Blue-green algae are primitive organisms sharing properties with bacteria and plants. Scientific investigations have identified multiple biologically-active substances inside the algae which are reported to have beneficial effects on human health. A specific species of blue-green algae, Aphanizomenon flos-aquae, contains potent plant-derived chemicals which are postulated to exert positive effects on the immune system, our bodies' frontline defense against disease.

The capacity and potential of the human immune system are measured not only by the absolute blood concentration of circulating immune cells, but also depend on the ability of the immune cells to reach invading foreign particles in various tissues.

This immune response requires a complex interaction between the production of immune cells, their bloodstream transport throughout the body, their entry into the target tissue through blood vessels walls, and the targeting and destruction of the invading cells.

Multiple mediators (cytokines, cell receptors, nerve impulses) orchestrate this immune response, and allow for the so-called "trafficking" of immune cells throughout the human body.

Stress-induced increase of adrenaline-like substances (catecholamines) and cortisol can unfavorably affect the immune response, and weaken the body's self-defense system. These types of stress responses specifically inhibit natural killer (NK) cells and impair their ability to enter tissue cells.

A research team led by Gitte Jensen, PhD, at McGill University in Montreal, Quebec, conducted a pilot study involving twenty-one healthy volunteers to examine the short-term effects of consumption of a moderate amount (1.5 grams) of Aph. flos-aquae on the immune system. The results of this study completed the scientific peer-review process and were published in the Journal of the American Nutraceutical Association (JANA, January 2000; 2 (3): 50-58).

To eliminate a bias, the study was blinded: none of the volunteers in the Jensen study knew if they received the algae, or a placebo. Blood samples were drawn prior to the ingestion of the test dose, and two hour later. The data analysis involved multiple cell lines including lymphocytes, monocytes, memory cells, natural killer cells, and others.

The results suggest a mild stimulating effect on the immune system, consisting of a mobilization of white blood cell strains (lymphocytes) and monocytes, and the entry of natural killer cells into the human tissue.

While application of the Jensen et al. study results into clinical practice are limited by the small number of participants, and the lack of continuous monitoring of the immune marker, the study is encouraging and serves as an excellent example of a pilot study, with results that should lead to expanded clinical trials.

*Dr. Wollschlaeger is a board certified Family Physician in Miami, Florida, and a Clinical Assistant Professor of Medicine and Family Medicine, University of Miami, School of Medicine (Voluntary Faculty). He lectures extensively throughout south Florida and the United States at continuing medical education (CME) conferences on the use and integration of nutraceuticals into medical practices. Dr. Wollschlaeger also serves as associate editor of the Journal of the American Nutraceutical Association, and as co-chair of the ANA Continuing Medical Education Advisory Council.