Goji berries may ward off age-related vision loss
New research has found that regular intake of dried goji berries in healthy middle-aged individuals can prevent age-related macular degeneration, or AMD.
The study, led by researchers at the University of California and published in the journal, Nutrients, examined the effects of Z-rich goji berry intake on Macular pigment optical density (MPOD) and skin carotenoids in healthy adults. MPOD is a biomarker for AMD and a non-invasive measure to assess risk. The macula xanthophyll pigments lutein (L) and zeaxanthin (Z) protect against blue light and provide oxidant defense, which can be indexed by MPOD.
Twenty-seven participants, between the ages 45 to 65, consumed either 28 grams of goji berries or a commercial supplement containing L and Z for eye health, five times a week for 90 days.
After 90 days, according to the study, MPOD was significantly increased in the goji berry group at 0.25 and 1.75 retinal eccentricities, while no changes were noted in the commercial supplement group. In addition, the study found that skin carotenoids only significantly increased in the goji berry group at day 45 and day 90. As a result, researchers said regular intake of goji berries in healthy middle-aged adults increases MPOD and may help prevent or delay the development of AMD.
Dietary L and Z are found in certain fruits and vegetables with red, yellow, or orange color, egg yolk, and in some green leafy vegetables. Dietary intakes of L and Z are strongly associated with their serum levels, as well as with MPOD. Previous research has shown that high intake of these carotenoids from dietary sources or supplements can increase plasma L and Z, and MPOD.
Goji berries contain the highest amount of Z among all known dietary sources and is mainly present in a dipalmitate form, according to the study. In addition, the typical adult human eye has approximately 2.4 times more Z than L in the central fovea of the macula, making goji berry intake a prime candidate for increasing MPOD.
According to the study's scientists, further research on goji berries is needed, as both a dietary strategy to reduce the risk of AMD and to serve as part of an integrative approach to lessen the impact of this disorder.