Abstract

Lutein, an oxygenated carotenoid synthesized by plants and microbes, is concentrated in the retina of the eye in a variety of species, and may enhance ocular health.² Given the high incidence of ocular pathology in captive marine mammals,¹ it was hypothesized that a lutein supplement may provide protection against some of these conditions.

To determine the ability of marine mammals to absorb dietary lutein, a variety of marine mammals (n=1 beluga whale, harp seal, northern fur seal, Steller sea lion, grey seal and harbor seal) were fed a lutein supplement containing either 38 mg lutein/tablet as lutein beadlets or 6.9 mg lutein/tablet as lutein esters at 0.89-3.60 mg lutein/kg^0.75 per day. Collection animals (beluga, fur seal, sea lion) were fed each supplement for 30 d, with a 30 d washout period between supplements, and blood was collected at the end of each feeding period. Stranded seals (harbor, harp and grey) were rehabilitated to a healthy state, then supplemented for 15 d prior to release. Blood was collected pre- and post-supplementation. At another institution, dolphins (n = 5) and pinnipeds (n = 3) were fed a lutein supplement containing 12.5 mg lutein/tablet as lutein beadlets for up to 24 months. Blood was collected opportunistically.

For all animals, blood samples were analyzed by HPLC for lutein and zeaxanthin, retinol and α-tocopherol (Arizona State University). Data were analyzed subjectively, given the small sample numbers in this trial.

There was no major change in retinol or α-tocopherol after supplementation with lutein. There was an approximately 2-fold increase in lutein and zeaxanthin after lutein beadlet supplementation, but very little change in lutein or zeaxanthin after lutein ester supplementation. Additionally, species differences in responses were noted. A beluga whale had no detectable lutein prior to supplementation, but had detectable lutein post-supplementation. Dolphins had detectable levels of lutein after at least 24 months of feeding the lutein beadlet. In contrast, seals and sea lions did not have such noticeable increases in serum lutein.

These data demonstrate that some marine mammals had circulating lutein following supplementation. Cetaceans have higher levels of blood lutein after similar dosages were fed, as compared to pinnipeds. Wild dolphins have been previously shown to have ~ 11 ng lutein + zeaxanthin/ml blood,³ demonstrating capacity for some absorption. It remains to be determined whether lutein or zeaxanthin are being concentrated in the eye of marine mammals.

References

1.  Dunn J.L., N.A. Overstrom, and D.J. St. Aubin. 1996. An epidemiologic survey to determine factors associated with corneal and lenticular lesions in captive harbor seals and California sea lions. IAAAM 27^th Annual Conference Proceedings, Chattanooga, TN; Pp. 108-109.

2.  Mares-Perlman J.A., A.E. Millen, T.L. Ficek, and S.E. Hankinson. 2002. The body of evidence to support a protective role for lutein and zeaxanthin in delaying chronic disease. Overview. J Nutr 132: 518S-524S.

3.  Slifka K.A., P.E. Bowen, M. Stacewicz-Sapuntzakis, and S.D. Crissey. 1999. A survey of serum and dietary carotenoids in captive wild animals. J Nutr 129: 380-390.