Dietary strawberries significantly improve cardiometabolic risks, mainly via improving insulin resistance and lipid particles, and improve vascular health, according to two separate studies led by University of Nevada and Illinois Institute of Technology researchers, respectively.
Daily consumption of strawberries at a dose of two-and-a-half cups per day significantly improved insulin resistance and moderately improved high-density lipoprotein particle size. Image credit: Roberto Barresi.
Historically, fruits and vegetables, as plant-based food groups, have been promoted for various health benefits, especially in the context of reducing risks of adiposity, type 2 diabetes, cancer, and cardiovascular disease.
Several components in fruits and vegetables are identified for their physiological effects in reducing risks of chronic diseases among which the phytochemicals deserve special attention.
The benefits of commonly consumed whole berry fruits, especially blueberries and strawberries, have been emphasized for their distinct effects in improving metabolic syndrome, a constellation of diabetes and cardiovascular disease risks.
These improvements are ascribed mainly via mediating weight loss and reducing blood pressure at recommended levels of intakes.
Most of the health benefits of berry fruits, especially blueberries, cranberries, and strawberries, have been explained by their high polyphenol and fiber content, and concomitant low caloric contributions to the diet.
Despite this scientific evidence on why whole fruits and vegetables must be essential food groups in the daily diet, U.S. adults have continued low intake of fruits and vegetables associated with increased risk of type 2 diabetes and cardiovascular disease.
“To address the ‘fruit gap,’ we need to increase the amount of total fruit consumed as well as the diversity of fruit in the diet,” said Illinois Institute of Technology’s Professor Britt Burton-Freeman.
“Accumulating evidence in cardiometabolic health suggests that as little as one cup of strawberries per day may show beneficial effects.”
The study led by Professor Burton-Freeman involved 34 adult men and women with moderate hypercholesterolemia.
The participants drank study beverages twice daily containing freeze-dried strawberry powder (2 x 25 g) or energy-, volume-matched control powder for 4 weeks separated by a 4-week washout.
According to the authors, vascular function, as indicated by flow-mediated dilation, improved one hour after strawberry intake.
“The effect may be related to changes in microbial-derived phenolic metabolites after strawberry consumption influencing endothelial function,” they said.
The second study, led by University of Nevada researcher Arpita Basu, involved 33 obese adults.
The participants were assigned to one of the three arms for four weeks separated by a one-week washout period: control powder, one serving (low dose: 13 g strawberry powder/day), or two-and-a -half servings (high dose: 32 g strawberry powder/day).
They were instructed to follow their usual diet and lifestyle while refraining from consuming other berries and related products throughout the study interval.
Daily consumption of strawberries at a dose of two-and-a-half cups per day significantly improved insulin resistance and moderately improved high-density lipoprotein particle size in comparison to the control group.
“Our study supports the hypothesis that strawberry consumption can improve cardiometabolic risks,” Dr. Basu said.
“Furthermore, we believe this evidence supports the role of strawberries in a ‘food as medicine’ approach for the prevention of type 2 diabetes and cardiovascular disease in adults.”
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Leailin Huang et al. 2021. Strawberry Consumption, Cardiometabolic Risk Factors, and Vascular Function: A Randomized Controlled Trial in Adults with Moderate Hypercholesterolemia. Journal of Nutrition 151 (6): 1517-1526; doi: 10.1093/jn/nxab034
Arpita Basu et al. 2021. Dietary Strawberries Improve Cardiometabolic Risks in Adults with Obesity and Elevated Serum LDL Cholesterol in a Randomized Controlled Crossover Trial. Nutrients 13 (5): 1421; doi: 10.3390/nu13051421
