Carotenoids for Collision Athletes

This is a supplement study being conducted to find out if collision sport athletes who are exposed to repetitive head impacts while supplementing with carotenoids will have decreased pro-inflammatory blood biomarkers, increases in macular pigment optical density, improved contrast sensitivity, greater retinal nerve fiber thickness, and better overall visual quality of life scores compared to collision athletes taking a placebo.

Originally adapted to augment macular pigment for anti-inflammatory, antioxidative, blue light, and visual performance purposes, supplementation with carotenoids has been tested in animal models for protective effects against traumatic brain injury (TBI). Results have been promising, as mice provided with the three main carotenoids (Lutein, Meso-Zeaxanthin, and Zeaxanthin) following TBI displayed reduced levels of pro-inflammatory markers (IL-1β, IL-6, and GFAP) and increased levels of GAP43, NCAM, and BDNF, signaling activation of anti-oxidant systems. Due to inflammation of the visual system following trauma, immune responses in the eye are for both reparative and protective purposes. However, cytokines released by immune cells compromise visual acuity by means of inflammation and fibrosis (scarring). As such, inflammation to the visual system (including visual processing structures in the brain) carries the danger of visual impairment. Research examining chronic inflammatory responses in the optic tract and subsequent visual dysfunction found mTBI in rodent models to increase GFAP, tumor necrosis factor (TNF), and degeneration of axons up to 3.5 months post-injury. As such, inflammation of the visual system is a measurable phenomenon in rodent models, conveying the need for human subjects research. The nutrients found in the proposed test supplement, lutein, zeaxanthin, meso-zeaxanthin, along with the omega-3 fatty acids DHA and EPA, are deposited in the brain regions that are often found to be affected by a collision-related head injury. Thus, an exploratory study of this topic is proposed, utilizing the three main carotenoids in the form of a MacuHealth supplement. Optical Coherence Tomography has become a critical clinical tool when discovering and diagnosing disease and neurological disorders of the eyes. It works to map the retina in order to give ophthalmologists precise measurements of the tissues which make up this important part of human anatomy and helps medical experts to diagnosis diseases of the eye such as Glaucoma and Macular Degeneration. In terms of retinal nerve fiber layer thickness (RNFL), a study found Olympic boxers to have thinner RNFL compared to controls. Another study found RNFL thickness as a significant predictor of athlete vs control status, with 4.8-um of thinning seen on average in athletes (boxing, football) when compared to controls. Although vision disorders are so common, VQOL - to our knowledge - is not specifically addressed following exposure to repetitive head impacts (RHI), concussion, or during return-to-play protocol. In sports such as football, hockey, and boxing where participants are exposed to RHI, participation while experiencing decreased VQOL or visual functionality could prove costly to the health of those athletes. Poor visual acuity and photophobia following concussion have been cited as indicators of poor VQOL. As such, use of the VFQ-25 and the 10-Item Supplement may be important additions to current clinical practice when evaluating the baseline health status of athletes, and following the completion of a collision-sport season.