Spirulina: pond scum or superfood?

On a recent layover in Chicago, I found myself standing in the smoothie line at the airport, dazed, jet-lagged, and craving kale. Or anything green. I’d been away from California too long.

No kale in sight, I added an impulsive $2 spirulina booster instead, rendering my smoothie the deepest, darkest green I could have imagined. It was an intimidating 12 ounces, with an ominous murk, as if they had crammed the Everglades into the blender and hit “pulse.”

I’ll save impulse decisions for a future column. It was the gritty mealiness of all that blue-green algae powder, and its overpowering pond-like flavor, that led me to wonder if spirulina is really all it’s cracked up to be. After all, this cyanobacterium, scorned by some and promoted with religious fervor by others, is still, quite literally, pond scum.

After consulting several local nutrition experts, the short answer is yes, spirulina can be quite nutritious, but not all spirulina is created equal—and the airport version I’d sprung for could have done more harm than good.

“Some spirulina supplements have been found to be contaminated with microcystins, very toxic compounds not produced by spirulina but by related algae that can grow with it,” says Dr. Randy Baker of Soquel’s Pacific Center for Integral Health. “Some may be contaminated with lead, mercury and arsenic. Because spirulina can be a magnet for toxins, I am cautious about spirulina harvested from wild sources.”

The reputability of spirulina harvested from the less-than-pristine Klamath Lake in Oregon, for instance, is frequently challenged. And if it’s coming from close to the radiation disaster in Japan, stay away.

The fact that spirulina doubles its biomass every two days without depleting topsoil makes it a sustainable and lucrative business endeavor. But spirulina is more than just a recent health fad promoted by multi-level marketing: the nutritious algae was harvested from Lake Texcoco and sold as cakes by the Aztecs and Mesoamericans. It forms a complete protein, and if you can find a pure source, there is every reason to give it a try.

“[Spirulina] is a concentrated source of amino acids, essential fatty acids, vitamins, minerals, and especially the antioxidant carotenoids like zeaxanthin,” says Dr. Baker.

But like many natural products, there is very little research on it—and it wasn’t until recently that Dr. Andrew Weil withdrew his conviction that the blue-green algae produces neurotoxins, thanks to a favorable safety rating by the United States Pharmacopeia Dietary Supplements Information Expert Committee in 2010.

“Research studies cost a lot of money, and for a product that can’t be patented, there is no profit motive for someone to fund research,” says Dr. Baker.

The limited human studies that have been done suggest that spirulina may be beneficial for allergic rhinitis, says Baker. “The study that impressed me the most was in people who chew tobacco and had precancerous oral lesions,” says Baker. “Twenty of 44 who took spirulina had these lesions resolve, compared to three of 43 who took a placebo.”

A 2007 study in Mexico, published by the U.S. National Library of Medicine, showed that spirulina supplements can help lower blood pressure and cholesterol.

“Greens expert” Christine Miyoshi of Way of Life in Capitola, has been taking spirulina for almost eight years now. “The thing that I notice most is the energy it gives me,” says Miyoshi, who also happens to never get sick despite working in an environment that sees a lot of sick people—and she credits spirulina. “Because it also helps to alkalize your system, and when your system is alkalized disease can’t get in.”

Like Baker, who has taken spirulina for the past 25 years, Myoshi takes hers as part of a concentrated green powder that combines wheat grass extracts, chlorella, and many other superfood extracts that cover a broad spectrum of nutrients and minerals. She recommends a $4 sample bottle from Health Force to start.

“I always tell people to start small with spirulina, because of its detoxifying effects,” says Miyoshi. She’s right: expect some gurgling in your stomach, and possibly even laxative effects.

And don’t throw caution to the wind either: if you don’t know where it was harvested, you should probably just skip it.

“Since most juice bar and natural food store employees will not know where their bulk spirulina is sourced, it’s better to go with local organic fresh greens in smoothies and to eat other forms of seaweed for iodine, calcium, iron and other potent nutrients,” says Joceylin Dubin, registered dietician at Nourish. Dubin recommends wakame, dulse, nori, kombu, hijiki and arame from Emerald Cove brand.