Gugija (goji berry)

Gugija is the fruit of the Chinese boxthorn or matrimony vine (Lycium chinense), a thorny deciduous shrub of the nightshade family about 1 to 1.5 meters tall. The Encyclopedia of Korean Culture describes purple flowers from June to September and oval red berries about a centimeter long that ripen in late summer and autumn, sweet at first with a bitter finish. Dried, they wrinkle and are packed with small seeds. In Korean herbal tradition the dried fruit is gugija, the leaves gugiyeop and the root bark jigolpi.

Gugija has long been a tonic food. The encyclopedia notes its use in Korean medicine as a strengthening herb and, in folk practice, as gugi-cha tea and gugi-ju liquor. Cheongyang in Chungcheongnam-do is the traditional collecting center for the crop, and Cheongyang gugija-ju, a rice wine brewed with the fruit, leaves and root bark in the Hadong Jeong head family for about 150 years, was designated a provincial intangible heritage in 2000. Recipes for goji liquor appear in Joseon texts such as Sallim gyeongje and Gyuhap chongseo. See traditional liquor.

On Jindo, off the southwest tip of the peninsula, goji is a signature crop. The Digital Jindo Culture Encyclopedia credits the island's long hours of sunshine for glossy, sweet, syrupy berries that herbal traders prize, reports about 60 tonnes harvested from 26 hectares in 2022, and notes that Jindo goji was registered as forest-product geographical indication No. 34 in 2007. Local producers turn it into goji doenjang, gochujang, liquor and tea.

At home, dried berries are most often simmered as tea. See traditional Korean teas.

• Fruit nutrients: Per the Korean Food Composition Table, fresh native goji fruit provides fiber, vitamin C and potassium.
• Tonic reputation: Korean herbal tradition treats gugija as a restorative for the liver, eyes and stamina. Those are traditional uses; claims about eye health or aging are not established for goji eaten as food.
• Warfarin interaction: Several case reports describe raised INR and bleeding in people on warfarin after drinking goji tea, juice or goji wine, including a 2001 report and a 2012 report of hospitalization. Most involved the closely related Lycium barbarum. If you take warfarin, talk to your doctor before using goji regularly, and MedlinePlus advises telling your clinician about all herbal products you take.
• Nightshade family: Goji belongs to the same family as tomatoes and peppers; people with known allergies to those plants may want to take care.