What are goji berries?

Benefits of Goji Berries

Goji berries are rich in antioxidants.
Photo courtesy Scott Bauer, United States Department of Agriculture
Like the foods pictured here, goji berries are filled with antioxidants.

Goji berry marketers have made bold claims about their products’ powers: Goji berries can prevent or even cure cancer. They provide more oxidants than any other fruit. They boost sexual function and keep people looking and feeling young. Of course, not all of these claims are true, and some may be difficult to verify. But there are some things about goji berries that we can determine with certainty.

Goji berries are incredibly nutritious. For their weight -- a daily serving is only 10 to 30 grams -- goji berries have more vitamin C than oranges, more beta carotene than carrots and more iron than steak. Beta carotene is believed to help fight heart disease and also protects the skin from sun damage. Goji berries are also a good source of B vitamins and antioxidants, which protect against harmful free radicals that damage cells in your body. They’re also rich in polysaccharides, which aid the immune system, have 18 kinds of amino acids, and are a rich source of potassium. And, as if protecting your heart, skin and immune system weren’t enough, beta carotene and antioxidants are thought to help fight cancer.

In fact, the claim that goji berry producers frequently refer to is the fruit’s supposed cancer-fighting power. This ability, they say, stems from goji berries’ high antioxidant content. Antioxidants are actually a class of vitamins that includes beta carotene and vitamins E and C. Goji berries rate highly in terms of Oxygen Radical Absorbance Capacity (ORAC), a test developed by the U.S. Department of Agriculture. Here are ORAC values (in units per 100 grams) for some foods with high amounts of antioxidants:

  • Prunes – 5,770
  • Raisins – 2,830
  • Blueberries – 2,400
  • Kale – 1,770
  • Strawberries – 1,540
  • Spinach – 1,260
  • Brussels sprouts – 980
  • Plums – 949
  • Oranges – 750

According to several sources, goji berries’ ORAC value is more than 25,000! But what does this mean?

Dried goji berries
Image credit: photo used in public domain
Dried goji berries have become a popular, healthy snack, especially in the UK.

In 1999, the U.S. Department of Agriculture released the details of a study finding that foods with high ORAC values may help to slow the aging process and to protect cells from oxidative damage (from free radicals). The 25,000 ORAC number is difficult to verify, but if it is to be believed, it doesn’t mean that we should abandon all other antioxidant-carrying fruits for goji berries. Antioxidants are good for the body, but like many vitamins and minerals, there’s only so much we can absorb. Anything more than a certain amount will pass through the body unprocessed. In the case of selenium, which is found in goji berries, the right quantity helps to keep your liver healthy; too much can be toxic. For that reason, it’s good to stick to somewhere around the daily serving of goji berries –- 10 to 30 grams -- and to mix other healthy, nutritious foods into your diet.

Do we need supplements?
The Cleveland Clinic, in a survey of numerous studies on antioxidants and supplements, found that excessive amounts of Vitamin E and beta carotene supplements increased the risk of heart disease. They still recommended eating foods rich in vitamins and antioxidants. The Mayo Clinic also recommends avoiding high antioxidant supplements until their effects are better known. Some antioxidant supplements contain thousands of times the amount found in food sources, so in general, it’s safer to stick to foods that you know are safe and nutritious.