Effect of Acute Red Raspberry Consumption on Post-prandial Oxidative Stress

An Acute Intervention Study Investigating the Effect of Red Raspberry Consumption on Post-prandial Oxidative Stress

Eight healthy adult subjects will be given a meal of one, two or four cups red raspberries, or two slices white bread with or without 200 mg vitamin C, after an overnight fast and consumption of a low polyphenol diet for two days. Blood samples will be taken at various time points over an eight hour period to measure oxidative stress and antioxidant levels in the blood. Each subject will attend 5 study visits with one week intervals and be given each meal in a random order. It is hypothesized that raspberry consumption at higher doses will greater protect against meal-induced oxidative stress compared to bread controls.

Study Overview

• Status: Completed
• Conditions: Oxidative Stress; Antioxidants
• Intervention / Treatment: Dietary supplement: red raspberries; Dietary supplement: bread controls

• Study Type: Interventional
• Enrollment (Actual): 8
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5C 2T2
      • Clinical Nutrition and Risk Factor Modification Centre; St. Michael's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 30 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• healthy adults

Exclusion Criteria:

• blood pressure greater than 120/80 mm Hg
• body mass index greater than 24.9 kg/m^2
• history of any chronic disease
• currently taking medications
• allergy to fruit

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: one cup red raspberries; treatment meal consists of one cup red raspberries	Dietary supplement: red raspberries; single serving of one, two or four cups red raspberries
Experimental: two cups red raspberries; treatment meal consists of two cups red raspberries	Dietary supplement: red raspberries; single serving of one, two or four cups red raspberries
Experimental: four cups red raspberries; treatment meal consists of four cups red raspberries	Dietary supplement: red raspberries; single serving of one, two or four cups red raspberries
Placebo Comparator: bread; treatment meal consists of two slices white bread	Dietary supplement: bread controls; two slices white bread alone or with 200 mg vitamin C supplement
Active Comparator: vitamin C; treatment meal consists of two slices white bread and 200 mg vitamin C in the form of supplemental ascorbic acid	Dietary supplement: bread controls; two slices white bread alone or with 200 mg vitamin C supplement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
change in antioxidant capacity from baseline (-0.25 h)	plasma antioxidant capacity measured using the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation assay and expressed in Trolox Equivalents (TE)	-0.25, 0.25, 0.5, 1, 2, 4 hours post-intake

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
change in lipid peroxidation from baseline (-0.25 h)	serum thiobarbituric acid reactive substances (TBARS) measured as an indicator of the lipid peroxidation product malondialdehyde (MDA)	-0.25, 0.25, 0.5, 1, 2, 4 hours post-intake
change in thiols compared to baseline (-0.25 h)	plasma thiols quantified by 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) assay as an indicator of the level of protection against protein oxidation	-025, 0.25, 0.5, 1, 2, 4 hours post-intake

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Unity Health Toronto
• Investigators: Principal Investigator: A V Rao, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start: February 1, 2010
• Primary Completion (Actual): March 1, 2010
• Study Completion (Actual): March 1, 2010

Study Registration Dates

• First Submitted: November 8, 2010
• First Submitted That Met QC Criteria: November 12, 2010
• First Posted (Estimate): November 16, 2010

Study Record Updates

• Last Update Posted (Estimate): December 6, 2010
• Last Update Submitted That Met QC Criteria: December 3, 2010
• Last Verified: November 1, 2010

More Information

Terms related to this study

• Keywords: oxidative stress; antioxidants; polyphenols; vitamin C; post-prandial; red raspberries; acute dietary intervention
• Other Study ID Numbers: 24774