Related Experiment Video
Updated: Oct 8, 2025

Measurement of Carotenoids in Perifovea using the Macular Pigment Reflectometer
Published on: January 29, 2020
Goji Berry Intake Increases Macular Pigment Optical Density in Healthy Adults: A Randomized Pilot Trial
Xiang Li1, Roberta R Holt1, Carl L Keen1,2
1Department of Nutrition, UC Davis, Davis, CA 95616, USA.
Abstract:
Age-related macular degeneration (AMD) is the third leading cause of blindness worldwide. Macular pigment optical density (MPOD), a biomarker for AMD, is 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. This study examined the effects of Z-rich goji berry intake on MPOD and skin carotenoids in healthy individuals. A randomized, unmasked, parallel-arm study was conducted with 27 participants, aged 45-65, who consumed either 28 g of goji berries or a supplement containing 6 mg L and 4 mg Z (LZ), five times weekly for 90 days. After 90 days, MPOD was significantly increased in the goji berry group at 0.25 and 1.75 retinal eccentricities (p = 0.029 and p = 0.044, respectively), while no changes were noted in the LZ group. Skin carotenoids were significantly increased in the goji berry group at day 45 (p = 0.025) and day 90 (p = 0.006), but not in the LZ group. Regular intake of goji berries in a healthy middle-aged population increases MPOD may help prevent or delay the development of AMD.
Related Concept Videos
Bioavailability Study Design: Healthy Subjects Versus Patients
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Bioavailability Study Design: Single Versus Multiple Dose Studies
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Bioavailability Study Design: Absolute Versus Relative Bioavailability
Open Angle Glaucoma: Treatment
Drugs such as carbonic anhydrase inhibitors, α2- and...

