Astaxanthin (2002-2006) Reduces Eye Fatigue
A number of double blind controlled pilot studies suggest beneficial results from supplementation with the carotenoid astaxanthin on vision health. Thirteen subjects who received 5mg astaxanthin daily for a month showed a 54% reduction in complaints of eye fatigue1. Another study of of 9 patients in a sports vision study found that depth perception and critical flicker fusion had improved by 46% and 5% respectively following daily 6mg astaxanthin2.
These and other results prompted more clinical studies to investigate optimum dose and understand why the benefits occurred.
Dosages of 4mg and 12mg were evaluated, both showing benefit in eye fatigue3. An optimum daily dosage of 6mg was determined in a study of 10 patients4 over the course of a month. Patients' results were evaluated by comparing eye fatigue using a standardized visual questionnaire in which a 6mg test group improved significantly at testing in 4 and 6 weeks. Later results substantiated these results in which 6mg taken for 4 weeks notedly improved eye fatigue, sore dry eyes, and blurry vision5, 6.
Yet another study demonstrated the same results; this time the study was designed to demonstrate that astaxanthin supplementation is effective as a preventative. Patients who had been taking astaxanthin recovered more quickly from intense visual stimulus than those who had not.7 These results of preventative value of astaxanthin were substantiated by later research in another randominzed, placebo-controlled, double-blind study.8
1. Nagaki, Y, Hayasaka, S, Yamada, T, Hayasaka, Y, Sanada, M, et al. (2002). Effects of astaxanthin on accommodation, critical flicker fusions, and pattern evoked potential in visual display terminal workers. J Trad Med, 19(5):170-173.
2. Sawaki, K., et al. (2002). Sports performance benefits from taking natural astaxanthin characterized by visual acuity and muscle fatigue improvement in humans. J Clin Ther Med, 18(9):1085-1100.
3. Nakamura, A., Isobe, R., Otaka, Y., Abematsu, Y., Nakata, D., et al. (2004). Changes in Visual Function Following Peroral Astaxanthin. Japan J Clin Opthal, 58(6):1051-1054.
4. Nitta, T., Ogami, K., Shiratori, K. (2005). The effects of Astaxanthin on Accommodation and Asthenopia-Dose Finding Study in Healthy Volunteers. Clin Med, 21(5):543-556.
5. Shiratori K, Ohgami K, Nitta T, Shinmei Y, Chin S, et al. (2005). Effect of astaxanthin on accommodation and asthenopia - Efficacy identification study in healthy volunteers. J Clin Therap Med. 21(5):543-556.
6. Nagaki Y, Mihara M, Tsukuhara H, Ohno S. (2006). The supplementation effect of astaxanthin on accommodation and asthenopia. J Clin Therap Med, 22(1):41-54.
7. Takahashi, N., Kajita, M. (2005). Effects of astaxanthin on accommodative recovery. J Clin Therap Med, 21(4):431-436.
8. Iwasaki T, Tawara A. (2006). Effects of Astaxanthin on Eyestrain Induced by Accommodative Dysfunction. Atarashii Ganka,, (6):829-834