Doctors in this study reviewed 19 placebo-controlled trials of chlorella, covering male and female adults of varying health status.

Chlorella is a type of green micro-algae. It is considered a "superfood" because it is packed with the highest concentrations of chlorophyll known. It contains vitamin B12, iron, RNA, DNA and protein.

In this meta-analysis, researchers set out to examine multiple studies that measured how chlorella supplementation affects  cardiovascular risk factors. The studies varied in dosage and length, but doctors found that the studies lasting eight weeks or more, using doses of chlorella higher than 4 grams per day, had the most significant benefits.

On average overall, those taking chlorella saw decreases in total cholesterol of 9.09 mg per deciliter of blood (mg/dL); LDL cholesterol was lower by 8.32 mg/dL; fasting blood sugar levels decreased by 4.23 mg/dL; systolic blood pressure went down by 4.51 mmHg, and diastolic blood pressure decreased by 1.64 mmHg. Commenting on the findings, doctors said chlorella was more effective in unhealthy subjects than in healthy ones for improving blood pressure and total cholesterol.

Reference: Clinical Nutrition Journal; 2017, 5614 – 31351-1, Published Online.