Dose Response Bioavailability of Coffee and Green Tea Antioxidants in Humans

Dose Response Bioavailability of Coffee and Green Tea Antioxidants in Humans

Coffee and green tea are 2 widely consumed beverages. Both contain polyphenol antioxidant compounds (chlorogenic acids for coffee and catechins for tea). The bioavailability of catechins is somewhat known and has been referenced in the literature. However, bioavailability data from tea infusion is non-existent, even though it reflects better how consumers drink this beverage. In addition, bioavailability of coffee chlorogenic acids is less understood and no dose response study has been reported so far in the literature. Thus, there is a great need to understand and reinforce our knowledge on the bioavailability of coffee and tea polyphenol compounds.

Inclusion Criteria:

• 18 - 65 years, male and female
• Healthy as determined by the medical questionnaire and the medical visit
• Normal weight: BMI 18 - 25
• Coffee drinkers with an average consumption of 2-5 cups per day
• Having given informed consent

Exclusion Criteria:

• Intestinal or metabolic diseases / disorders such as diabetic, renal, hepatic, hypertension, pancreatic or ulcer
• Have had a gastrointestinal surgery, except appendicectomy
• Difficulty to swallow
• Have a regular consumption of medication
• Have taken antibiotic therapy within the last 6 months
• Alcohol consumption > 2 units a day
• Smokers (more than 5 cigarettes per day)
• Have given blood within the last 3 weeks
• Volunteers who cannot be expected to comply with treatment
• Currently participating or having participated in another clinical trial during the last 3 weeks