Blue-Green Algae

Blue-green algae supplements come in the form of capsules, pills, and powders. An important part of the food chain in lakes and ponds worldwide, blue-green algae are microscopic plants with characteristics of both bacteria and algae (such as seaweed), but are more closely akin to bacteria. The two main blue-green algae types are Spirulina and Aphanizomenon flos-aquae (AFA). AFA is chiefly harvested from Upper Klamath Lake in southern Oregon and then freeze-dried and sold in capsules and other forms. The largest manufacturer is Cell Tech, which sells its "Super Blue-Green Algae" via thousands of special distributors.

Blue-green algae contain small amounts of protein, vitamins (including C, E, and folate), beta carotene, and some minerals. But unless you eat huge amounts of algae, they are a negligible source of nutrients. Like green plants, they are rich in chlorophyll, a pigment that enables them to turn sunlight into energy. But chlorophyll is of no use to the human body.

Claims, purported benefits: Prevents cancer and heart disease and boosts immunity. Treats or cures a host of ailments, including asthma, allergies, anxiety, depression, fatigue, hypoglycemia, digestive problems, and attention deficit disorder. Helps with weight loss, improves memory and mental ability, "detoxifies" the body.

Bottom Line: Blue-green algae is not a medicine or a good source of nutrients. The few nutrients in blue-green algae are more plentiful and cheaper in foods. There’s no scientific evidence that blue-green algae can treat or cure any illness or has any health benefit. In a recent court decision in California, marketers of blue-green algae were told to stop making health claims. Blue-green algae, especially AFA harvested from natural lakes, are easily contaminated with toxins such as microcystins and heavy metals. Because Health Canada, the equivalent of the U.S. FDA, found that some blue-green algae supplements (but not spirulina) contain high levels of microcystin, it has warned consumers—especially those thinking of giving AFA to their children—about potential contamination.