Table 1.

PICOS criteria for inclusion of studies

Parameter	Description
Population	Adult participants >18 years old (healthy or otherwise)
Intervention	Hibiscus sabdariffa as a stand-alone intervention
Comparator	Placebo, diet, other tea beverage, pharmaceutical medication
Outcomes	Outcomes regarding both systolic blood pressure and diastolic blood pressure (and pulse pressure, where included) and/or the following: levels of low-density lipoprotein, high-density lipoprotein, total cholesterol, triglycerides, fasting plasma glucose
Study design	Randomized controlled trial with parallel design