LDL-cholesterol levels were reduced by 11 percent following eight weeks of strawberry powder supplementation, according to findings of a study with 27 obese people published in Nutrition Research.
“To our knowledge, this is the first randomized controlled trial investigating the effects of strawberry supplementation on lipid profiles in subjects with metabolic syndrome,” wrote researchers from Oklahoma State University.
Metabolic syndrome (MetS), or Syndrome X, is a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type-2 diabetes and cardiovascular disease (CVD).
The researchers add a caveat, noting that the freeze-dried strawberry powder used in their study is not currently commercially available and the practical relevance of their findings requires confirmation in other interventions.
Growing the science
The study follows an earlier study by the same researchers in overweight women. Results published last year in the Nutrition Journal (2009, 8:43, doi:10.1186/1475-2891-8-43) indicated that freeze-dried strawberry powder may reduce total and LDL cholesterol levels by 5 and 6 per cent, respectively.
The earlier study was said to be the first to show such effects in women with metabolic syndrome, with the benefits linked to the polyphenol content of the berries.
The researchers recruited 27 people with an average age of 47 and an average BMI of 37.5 kg/m2. All of the participants had metabolic syndrome and were assigned to consume 4 cups of freeze-dried strawberry beverages (California Strawberry Commission) or 4 cups of water every day for eight weeks.
At the end of the study the researchers report statistically significant reductions in levels of total and LDL cholesterol of 10 and 11 percent, respectively, in the strawberry group, compared with the control group.
Furthermore, the strawberry group also experienced a decrease in levels of a compound called vascular cell adhesion molecule-1 (sVCAM-1) of 18 percent. Adhesion molecules are considered a “surrogate marker of atherosclerosis in subjects with metabolic syndrome”, and a reduction is considered beneficial.
“Our short-term feeding trial shows the hypocholesterolemic effects of strawberries in un-medicated subjects with metabolic syndrome on usual diet and lifestyle,” wrote the researchers.
“These findings warrant further investigation in larger dose-response controlled studies,” they added.
Source: Nutrition Research
Volume 30, Pages 462-469, doi: 10.1016/j.nutres.2010.06.016
“Strawberries decrease atherosclerotic markers in subjects with metabolic syndrome”
Authors: A. Basu, D.X. Fu, M. Wilkinson, B. Simmons, M. Wu, N.M. Betts, M. Du, T.J. Lyons