Age-related macular degeneration is an eye disease characterized by vision loss in the center of the field of vision. It is one of the leading causes of vision loss in older adults worldwide and is often accompanied by marked losses of autonomy, independence, and quality of life. Findings from a recent study suggest that eating goji berries may prevent or delay age-related macular degeneration.
The macula is the portion of the retina directly behind the pupil. Due to pigmentation from high levels of the antioxidant carotenoids, lutein and zeaxanthin, the macula appears yellow. A diet high in lutein and zeaxanthin from foods such as goji berries, kale, pumpkin, salmon, and eggs increases the density of carotenoids in the macula, protecting the tissue from photodamage. In people with early macular degeneration, increasing the amount of lutein in the eye can improve vision; however, less is known about the disease prevention of high lutein levels in healthy adults.
The authors recruited healthy adults between the ages of 45 and 65 years who did not have signs of macular degeneration, verified by an optometrist. They randomly assigned participants to consume either one ounce of goji berries per day or take a supplement containing six milligrams of lutein and four milligrams of zeaxanthin for 90 days. The researchers measured the intensity of yellow color in the macular, which is a good approximation of the density of lutein and zeaxanthin in the eye. Finally, they also measured the yellow color of the skin on participants' finger tips using a device called a “Veggie Meter,” which has demonstrated accuracy in objectively measuring fruit and vegetable intake.
Over 90 days, participants consuming goji berries significantly increased the density of carotenoids in their eyes compared to their baseline values. The lutein and zeaxanthin supplement did not increase carotenoid deposition in the eyes. Participants consuming goji berries had a significant increase in the yellow hue of their skin after just 45 days of consumption, while there was no change for participants taking the carotenoid supplement.
These results support the consumption of goji berries as a strategy for increasing carotenoid density in the eye in healthy adults, which may reduce the risk of age-related macular degeneration.
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