Karatzi 2013.

Study characteristics
Methods	Randomised controlled trial, single‐blinded, cross‐over design
Participants	17 healthy, non‐smoking male volunteers with a mean age of 28.5 ± 5.2 years and body mass index (BMI) of 24.4 ± 2.5 kg/m2 Exclusion criteria: Medical history of coronary artery disease, diabetes mellitus, or liver or endocrine disease Smoking, alcohol consumption greater than recommended amount (20 to 30 gr alcohol/d), vigorous exercise, antioxidant vitamin supplementation Dieting at the time of the study
Interventions	400 mL of beer and 400 mL of water (~ 20 g of ethanol and ~ 48 mg polyphenol) 800 mL of de‐alcoholised beer (same quantity of polyphenols) 67 mL of vodka and 733 mL of water (same amount of alcohol) Consumed within 15 minutes
Outcomes	Endothelial function (brachial flow‐mediated dilatation) Aortic and brachial pressure Aortic stiffness (pulse wave velocity, pressure wave reflections (AIx)) Assessed at fast and at 1 and 2 hours postprandially
Notes	All vascular and haemodynamic tests were performed at the Cardiovascular Research Laboratory (Laiko Hospital) in the morning hours (at 8:00) and after 10 to 12 hours of fast and absence of alcohol, coffee, and caffeinated drinks since noon of the previous day Washout period was at least 1 week Test drinks were accompanied with a sandwich (2 slices of white bread, 1 slice of turkey, and 1 slice of low‐fat cheese) The above‐mentioned drinks were matched for their antioxidant and alcohol content, namely, 400 mL of beer had the same antioxidant concentration as 800 mL of de‐alcoholised beer (∼ 48 mg polyphenols), and 400 mL of beer had the same alcohol concentration as 67 mL of vodka (∼ 20 g of ethanol) All volunteers were instructed to avoid significant changes in their physical activity and in their diet between the 3 visits They were also advised to consume the same quality and quantity of food 1 day before the study days began
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"all volunteers consumed in a randomized order either a) 400 ml of beer & 400 ml water, b) 800 ml of dealcoholized beer (same amount of polyphenols), or c) 67 ml of vodka & 733 ml water" Comment ‐ method of randomisation was not described
Allocation concealment (selection bias)	Unclear risk	Comment ‐ method of allocation concealment was not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment ‐ study was not blinded for participants
Blinding of outcome assessment (detection bias) All outcomes	Low risk	“The same trained observer who was blinded for the type of intervention performed all measurements" Comment ‐ blinding of outcome assessors was probably done
Incomplete outcome data (attrition bias) All outcomes	Low risk	“Data from 16 subjects were available for the final analysis due to missing values related to poor quality of vascular recordings in at least one of the visits” Comment ‐ reasons for exclusion of a participant were reported and balanced across groups, so missing data should not affect the final analysis
Selective reporting (reporting bias) For systolic blood pressure (SBP)	High risk	Comment ‐ study authors did not report SBP
Selective reporting (reporting bias) For diastolic blood pressure (DBP)	High risk	Comment ‐ study authors did not report DBP
Selective reporting (reporting bias) For mean arterial blood pressure (MAP)	Low risk	Comment ‐ study authors reported MAP with 95% confidence interval
Selective reporting (reporting bias) For heart rate (HR)	Low risk	Comment ‐ study authors reported HR with 95% confidence interval
Other bias (conflict of interest, industry sponsorship)	Low risk	“The authors declare that they have no conflict of interest”
Other bias (was the study registered in clinical trials.gov/ was the protocol available?)	High risk	Comment ‐ protocol was not registered and study identifier was not reported