Macroalgae are large algae that can be seen without a microscope. They are often found in dense seawater beds and are commonly known as seaweeds; one familiar example is kelp. Macroalgae come in many colors including green, red, brown, and blue, as well as in a variety of forms; some grow tall, while others grow in mat-like structures.

Typically found in freshwater and marine systems, microalgae are very small unicellular organisms that can exist individually or in chains or groups. Although virtually invisible individually, when these single-celled microscopic algae organisms join or chain themselves together in large enough numbers, they become visible to the unaided eye.

What are the advantages of each type of algae?

Macroalgae are known to have many nutrition and health benefits. They contain key antioxidants and have anti-inflammatory, antibacterial, anticoagulant, and antiviral properties.¹ As a result, seaweed-derived compounds have important applications in a range of products, from foods to pharmaceuticals and cosmetics. In addition to bioactive components, macroalgae are a rich source of dietary fiber (25-75% dry weight), of which water-soluble fiber constitutes approximately 50-85%.

Microalgae, while naturally available in a few global ecosystems, can also be cultivated under difficult environmental conditions and are able to produce a wide range of commercially useful byproducts such as fats, oils, sugars, and functional bioactive components, including carotenoids, chlorophyll, and phycocyanin. Microalgae have also generated great interest as a potential renewable energy source.² Because of their nutrient-rich characteristics, cyanobacteria (blue-green microalgae) such as Aphanizomenon flos-aquae (AFA) have come to be known as a natural 'superfood.' Nutrients found naturally in wild-crafted AFA include: antioxidants such as beta-carotene that help neutralize free radicals; an ideal ratio of Omega-3 to Omega-6 essential fatty acids to help maintain normal cholesterol levels; 13 readily available vitamins; all 20 amino acids that provide the building blocks for cellular health; 23 minerals and trace minerals; over 60% fully digestible vegetarian protein by weight; phytonutrients vital to support the health of the immune system; complex sugars that offer a stable energy source; and active enzymes that permit maximum absorption of nutrients.³

While most forms of algae, both macro and micro, can be beneficial, microalgae—in particular, Aphanizomenon flos-aquae—have been shown to be superior in many areas of health when used as part of a balanced diet along with sufficient exercise and plenty of fresh water.⁴

______

1. O’Sullivan L., et al. Prebiotics from Marine Macroalgae for Human and Animal Health Applications Mar. Drugs 2010, 8, 2038-2064; doi:10.3390/md8072038.
2. Satin M. Microalgae, Agro-Industries and Post-Harvest Management Service, Food and Agricultural Organization of the United Nations.
3. Kay R. A., Microalgae as Food and Supplement. Critical Reviews in Food Science and Nutrition. 30(6):555-573 (1991) by CRC Press Inc.
4. Bruno J. Edible Microalgae: A Review of the Health Research (Version 3.0), 2001, Center for Nutritional Psychology Press.