The goal of this clinical trial is to test if coffee consumed as a tablet is biologically equivalent to that consumed traditionally as a drink. It will also learn about the impact of the short-term intake of coffee on markers of cardiovascular and liver health. The main questions it aims to answer are: * Do coffee bioactive compounds produce the same levels in blood and urine regardless of how the coffee is consumed (tablet or drink)? * How does coffee as a tablet or drink impact cardiovascular risk and liver health versus a non-coffee control? Participants will: * Visit the clinical unit for three phases; each phase is 1x 480 minute (eight hour) acute postprandial visit and 1 x one hour visit the following day. During each phase they will be randomly assigned to take a different intervention (coffee drink, coffee tablet, coffee-free control) * Be cannulated during the 480 minute (8 hour) acute visits and have regular blood draws as well as basic clinical assessments * Return on day two for a fasting blood sample and basic clinical assessment * Collect their urine for 24 h * Be asked to record their intake of foods and drinks for 3 days to assess their usual diet (dietary assessment).
Coffee has gained interest for its role in the prevention of non-communicable diseases such as heart and liver diseases. Population-based studies have reported that consuming 2-4 cups of coffee per day is associated with lower death rates and, notably reductions in the incidence of heart disease. However, these observational trials do not directly prove causality and carefully designed randomised controlled trials are needed. This current trial will provide vital information to inform a large-scale randomised controlled trial assessing the effects of coffee consumption on risk markers for developing cardiometabolic disease (such as type 2 diabetes, heart and liver diseases) to test causality. In this follow-up trial to be conducted in 2025, non-coffee consumers will be recruited. To maximise recruitment, retention and adherence in the trial, we are considering providing instant coffee as tablets rather than as a drink. Hence, the current study will help to understand if coffee delivered in a tablet is biologically equivalent to consuming coffee as a drink. A 3 armed, randomised, controlled crossover trial in healthy participants wil be performed. The primary outcome is the pharmacokinetic profile of coffee bioactives in coffee drink versus the coffee tablet. Secondary outcomes will be assessing the impact of the coffee both as a drink and tablet on cardiovascular and liver health markers (versus a coffee-free control). Briefly, participants will attend three study phases. Each study phase includes a 480 minute (8-hour) acute postprandial visit and a shorter visit (\~one hour) the following morning. On the first day participants will arrive having fasted overnight and having followed dietary and lifestyle restrictions in the preceding days. They will have baseline anthropometric measures performed and a cannula will be inserted; two baseline blood samples will be collected (14 mL in total). Blood samples will be collected regularly from the cannula, and a clinic blood pressure measurement will be performed at regular intervals following the intervention (a different intervention will be given in a random order at each of the three phases). A breakfast meal and lunch will be provided to the participants during the visit and participants will leave with a standardised meal and snack to consume in the evening. They will return, fasted the following morning to provide a blood samples and have their blood pressure measured. Participants will be asked to collect their urine for 24h following the intervention; this will be returned that morning. There will be a 4-week period between each study phase.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
16
Commercially available instant coffee (3.6 g) will be provided in the form of a drink prepared with 400 ml of water. A standard breakfast consisting of cereal with milk will be provided at 60 mins after the intervention. A standard lunch (cheese sandwiches, potato crisps and shortbread biscuits) will be given at 300 after coffee intake.
Commercially available instant coffee (3.6 g) will be provided as 4 tablets given with 400 ml of water. A standard breakfast consisting of cereal with milk will be provided at 60 mins after the intervention. A standard lunch (cheese sandwiches, potato crisps and shortbread biscuits) will be given at 300 after coffee intake.
A caffeine and coffee free control (3.6 g) will be provided as 4 tablets given with 400 ml of water. A standard breakfast consisting of cereal with milk will be provided at 60 mins after the intervention. A standard lunch (cheese sandwiches, potato crisps and shortbread biscuits) will be given at 300 after coffee intake.
Hugh Sinclair Unit of Human Nutrition, Department of Food and Nutritional Sciences, University of Reading
Reading, Berkshire, United Kingdom
Pharmacokinetic profile of key coffee biologically active compounds and their metabolites after consuming a coffee drink, a coffee tablet and control.
Key coffee biologically active compounds and their metabolites (e.g. chlorogenic acids, caffeine, trigonelline) will be measured in plasma samples collected over a 24 h period after each intervention. The pharmacokinetic profile (absorption, metabolism and excretion), maximal concentration, Cmax will be calculated.
Time frame: Blood taken prior to consuming the intervention (0 minutes) and then 30, 45, 60, 90, 120, 180, 240, 300, 360, 420, 480 and 1440 minutes post intervention.
Pharmacokinetic profile of key coffee biologically active compounds and their metabolites after consuming a coffee drink, a coffee tablet and control.
Key coffee biologically active compounds and their metabolites (e.g. chlorogenic acids, caffeine, trigonelline) will be measured in plasma samples collected over a 24 h period after each intervention. The pharmacokinetic profile (absorption, metabolism and excretion), area under the concentration curve will be calculated.
Time frame: Blood taken prior to consuming the intervention (0 minutes) and then 30, 45, 60, 90, 120, 180, 240, 300, 360, 420, 480 and 1440 minutes post intervention.
Fasting concentrations of total cholesterol and high-density lipoprotein cholesterol.
Serum lipids will be measured directly using a clinical chemistry analyser.
Time frame: Acute study days prior to the intervention (0 minutes).
Fasting and postprandial lipids concentrations after consuming the coffee drink, coffee tablet and control interventions
Serum triacylglycerol and non-esterified fatty acids will be measured in the fasting and postprandial blood samples collected for 480 min after each intervention.
Time frame: Acute study days, blood taken prior to the intervention (0 minutes) and then 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes.
Fasting and postprandial glucose concentrations after consuming the coffee drink, coffee tablet and control interventions
Serum glucose will be measured in the acute study day blood samples collected for 480 minutes after each intervention using a clinical chemistry analyser.
Time frame: Acute study days, blood taken prior to consuming the intervention (0 minutes) and then 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes.
Fasting and postprandial insulin concentrations after consuming the coffee drink, coffee tablet and control interventions
Serum insulin will be measured in the acute study day blood samples collected for 480 minutes after each intervention using an enzyme-lined immunosorbent assay.
Time frame: Acute study days, blood taken prior to consuming the intervention (0 minutes) and then 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes.
Fasting and postprandial liver enzyme concentrations after consuming the coffee drink, coffee tablet and control interventions
Serum alanine transaminase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) and glutamate dehydrogenase (GLDH) will be measured in the acute study day blood samples collected for 480 minutes after each intervention using a clinical chemistry analyser.
Time frame: Acute study days, blood taken prior to consuming the intervention (0 minutes) and then 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes.
Fasting and postprandial gut hormone concentrations after consuming the coffee drink, coffee tablet and control interventions
C-peptide, GIP, GLP-1 and Ghrelin will be measured in the postprandial blood samples collected for 480 min after each interventions.
Time frame: Acute study days, blood taken prior to the intervention (0 minutes) and then 30, 60, 120, 180, 240, 300, 360 and 480 minutes.
Fasting and postprandial plasma metabolomics after consuming the coffee drink, coffee tablet and control interventions
Metabolomics will be measured in the postprandial blood samples collected for 480 min after the interventions using NMR.
Time frame: Acute study days, blood taken prior to the intervention (0 minutes) and then 30, 60, 120, 180, 240, 300, 360, 420 and 480 minutes.
Fasting and postprandial plasma nitrate and nitrite concentrations after consuming the coffee drink, coffee tablet and control interventions
Nitrate, nitrite and Nox (sum of nitrate and nitrite) will be measured in the postprandial blood samples collected for 480 min after each intervention.
Time frame: Acute study days, blood taken prior to the intervention (0 minutes) and then 15, 30, 45, 60, 120, 180, 240, 300, 360, 420 and 480 minutes.
Urinary metabolomics
Metabolomics will be performed on the 24 h urine samples using NMR .
Time frame: Urine will be collected prior to (0 minutes) and for 1440 minutes after each intervention.
Urinary creatinine
Creatinine will be measured in the 24 h urine samples using a clinical chemistry analyser.
Time frame: Urine will be collected prior to (0 minutes) and for 1440 minutes after each intervention.
Urinary osmolality and pH
Osmolality will be determined as a measure of the concentration of solutes in the 24 h urine sample and pH to indicate whether the sample is acidic or alkaline after consuming the study interventions.
Time frame: Urine will be collected prior to (0 minutes) and for 1440 minutes after each intervention.
Urinary sodium and potassium
Sodium and potassium will be determined in the 24 h urine sample as a marker of kidney function and a nutritional biomarker after consuming the study interventions.
Time frame: Urine will be collected prior to (0 minutes) and for 1440 minutes after each intervention.
Body weight
Body weight will be measured using a Tanita scale.
Time frame: On each acute study visit prior to the collection of the first blood sample (0 minutes).
Height
Height will be measured to the nearest cm using a stadiometer
Time frame: First acute study visit (0 minutes on visit 1)
Blood pressure
Blood pressure will be measured using blood pressure monitor.
Time frame: -15, 30, 60, 120, 180, 240, 300, 360, 420, 480 minutes
Body fat percentage
Body fat percentage will be measured using the Tanita scale by bioelectrical impedance.
Time frame: Each acute study visit (0 minutes)
Body fat mass
Body fat mass will be measured using a Tanita scale.
Time frame: On each acute study visit prior to the collection of the first blood sample (0 minutes).
Body lean mass
Body lean mass will be measured using a Tanita scale.
Time frame: On each acute study visit prior to the collection of the first blood sample (0 minutes).
Body mass index
Body mass index will be calculated using the body weight (kg) and height (m) data.
Time frame: On each acute study visit (0 minutes)
Waist and hip circumferences
A non-stretch tape will be used to measure waist and hip circumferences
Time frame: On each acute study visit (0 minutes).
Habitual dietary intake of the study participants
Record of the food and drink prior to the first study visit
Time frame: Two weeks prior to the first acute study visit (t- 2 weeks from visit 1).
Fasting estimate of insulin resistance and insulin sensitivity
HOMA-IR (Homeostasis model assessment estimated insulin resistance) and QUICKI (Quantitative Insulin Sensitivity Check Index) will be calculated using the fasting glucose and insulin data.
Time frame: On each acute study visit (0 minutes).
Fasting low-density lipoprotein-cholesterol concentration
The low-density lipoprotein-cholesterol concentration will be calculated from aforementioned outcomes using the Friedewald formula.
Time frame: On each acute study visit (0 minutes).
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.