Consuming spirulina is one way to supplement protein and vitamins in people’s diets without notable side effects.

One tablespoon or 7 grams (g) of dried spirulina contains:

• 20 calories
• 4.02 g of protein
• 1.67 g of carbohydrate
• 0.54 g of fat
• 8 milligrams (mg) of calcium
• 2 mg of iron
• 14 mg of magnesium
• 8 mg of phosphorous
• 95 mg of potassium
• 73 mg of sodium
• 0.7 mg of vitamin C

It also contains thiamin, riboflavin, niacin, folate, and vitamins B-6, A, and K.

Taking spirulina, as part of a balanced diet, may help a person to stay well nourished.

 Losing weight

People can usually lose weight if they eat fewer calories than they use. Spirulina is a high-nutrient, low-calorie food that contains a lot of nutrition in a small amount of powder. Introducing spirulina to the diet may help people lose weight without losing nutrition.

The results of a 2016 double-blind placebo-controlled trial suggest that spirulina may aid weight management. In the study, people who were overweight and regularly ate spirulina for 3 months showed improved body mass index or BMI.

Improving gut health

Spirulina can be digested easily because of its structure where the cells do not have tough, fibrous walls. But can consuming it improve gut health?

More research on humans is needed, but animal studies indicate spirulina may support gut health as people age. A 2017 study on older mice suggests that spirulina may preserve healthy gut bacteria during the aging process.

Spirulina does not contain much fiber, so it is essential to include other gut-healthful, high-fiber foods in the diet.

Managing diabetes

Spirulina shows promise as a way to manage the symptoms of diabetes. But more research is needed before doctors can recommend it.

A 2018 review study found that spirulina supplementation significantly lowered people’s fasting blood glucose levels. High fasting blood sugar is a common problem in people with diabetes type 1 and 2. This suggests that spirulina supplements may help people control diabetes.

These results suggest that spirulina shows promise as a food to support type 2 diabetes management.

A 2017 animal study supports the idea that spirulina may help manage diabetes. In this study, the researchers gave mice with type 1 diabetes spirulina extract orally. As a result, the mice showed:

• lower blood sugar
• higher insulin levels
• improved liver enzyme markers

The researchers note that the antioxidant effect of spirulina may be helpful in treating type 1 diabetes.

Lowering cholesterol

Reducing blood pressure

As discussed above, spirulina may lower cholesterol, and there is also evidence that it could help control a person’s blood pressure.

A small-scale 2016 study found that eating spirulina regularly for 3 months reduced people’s blood pressure when they were overweight and had hypertension.

High blood pressure and cholesterol levels are both linked to heart disease. As spirulina may reduce both of these risk factors, is it possible that it could help prevent heart disease?

A 2013 review suggests that these blue-green algae may play a role in preventing heart disease. This might be due to their cholesterol-lowering, anti-inflammatory, and antioxidative effects.

Taking spirulina may help boost a person’s metabolism. A higher metabolic rate may make a person feel as if they have more energy. It may also increase the number of calories they burn each day, which may aid weight loss.

In a small-scale 2014 study, people who took 6 g of spirulina a day experienced beneficial metabolic effects, alongside weight loss and better health-related quality of life.

The people in this study had non-alcoholic fatty liver disease, and so more research is needed to see if spirulina may boost metabolism in others without this condition.

When a person has allergies to pollen, dust, or pets, the inside of their nose may swell. This reaction is called allergic rhinitis. There is some evidence that spirulina could help improve the symptoms of this condition.

A 2013 study states that spirulina can relieve nasal inflammation and reduce histamine in the body. Compared to a placebo, it may reduce the symptoms of allergic rhinitis, including:

• runny nose
• sneezing
• nasal congestion
• itching

A 2011 review notes that there is a reasonable amount of evidence for the positive effects of spirulina on allergic rhinitis, but that larger trials are needed before researchers know the true impact.

Antitoxic action

In certain parts of the world, people are at risk of poisoning from contaminated drinking water and other sources of pollutants. Early research suggests that spirulina may offer a way to treat those affected.

A later 2016 review found that spirulina had antitoxic properties that could counteract pollutants in the body, including:

• arsenic
• fluoride
• iron
• lead
• mercury

The authors of the review suggest that spirulina could be a useful substance to use alongside clinical treatment of pollutant poisoning.

A 2018 paper highlights the potential role that spirulina could play in treating mood disorders.

The theory is that spirulina is a source of tryptophan. Tryptophan is an amino acid that supports serotonin production. Serotonin plays an important role in mental health.

People with certain mental health conditions, such as depression and anxiety, may have reduced levels of serotonin. Taking tryptophan supplements to maintain healthful serotonin levels may play a role in supporting mental wellbeing.

Researchers need to conduct more clinical trials before they know the true role of spirulina in supporting mental health.