Study: Daily serving of strawberries improves cholesterol

A new study found consuming freeze-dried strawberry powder equivalent to 1 cup of fresh strawberries daily may lower cholesterol in people who are overweight or obese (J Am Nutr Assoc. 2022;1-11). 

High cholesterol levels increase the risk of heart disease, the leading cause of death in the United States, according to the Centers for Disease Control and Prevention. More than 120 million Americans have total cholesterol levels that are considered higher than normal levels (above 200 mg/dL), according to CDC. Of that, 28 million have cholesterol levels above 240 mg/dL. 

Strawberries are a rich source of antioxidants, including anthocyanins, and vitamins such vitamins A and C. Antioxidant-rich fruits are well known for their benefits to health, including heart health. Cranberries, for example, improved vascular function in healthy men in a recent study. 

For the present study, published in the Journal of the American Nutrition Association, 40 men and women aged 35-60 who were overweight or obese and had elevated serum cholesterol were administered either a high dose (40 grams) or low dose (13 grams) of freeze-dried strawberry powder, or placebo, daily for three periods of four weeks each. Each four-week period was separated by a two-week washout period. The high dose of strawberry powder was equivalent to 3 cups of strawberries while the low dose was equivalent to 1 cup. 

The study was supported by the California Strawberry Commission, which also provided the strawberry powder.   

Results showed supplementation with the low dose of strawberry powder resulted in a 4.9% reduction in low-density lipoprotein (LDL) or “bad” cholesterol compared to the high dose, but not compared to placebo. The low dose also resulted in a 2.4% reduction in total cholesterol compared to the high dose, and a 2.8% reduction compared to the control.  

The authors were unable to explain the lack of a dose-response effect.  

“Although previous research indicates potential benefits of strawberry consumption for multiple cardiovascular disease risk factors, the optimal dose for clinical outcomes remains unclear,” researchers wrote. “Prior findings suggested that a higher dose of strawberry supplementation (i.e., 50 g/d of freeze-dried strawberry powder) would be more effective, but few head-to-head dose-response comparisons have been conducted.” 

Importantly, researchers noted the powder used for placebo was matched for fiber content in the strawberry powders and did not act as a “true placebo comparison,” which “may in part account for the lack of significant LDL-lowering compared to the control.”