Goji

Wolfberry
File:Chinese wolfberries.jpg
Ripe Chinese Wolfberries on the vine
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Solanales
Family:	Solanaceae
Genus:	Lycium
Species
Lycium barbarum L. Lycium chinense Miller

Wolfberry is also another name for the western snowberry, Symphoricarpos occidentalis.

Wolfberry (also known as Chinese Wolfberry, Duke of Argyll's Tea Tree, or Matrimony Vine) is the common name for the fruit of Lycium barbarum (Chinese: 宁夏枸杞; pinyin: Níngxià gǒuqǐ) or L. chinense (Chinese: 枸杞; pinyin: gǒuqǐ), two species of boxthorn in the family Solanaceae (which also includes the potato, tomato, eggplant, and tobacco). Although its original habitat is obscure (probably southeastern Europe to southwest Asia), wolfberry species are now grown around the world, including in China.

Description

Wolfberry leaves and flower

Wolfberry species are deciduous woody perennial plants, growing 1-3 m high. L. chinense is grown in the south of China and tends to be somewhat shorter, while L. barbarum is grown in the north, primarily in the Ningxia Hui Autonomous Region, and tends to be somewhat taller. L. halimifolium (Miller) is also common to Ningxia. These species produce a bright red, ellipsoid berry 1-2 cm long, each containing 10-30 tiny yellow seeds that are compressed with a curved embryo.

The botanical division named to the upper right, Magnoliophyta, identifies plants that flower and the class Magnoliopsida represents flowering plants (Dicotyledons) with two embryonic seed leaves called cotyledons appearing at germination.

The order Solanales names a perennial plant with five-petaled flowers having fragrance and edible fruit like the relatives potato, tomato, eggplant, and wolfberry.

Lastly, Solanaceae is the nightshade superfamily that includes hundreds of plant foods like those above, herbs (paprika), crop commodities (tobacco), and flowers (petunia).

Leaves and flower

Wolfberry leaves form on the shoot either in an alternating arrangement or in bundles of up to 3, each having a shape that is either lanceolate (as it is shaped like a spearhead longer than it is wide) or ovate (egg-like). Leaf dimensions are 7 cm long by 3.5 cm wide with blunted or round tips.

One to 3 flowers (picture above) occur on stems 1-2 cm in length. The calyx (eventually ruptured by the growing berry) is comprised of bell-shaped or tubular sepals forming short, triangular lobes. The corolla are lavender or light purple, 9-14 cm long with 5 or 6 lobes shorter than the tube. The stamens are structured with anthers that open length-wise, shorter in length than the filaments (picture).

In the northern hemisphere, flowering occurs from June through September and berry maturation from August to October, depending on latitude, altitude and climate.

Etymology

"Wolfberry" is the most commonly used English name for the plant, while gǒuqǐ (枸杞) is the Chinese name. In Chinese, the berries themselves are called gǒuqǐzi (枸杞子), with zi meaning "seed". Other common names are "the Duke of Argyll's Tea Tree", and "matrimony vine." Wolfberry is also known pharmacologically as Lycii Fructus (lycium fruit).

Lycium, the genus name, is believed to derive from the ancient Mid-Asian region of Lydia whereas barbarum, the species name, suggests that the plant was of foreign origin, perhaps originating outside China. Together, these names are used as specific botanical identifiers in the binomial (or binary) epithet. The end abbreviation, L., represents the nomenclature system devised by Carolus Linnaeus, the father of modern biological taxonomy. Lycium barbarum L. was apparently first named in the Linnaeus system in 1753.

In the English-speaking world, "goji berry" has been widely used in recent years as a synonym for wolfberry. While the origin of this spelling is unclear, it is probably a simplified spelling of gǒuqǐ.

In Japan the plant is known as kuko (クコ), in Korea the berries are known as gugija (hangul: 구기자; hanja: 枸杞子), and in Thailand the plant is called găo gèe (เก๋ากี่).

Cultivation

The name Tibetan Goji berry is in common use in the health food market for berries from this plant that are claimed to have been grown in the Himalaya region. Tibet as a significant wolfberry source is almost certainly a myth, however, as it is an unlikely region for commercial supplies of berries of any kind. The Tibetan Plateau is more than 10,000 ft altitude with poor soil and climate conditions unfavorable for fruit crops. Year-round cold temperatures and frost would inhibit bud development and prevent fruit formation. Minimal subsistence agriculture exists in Tibet. There are no objective commercial, scientific, or government reports on wolfberries from Tibet, whereas reports on wolfberries from the Xinjiang Uyghur Autonomous Region and the Ningxia Hui Autonomous Region of north-central China are abundant and the reputation of Ningxia wolfberries is widespread throughout Asia.

In addition to being cultivated mainly in Ningxia, wolfberry also grows in the Chinese regions of Inner Mongolia, Xinjiang, Gansu, Shaanxi, and Shanxi. The oblong, red berries (photo top right) are very tender and must be picked carefully or shaken from the vine to avoid spoiling. The fruits are preserved by slowly drying them in the shade. The berry has been eaten locally in Asia for centuries and is celebrated in an annual festival held in Ningxia. The fruit is nicknamed the "happy berry" because of the sense of well being it is said to induce.

The plant also grows wild in English hedgerows. On 15th January 2003, the Department for Environment, Food and Rural Affairs (of the United Kingdom Government) launched a project to improve the regulations protecting traditional countryside hedgerows, and specifically mentioned Duke of Argyll's Tea Tree as one of the species to be found growing in hedges located at Suffolk Sandlings, Hadley, Bawdsey, near Ipswich, and Wookerswick.

File:Gouqi-dried.jpg

Dried Chinese Wolfberries

Medicinal use

Wolfberries and Lycium bark have long played important roles in traditional Chinese medicine (TCM), where they are believed to enhance immune system function, improve eyesight, protect the liver, boost sperm production, and improve circulation, among other effects. In TCM terms, wolfberries are sweet in taste and neutral in nature; they act on the liver, lung, and kidney channels and enrich yin. They can be eaten raw, consumed as juice or wine, brewed into a tea, or prepared as a tincture.

An early mention of wolfberry occurs in the 7th century Tang Dynasty treatise Yaoxing Lun. It is also discussed in the 16th century Ming Dynasty Compendium of Materia Medica of Li Shizhen.

There are also many published studies, mostly from China (see Pubmed), on the possible medicinal benefits of Lycium barbarum, including research on cancer, aging, immune functions and diabetes. Little of this research has been confirmed by western science, approved as clinical conclusions, or accepted by regulatory authorities to allow any health claims.

Culinary use

As a food, dried wolfberries are also eaten raw or cooked. Their taste is similar to that of raisins with trace tastes of tomato (a plant family relative) and nuts. Dried wolfberry is an ingredient often used in Chinese soups. Young shoots and leaves are also grown commercially as a leaf vegetable. A wine containing wolfberries (called gǒuqǐ jiǔ; 枸杞酒) is also produced.

Nutrient content

Wolfberries are nutritionally rich, containing beta-carotene, Vitamins C, B₁, B₂ and other vitamins, minerals, antioxidants, and amino acids. Companies marketing the berries also claim the berries contain such nutrients as isoleucine and tryptophan (both amino acids), as well as zinc, iron, copper, calcium, germanium, selenium, phosphorus, vitamin B6 (pyridoxine), and vitamin E.

Two recent book publications describe exceptional nutritional qualities of wolfberries, advancing a working proposal that wolfberry is one of the most nutrient-rich plant foods on Earth (References: Young et al., 2005; Gross et al., 2006).

Macronutrients

Wolfberry contains significant percentages of a day's macronutrient needs – carbohydrates, protein, fat and dietary fiber. 68% of the mass of a wolfberry exists as carbohydrate, 12% as protein, and 10% each as fiber and fat, giving a total caloric value of 370 for a 100 gram serving.

Soybean, another ancient Chinese plant among the world's most complete foods, is comparable across macronutrients. Although wolfberries and soybeans are similar as regards their macronutrient content, wolfberries provide a significantly higher source of calories as energy from carbohydrates (soybeans = 173 calories). Blueberries, by contrast, do not have as much macronutrient or caloric value.

Seeds contain the wolfberry's polyunsaturated fats such as linoleic (omega-6) and linolenic (omega-3) acids.

Micronutrients

Wolfberry's diversity and high concentration of micronutrients brand it as an exceptional health food. 11 essential minerals, 22 trace minerals, 7 vitamins and 18 amino acids profile extraordinary micronutrient richness, with examples below:

1. Calcium. The primary constituent of teeth and bones, calcium has a diverse role also in soft tissues where it is involved in cardiac, neuromuscular, enzymatic, hormonal, and transport mechanisms across cell membranes. Wolfberries and soybeans contain 112 mg and 102 mg per 100 gram serving, respectively, providing about 8-10% of the Reference Daily Intake (RDI).
2. Potassium. An essential electrolyte and enzyme cofactor, dietary potassium can lower high blood pressure. Giving about 24% of the RDI (1132 mg/100 gram), wolfberries are an excellent source, providing more than twice the amount of soybeans.
3. Iron. An oxygen carrier on hemoglobin, iron also is a cofactor for enzymes involved in numerous metabolic reactions. When intake is deficient, low iron levels cause iron deficiency anemia affecting millions of children worldwide. Wolfberry’s exceptional iron content, 100% DRI at 9 mg/100 grams, is twice that provided by soybeans, often regarded as the best plant source of iron.
4. Zinc. Essential for making proteins, DNA and functions of over 100 enzymes, zinc is involved in critical cell activities such as membrane transport, repair and growth, especially in infants. Zinc in wolfberries (2 mg/100 grams) has a high content (double the amount of soybeans), meeting 20% of RDI.
5. Selenium. Sometimes called the “antioxidant mineral”, selenium is often included in supplements. Selenium has unusually high concentration in wolfberries (50 micrograms/100 grams), nearly 100% of the RDI whereas blueberries and soybeans are not important sources (8 micrograms or less).
6. Riboflavin (vitamin B2). An essential vitamin supporting energy metabolism, riboflavin is needed for synthesizing other vitamins and enzymes. A daily wolfberry serving provides the complete RDI (1.3 micrograms) whereas soybeans and blueberries have only trace levels of this important vitamin.
7. Vitamin C. A universal antioxidant vitamin protecting other antioxidant molecules from free radical damage, vitamin C content in dried wolfberries has a range (from different sources) of 29 mg/100 grams to as high as 148 mg/100 grams. Even the lower estimate is a multiple of equal weights of blueberries or soybeans, providing about 35% of the RDI. Reports on vitamin C content from other wolfberry preparations, such as juice concentrate or juice powder, have been significantly higher. The note below offers possible explanation for these discrepancies.

[Note on micronutrient contents: differences in the degree of berry maturation at the time of picking, soil conditions and geographic region where the berries were grown, post-harvest handling and processing, duration of storage, residual water content and assay preparation can significantly affect individual nutrient contents, especially those for vitamins and phytochemicals. These factors make data comparisons between different assays or sources difficult to reconcile].

Phytochemicals

Wolfberries contain dozens of phytochemicals whose properties are under scientific study. Four of these are of particular interest:

1. Beta carotene. A carotenoid pigment in orange-red foods like wolfberries, pumpkins, carrots and salmon, beta-carotene is important for synthesis of vitamin A, a fat-soluble nutrient and antioxidant essential for normal growth, vision, cell structure, bones and teeth and healthy skin. Wolfberry's beta-carotene content per unit weight (7 mg/100 grams) is among the highest for edible plants.
2. Zeaxanthin. Wolfberries are an extraordinary source for this carotenoid important as a retinal antioxidant and pigment filter of ultraviolet light. Wolfberries contain 162 mg/100 grams.
3. Polysaccharides. Long-chain sugar molecules characteristic of many herbal medicines like mushrooms and roots, polysaccharides are a signature constituent of wolfberries, making up 31% of pulp weight in premium quality wolfberries. Polysaccharides are a primary source of fermentable dietary fiber in the intestinal system. Upon colonic metabolism, fermentable or "soluble fibers" yield short-chain fatty acids which 1) are valuable for health of the colonic mucosal lining, 2) enhance mineral uptake, 3) stabilize blood glucose levels, 4) lower pH and reduce colon cancer risk and 5) stimulate the immune system. Polysaccharides also display antioxidant activity.
4. Phenolics. Also called phenols or polyphenols, this group of phytochemicals numbers in the thousands of individual chemicals existing across the plant kingdom, mainly as protective astringents or pigments that give bright colors to plants like the red, ripe wolfberry (photo top right). Phenolic pigments have the metabolic property of high antioxidant capability transferable to animals by eating the plant. New assays have revealed the presence in wolfberries of phenolics such as ellagic acid (86 mg/100 grams) and p-coumaric acid (likely, future research will reveal many more), with a total phenolics content of 1,309 mg/100 grams -- one of the highest values for any plant food yet tested (Young et al., 2005; Brunswick Laboratories).

Oxygen Radical Absorbance Capacity

Wolfberry's richness in carotenoids, phenolics and vitamin C creates potential for an extraordinary synergy of antioxidant strength, a measure determined by test tube assays of oxygen radical absorbance capacity (ORAC).

In 2004, scientists with the U.S. Department of Agriculture (References, Wu et al.) published an extensive list of ORAC values for over 100 common foods (fruits, vegetables, nuts, seeds, spices, grains, etc.). Values were reported as micromoles (μmol) of Trolox equivalents (TE, vitamin E derivative) per gram both for lipid-soluble ("lipophilic" as for carotenoids) and water-soluble ("hydrophilic" as for phenolics) antioxidant chemicals in foods, thus were a sum of lipophilic and hydrophilic values or total ORAC. The data of Wu et al. showed that all plants have variable amounts of both lipophilic and hydrophilic phytochemicals with antioxidant properties contributing to total ORAC.

Spices (clove, cinnamon) showed the highest ORAC values (>250,000, converted to μmol TE per 100 grams) whereas, among commonly eaten foods, dark berries (known to be rich in phenolics), such as cranberry and lowbush blueberry, were highest (around 9,300 μmol TE per 100 grams) (note: wolfberries were not assessed in this study). By comparison, different species of apples had ORAC values of 4,275 μmol TE per 100 grams or less, white potato was under 1,100, peanut was 3,166 and tomato about 400.

In their 2005 book (References), Young et al. report ORAC for dried wolfberries as 30,300 μmol TE per 100 grams, indicating exceptional antioxidant strength likely resulting from the synergy mentioned above for wolfberry's diversity of antioxidant phytochemicals. This exceptional ORAC has not been peer-reviewed or confirmed in publication by other research.

Among high-antioxidant berries and fruits whose ORAC values have been reported as marketing information (unconfirmed by scientific peer-review) are açaí at 34,000 (freeze dried powder, Sambazon) and pomegranate at 10,500 (References, Brunswick Laboratories).

Functional food and beverage applications

Cultivated for a variety of food and beverage applications within China, but increasingly today for export as dried berries, juice and powders of pulp or juice, wolfberries are prized for their versatility of color and nut-like taste in common meals, snacks, beverages and medicinal applications. A major effort is underway in Ningxia, China to process wolfberries for “functional” wine.

Despite no evidence from clinical research, myths of wolfberry’s traditional health benefits endure, including longevity, aphrodisia, analgesia, anti-cancer, anti-inflammatory, antiviral, and immune-stimulating properties, muscular strength, energy, and vision health.

In laboratory and preliminary human research to date, wolfberries have been shown to have potential benefits against cardiovascular and inflammatory diseases, some forms of cancer, diabetes, premature aging, memory deficits, vision degeneration (such as age-related macular degeneration), and lung disorders, among other diseases of oxidative stress.

Although not adequately demonstrated yet in published research, a synergy of antioxidant carotenoids (primarily beta-carotene and zeaxanthin) with polysaccharides and vitamin C may make wolfberries an exceptionally rich antioxidant food source. Particularly for retinal health, wolfberry vitamin C, carotenoids and minerals like zinc would support prevention against age-related macular degeneration (the most common cause of blindness among the elderly), as these nutrients are used together in commercial supplements for eye health during aging.

Although not yet confirmed in peer-reviewed literature, wolfberries may contain an abundance of phenolic acids (phenolics, phenols or polyphenols), the major class of water-soluble antioxidant pigments in blueberry, cranberry, black raspberry and açaí. At a reported 86 mg per 100 grams of fruit, the phenolic ellagic acid appears to be especially rich in wolfberries (Young et al., 2005). Should this phenolic capacity be confirmed and extended to include the likely presence of other phenolic chemicals, the combination of rich contents in wolfberries of lipid-soluble ("lipophilic") antioxidants (carotenoids) plus water-soluble ("hydrophilic") antioxidants (phenolics) would make wolfberries exceptional as an antioxidant food source.

Micronutrient density combined with key health phytochemicals like carotenoids and polysaccharides give wolfberries remarkable nutritional qualities, making this berry one of Nature's most nutrient-rich plant foods.

Ningxia: Importance of soil and growing region

Interesting speculation about soil origins has arisen to explain the exceptional nutrient qualities of the Ningxia wolfberry. To the west of Ningxia is the province of Gansu, notable for its expansive mineral-rich desert, the Loess Plateau.

As the Yellow River passes through Gansu downstream toward Ningxia, loessal dust is wind-eroded into the river water where it is carried as silt in its downstream course. The Yellow River is renowned as the most silt-laden body of water in the world, as this is where the river's name is derived.

Finer than sand, yellow Gansu loess was formed 2 million years ago after glaciation left behind dust rich in a host of minerals unlike anywhere else on Earth. Gansu erosion into the Yellow River is so dense that silt content in the Yellow River in Ningxia weighs 35 kg for every cubic meter of water -- the highest silt density measured.

Yellow River floods in Ningxia have occurred repeatedly over millennia, depositing the mineral-rich silt over the river's flood plains where wolfberry fields and other crops are renewed and fertilized.

The dense mineral content of Gansu loess, therefore, may be the origin of enriched soil nourishing Ningxia wolfberries (Young et al., 2005; Gross et al., 2006).

Marketing

Since the early 21st century the dried fruit has begun to be sold in the West as a health food (typically under the name "Tibetan goji berry"), often accompanied by extensive claims regarding its purported health benefits. In some cases these claims are clearly false; the berry is often purported to contain 2500 mg of vitamin C per 100 grams of fruit, making it one of the world's richest sources of vitamin C behind the Australian billygoat plum and the South American camu camu (Wikipedia lists and References for vitamin C).

However, the amount of vitamin C in dried berries is actually in a range of 29-148 mg per 100 grams of fruit (Young et al., 2005; Gross et al., 2006), still a healthful serving amount similar to citrus fruits and raspberries. As stated above (Note on micronutrient contents), numerous factors of post-harvest handling can affect determination of vitamin C content. Of interest concerning vitamin C content is a soluble powder from wolfberry juice concentrate containing nearly 1000 mg per 100 grams (Rich Nature Labs)..

Companies marketing the berries often also include the unsupported claim that a Chinese man named Li Qing Yuen, who was said to have consumed wolfberries daily, lived to the age of 252 years (1678-1930).

Commercial products marketed outside Asia

Typical of many exotic fruits being introduced into western food and beverage commerce, wolfberry is best known in the United States and Canada as a juice marketed over the Internet since 2002 with an increasing presence in North American health food stores and grocery markets. While juice prepared entirely from fresh wolfberries is rare, blends of several berry and other fruit juices are used for nearly all "wolfberry" juice products, many of which are labeled "goji" juice.

Some exotic fruits, such as açaí, have found successful applications in franchised smoothie bars across the U.S. or Canada, but this has not yet occurred for wolfberry.

During 2005 to 2006, wolfberry has been increasingly mentioned in reports on the emerging functional food industry as an "exotic superfruit." The backing of celebrity nutritionalists such as Earl Mindell have helped to create the hype behind products containing Goji extract. Other such "superfruits" include açaí, pomegranate, mangosteen and noni. "Superfruit" is meant to imply nutrient richness with medical research results indicating potential health benefits, combined with uncommon but appealing taste, pigmentation and antioxidant strength.

Other wolfberry consumer applications are as dried berries (picture above), berry pieces in granola bars and skin soap made from seed oils.

Commercial suppliers have prepared products for using wolfberry as an additive in manufacturing, such as juice concentrate, powders from juice or juice concentrate made from spray-drying, pulp powders, whole or ground wolfberry seeds, wolfberry seed oils (as done for grape seed oil) and essential oils derived from wolfberry seeds.

The main supplier of wolfberry products in the world, China had total exports generating US$120 million in 2004. This production derived from 82,000 hectares farmed nationwide, yielding 95,000 tons of wolfberries.

References

• Mindell, E., and R. Handel (2003). Goji: The Himalayan Health Secret. Momentum Media, ISBN 0-9672855-2-6.
• Young G., R. Lawrence, and M. Schreuder (2005). Discovery of the Ultimate Superfood. Essential Science Publishing. ISBN 0-943685-44-3.
• Gross, P.M., X. Zhang, and R. Zhang (2006). Wolfberry: Nature's Bounty of Nutrition and Health. Booksurge Publishing. ISBN 1-4196-2048-7.
• Wu, X., G. R. Beecher, J. M. Holden, D. B., Haytowitz, S. E. Gebhardt, and R. L. Prior (2004). "Lipophilic and Hydrophilic Antioxidant Capacities of Common Foods in the United States." Journal of Agricultural Food Chemistry 52:4026-37.

External links

• BBC News coverage
• NHIondemand database
• PDR for Herbal Remedies
• Plant-life.org
• Searching for wolfberry on the Pubmed database finds 88 papers of interest (June 2006)
• A Friendly Skeptic Looks at Goji Juice By Dr. Ralph Moss
• Searching for Lycium on the Pubmed database finds 100+ papers of interest.
• Plants For A Future database
• Information about Lycium barbarum L. (matrimony vine) from the United States Department of Agriculture
• Wolfberry festival in Ningxia
• Plant viruses associated with Lycium barbarum (goji) from the Plant Viruses Online VIDE database