The Acute and Chronic Effects of Fruit Polyphenols on Chronic Disease (PPF)
Condition: Nutritional and Metabolic Disease; Overweight
MeSH terms: Overweight; Metabolic Diseases; Chronic Disease
Study type: Interventional

Summary: 
      1. The primary objective is to determine the effect of fruit polyphenols on postprandial
           lipoprotein triglyceride metabolism after consumption a standard high carbohydrate/fat
           breakfast meal with a beverage rich in fruit-derived polyphenols compared to energy and
           macro-/micro-nutrient matched control beverage (acute, Part 1).

        2. Secondary objectives are: 1)to assess the effects of consuming daily for 8 weeks
           (chronic, Part 2) a beverage rich in fruit polyphenols compared to an energy and
           macro-/micro- nutrient matched control beverage on fasting glucose, insulin, lipids and
           markers of oxidative stress; and 2) to assess the effects of these beverages on
           meal-related changes in metabolic and oxidative stress measures after 8 weeks daily
           consumption.
    

Detailed description: 
      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.
    

Intervention name(s): Active Treatment Beverage; Placebo Treatment Beverage
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Strawberry and Blackcurrent extract; without active components
Other intervention name(s): Active Comparator; Placebo Comparator
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Nutrition; Polyphenols; Berries; Overweight; Lipid Panels