By Lauren Cox – Live Science Contributor February 06, 2018
Spirulina is a microalgae that has been consumed for centuries due to its high nutritional value and supposed health benefits. Today, popular lifestyle personalities endorse Spirulina as a secret, potent “superfood,” and a “miracle from the sea.”
“Spirulina” sounds so much better than “pond scum,” but that’s what the popular supplement really is — a type of blue-green algae that grows naturally in oceans and salty lakes in subtropical climates. The Aztecs harvested Spirulina from Lake Texcoco in central Mexico, and it is still harvested from Lake Chad in west-central Africa and turned into dry cakes.
Spirulina was once classified as a plant because of “its richness in plant pigments as well as its ability of photosynthesis,” according to a study published in the journal Cardiovascular Therapeutics. New understanding of its genetics, physiology and biochemical properties caused scientists to move it to the Bacteria kingdom and the Cyanobacteria phylum. At first it was classified in the genus Arthrospira, but later it was placed into the genus Spirulina. There are several species, but three — Spirulina platensis, Spirulina maxima and Spirulina fusiformis — are studied extensively because of their high nutritional as well as potential therapeutic values, according to the study’s authors.
Spirulina grows in microscopic spirals, which tend to stick together, making it easy to harvest. It has an intense blue-green color, but a relatively mild taste. Aside from supplements, the U.S. Food and Drug Administration (FDA) allows manufacturers to use Spirulina as a color additive in gum, candy and other packaged foods.
Health claims about Spirulina
Many people promote Spirulina as a treatment for a range of metabolism and heart health issues, including weight loss, diabetes and high cholesterol, according to the National Institutes of Health (NIH). People may also recommend Spirulina as an aid for various mental and emotional disorders, including anxiety, stress, depression and attention deficit-hyperactivity disorder (ADHD).
Spirulina is said to help a range of eclectic health problems, including premenstrual symptoms and amyotrophic lateral sclerosis (Lou Gehrig’s disease), according to the NIH. A combination of zinc and Spirulina may help the body clear arsenic in people whose drinking water has unusually high levels, according to the NIH.
Does Spirulina work?
The NIH says there is not enough scientific evidence to determine if Spirulina is effective in treating any health conditions. However, Spirulina is rich in nutrients, some of which aren’t found in the average daily vitamin. According to the FDA, Spirulina contains significant amounts of calcium, niacin, potassium, magnesium, B vitamins and iron. It also has essential amino acids (compounds that are the building blocks of proteins). In fact, protein makes up about 60 to 70 percent of Spirulina‘s dry weight.
Nevertheless, a person would have to take Spirulina supplements all day to come close to the recommended daily amounts of the nutrients it contains, said Heather Mangieri, a spokeswoman for the Academy of Nutrition and Dietetics and owner of Nutrition Checkup in Pittsburgh, Pa. And that’s not the only issue with superfood supplements.
“There’s lots of foods that, yes, they have a lot of nutrients in them, but we don’t necessarily know the bioavailability so we don’t know how much of that nutrient you are actually getting,” Mangieri said.
Bioavailability describes how much of the nutrients you swallow are actually used by the body. In some cases, eating two different foods at once will help the body absorb nutrients better than if the person ate the foods separately. For example, Mangieri said, the leucine found in tomatoes is better absorbed by the body if you eat oil with tomatoes. Scientists are still studying the bioavailability of nutrients in individual foods, as well as how nutrients work to help prevent disease.
“As a registered dietitian, I highly recommend people get their nutrients from foods in a healthy diet because nutrients work synergistically, and that increases the bioavailability,” Mangieri said.
Spirulina to stop malnutrition
Given its high nutritional profile, scientists examining malnutrition have shown an interest in Spirulina. Several studies have looked at the effects of its supplementation among malnourished populations, including anemic pregnant women and children in developing countries with high poverty rates, according to a 2017 review published in the Journal of International Medical Research.
One such study, published in Maternal and Pediatric Nutrition in 2016, involved 87 malnourished and anemic children under age 5 from Gaza. Researchers gave half the children vitamin and mineral supplements and half Spirulina supplements for three months. The children who received Spirulina saw significantly more improvement in…