Algal protein, derived from microalgae such as Spirulina and Chlorella, has been investigated in recent years for its potential benefits in metabolic disorders, including non-alcoholic fatty liver disease (NAFLD). The scientific interest stems from algae’s high protein content, presence of bioactive compounds (phycocyanins, polyunsaturated fatty acids, antioxidants), and their effects on lipid metabolism and inflammation.

Several animal studies have shown that supplementation with algal protein or whole algae can reduce hepatic lipid accumulation, improve antioxidant status, and modulate inflammatory markers in models of fatty liver disease. For example, studies using Spirulina platensis in rodents demonstrated reduced liver fat and improved serum lipid profiles. Some mechanisms proposed include downregulation of genes involved in lipid synthesis and upregulation of fatty acid oxidation.

Human evidence, however, remains limited. Small clinical trials with Spirulina have shown improvements in serum liver enzymes and lipid profiles in individuals with NAFLD or metabolic syndrome, but these studies are few, often use whole algae rather than isolated protein, and are of modest quality. There are no large-scale, high-quality randomized controlled trials directly evaluating isolated algal protein for fatty liver disease in humans.

In summary, while preclinical evidence is promising and supports a potential role for algal protein (or whole algae), human data is limited and of low to moderate quality. Therefore, the overall scientific evidence supporting algal protein specifically for fatty liver disease is currently rated as low to moderate.