Spinach and kale, of all the vegetables tested to date, possess the highest total capacity to inhibit oxidation and oxidative damage, i.e. antioxidant activity. Antioxidant Capacity of Tea and Common Vegetables by G. Cao, E. Sofic, and R.L. Prior. Spinach consumption significantly increases the total antioxidant activity in the blood. Serum Antioxidant Capacity Is Increased by Consumption of Strawberries, Spinach, Red Wine or Vitamin C in Elderly Women by C. Cao, R.M. Russell, N. Lischner, and R.L. Prior. Dietary Carotenoids, Vitamins A, C, and E, and Advanced Age-Related Macular Degeneration by J.M. Seddon, et al.
Sight is improved in macular degeneration patients who eat spinach every day.
A Protocol for the Evaluation and Treatment of Atrophic Age-Related Macular Degeneration by S. Richer. Environmental Intervention Data by S. Richer. Lutein, zeaxanthin, and beta-carotene are potent antioxidants. The human body can not make lutein or zeaxanthin de novo. Antioxidant potency is synergistically increased by combining lutein with beta-carotene.