New research presented at the recent Experimental Biology 2015 conference in Boston provides new reasons for consumers to choose strawberries. Two new studies focus on the benefits of eating strawberries daily to help reduce the risk of diabetes and heart disease, two chronic diseases with significant public health impact in America.
The first study, conducted at the Institute for Food Safety and Health (IFSH) at Illinois Institute of Technology, examined the effects of strawberries on insulin resistance, a major risk factor for type 2 diabetes. Previous studies suggest that eating foods with anthocyanins, one of the most powerful anti-inflammatory antioxidants, may help lower insulin resistance and the risk for type 2 diabetes. Strawberries are one of the major food sources of anthocyanins many Americans enjoy regularly.
In this study, 23 obese adults were randomly assigned to one of four groups. Each group drank a beverage containing differing amounts of freeze-dried strawberry powder. Blood was drawn on several occasions 6 hours after consuming the freeze-dried strawberry drink. Data revealed that insulin was significantly lowered in the group who drank the highest concentration of the freeze-dried strawberry beverage. Further, while researchers found no difference in oxidative stress as measured by the ORAC, a method of measuring antioxidant capacities of different foods, there was a modest but significant decrease in LDL (or “bad” cholesterol). Additionally, a marker for inflammation called IL-6 was found to be reduced in the group with the less severe insulin resistance. Scientists concluded that 3 servings of strawberries per day – about 24 strawberries – can help decrease insulin resistance and lower the risk of type 2 diabetes.
Two-thirds of Americans are obese or overweight, both which have been associated with a higher risk of heart disease. The second study, conducted at Oklahoma State University, examined the effects of strawberries on heart disease risk factors. Previous studies have shown that eating foods high in flavonoids, like strawberries, can help reduce the risks of heart disease. In this study, 60 adults drank one of four drinks with varying amounts of freeze-dried strawberries over 12 weeks. Data revealed a greater decrease in total cholesterol and LDL (or “bad” cholesterol) in those who drank the high dose verses the low dose freeze-dried strawberry drink. Further, glutathione (an anti-oxidant biomarker) levels were higher in those same individuals, and catalase activity was lower. Scientists concluded that about 3½ to 4 servings of strawberries daily – about 28 to 32 strawberries – can help lower the risk for heart disease by positively affecting antioxidant biomarkers that influence risk factors.
Park, et. al. Strawberry polyphenols and insulin resistance: a dose-response study in obese individuals with insulin resistance. Presented at Experimental Biology 2015, March 30, 2015.
Morris, et. al. Dietary strawberries increase glutathione in obese participants with above optimal serum lipids. Presented at Experimental Biology 2015, March 31, 2015.