Bioavailability and Beneficial Properties of Coffee and Cocoa Bioactive Compounds
Condition: Diet Modification; Cardiovascular Risk Factor; Nutritional and Metabolic Diseases
MeSH terms: Metabolic Diseases
Study type: Interventional

Summary: 
      The aim of this study will be to define the bioavailability and the beneficial properties of
      coffee bioactive compounds. Moreover, the contribution of cocoa-based products containing
      coffee to the pool of circulating metabolites will be investigated with the aim of evaluating
      the effect of the combination of bioactives from different sources.

      To study the bioavailability of coffee/cocoa bioactive compounds and their effects in
      cardiometabolic health, the objectives will be:

      i) Assessing the bioavailability of the four main groups of phytochemicals in roasted coffee
      (methylxanthines, phenolic compounds, trigonelline, and diterpenes), its modulation by the
      level of consumption, and establishing the daily average concentration of coffee-derived
      plasma circulating metabolites; ii) Investigating the effect of different levels of coffee
      consumption on cardiometabolic risk factors; iii) Evaluating circulating metabolites and
      their putative bioactivity when substituting coffee consumption with the intake of
      cocoa-based products containing coffee.

      A 3-arm, crossover, randomized trial will be conducted. Twenty-one volunteers will be
      randomly assigned to consume three treatments in a random order for 1 month: 1 cup of
      espresso coffee/day, 3 cups of espresso coffee/day, 1 cup of espresso coffee at breakfast and
      2 cocoa-based products containing coffee two times per day. The last day of the treatment
      subjects will refer to the ambulatory where blood and urine samples will be collected at
      specific time points up to 24 hours following the consumption of the testing coffee or of the
      cocoa-based products containing coffee. In addition to the bioavailability of the bioactive
      compounds, the effect of the coffee consumption on several cardiometabolic risk factors
      (blood pressure, anthropometric measures, inflammatory markers, nitric oxide, blood lipids,
      fasting indices of glucose/insulin metabolism, DNA damage, eicosanoids, nutri-metabolomics)
      will be investigated. At the end of the treatment, the same protocol will be repeated,
      switching the allocation group.
    

Detailed description: 
      A human bioavailability study will be carried out to achieve the above-described goals. The
      human intervention study will consist of a short-term randomized cross-over trial, addressed
      at measuring the daily mean concentrations of each coffee/cocoa-derived circulating
      metabolite (CCDCM) for the four main groups of coffee/cocoa phytochemicals (methylxanthines,
      trigonelline, phenolics, diterpenes). On the basis of different patterns of consumption, this
      free-living study (although some minimal dietary restrictions will be provided two days
      before sampling times) will also take into consideration the effects of repeated doses on the
      bioavailability of coffee/cocoa bioactives.

      The study will follow a repeat-dose, 3-arm, cross-over design. This design has been chosen
      according to ILSI's guidelines for intervention trials with dietary products.

      Subjects were assigned to consume the following treatments in a random order for 1 month:

        1. 1 cup of espresso coffee/day ("low consumers") at 9.00 A.M.

        2. 3 cups of espresso coffee/day ("high consumers") at 9.00 A.M., 12.00 P.M.noon and 3.00
           P.M.

        3. 1 cup of espresso coffee at breakfast 9.00 A.M. and 2 cocoa-based products containing
           coffee two times per day (at 12.00 P.M.noon and 3.00 P.M.). The group will be named
           "medium consumers", considering the caffeine content of the cocoa-based products
           containing coffee.

      Minimal recommendations to avoid other sources of coffee/cocoa phytochemicals besides what
      introduced through the assigned treatment, and to standardise the time of coffee consumption,
      will be provided for the two days prior to each sampling day and on the sampling day. Dinner
      timing and composition will also be standardised the day before the sampling day. Only water
      could be drunk during the night. At the sampling day (i.e. the last day of each intervention
      period), the subjects will refer in the morning at the ambulatory where fasting baseline
      blood and urine samples will be collected. Then, low and high consumers will drink one or
      three cups of espresso coffee, respectively (without sugar, sweeteners, and milk for the
      first coffee; with 5 g of sugar for the last two coffees), while medium consumers will drink
      a cup of espresso coffee and 2 cocoa-based products containing coffee twice during the day,
      following the above-described timing. After ingestion of the first coffee together with a
      phytochemical-free breakfast (a pastry), blood and urine samples will be collected at
      selected time points along the following 24-h. Five hours after the consumption of the first
      coffee, participants will receive a standardised mixed meal (sandwich with ham and cheese)
      free of coffee/cocoa phytochemical-related compounds. Water will be available ad libitum.
      Twenty-four hours after receiving the treatment, blood and urine samples will also be taken
      in order to assess return to baseline. In addition, anthropometric characteristics and blood
      pressure (BP) will be measured.

      Socio-demographic variables will be assessed through a generic questionnaire filled at
      recruitment. The questionnaire will also contain questions useful to identify possible
      exclusion criteria (e.g. diagnosis for diseases, regular consumption of medication, food
      allergy). Dietary habits of volunteers will also be evaluated during the enrollment, through
      a semi-quantitative food frequency questionnaire (FFQ) for the assessment of dietary total
      antioxidant capacity. In addition, participants' food intakes and compliance with the study
      requirements will be assessed by means of 3-day dietary records, administered throughout each
      intervention period at two time points: i) in the middle of each intervention period during
      two weekdays and a weekend day, and ii) at the end of each intervention period, 2 days prior
      to the sampling day and the sampling day. The habitual physical activity level of each
      participant will be measured through a validated International Physical Activity
      Questionnaires.

      Blood sample collection will be carried out in the ambulatory unit of the Department of
      Medicine and Surgery. Blood collection will be carried out by a physician. A venous catheter
      will be inserted into the antecubital vein and blood samples from each subject will be
      collected in specific tubes over 24 hours. Blood sampling at time-point 24h after first
      coffee consumption will be done by venipuncture. Urine samples will be collected during
      different periods of time using urine collectors.

      Blood samples will be centrifuged and plasma, serum and peripheral blood mononuclear cells
      (PBMCs) will be collected, aliquoted, and stored at -80 °C for further processing. Urine
      samples will be aliquoted and stored at -80°C for further processing.

      The primary selected endpoint of the study is the quantification of the daily mean
      concentration of coffee-derived plasma circulating phenolic metabolites, whereas the study of
      the bioavailability of other coffee-derived circulating bioactives, the bioavailability of
      cocoa-derived circulating phytochemicals, and the assessment of cardiometabolic markers will
      be considered secondary endpoints.
    

Intervention name(s): cup of espresso coffee; cocoa-based products containing coffee
Intervention type(s): Other; Other
Intervention description(s): Subjects will consume the assigned treatment for one month. Espresso coffee will be prepared by using coffee capsules. Serving size: approximately 45 mL. The last day of the intervention is the sampling day.; Subjects will consume the assigned treatment (2 products per serving) for one month. Serving size: approximately 37 g. The last day of the intervention is the sampling day.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Basic Science
Keywords: coffee; cocoa; bioavailability; pharmacokinetics; cardiometabolic risk factors; caffeoylquinic acids; flavan-3-ol; caffeine; trigonelline; diterpene