A new research study published in the American Journal of Clinical Nutrition found that participants with metabolic syndrome who consumed the equivalent of one cup of fresh blueberries per day, given as 26g of freeze-dried blueberries, showed positive changes in measures of heart health.
Specifically, the study participants who ate one cup of blueberries per day significantly increased their “good cholesterol” levels. They also improved their endothelial function and reduced arterial stiffness – both of which are associated with a reduced risk of heart attack and stroke.
Over six months of study, participants with metabolic syndrome were randomly assigned to receive one of three daily treatments: 26g freeze-dried blueberries per day, 13g freeze-dried blueberries per day, or a placebo powder with the same color, taste, and consistency as freeze-dried blueberries.
All study participants were instructed to limit the intake of other anthocyanin containing foods to ensure benefits were from the blueberries. Anthocyanins are heart-healthy constituents that give blueberries their blue-purple color. Anthocyanins are also found in fruits and vegetables such as black grapes, raisins, blackberries, plums, purple cabbage, eggplant, purple cauliflower, and purple potatoes. Participants also refrained from blueberry intake beyond the assigned daily treatments.
Metabolic syndrome is a group of risk factors that includes low levels of HDL-C, or “good cholesterol,” high blood pressure, increased abdominal obesity, high triglyceride levels, and elevated fasting glucose levels.