Goji Berries - The Anti-Cancer Berries
Goji berries (fruits: Fructus lycii of closely related plants: Lycium barbarum and Lycium chinense) are also known as wolfberries. The 1 to 2 cm long berries come from the goji plant, which belongs to the nightshade family, which also includes tomatoes and potatoes. The plants are mainly cultivated in Asian and Southeast European regions. Goji is the simplified name of the high Chinese word Gouqi. Due to their valuable ingredients and numerous healthy benefits, the berries are also considered functional foods.
In traditional Chinese medicine, they have been used for over 2000 years for better health and longevity, as well as against gray hair, fatigue, dry cough, decreased visual acuity, infertility, headaches, and abdominal pain 1. They are either eaten raw or consumed as goji extracts in the form of juice or tea.
Fighting Cancer with Goji Berries
Goji berries are a potential anticancer agent and adjunct in cancer treatment 2. They contain polysaccharide-protein complexes, chemically composed of a branched, long chain of sugar substances and amino acids. These complexes predominantly possess anti-inflammatory and antioxidant properties. Additionally, scopoletin and 2-O-β-D-glucopyranosyl-L-ascorbic acid (AA-2βG; precursor of vitamin C) are present in the berries 3. According to scientists, all three have apoptotic (cell suicide) and antiproliferative (against tissue growth) effects on cancer cell lines.
Among the polysaccharide-protein complexes is LBP3p, which can trigger immune responses and thus has potential effectiveness in cancer diseases 4. In another study, the anticancer benefits of polysaccharides from Goji berries was examined on human colon cancer cells 5. The polysaccharides induced cell cycle arrest in colon carcinoma cells, suggesting their potential as an anticancer agent.
Further investigation results demonstrate that the polysaccharide-protein complex (LBPF4) improves the function of T and B cells, as well as macrophages (phagocytic cells) 6. The polysaccharide called LBPF4-OL from goji berries improved the functions of B cells and macrophages.
According to other studies, goji fruits can potentially be an anticancer agent for the prevention and treatment of cervical cancer 7.
The results of an observational study showed that in 75 patients who orally consumed lymphokine-activated killer cells/interleukin-2 (LAK/IL2) along with polysaccharides from Goji berries, there was a reduction in cancer 8. The polysaccharides acted as enhancers of LAK/IL2 in cancer regression among patients with melanoma, renal cell carcinoma, colorectal carcinoma, lung cancer, nasopharyngeal carcinoma, and malignant pleural effusion.
An extract from the fruits inhibited the growth of estrogen receptor-positive human breast cancer cell line MCF-7 (used in breast cancer studies) by altering the metabolic pathways of estradiol in studies 9. Another study with polysaccharides from Goji berries confirmed the inducing antiproliferative effect on MCF-7 cells through the activation of ERK (extracellular signal-regulated protein kinase, mediating intracellular signals) 10. Goji berries may potentially prevent breast cancer and slow down the growth of cancer tumors.
In a further study, the benefit and mechanism of Lycium barbarum polysaccharide (LBP-X) in inhibiting the growth of human leukemia HL-60 cells were investigated. 11. LBP-X at various dosages inhibited the growth of HL-60 cells and reduced the cell membrane fluidity. The results demonstrated the apoptosis of HL-60 cells induced by LBP-X. This may be the important mechanism underlying the anti-tumor activity.
Similarly, the polysaccharides also seem to exhibit anti-cancer activity against gastric cancer cells and prevent the growth of specific cells. 12.
Other findings suggest that polysaccharides are potent immune regulators and can promote immune functions 13. The polysaccharides significantly enhanced the cytotoxic activity of NK cells. NK cells are natural killer cells and lymphocytes of the immune system that kill tumors and infected cells while protecting healthy cells.
In most cases, polysaccharides constitute approximately 90-95% of the mass and consist of arabinose, glucose, galactose, mannose, rhamnose, xylose, and/or galacturonic acid 14.
Antioxidant properties and benefits of goji berries
Goji berries are considered an excellent source of antioxidants for human nutrition 15. Multiple studies demonstrate the high antioxidant activity and benefit of goji berries as free radical scavengers 16 17 18 19. In particular, polysaccharides and polyphenols contribute to the high antioxidant activity 20 21. Polyphenols are aromatic compounds associated with secondary plant metabolites.
Phenolic compounds are abundant in goji berries. The healthy berries contain the antioxidants caffeic acid, p-coumaric acid, rutin, scopoletin, N-trans-feruloyl-tyramine, N-cis-feruloyl-tyramine, and N-feruloyl-tyramine as a novel molecule 22. According to scientists, the new N-feruloyl-tyramine dimer was identified as the most abundant polyphenol and antioxidant. In total, goji berries contain 53 different polyphenols 23. The polyphenols also exhibit high oxygen radical absorbance capacity (ORAC activity) 24. The ORAC method expresses the ability to capture harmful oxygen radicals in the body.
Dried goji berries also contain significant amounts of three antioxidant flavonoids: kaempferol (62 μg per gram), myricetin (114 μg), and quercetin (136 μg) 25. Other notable ingredients with antioxidant benefits include gallic acid, caffeic acid, protocatechuic acid, chlorogenic acid, and neochlorogenic acid 26 27.
Carotenoid zeaxanthin for healthy eyes
Age-related macular degeneration (AMD) is a common disease that leads to irreversible loss of central vision. Scientists consider the carotenoids lutein and zeaxanthin (both are macular pigments) as effective plant compounds for reducing the risk of AMD. 28. Goji berries are a very good source of naturally occurring zeaxanthin. 29 30 31. The zeaxanthin content depends on the ripeness stage, season, and drying process, resulting in values ranging from 1.18 to 2.41 mg per gram in dried fruits 32. Interestingly, these healthy berries may even be a better source of macular pigments than green leafy vegetables like spinach 33.
Zeaxanthin can be effective in preventing AMD, according to scientists 34. In this context, they conducted a study using available zeaxanthin from goji berries. The participants supplemented their diet with 15 g of goji berries per day, resulting in a 2.5-fold increase in plasma concentrations of zeaxanthin. However, further studies are needed to obtain conclusive results on maintaining macular pigment density in humans.
Other carotenoids present include β-cryptoxanthin palmitate, zeaxanthin monopalmitate, and β-carotene 35.
Goji berries are a good source of vitamin C, vitamin E, and beta-carotene. Dried goji berries contain about 48 mg of Vitamin C per 100 g, which is similar to the amount in lemons (53 mg).
In studies, the compounds found in Goji berries showed antiviral activities 36.
Goji berries protect the liver
Scientists have isolated three hepatoprotective (liver-protective) compounds (pyrrole derivatives) from the berries. Two of the compounds showed hepatoprotective effects comparable to the liver-protective Silybin (Silibinin) 37.
Dried Goji berries are among the richest fruits in protein with 14g of protein per 100g. The fruits contain 1 to 2.7% of freely available amino acids, with proline being the main component 38 39. Additionally, according to the previously linked studies, the non-essential amino acids taurine and γ-aminobutyric acid (GABA) are also present in the berries.
Additional amino acids with high proportions are aspartic acid (1.7 g), glutamic acid (1.4 g), and arginine (0.7 g).
The nutritional values and nutrients of goji berries can be viewed here.
The small berries contain very little fat, with 0.39 g per 100 g of dried fruits. Nevertheless, the oil extracted from goji berries has been examined for its composition. The main components are hexadecanoic acid (47.5%), linoleic acid (9.1%), β-elemene (5.4%), myristic acid (4.2%), and ethyl hexadecanoate (4.0%) 40.
Side Effects of Goji Berries?
Caution is advised for those using the blood thinner warfarin. There may be potential side effects 41.
Other studies have shown an allergenic potential of goji berries in people with food allergies, likely due to cross-reactivity with lipid transfer proteins (LTP) from other foods 42 43. People allergic to LTP should rather avoid the berries.
Scientists also examined the atropine content of eight berry samples from China and Thailand 44. The toxic alkaloid found in nightshade plants was detected in all the samples analyzed, with concentrations of up to 19 ppb (parts per billion). The concentrations are well below the toxic level.
The Goji berries have a sweet taste. In terms of texture, they are similar to raisins. Therefore, they also blend well with muesli and salads. They can also be used for baking (cookies and chocolate cake) and as an ingredient in smoothies.
However, Goji berries can also be eaten as a snack on their own. Additionally, the berries are used for making tea.
In southern China, Goji berries are used as an ingredient in soups and sweet or savory porridge 45.
Buying Goji Berries
These healthy berries can be found in drugstores, organic stores, and health food stores. They are also gradually appearing on the shelves of larger supermarkets. Occasionally, Goji juice and Goji tea are also available for purchase. Both the berries and the juice can be ordered online.