Are there any side effects known to be caused by astaxanthin?

What is known about dietary astaxanthin intake by humans?

Astaxanthin occurs naturally in several of our commonly eaten foods, perhaps most importantly in salmon. Astaxanthin levels in the flesh of farm-raised Atlantic salmon range from about 4 to 10 mg/kg, whereas levels in wild Pacific salmon can be much higher with a recent FDA study reporting an average of about 14 mg/kg in coho salmon and about 40 mg/kg in sockeye salmon (Turujman et al. 1997). Thus, a reasonable serving portion of 4 ounces (one-fourth of a pound, 113.4 g) of farmed Atlantic salmon would contain from 0.5 to 1.1 mg of astaxanthin, whereas the same amount of wild-caught sockeye salmon would contain 4.5 mg of astaxanthin.

A short-term study in healthy human subjects is described in a published unexamined Japanese patent application for the use of an astaxanthin-containing drink to protect low-density lipoprotein (LDL) from oxidation (Miki et al. 1998). In that study, astaxanthin was administered daily over 2 weeks to 5 subjects at 3.6 mg/day, to 5 subjects at 7.2 mg/day, and to 3 subjects at 14.4 mg/day. No ill effects were reported at any dose, and in fact an antioxidant effect on serum LDL was observed, with LDL oxidation progressively slowed with increasing doses of astaxanthin (Miki et al. 1998).

One study on the kinetics of dietary astaxanthin uptake by humans has been reported (Østerlie et al. 1999a, 1999b). In this study, three middle-aged, smoking, male volunteers were given a single olive oil-containing meal with 100 mg of synthetic astaxanthin as a defined mixture of all-E (all-trans), 9Z (9-cis), and 13Z (13-cis) geometric isomers (and with the 3S,3'S:3R,3'S:3S,3'S stereochemical ratio of 1:2:1). The appearance and distribution of astaxanthin was quantified by HPLC analysis of blood samples taken ten times over the 72 hours following the meal. The maximum plasma concentration of astaxanthin was 1.24 mg/L, observed 6 hours postprandially. There was an enrichment of the 13Z isomer in plasma; whether this was due to a preferential uptake of the 13Z isomers, preferential catabolism of the all-E and 9Z isomers, in vivo isomerization, or some other process was not determined. Distribution of the E/Z isomers was consistent among chylomicrons/VLDL, LDL, and HDL lipoprotein fractions. During the absorptive phase, the relative concentration of total astaxanthin in HDL decreased compared to the other lipoprotein fractions. The relative ratio of stereochemical isomers remained unchanged.

An international patent application describes studies of the effect astaxanthin has on mammalian muscle function (Lignell 1999). One experiment was conducted over 6 months with 40 healthy volunteers, half of whom received 1 capsule containing 4 mg astaxanthin (in the form of algal meal) each morning in association with food, and half of whom received a placebo. Changes in physical performance parameters were measured by standardized tests as follows. Strength/endurance was estimated when a person made a maximum number of knee-bends in a Smith machine with 40 kg load. Strength/explosiveness was tested under standardized conditions in a Wingate machine. Condition was tested by a step test with 17 kg load and a bench height of 32 cm until a steady-state pulse rate was reached. Body weight was measured before and after the experiment. No significant difference was observed between the treatment and placebo groups in any of the parameters measured except for strength/endurance, where the number of knee-bends increased in both groups (placebo mean of 23.78% and treatment mean of 61.74%).

A recent study was designed specifically to examine the effects by dietary astaxanthin on the health of humans (Mera Pharmaceuticals, Inc. 1999). In this study, 33 healthy adult volunteers were given astaxanthin from a natural source (Haematococcus pluvialis dry algal meal). Over a period of 29 days, each subject consumed daily either 3.85 mg astaxanthin (low dose) or 19.25 mg astaxanthin (high dose). Volunteers underwent a complete medical examination before, during, and at the end of the study. The parameters examined by an independent physician included weight, skin coloration, general appearance, blood pressure, near and distant vision, color vision, depth perception, general eye condition, ears and nose, mouth, throat and teeth, chest and lungs, and reflexes. This medical examination was complemented by extensive urinalyses and blood analyses (cell counts, hemoglobin, liver enzyme activity indicators, and other blood parameters). No ill effects or toxicity from ingestion of the astaxanthin supplement were observed.

Lignell, Å. (1999) Medicament for improvement of duration of muscle function or treatment of muscle disorders or diseases, Patent Cooperation Treaty application #9911251. AstaCarotene AB, Sweden.

Miki, W., Hosoda, K., Kondo, K., and Itakura, H. (1998) Astaxanthin-containing drink. Patent application number 10155459. Japanese Patent Office. Publication date 16 June 1998.

Østerlie, M., Bjerkeng, B., and Liaaen-Jensen, S. (1999a) On bioavailability and deposition of bent Z-isomers of astaxanthin. Proceedings of the First International Congress on Pigments in Food Technology, Sevilla, Spain, 24-26 March 1999, pp.157-161.

Østerlie, M., Bjerkeng, B., and Liaaen-Jensen, S. (1999b) Blood appearance and distribution of astaxanthin E/Z siomers among plasma lipoproteins in humans adminstered a single meal with astaxanthin. Abstract 2A-13. Abstracts of the Twelfth International Carotenoid Symposium, Cairns, Australia, 18-23 July 1999, p. 72.

Turujman, S. A., Wamer, W. G., Wei, R. R., and Albert, R. H. (1997) Rapid liquid chromatographic method to distinguish wild salmon from aquacultured salmon fed synthetic astaxanthin. J. AOAC Int., 80(3):622-632.

Are there any side effects known to be caused by astaxanthin?

No negative effects on health have been described in the limited number of human studies of dietary astaxanthin (Mera Pharmaceuticals 1999, Lignell 1999, Miki et al. 1998, Østerlie et al. 1999a, Østerlie et al. 1999b).

Lignell, Å. (1999) Medicament for improvement of duration of muscle function or treatment of muscle disorders or diseases, Patent Cooperation Treaty application #9911251. AstaCarotene AB, Sweden.

Miki, W., Hosoda, K., Kondo, K., and Itakura, H. (1998) Astaxanthin-containing drink. Patent application number 10155459. Japanese Patent Office. Publication date 16 June 1998.

Østerlie, M., Bjerkeng, B., and Liaaen-Jensen, S. (1999a) On bioavailability and deposition of bent Z-isomers of astaxanthin. Proceedings of the First International Congress on Pigments in Food Technology, Sevilla, Spain, 24-26 March 1999, pp.157-161.

Østerlie, M., Bjerkeng, B., and Liaaen-Jensen, S. (1999b) Blood appearance and distribution of astaxanthin E/Z siomers among plasma lipoproteins in humans adminstered a single meal with astaxanthin. Abstract 2A-13. Abstracts of the Twelfth International Carotenoid Symposium, Cairns, Australia, 18-23 July 1999, p. 72.