The Acute and Chronic Effects of Fruit Polyphenols on Chronic Disease (PPF)

The study is a single-center, double-blinded, randomized, 2-part, 2-arm, 4-sequence, crossover study that incorporates both the acute and chronic evaluations of fruit polyphenols on metabolic indices and markers of oxidative stress.

A planned sample size of 30 overweight men and women will be recruited into the study. Subjects will be required to meet several inclusion and exclusion criteria, which will be assessed through online and clinic screening mechanisms, including questionnaires, blood analysis, and anthropometric measurements. Eligible subjects will be invited to participate in the study. Subjects will begin by completing a 7-day pre-study assessment of their usual dietary intake using 3-day food diary followed by washout of dietary polyphenols. Subjects will participate in 4, 6 h postprandial study days: 2 preceding the chronic intervention and 2 after 8 weeks each of active (fruit polyphenols) and placebo beverages. Subjects will be randomized on the first day of starting the acute and chronic study phases. Subjects will be asked to limit polyphenolic containing foods and beverages for 3 days prior to each 6 h postprandial study visit as well through the chronic dietary intervention. Subjects will be provided a standardized dinner meal pack on the day before each 6 h postprandial visit.

For each 6 h postprandial study visit, subjects will arrive fasted and follow procedures published by our lab previously. This includes: pre-study evaluation for compliance (fasting, dinner consumption, limited polyphenol intake) and readiness for study visit, catheter placement by registered nurse, fasting blood sample, consumption of high fat/carbohydrate meal accompanied by 1 of the two treatment beverages (active/fruit polyphenol or placebo beverage), subsequent blood sampling from catheter [ ~1 tablespoon (12ml)] at designated time points for 6 hours. Each postprandial study visit day will last approximately 7 hours and subjects will be required to remain at the Clinical Nutrition Research Center at the Illinois Institute of Technology main campus for the duration of the visit. The visit procedures are repeated twice ~ 1 week apart to accommodate subject testing with both beverages.

After completing both acute 6 h postprandial study visits, subjects will roll over to the chronic phase of the study and receive a 2nd randomization sequence for consuming the active or the placebo beverage daily for 8 weeks. Before crossing over to the alternative treatment beverage for another 8 weeks, subjects will have a 4-week break (wash out). Subjects will be counseled for a low polyphenolic diet throughout the study to consume the assigned beverage twice per day with lunch and evening meals (except during 4-week washout).

At the end of each week 8 treatment period, subjects will come to the research center for a 6 h postprandial study visit day: all procedures are identical on each postprandial study test visit with the exception that only the placebo beverage will be consumed with the breakfast.

Inclusion criteria

• Non-smoking healthy overweight or class I obesity adult men and women
• Age 40-65yr
• Weight stable
• Able to provide informed consent
• Able to comply and perform the procedures requested by the protocol.

Exclusion criteria

• Smokers or recent past smokers
• Men or women with known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients
• Diabetes
• Fasting blood glucose concentrations >125 mg/dL
• Fasting Total Cholesterol >250 mg/dL (6.47mmol/L)
• Fasting Triglycerides >250 mg/dL (2.82 mmol/L)
• Fasting LDL cholesterol >180 mg/dL (4.66 mmol/L)
• Uncontrolled blood pressure >140 mmHg/90 mmHg
• Documented vascular disease
• Cancer other than skin (non-melanoma) in previous 5 years
• Lactating and/or pregnant
• Taking medications or dietary supplements eg., antioxidant supplements, lipid lowering medication, blood pressure lowering medications.
• Recent blood donors (within 3 months)
• Vegans
• Substance (alcohol or drug) abuser (within the last 2 years)
• Participated in a chronic feeding or medication clinical trial in the last 3 months.
• Excessive coffee and tea consumers (> 4 cups/d)