The Role of Chlorella and Spirulina as Adjuvants of Cardiovascular Risk Factor Control: A Systematic Review and...

Background/Objectives: Chlorella and Spirulina supplementation may reduce the risk of cardiometabolic diseases by better controlling blood cholesterol, triglycerides, glucose, weight, and blood pressure (BP). However, the available studies are limited in size and have used different outcomes. Methods: To gain power in assessing the impact of microalgae supplements on cardiovascular risk factors, we searched PubMed on 3 February 2023 for randomised controlled trials assessing the effects of Chlorella and Spirulina on modifiable cardiovascular risk factors. Results: We found 12 studies in Chlorella and 9 studies on Spirulina. Depending on the available outcomes, varying numbers of participants (Chlorella: 168 to 279; Spirulina: 101 to 299) were included. Our analysis showed that Chlorella supplementation had a neutral effect on BP and lipemia. On the other hand, Spirulina intake led to a significant reduction in diastolic BP (-0.42, 95% CI: -0.81 to -0.02, p = 0.04) but did not significantly affect lipemia indexes, despite a trend toward a reduction in total cholesterol (-0.17, 95% CI: -0.39 to 0.06, p = 0.15). This meta-analysis suggests Spirulina supplementation can be used as an adjuvant to control cardiometabolic risk factors, particularly for BP. However, the magnitude of this effect is small and of uncertain clinical significance. Conclusions: Further randomised trials are needed to better assess the potential of these supplements as adjuvants for the control of cardiovascular risk factors.