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Immunomodulatory effect of astaxanthin on oral mucosal immunity

by Karen Hecht, Ph.D.

Pathogens taking advantage of inhalation and ingestion routes of entry into the body will encounter the mucosal immune system as the body’s first line of defense. The mucous membranes that line the gastrointestinal and respiratory tracts are formidable in size, taking up 200x more real estate than the skin’s surface area. Mucous membranes secrete saliva in the mouth, and mucous in the gut and lungs, helping to trap debris and pathogens. Mucous membranes also secrete factors involved in innate and acquired immune defense. As much as 80% of the body’s antibody production takes place in the gut, serving as a defense against harmful microbiota and food antigens. Immunoglobulin A (IgA) accounts for most of the antibody production in the gut. To illustrate the importance of IgA in defense against pathogens, note that the total daily production of IgA (66mg/kg body weight) surpasses that of all other immunoglobulins combined.

The two principle antibody classes present in saliva are secretory IgA (SIgA) and IgG, with the IgA to IgG ratio in saliva being 500x greater than that found in serum. SIgA binds to opportunistic pathogens, including bacteria and viruses, and blocks them from accessing and entering the epithelial cells lining the inside of the mouth. This process is called “immune exclusion,” and SIgA levels are affected differently by age, physical activity level, as well as stress intensity and duration. Under certain adverse conditions, such as during chronic stress, SIgA levels may drop and increase susceptibility to inhaled and ingested pathogens.

AstaReal® Astaxanthin has been shown to support SIgA levels in response to varying levels of physical and mental stress. In addition to stress as a mediator of SIgA production, older individuals have reduced SIgA secretion rates compared to their younger counterparts. Hongo et al. 2016 reported a randomized, double-blind, placebo-controlled study of 39 healthy subjects (average 48 years old) given 12mg AstaReal® Astaxanthin and 20mg tocotrienol (n=20) for 8 weeks or placebo (n=19). Subjects in this study underwent daily levels of stress simulated using a mental calculation task and stationary bike exercise. This mental and physical load caused a significant decrease in SIgA levels in the placebo group after 8 weeks (p<0.05), while the AstaReal® group maintained consistent SIgA levels throughout the 8 week protocol.

A second randomized double-blind placebo-controlled study, Baralic et al. 2015 examined 40 male elite soccer players (average 18 years old) whom received 4mg/day AstaReal® Astaxanthin (n=21) or placebo capsules (n=19) for 90 days. Previous studies have shown that while a single bout of exercise in soccer players results in increased SIgA output, consecutive bouts of exercise training did not reduce SIgA output as has been seen in cases of prolonged exercise at a high intensity level (as in ultra- marathon runners). This younger, well-trained group of athletes taking AstaReal® had a significant increase of SIgA absolute concentration in saliva, and an increase in SIgA secretion rate after 90 days compared to baseline (p< 0.05). In contrast, there were no significant changes in SIgA concentration or secretion rate in the placebo group.

These studies suggest that AstaReal® Astaxanthin may support mucosal immunity, which functions as a first line of defense against inhaled and ingested pathogens, under conditions of mental and physical stress.

To learn more about clinically-proven benefits of AstaReal® Astaxanthin, and state of the art indoor photobioreactor production technology, visit

Karen Hecht

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