Dried goji berries found to boost protective pigments in the eyes

Research at the University of California-Davis (UCDavis) shows how eating a small serving of dried goji berries regularly helps to increase the density of protective pigments in eyes, in turn preventing or delaying the onset of age-related macular degeneration (AMD). AMD is the leading cause of vision loss in older adults, affecting more than 11 million in the US and 170 million globally.

[Goji berries are native to northwest China. The dried berries are similar to raisins and are a common ingredient in Chinese soups and herbal tea; they can also be eaten as a snack.]

In a small, randomised trial, it was found that the density of eye pigments lutein and zeaxanthin were increased in 13 healthy middle-aged participants who consumed 28 grams (about one ounce, or a handful) of dried goji berries five times a week for 90 days. Meanwhile, another 14 participants who consumed a commercial supplement for eye health over the same period did not show an increase.

“Lutein and zeaxanthin are like sunscreen for your eyes,” said Xiang Li, a doctoral candidate of Nutritional Biology at UCDavis. Lutein and zeaxanthin primarily filter out harmful blue light and provide antioxidant protection.

According to Li, the high quantities of lutein and zeaxanthin in goji berries can reduce the risk of eye diseases related to AMD. The form of zeaxanthin in dried goji berries is also a highly bioavailable form meaning it is readily absorbed in the digestive system so the body can use it.

“The higher the lutein and zeaxanthin in your retina, the more protection you have. Our study found that even in normal healthy eyes, these optical pigments can be increased with a small daily serving of goji berries,” said Li.

No known therapy has yet been shown to impact early stages of AMD, which can develop due to a mix of genetic risks, age-associated changes, and environmental factors like smoking, diet, and sun exposure. “AMD affects your central field of vision and can affect your ability to read or recognise faces,” said Glenn Yiu, an Associate Professor in the Department of Ophthalmology and Vision Sciences. “Our study shows goji berries, which are a natural food source, can improve macular pigments of healthy participants beyond taking high-dose nutritional supplements. The next step for our research will be to examine goji berries in patients with early-stage AMD.”

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Category: Education, Features