None listed
Conditions
Brief summary
Kawakawa (Piper excelsum) a native NZ plant species, of cultural importance to Maori, and extensively used in rongoa Maori (traditional Maori healing). Despite considerable matauranga Maori of the therapeutic benefits of Kawakawa, research into the pharmacology of kawakawa is progressed little beyond identification the chemical profile. Kawakawa is reported to contain a number of pharmacologically active compounds demonstrated to influence pathways related to thermogenesis. We aim to explore the effect of adding kawakawa to a commercial beverage containing kiwi fruit powder and extracts of turmeric and ginger that has been formulated to stimulate postprandial thermogenesis. We hypothesise that consumption of the kawakawa-containing beverage will yield postprandial thermogenesis, measured as metabolic rate (energy expenditure) and respiratory quotient (relative substrate utilisation), proportional to the sum of that yielded by consumption of the beverage without kawakawa and that from an equivalent volume and strength of kawakawa tea.
Interventions
This study will examine the postprandial thermogenic and substrate utilisation effect of kawakawa containing beverage. As previously reported, the postprandial state lasts for approximately 4-5 h post-meal period (1). Thus, the study will require participants to attend the Clinical Research Unit (CRU), of the Liggins Institute on each intervention visit for a period of 3 hours. Participants will complete a screening assessment (Visit 1) and if eligible for entry into the trial will be required t
This study will examine the postprandial thermogenic and substrate utilisation effect of kawakawa containing beverage. As previously reported, the postprandial state lasts for approximately 4-5 h post-meal period (1). Thus, the study will require participants to attend the Clinical Research Unit (CRU), of the Liggins Institute on each intervention visit for a period of 3 hours. Participants will complete a screening assessment (Visit 1) and if eligible for entry into the trial will be required to visit Liggins Institute in fasted condition. Participants will be provided with a standardised meal (Vegetable pulao, 300gm, 526Kcalories) supplied from muscle chow NZ (www.musclechow.co.nz) to eat the evening before each study visit to reduce variability in the fasting substrate oxidation profile. This meal will be of identical macronutrient composition and energy content within- and between-participants. Participants will be advised to abstain from intense exercise, caffeinated or herbal drinks, spices and alcoholic drinks in the 24 hrs prior to the study visits. Participants will be asked to arrive at the CRU in the morning, following a 12 h fast. Screening visit : This screening visit will take place prior to the commencement of the intervention period. The subject will be asked to attend the Clinical Research Unit (CRU) of the Liggins Institute for a 30 minute visit. Written and verbal description of the study will be provided and informed consent obtained from eligible participants. Subjects who meet the inclusion/exclusion criteria will then be registered into the trial. Demographics (age and ethnicity) and anthropometry (height, body weight, BMI) will be recorded. Participant will also be asked to complete screening questionnaire. Prior to their intervention visits, participants will have their body composition assessed by dual Energy X-Ray Absorptiometry (iDXA, GE-Lunar) at the Clinical Research Unit (CRU) of the Liggins Institute. DXA is based on the 3-compartment model of body composition, and uses two x-ray energies to measure body fat mass, lean mass, and bone mineral. The participant is required to lie recumbent on the open scanner bed for ~10 minutes. Body composition comprising total body fat, fat-free soft tissue and bone mineral content as well as regional fat deposition will be determined from DXA whole-body and segmental scans. Fat-free mass is the main determinant of resting energy expenditure, and hence this information will enable us to mathematically adjust our metabolic rate measurements accordingly. Intervention visit: Four acute intervention visits (4 hrs each, separated by at least 48 hrs washout). Treatment-1: 15 mL base beverage formulation containing Livaux gold kiwifruit powder, lemon juice, ginger, turmeric. Washed down with 235 mL water.Treatment-2: 15 mL base formulation + aqueous kawakawa infusion equivalent to tea made with 16 g kawakawa per litre of hot water. Washed down with 235 mL water.Treatment-3: Aqueous kawakawa infusion equivalent to tea made with 16 g kawakawa per litre of hot water. Control: Hot water (250mL) Upon arrival, the participant’s anthropometric measurements (weight) will be taken and a spot urine sample collected. Participants will then be asked to sit in a comfortable seat, in a quiet, temperature-controlled (20-22°C) laboratory. Body temperature will be measured using a tympanic thermometer to exclude the presence of fever. A peripheral venous cannula will be inserted by the Research Nurse for repeated blood sampling. A 16mL fasting baseline blood sample will be collected, and baseline Visual Analogue Scale (VAS) ratings of hunger, comfort and nausea will be measured using standard VAS methods. Participants will then be connected to equipment for continuous physiological monitoring. The respiratory gas exchange will be measured non-invasively by indirect calorimetry. Continuous, non-invasive, haemodynamic monitoring will also be undertaken. Participants will also be instrumented with autonomous wireless temperature sensors to measure changes in skin temperature. After 30 mins of baseline measurements by indirect calorimetry using an open-circuit ventilated hood system, the hood will be removed and participants will be provided with the randomised test beverage (t= 0 mins) and requested to consume this in entirety within 10 mins prior to recommencing indirect calorimetry measurements. Following 3 h of postprandial monitoring, participants will be invited to eat a controlled lunch meal ad libitum to objectively assess appetite and satiety. Participants will be permitted to watch calm documentaries or films during cardio-metabolic monitoring. Throughout the morning, a total of 6x blood samples will be collected after the test beverage at the following time-points: t= 15, 30, 60, 90, 120, and 180. A total volume of 70mL will be taken at each study visit. Reference 1. Monnier L, Colette C. Target for glycemic control: concentrating on glucose. Vol. 32 Suppl 2, Diabetes care. 2009.
Sponsors
Liggins Institute, The University of Auckland
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
Participants will be eligible to participate if: • Gender: both males and females. To control for menstruation cycle variation in results, female participants would be required to come in the same phase of their cycle for all the intervention visits. • Age: 18-45 yr. • BMI: 18-30kg/m2 • Non-smokers • Self-reported not consuming dietary supplements • Self-reported healthy
Exclusion criteria
Participants will be excluded from participation if they: • Are taking dietary supplements or herbal remedies which may affect the study outcome • Are allergic to pepper, nutmeg or similar spices • Are diagnosed with gastrointestinal disease (i.e. celiac, Crohn’s, colitis, etc.) or pre-existing metabolic disease • Are currently taking medications expected to interfere with normal digestive or metabolic processes including proton pump inhibitors, laxatives, etc. • Have used antibiotics within the previous one month or were on long-term antibiotic therapy. • Have a medical history precluding a healthy state: history of myocardial infarction, angina, stroke, cancer or pre-existing diabetes • Are Claustrophobic • Have recently gained or lost around >5% body weight
Outcome results
None listed