South China Morning Post reports that the latest innovation in urban farming does not focus on soil or seeds, tomato plants or mint leaves. No, sustainability in city settings is all about barrels of green liquid bubbling under the sun: spirulina, long-known as an ‘edible algae,’ is now being successfully farmed throughout Bangkok... on its rooftops.

"The algae is growing so fast, normally the doubling time is around 24 hours," Patsakorn Thaveeuchukorn told Agence France-Presse. His employer, EnerGaia Company, Ltd., which routinely uses Bangkok's many rooftops to grow spirulina, assigns Thaveeuchukorn the task of harvesting the green algae three times a week. (He is the production and sourcing director for the company.) Once collected, the algae is hand-rinsed and spun dry. The final step is to hand-press the resulting jelly-like substance into jars, which are then made available to consumers.

EnerGaia, which was ‘newly incorporated’ in April 2009, is managed by a primarily American-educated team. Addressing questions of contamination on its website, the company states that it “uses food safe plastics to ensure the best quality, chemical free Spirulina possible. Our bio-reactors are 100% polypropylene which is widely considered to be one of the safest plastics for food storage.”

The company states its product has been tested to ensure it meets the food and safety standards of the Food and Drug Administration, EU, and the Thai government.

Food Resource

According to Boundless, an educational company founded in 2011, algae are a diverse group of simple unicellular or multicellular organisms with a distinct membrane-bound nucleus. Because they contain protein, fiber, and high levels of omega-3 fatty acids, algae are of excellent nutritional value; they are also known to be rich in vitamins, including A, C, B1, B2, B3, and B6, and minerals, including iodine, calcium, potassium, magnesium, and iron. Seaweeds are edible algae that have been used for centuries as food worldwide, while cultivated cyanobacteria, such as spirulina, are generally sold as nutritional supplements in the U.S.

Meanwhile, Livestrong reports that spirulina may enhance the immune system and may also possess detoxifying abilities, helping to increase urinary excretion of arsenic in people with chronic exposure. The edible algae was found to increase hemoglobin levels in malnourished children in West Africa. As it is long known as a bodybuilder's nutraceutical food supplement, a study published in the European Journal of Applied Physiology recorded the reactions of volunteers who underwent a physically demanding treadmill exercise after taking spirulina for three weeks; researchers found that spirulina prevented damage to skeletal muscles, Livestrong reports.

Finally, research published in Cardiovascular Therapy found that spirulina also boasts hypolipidemic (meaning it reduces lipid concentrations in blood), antioxidant, and anti-inflammatory activities. Data from preclinical studies with various animal models demonstrates these activities, though human studies have been inconclusive due to the small number of participants, noted the study's researchers from the University of Rhode Island.

“Spirulina is generally considered safe for human consumption supported by its long history of use as food source and its favorable safety profile in animal studies,” wrote the authors. Judging from these diverse reports on its nutritional benefits and its sustainability profile, spirulina is an important food resource both for the present and future.

Source: Deng R, Chow TJ. Hypolipidemic, antioxidant, and antiinflammatory activities of microalgae Spirulina. Cardiovascular Therapy. 2010.