Chlorella

What is chlorella?

Chlorella is a green microalga that is primarily composed of protein (up to 60% of its dry weight), including all of the essential and nonessential amino acids, with the most abundant of these being glutamate, leucine, aspartate, and lysine. Chlorella also contains fatty acids — mostly alpha-linolenic acid and linoleic acid — and carbohydrates, most of which are polysaccharides (dietary fibers), including alpha-glucans and beta-glucans. Chlorella is also a rich source of micronutrients, including the minerals sodium, potassium, iron, calcium, magnesium, and zinc; vitamins A, C, E K1 and the B vitamins (notably vitamin B12 ); and carotenoids, including astaxanthin, zeaxanthin, beta-carotene, and lutein. Because chlorella is a rich source of vitamin B12, it’s often consumed as a plant-based source of this nutrient by vegans and vegetarians.

What’s the difference between chlorella and spirulina?

Chlorella is a single-cell green alga that lives in freshwater, while spirulina, despite its common name of “blue-green algae”, is a genus of cyanobacteria that forms filamentous, multicellular colonies in saltwater. The nutrient profiles of chlorella and spirulina are quite similar — both contain carbohydrates, protein, folate, riboflavin, thiamine, iron, and polyunsaturated fatty acids, though chlorella contains more omega-3 fatty acids while spirulina is higher in omega-6 fatty acids. Spirulina also contains copper, which is absent from chlorella. Chlorella has higher levels of vitamin A, iron, magnesium, niacinamide, and phosphorus compared to spirulina. Finally, while chlorella supplements are a good source of vitamin B12, the B12 in spirulina supplements is often biologically-inactive pseudovitamin B12.

What are chlorella’s main drawbacks?

Because chlorella contains a cellulose cell wall (unlike spirulina), it must undergo mechanical processing to break down these cell walls before human consumption to avoid gastrointestinal side effects like nausea, vomiting, and stomach pain. Furthermore, some studies have confirmed that chlorella is an allergen, so some individuals (notably children) may be sensitive to it or want to avoid its consumption.

How does chlorella work?

Supplementing with chlorella reduces oxidative stress and increases the activity of enzymatic and non-enzymatic antioxidants in rats and increases antioxidant activity (by increasing levels of catalase and superoxide dismutase) in male smokers. In humans, chlorella has notable antilipidemic, antihypertensive, and antihyperglycemic effects — it reduces total and LDL cholesterol, systolic and diastolic blood pressure, and blood glucose. The blood-glucose-lowering effects of chlorella may be due to its ability to improve insulin sensitivity and glucose uptake in the liver and skeletal muscles; these effects may be more potent when chlorella is combined with exercise training. Certain constituents of chlorella bind to digested dietary fat, increase the scavenging of LDL cholesterol, and reduce the absorption of sterols in the intestine, explaining chlorella’s cholesterol-lowering effects. Chlorella has exhibited detoxifying effects. It inhibited the intestinal absorption of dioxins (environmental contaminants and pollutants) in animal models and the absorption of heterocyclic amines in humans. Chlorella also reduced mercury levels in the hair and blood of healthy adults.

What are chlorella’s main benefits?

Although the evidence in humans is somewhat limited, chlorella appears to reduce blood pressure and enhance immune system function. For pregnant women, chlorella supplementation is well-tolerated, may reduce the risk of pregnancy-associated anemia, is associated with less leg edema, and increases levels of immunoglobulin A in breast milk. Chlorella has synergistic effects with exercise on body composition and metabolic health. It also may be ergogenic, improving maximal and submaximal exercise performance in healthy adults, adults with overweight/obesity, and trained athletes.