Effects of Freeze Dried Strawberry Powder Supplementation on Vascular Function and Blood Markers of Cardiovascular Risk

Effects of Freeze Dried Strawberry Powder Supplementation on Vascular Function and Blood Markers of Cardiovascular Risk

The purpose of this study is to evaluate the effects of freeze dried strawberry powder on LDL cholesterol, central and peripheral blood pressure, indices of arterial stiffness, and other lipid and lipoprotein concentrations. The investigators hypothesize that the bioactive compounds in freeze dried strawberry powder may elicit beneficial effects on LDL cholesterol, as well as blood pressure and arterial health.

The proposed study design is a 3-period randomized crossover dose-response study to evaluate the effect of freeze dried strawberry powder supplementation on LDL-C and vascular health. Research participants will be overweight or obese (BMI 25-39 kg/m^2) but otherwise healthy adults with moderately elevated LDL-C (>116 mg/dL or >3.0mmol/L), blood pressure <160/100 mmHg, total cholesterol below 273 mg/dL for men and below 284 mg/dL for women, and triglycerides below 350 mg/dL. Subjects will be randomly assigned to three supplementation periods: 1) low dose freeze dried strawberry powder (13 g/d); 2) high dose freeze dried strawberry powder (40 g/d); and 3) a placebo powder. Each powder will be provided for 4-6 weeks, separated by a 2-week washout period between treatment periods. Baseline and endpoint testing will include blood collection and vascular testing.

Inclusion Criteria:

1. Men and women 35-65 years of age
2. BMI ≥ 25 and ≤ 39 kg/m^2
3. LDL-C > 116 mg/dL
4. Total Cholesterol below 273 mg/dL for men and below 284 mg/dL for women
5. Triglycerides below 350 mg/d
6. Non-smokers
7. Blood pressure < 160/100 mmHg

Exclusion Criteria:

1. History of acute or chronic inflammatory conditions or heart disease, kidney disease, liver disease, autoimmune disorders, or thyroid disease (unless controlled by medication and blood results within the previous 6 months are provided)
2. History of diabetes mellitus (and/or a fasting glucose > 126 mg/dL at screening)
3. Stage II hypertension (blood pressure ≥ 160/100 mmHg)
4. Lactation, pregnancy, or desire to become pregnant during the study
5. Unwillingness to discontinue nutritional supplements, herbs, or vitamins, unless approved by investigator
6. Use of medications/supplements for elevated lipids, blood pressure, or glucose
7. Chronic use of non-steroidal anti-inflammatory or immunosuppressant medication
8. Conditions requiring the use of steroids
9. Unwillingness to refrain from blood donation prior to and during the study
10. Any medical condition or abnormal laboratory value that is judged clinically significant by an investigator
11. Allergy or sensitivity to strawberries or any ingredient in the study powders