Jujube

Jujube is the common name for Ziziphus jujuba, a small deciduous tree or shrub of the buckthorn family, Rhamnaceae, usually bearing thorny branches and reaching several meters in height ^[1]. Its fruit is an oval drupe that is smooth and green when unripe, with the crisp texture and mild flavor of an apple, and that darkens, wrinkles, and sweetens as it dries, taking on the look of a small date; for this reason it is widely called the red date or Chinese date ^[1].

The plant is thought to have originated in eastern Asia, across the region spanning southern and central China, India, Korea, and Japan, where wild jujube remains have been recovered from Neolithic-era sites ^[1]. It has been cultivated for several thousand years, is most extensively grown in China, and has spread to many warm-temperate parts of the world; it tolerates a wide range of climates and a degree of winter cold ^[1].

Jujube is valued first of all as a food. The fruit is eaten fresh as a crisp snack and, more commonly, dried or candied, and it is made into tea, juice, vinegar, pickles, wine, and a variety of desserts ^[1]. In some countries the fruit is smoked and sold as black jujube ^[1]. Dried jujubes are energy-rich and carbohydrate-dense, while the fresh fruit is a notable source of vitamin C ^[1].

In traditional Chinese and other Asian medicine the fruit has long been used as a tonic and gentle remedy, including to ease stress and encourage sleep, and the seed of the closely related sour jujube, known as suanzaoren, is a classic ingredient for insomnia and restlessness ^[1][4]. The characteristic constituents include saponins such as the jujubosides, flavonoids, triterpenic acids, and polysaccharides; the plant also contains ziziphin, a compound that temporarily suppresses the perception of sweetness ^[1][2].

Contemporary research, largely in the laboratory and in animals, has reported sedative, antioxidant, anti-inflammatory, hepatoprotective, immunomodulatory, and metabolic effects for jujube fruit and seed extracts ^[1][2][4]. Much of this work aims to identify the active molecules and their mechanisms, and reviewers generally caution that robust human clinical evidence is still limited ^[1][4]. As a common food, jujube is regarded as safe and well tolerated when eaten in normal amounts ^[1].

Jujube is a food and is considered very safe, with side effects being uncommon and mild, like drowsiness or digestive upset. Because it can add to sedation, combining it with alcohol, benzodiazepines, or other sleep aids should be done cautiously. People with diabetes should note the fruit is fairly sugary, though seed extracts are not.