Scientists are still exploring the benefits of spirulina. Some evidence suggests that it may aid in weight loss, lower cholesterol, and regulate blood sugar if you take spirulina every day.
Spirulina is a type of cyanobacteria (blue-green algae) that grows naturally in saltwater lakes and oceans. It's rich in protein, vitamins, minerals, carotenoids, and antioxidants that can protect cells from damage.
The Aztecs in Mexico and people in the Lake Chad area of Africa have used spirulina for centuries. Spirulina didn't become popular in the U.S. until the 1970s. You can buy this algae in capsules or green or blue spirulina powder that you add to baked goods, smoothies, or water.
Spirulina may be beneficial for people with obesity. A review published in 2019 found that spirulina may reduce body fat percent and waist circumference in people who carry more weight. This review only included five studies, so more studies are needed to conclude how spirulina may aid in weight loss.
Can Reduce Blood Pressure
Some evidence suggests that spirulina can help regulate blood pressure and manage hypertension (high blood pressure). A review published in 2021 looked at people diagnosed with hypertension. The researchers noted that those who took 4.5 grams (g) of spirulina daily for six weeks saw decreases in blood pressure.
The study authors also found that supplementing with 2 g of spirulina for twelve weeks decreased systolic blood pressure by 7 millimeters of mercury (mmHG). Spirulina also reduced diastolic blood pressure by 6 mmHG.
Systolic blood pressure is the top number on a blood pressure reading. It tells you the pressure inside the arteries is when your heart beats. Diastolic blood pressure is the bottom number, which tells you the pressure inside the arteries when your heart is at rest.
Research has shown that supplementing with spirulina can decrease cholesterol levels and help with overall metabolic health. High cholesterol levels increase the risk of atherosclerosis, or plaque build-up in the arteries. This condition is a risk factor for coronary artery disease (CAD).
Has Been Shown To Manage Anemia
Spirulina is a source of iron, and it's been shown to help people with anemia. Anemia causes reduced amounts of hemoglobin and red blood cells. The body can't produce enough hemoglobin, which is an essential part of red blood cells that carry oxygen to the tissues, without iron.
Some evidence suggests that spirulina can reduce allergy symptoms in the nose, or allergic rhinitis. A small study published in 2020 found that spirulina was more effective at reducing allergies than the medication Zyrtec (cetirizine). More research is needed, but the results of this study may have promising implications.
Is a Good Source of Protein
Spirulina is a good source of protein, especially for vegans or those who don't eat animal products. Spirulina has 4 g of protein per tablespoon (tbsp), which is more protein than many plant-based sources.
Spirulina is an antioxidant that has anti-inflammatory properties. Supplementing with spirulina may boost the efficiency of the immune system, potentially stimulating white blood cells that destroy infectious or cancer cells.
Spirulina also has probiotic qualities that may improve gut health. Probiotics may have an antioxidant effect. They neutralize free radicals, which are unstable compounds that damage cells, causing illness and premature aging.
Is Rich in Nutrients
Spirulina is a nutrient-rich food that contains a variety of vitamins, minerals, amino acids, coenzymes, and antioxidants. It's a good source of protein and provides essential amino acids.
Spirulina contains high amounts of antioxidants like beta-carotene and vitamin E and minerals like magnesium, zinc, copper, selenium, and iron. Spirulina is also a good source of both omega-6 and omega-3 fatty acids.
Some evidence suggests that spirulina may protect against cancer. A review published in 2021 found that cyanobacteria like spirulina act as anticancer agents in the body. Spirulina may have the ability to slow or stop the growth of cancer cells.
Substances in blue-green algae have antioxidant and antimetastatic (cancer-spreading) qualities. There are also indications that blue-green algae could work well with other cancer-fighting drugs. It's important to note that this research doesn't mean that taking spirulina supplements you buy online or from a health foods store will stop or prevent cancer.
May Regulate Blood Sugar
It's important to regulate your blood sugar if you have diabetes or are at risk of diabetes. A review published in 2021 found that spirulina supplementation in doses ranging from 0.8 g to 8 g daily can improve fasting blood sugar levels and lipid profiles in people with type 2 diabetes. More studies are needed to draw conclusive findings.
Research has shown that spirulina might support oral health. A study published in 2019 found that spirulina can fight oral submucous fibrosis (OSMF), but more studies are needed.This condition can lead to cancerous lesions in the mouth.
Might Treat Fatty Liver Disease
A small study published in 2014 found that supplementing with spirulina may help people who have non-alcoholic fatty liver disease (NAFLD). The participants took a high dose of spirulina (6 g) daily for six months.
There were significant reductions in liver enzyme levels, triglycerides, total cholesterol, and LDL ("bad") cholesterol. The study authors also noted a reduction in the total ratio to HDL ("good") cholesterol levels. All of these reductions indicate a more healthily functioning liver.
Spirulina is sold either in capsules or as a green or blue powder that you add to food. It's savory and has a vague seafood-like flavor that can be offset with fruit or other sweeteners. Many people enjoy the flavor on its own.
There are many uses for spirulina in powder form, including:
- Baking it into bread or other baked goods
- Blending it into a smoothie
- Mixing it into yogurt or water
- Using it as an ingredient in energy bites or salad dressings
Dosage
People have taken up to 10 g of spirulina daily for up to six months without any issues. You may start with a low dose and work your way up if you are just starting to consume spirulina. This helps avoid unpleasant side effects such as gas, bloating, or diarrhea.
Is Spirulina Safe?
Children, pregnant people, and those who are breastfeeding shouldn't consume spirulina. Research has shown that people with autoimmune disorders shouldn't consume spirulina. It may stimulate the immune system and worsen the condition.
Standard Disclaimer
When buying a supplement, make sure the product is third-party tested. Unlike medications, supplements are not regulated by the FDA. This means their quality and safety can vary. Third-party testing confirms that the supplement contains the ingredients listed on the label and is free from harmful contaminants. Check for seals from reputable organizations such as NSF International, USP (United States Pharmacopeia), or ConsumerLab.
Potential Drug Interactions
It's important to not take spirulina alongside certain medications, including:
- Anticoagulant drugs
- Antiplatelet drugs
- Any medications that lower the immune system
- Diabetes medications
Talk to a healthcare provider if you're taking any herbal supplements, especially ones that lower blood sugar or slow blood clotting. These supplements may be dangerous to mix with spirulina. Spirulina contains about 0.26 micrograms (mcg) of vitamin K per gram. Anything more than this can enhancethe blood-thinning effect of other supplements.
What To Look For
Spirulina is typically found in saltwater lakes and oceans, but it's important not to consume spirulina that you detect in the wild. This blue-green algae may be contaminated with harmful substances. Look for capsules or a green or blue powder that are sold by reputable companies and are third-party tested.
Can You Take Too Much?
You can take too much spirulina. Taking more than the recommended dosage increases the risk of excess nutrients in the body. Too much iron, for example, can cause abdominal pain, diarrhea, nausea, and vomiting.
It's important to consult a healthcare provider about how much spirulina is safe to take per day. They can help you avoid the health risks of excess nutrients.
Spirulina may be contaminated with toxins if it grows in bodies of water that are polluted with heavy metals, bacteria, or microcystins. This type of bacteria is produced by blue algae to protect it against predators.
Stop consuming spirulina and contact a healthcare provider if you develop any of the following adverse effects:
- Allergic reactions, such as rashes and hives
- Abdominal pain or cramps
- Dark-colored urine
- Headache
- Muscle aches
- Rhabdomyolysis, or the harmful breakdown of muscle tissue
- Sweating
- Swelling
- Trouble concentrating
A Quick Review
Spirulina is a nutrient-rich blue-green algae that people have consumed for decades. It has antioxidant qualities and may reduce blood pressure, decrease high cholesterol, regulate blood sugar, and improve oral health.
It's important not to use spirulina as a substitute for medical care. Be sure to speak with a healthcare provider or pharmacist before you introduce a new supplement to your daily routine.
Frequently Asked Questions
Does spirulina block vitamin B12 absorption?
It’s not clear whether taking spirulina blocks vitamin B12 absorption. The type of B12 found in spirulina is not found naturally in the human body. It may not be helpful for people looking to raise their B12 levels.
How is spirulina different from chlorella?
Both spirulina and chlorella are nutrient-rich forms of algae, but they're not the same organism. Chlorella is higher in calories and fat than spirulina. Unlike spirulina, chlorella contains vitamin D2.
Is spirulina safe for the kidneys?
Spirulina is generally safe for the kidneys. It's a source of protein and amino acids, which may support the function of the kidneys. More research is needed to know the effects of amino acids on the kidneys.
