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What are goji berries?

Other Names: Lycium barbarum, wolfberry, gou qi zi, Fructus lycii

Goji berries grow on an evergreen shrub found in temperate and subtropical regions in China, Mongolia and in the Himalayas in Tibet. They are in the nightshade (Solonaceae) family.

Goji berries are usually found dried. They are shriveled red berries that look like red raisins.

Why do people use goji berries?

Goji berries have been used for 6,000 years by herbalists in China, Tibet and India to:

• protect the liver
  
• help eyesight
  
• improve sexual function and fertility
  
• strengthen the legs
  
• boost immune function
  
• improve circulation
  
• promote longevity

Goji berries are rich in antioxidants, particularly carotenoids such as beta-carotene and zeaxanthin. One of zeaxanthin's key roles is to protect the retina of the eye by absorbing blue light and acting as an antioxidant. In fact, increased intake of foods containing zeathanthin may decrease the risk of developing age-related macular degeneration (AMD), the leading cause of vision loss and blindness in people over the age of 65.

In recent years, goji juice has become popular as a health beverage. Companies marketing goji juice often mention the unsupported claim that a man named Li Qing Yuen consumed goji berries daily and lived to be 252 years old. Marketers also list extensive health benefits of goji juice, even though there are few published clinical trials in humans.

What research has been done on goji berries?

Goji has only been tested on humans in two published studies. A Chinese study published in the Chinese Journal of Oncology in 1994 found that 79 people with cancer responded better to treatment when goji was added to their regimen.

There have been several test tube studies that show that goji berry contains antioxidants and that goji extracts may prevent the growth of cancer cells, reduce blood glucose, and lower cholesterol levels. However, that doesn't necessary mean that goji will have the same benefits when taken as a juice or tea.

Although goji berries like the ones used in traditional Chinese medicine aren't very expensive, goji juice is very pricey. Considering that a 32-ounce bottle of goji juice (about an 18-day supply) can run as high as $50 USD, the evidence isn't compelling enough at this time to justify the cost of goji juice.

Also, we don't know the side effects of regular goji consumption, or whether it will interfere with treatments or medications.

What do goji berries taste like?

Goji berries have a mild tangy taste that is slightly sweet and sour. They have a similar shape and chewy texture as raisins.

Common forms

In traditional Chinese medicine, goji berries are eaten raw, brewed into a tea, added to Chinese soups, or made into liquid extracts.

Goji juice is also available, usually in 32-ounce bottles.

Goji berries have appeared in snack foods in North America. For example, the health food store Trader Joe's sells a goji berry trail mix.

Possible drug interactions

Goji berries may interact with anticoagulant drugs (commonly called "blood-thinners"), such as warfarin (Coumadin®). There was one case report published in the journal Annals of Pharmacotherapy of a 61-year old woman who had an increased risk of bleeding, indicated by an elevated international normalized ratio (INR). She had been drinking 3-4 cups daily of goji berry tea. Her blood work returned to normal after discontinuing the goji berry tea.

Where to find goji berries

Whole goji berries are available at Chinese herbal shops.

Goji juice can be found in some health food stores, online stores, and through network marketers.

Sources

Cheng CY et al. "Fasting plasma zeaxanthin response to Fructus barbarum L. (wolfberry; Kei Tze) in a food-based human supplementation trial." British Journal of Nutrition. 93.1 (2005):123-30.

Lam AY et al. "Possible interaction between warfarin and Lycium barbarum L." Annals of Pharmacotherapy. 35.10 (2001):1199-201.

Wu H et al. "Effect of Lycium barbarum polysaccharide on the improvement of antioxidant ability and DNA damage in NIDDM rats." Yakugaku Zasshi. 126.5 (2006):365-71.