Effects of three levels of macular carotenoid supplementation on macular pigment optical density, psychological stress levels, and overall health

INTERVENTION: 1. Placebo 2. Lutein 6 mg, zeaxanthin isomers (Zi) 1.2 mg 3. Lutein 10 mg, Zi 2 mg 4. Lutein 20 mg, Zi 4 mg CONDITION: Effect of lutein supplementation ; Nutritional, Metabolic, Endocrine PRIMARY OUTCOME: 1. MPOD, assessed with a non‐invasive, perceptual task called customized heterochromatic flicker photometry (cHFP; Stringham et al. 2008). A densitometer (Macular Metrics Corp., Rehoboth, MA) described by Wooten et al. (1999) was used for this purpose. Measurements were taken at baseline and every 2 weeks over the 12‐week study period. We obtained spatial profiles of MPOD at each visit, with measures at 10 degrees, 20 degrees, 30 degrees, 1.75 degrees, and 2.75 degrees of retinal eccentricity. ; 2. Psychological stress and overall health status ; 2. Cortisol; ; Measured at baseline and every two weeks over a 12‐week period SECONDARY OUTCOME: 1. Oxidative stress; 2. Inflammation; 3. Macular carotenoids; 4. Brain health markers; ; Measured at baseline and every two weeks over a 12‐week period INCLUSION CRITERIA: 1. Healthy volunteers 2. Aged 18‐25 years 3. Subjects willing to sign consent form 4. Subjects willing to participate for 3 month study 5. Non smoker 6. Normal BMI