Detrimental effects of carotenoid pigments: the dark side of bright coloration

Abstract

Carotenoid pigments produce yellow, orange, and red integumentary color displays that can serve as reliable signals of health and condition. In many birds and fish, individuals gain competitive or mating advantages by ingesting and utilizing large quantities of carotenoid pigments. Carotenoid pigments serve as antioxidants, performing important functions as free-radical scavengers. The beneficial effects of carotenoid pigments are well documented, but rarely have researchers considered potential detrimental effects of high-level accumulation of carotenoids. We maintained American goldfinches (Carduelis tristis) on high- or low-carotenoid diets through molt and tested for damage to the liver and skeletal muscle. High intake of carotenoids had no measurable effect on liver enzymes but caused an increase in creatine kinase, an indicator of skeletal muscle breakdown, and a reduction in vertical flight performance, a measure of skeletal muscle integrity. The detrimental effects of high-level carotenoid accumulation were approximately equivalent to the negative effects of removing carotenoids from the diet. The adverse effects observed in this study have important implications for theories of the function and evolution of colorful plumage.

BCDO2 acts as a carotenoid scavenger and gatekeeper for the mitochondrial apoptotic pathway

“…In chicken, a promoter mutation specifically alters bcdo2 expression in skin but other tissues are not affected (Eriksson et al, 2008). Studies in gold finches indicate that carotenoids can cause adverse health effects when large amounts of these dietary compounds are acquired for the coloration of feathers during molting of male animals (Huggins et al, 2010). In cattle, a putative loss-of-function mutation in bcdo2 alters BC and retinoid levels in blood and tissues (Berry et al, 2009;Tian et al, 2010).…”

Relationships among plumage coloration, blood selenium concentrations, and immune responses of adult and nestling tree swallows

“…In birds, the majority of micronutrient studies have focused on the role of carotenoids in immunity because these pigments are also used extensively in plumage coloration (Lozano, 1994;von Schantz et al, 1999). While carotenoid supplementation may be beneficial, high carotenoid intake may be detrimental (Huggins et al, 2010;Giraudeau et al, 2013), suggesting that there is an optimal level of micronutrient supplementation. Given that brighter plumage coloration is associated with greater antioxidant defenses in some species (Perez-Rodriguez et al, 2010;Marko et al, 2011), it is possible that the point at which micronutrients become toxic varies among individuals.…”

The influence of carotenoid supplementation at different life-stages on the foraging performance of the Southern Corroboree frog (Pseudophryne corroboree): A test of the Silver Spoon and Environmental Matching Hypotheses

“…Corroboree frogs lack the capacity to utilise dietary carotenoids, as appears to be the case for some other vertebrate species (Costantini et al, 2007;Huggins et al, 2010). An inability to utilise dietary carotenoids is expected for species that have had limited access to dietary carotenoids and have not evolved the cellular machinery (i.e.…”