The findings, published in Complementary Therapies in Medicine, pools data from 278 people who took part in five separate randomised clinical studies to reveal that supplementation with the blue-green microalgae can reduce body weight and body fat percentage.
Led by first author Sajjad Moradi from Kermanshah University of Medical Sciences and the FDA in Iran, the team noted that previous studies have suggested that Spirulina may be useful in the management of obesity, with indications that it may have beneficial effects on appetite, food absorption, the makeup of our gut microbiota and important inflammatory cascades.
“Although supplementation with Spirulina seems to be an appropriate choice for obese subjects, the scientific evidence in this field is relatively limited and heterogeneous,” noted the team – adding that current scientific literature reveals multiple smaller trials, each with mixed results, and no summary or pooled analysis of findings.
“Based on our searches in scientific databases, no article has been published to summarise the effects of Spirulina on weight management. Moreover, clinical trial studies have shown contradictory effects of Spirulina on obesity,” they confirmed.
Studies were identified using Embase, Scopus, ISI Web of Science, PubMed and Cochrane library databases up to May 2019. Through these methods the Iranian team identified five studies with 278 subjects, of these 145 were given Spirulina and 133 were a control.
Mean Differences (MD) were pooled using a random-effects model, they noted – adding that heterogeneity, sensitivity analysis and publication bias were reported using standard methods.
When pooled, results of the five studies (which had seven combined treatment arms) showed a significant reduction in weight – with an average weight reduction of 1.56 kg in the groups receiving Spirulina.
Further subgroup analysis based on health status found that weight change in obese subjects was greater than those classified as ‘overweight’ but not obese – with an average weight loss of 2.06 kg in obese people and an average reduction of 1.28kg in overweight subjects receiving Spirulina.
Pooled analysis also showed that Spirulina supplementation led to a significant reduction in body fat percent (with an average reduction of 1.02%) and waist circumference (1.40 reduction), but not in body mass index and waist to hip ratio.
“The findings of the present study support the beneficial effect of Spirulina on body weight, body fat percentage and waist circumference,” said the team – noting that effects of Spirulina supplementation on BMI and waist-to-hip ratio were not statistically significant.
“The impact may more pronounced on obese subjects rather than overweight individuals,” they added.
Source: Complementary Therapies in Medicine
Volume 47, December 2019, doi: 10.1016/j.ctim.2019.102211
“Effects of Spirulina supplementation on obesity: A systematic review and meta-analysis of randomized clinical trials”
Authors: Sajjad Moradi, et al