The goji berry, or wolfberry, is a red fruit that grows on a plant native to southeast Europe and Asia. Similarly to the acai berry fad, the goji berry has seen a dramatic uptick in popularity in recent years due to its being marketed as a "superfruit" with incredible nutritional and antioxidant properties.
According to proponents, some of the health benefits of consuming the goji berry include the prevention of cancer, treatment of diabetes, improved fertility and sexual performance, powerful antioxidant properties, lowering of cholesterol and blood pressure, anti-aging characteristics, boosting of the immune system, and easier weight loss.
The goji berry, like all berries, does contain antioxidants, which can help prevent cell oxidation and cancer. Also, animal studies have shown the potential for some benefits, including the prevention of cancer, macular degeneration, cardiovascular disease, and inflammation, although this has yet to be shown in human studies.
While the goji berry may indeed provide some benefit, there are a number of potential side effects associated with its consumption, including interacting with or intensifying the effects of certain medications, including the anticoagulant Warfarin, as well as some diabetes and blood pressure medications.
In large quantities, goji berries may cause nausea, dizziness, confusion, and blurred vision – possibly due to a toxin called atropine, which is present in low doses in the fruit. Because of its tendency to increase alertness, taking goji berry before bedtime may result in insomnia. Those who are pregnant should avoid taking goji berry in large quantities, as the fruit contains high levels of selenium, a mineral that may cause birth defects, and betaine, which may result in miscarriage.
To be sure, the possible side effects of taking goji berry are generally quite mild, and/or only occur when the fruit is eaten in large quantity or taken with certain medications. Regardless, it is recommended that anyone wishing to begin a goji berry regimen first speak with their healthcare provider.