Koenig 1997.

Study characteristics
Methods	Randomised controlled trial, open‐label, cross‐over design
Participants	15 males between the ages of 20 and 35 years (average gross height 184 cm, weight 76 kg) were enrolled in the study Exclusion criteria: Patients with acute or chronic disease
Interventions	10 mL/kg body weight of Kölsch (beer), or Same amount of Kolschbier brewing water was chosen as placebo Consumed within 30 minutes
Outcomes	Systolic blood pressure Diastolic blood pressure Serum electrolyte level Measured at baseline and at 2 and 3 hours after consumption
Notes	Washout period was 14 days between interventions Participants were told to abstain from alcohol for 5 days before the study
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	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 and personnel
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment ‐ study was not blinded for outcome assessors
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment ‐ it is not explicitly mentioned whether all participants were included in the final analysis
Selective reporting (reporting bias) For systolic blood pressure (SBP)	Low risk	Comment ‐ study authors reported SBP with SD in a figure
Selective reporting (reporting bias) For diastolic blood pressure (DBP)	Low risk	Comment ‐ study authors reported DBP with SD in a figure
Selective reporting (reporting bias) For mean arterial blood pressure (MAP)	High risk	Comment ‐ study authors did not report MAP
Selective reporting (reporting bias) For heart rate (HR)	High risk	Comment ‐ study authors did not report HR
Other bias (conflict of interest, industry sponsorship)	Unclear risk	Comment ‐ study authors did not mention any funding source or declare any 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