Cardiovascular disease is the number one cause of death in the United States, and is positively correlated with obesity and metabolic syndrome (1). Metabolic syndrome is cluster of conditions that increase the risk for coronary heart disease. These risk factors include large waist circumference, high blood pressure, high triglycerides with low highdensity lipoprotein (HDL, also known as “good” cholesterol) levels, and insulin resistance. It is estimated that over 50 million Americans have this syndrome, thus there is a pressing need to identify dietary recommendations to prevent, or reverse these conditions. Incorporating foods with polyphenolic flavonoids, such as strawberries, has been associated with decreased risks for cardiovascular disease.
In a randomised controlled study, the effects of freeze-dried strawberries on cardiovascular disease risk factors were studied (2). Specifically, the study hoped to capture the effect the freeze-dried strawberry beverage has on clinical features of metabolic syndrome associated with atherosclerotic cardiovascular disease. The clinical features of metabolic syndrome assessed in the study included waist circumference, systolic and diastolic blood pressure, and blood levels of glucose, lipoproteins, and adhesion molecules.
Subjects with metabolic syndrome (n=27) either consumed 4 cups of freeze-dried strawberry beverage (containing 50g of freeze-dried strawberries, the equivalent of 3 cups of fresh strawberries), or 4 cups of water daily for 8 weeks. The results showed the people who consumed the strawberry beverage had significantly decreased total and lowdensity lipoprotein (LDL) cholesterol, and decreased levels of vascular cell adhesion molecules in their blood relative to the control group. This is of functional significance since high levels of LDL cholesterol and vascular cell adhesion molecules are positively correlated with cardiovascular disease. However, the supplementation of the strawberry beverage did not affect other clinical features of metabolic syndrome, such as large waist circumference, high blood pressure, impaired fasting glucose, high levels of triglycerides in the blood, and low levels of high-density lipoproteins in the blood. It’s important to note that including freeze-dried strawberries in people’s diets may not be practical, as they are unavailable commercially. However, this study provides evidence that including strawberries in the diets of people with metabolic syndrome and/or cardiovascular disease could be helpful in relieving some risk factors of atherosclerosis.
February is American Heart Month, 2010, Center for Disease Control and Prevention; 2010; http://www.cdc.gov/features/heartmonth/
Basu A, Fu DX, Wilkinson M, et al. Strawberries decrease atherosclerotic markers in subjects with metabolic syndrome. Nutr Res J; Jun. 29, 2010; 30(7): 462-469. Deborah Fetter, Department of Nutrition, University of California, Davis.