Effectiveness of a Grape Seed Extract on Circulatory Measures in Healthy Adults

The Effectiveness of a Grape Seed Extract on Circulatory Measures in Healthy Adults: a Randomised, Double-blind, Placebo-controlled Crossover Study

This is a randomized, double-blind, placebo-controlled, 2 arm crossover study conducted over 11 weeks, with participants randomised to a product for 4 weeks, followed by a 3-week washout period before completing the second product for 4 weeks, to study the effectiveness of a grape seed extract on circulatory measures in healthy adults.

Inclusion Criteria:

• Adults 25 years or older
• Generally healthy
• BMI 18 - 35kg/m2
• Able to provide informed consent
• Have prehypertensive blood pressure (systolic 120-139 mmHg and/or diastolic 80-89 mmHg)
• Agree to not change current diet and/or exercise frequency or intensity during entire study period
• Agree to not participate in another clinical trial while enrolled in this trial

Exclusion Criteria:

• Those with a history of myocardial infarction, angina or bleeding disorders

• Those who have uncontrolled thyroid diseases

• Currently taking dietary supplements for circulation (e.g. fatty acids, CoQ10, L-arginine, red ginseng, ginseng, natto, ginkgo) or use of these in the last 1 month

• Currently taking inflammation or circulatory associated medications (e.g. Pentoxifylline and vasodilators like nitroglycerin) or use of these in the last 1 month

• Currently taking statins medication including atorvastatin (e.g. Lipitor, Lorstat), fluvastatin (e.g. Lescol or Vastin), pravastatin (e.g. Pravachol, Cholstat), rosuvastatin (e.g. Cavstat, Crestor) or simvastatin (e,g, Lipex, Zocor, Zimstat).

• Currently taking Coumadin, Marevan (Warfarin), Heparin, Dalteparin, Enoxaparin or other anticoagulation therapy, or substrates of P-glycoprotein including (but not limited to) calcium channel blockers, cyclosporin, digoxin, erythromycin and protease inhibitors(1).

• Have a serious illness(2) e.g. mood disorders such as bipolar disorder, neurological disorders such as MS, kidney disease, liver disease or heart conditions

• Have an unstable illness(3) (i.e., changing medication/treatment)

• Malignancy or treatment for malignancy within the previous 2 years (this excludes non-melanoma (e.g. BCC and SCC) skin cancers not requiring radiation or chemotherapy)

• Active smokers, nicotine use or drug (prescription or illegal substances) abuse

• Chronic past and/or current alcohol use (>14 alcoholic drinks week)

• Allergic to any of the ingredients in active or placebo formula

• Pregnant or lactating woman or women trying to conceive

• Any condition which in the opinion of the investigator makes the participant unsuitable for inclusion

• Participated in another trial in the past 1 month

  1. Any participant that begins taking antiplatelet medication during the trial will be excluded from the study
  2. A serious illness is a condition that carries a risk of mortality, negatively impacts quality of life and daily function and/or is burdensome in symptoms and/or treatments.
  3. An unstable illness is any illness that is currently not being treated with a stable dose of medication or is fluctuating in severity.