There were no detectable adverse effects to 90 days of goji berry supplementation. Those with high zeaxanthin levels also performed better on vision tests and physical eye tests conducted by an optometrist. While the lutein levels in participants eating goji berries did not increase significantly, zeaxanthin levels did. Over the course of 90 days, the research team tracked patient levels of lutein and zeaxanthin, two carotenoids that are naturally occurring in goji berries and help give the fruit its pigment. All participants continued with their normal diets. Researchers then split the patients into two groups: Those who consumed 25 grams of goji berries per day, and those in a control group. To conduct the study, investigators recruited 114 patients who were in the early stages of age-related macular degeneration (AMD) and were between 59 and 92 years old. The disease is progressive and attacks the central area of the retina, which leads to serious visual impairment and even irreversible vision loss. According to research in the International Journal of Ophthalmology, a daily supplementation of goji berries can improve symptoms of macular degeneration, or age-related deterioration in the eyes. One of the best reasons to pick up a bag of these bright red berries is for their ability to improve eye sight.
