one of the most consistent findings. Trials included in the review suggest wild blueberries can help support endothelial function (or how well blood vessels relax and respond to stimuli), sometimes within hours after a single serving and in other cases with regular intake over weeks or months.
Beneficial changes to the gut microbiome:
The authors of the review explain that wild blueberries provide fiber and polyphenols that reach the colon (only about ~5–10% of these compounds are metabolized/absorbed in the small intestine) and are transformed by gut microbes into metabolites that can be absorbed into blood circulation.
Microbial metabolites may also account for up to 40% of the active compounds in blood after eating polyphenol-rich foods like wild blueberries.
In a six-week clinical study, adults who consumed 25 grams of freeze-dried wild blueberry powder daily increased beneficial
Bifidobacterium species.
The review highlights the gut microbiome as a likely contributor to the berries’ cardiometabolic effects, but more research is needed to better understand their role.
Cognitive performance
Sharper thinking and memory: The review summarizes clinical intervention studies in older adults showing wild blueberry intake may support aspects of cognitive performance, possibly due to benefits on whole body circulation among other cardiometabolic improvements, including thinking speed and memory, in both single-serving and longer interventions.
Clinically relevant improvements to blood pressure, lipids and glycemic control: For people with elevated cardiometabolic risk, several studies in the review show clinical improvements in blood pressure, glycemic control, and lipid markers such as total cholesterol, LDL cholesterol and triglycerides following weeks of wild blueberry intake.
The researchers note that baseline health status, medications, background diet, and differences in metabolism and the gut microbiome may influence outcomes. The authors encourage more research designed to identify “responders,” clarify optimal dosing and food forms, and evaluate a broader set of biomarkers.