The cranberry is a berry-bearing dwarf shrub that grows in bogs in the east of North America - on peat soils and with a lot of snow in winter. They are grown commercially in the United States on a large scale, and at the same time, Americans are the ones who consume the most berries. So cranberries are a common food. What about its medicinal effects?
Profile of the cranberry
- Scientific name: Vaccinium macrocarpon
- Common names: Cranberry, Cranberry, Cranberry
- Plant family: Heather Family (Ericaceae)
- Occurrence: Europe, Asia and North America, extensive cultivation in the USA
- Parts of plants used: Fruits, juice
- application areas: Urethral, kidney and bladder problems, especially for the prevention and complementary treatment of recurrent bladder infections in women, cardiovascular problems, tooth decay, prevention of colds, wound healing, inhibiting inflammation.
Cranberry has a high content of phytochemicals, especially proanthocyanidins (PAC) and condensed tannins (tannins) are bioactive. The dried and fresh fruits and the juice also contain flavonoids, anthocyanins and organic acids. There are also plenty of minerals
- and eleven milligrams of vitamin C per 100 grams.
The bioactivity of cranberries differs from that of other berries because the cranberries are rich in A-type proanthocyanidins - most other fruits, on the other hand, contain proanthocyanidins called "B-type". But these A-type proanthocyanidins are probably the substances with the strongest medicinal effects in cranberries.
Cranberries have antimicrobial properties, they inhibit inflammation and have an antioxidant effect. The proanthocyanidins, which prevent bacteria from getting stuck in the urinary bladder - especially E. coli bacteria - are said to be responsible. If Escherichia coli is now unable to implant in the urine or intestine, it is easily flushed out with the urine - a hypothesis. However, the available studies are controversial: The European Commission decided in 2017 that the adherence of bacteria to proanthocyanidins is very unlikely, rather that metabolites of PAC or other substances in cranberries would have a pharmacological effect.
The juice of the fruit has an antiviral, antibacterial and fungicidal effect. In the mouth, the antimicrobial substances can counteract caries. Presumed effects of the proanthocyanidins of the juice are prevention of gastric ulcers, the lowering of the LDL and in general the cholesterol level, as well as the raising of the HDL cholesterol level in the blood are proven. In this way, the substances could also fight cardiovascular diseases.
Bladder infections in women
Bladder infections affect women more than men; since their urethra is only up to four centimeters long, pathogens can quickly penetrate into the mucous membranes of the urinary tract and become lodged. This causes the mucous membranes to swell drastically and from then on there are the typical symptoms of cystitis that every woman knows from her own experience:
- violent burning sensation when urinating,
- frequent urge to urinate with a very small amount of urine,
- severe pain in the lower abdomen
- and constant difficulty holding urine.
Increased risk - menopause and pregnancy
Although this problem can affect every woman, women are affected more often by the hormonal changes during pregnancy. Finally, the hormonal changes widen the urinary tract, which makes it easier for germs and bacteria to enter the urethra. Menopausal women are also more prone to a urinary tract infection. A lack of estrogen is blamed for this by doctors, which makes the mucous membrane more sensitive to bacteria.
Does cranberry help with cystitis?
Can North American Cranberries Increase the Resistance of the Bladder? The American Indians already knew how to use the cranberry as a medicinal plant. The main component of the cranberry is the special plant substance, the proanthocyanidins, which drastically reduces the adhesion of germs and bacteria to the mucous membrane of the urinary tract.
The hypothesis after laboratory tests was: Proanthocyanidins constantly stick together the processes of the bacteria with which they hook onto the mucous membranes under normal circumstances. However, since this is no longer possible. the bacteria are simply washed out of the bladder the next time you urinate. However, since the cranberry extract only keeps the bacteria away from the mucous membrane and does not kill it, the natural flora of the vagina and intestine remains unchanged.
Cranberry is not the same as cranberry, and women should make sure that it contains at least 36 milligrams of proanthocyanidins, because only this amount ensures that healthy bladder and urinary tract function can be supported - at least according to an outdated recommendation from the French food agency AFSSA. Today, however, it is expressly emphasized that the data situation has changed and a preventive effect can no longer be confirmed.
In 2016, test subjects showed in a clinical study by the Yale School of Medicine in Connecticut that the proanthocyanidins, which are very effective in the laboratory, did not develop these effects in an emergency, i.e. in the body. 185 residents of retirement homes received either a placebo or cranberry capsules with berry powder for one year. At the end of the experiment, there were no clear differences in the infection rate between the two groups.
Cranberry instead of antibiotic?
Why do scientists do research on cranberries as a remedy for infections when antibiotics have long been available? Pathogens develop the more resistance to antibiotics, the more they “get used to” them. That means: the longer a person takes antibiotics, the greater the risk that they will have less of an effect on the germs. Cranberries could now significantly reduce the consumption of antibiotics against urinary tract infections and thus reduce the risk of developing resistance - if they actually fight the bacteria.
Cranberries in German
The Pilgrim Fathers in today's USA called the plant "Craneberry" because its shape reminded it of the head and neck, the stamens of a crane's beak. The cranberry, crane or crane berry is also called large-fruity cranberry and is closely related to the European cranberry (Vaccinium oxycoccos). The cranberry is used on a larger scale medically, since its effects have been better researched. The European cranberry probably has very similar properties and was also used similarly in folk medicine, but presuming does not mean knowing. The related cranberries and blueberries are similar to the effects of cranberries in some - but not all - ways. They also have antibacterial properties and they also have a high level of vitamin C. Incidentally, in German it means cranberries, not cranberries.
Cranberries are a safe, well-tolerated nutritional supplement that shows no significant negative interactions with other products.
Cranberries in folk medicine
Indian medicine used cranberries as food and medicinal plants long before Columbus appeared on the scene and for purposes similar to those that are now increasingly scientifically proven - against diseases of the kidneys and bladder.
Therapeutic uses of cranberries have been documented since the 17th century, both by European colonists in America and by professional doctors. They served against
- Gastrointestinal complaints,
- Liver problems,
- nausea associated with vomiting,
- Loss of appetite
- and cancer.
Cranberries have always been a popular medicine in folk medicine against urinary tract and bladder infections. She pushed the production of antibiotics a bit into the background, but today this traditional use of cranberries is again popular.
Cranberry for cancer, heart disease and arteriosclerosis
The cranberries are currently experiencing a renaissance - not only in naturopathy, but also in scientific research for new medicines for cancer and vascular diseases. Anthocyanins, procyanidins, and flavonols, which are well documented in the berries, have potentially good effects in preventing cancer.
Effects of cranberries to improve cardiac function have been proven in several clinical studies: The fruits balance the cholesterol level and thus have an effect against arteriosclerosis. Further research is needed to prove this trend in the long term and to develop appropriate medication.
Since studies have shown that substances in cranberries protect against urinary tract infections, there are various cranberry products on the market that are intended to serve as nutritional supplements, and it is often suggested that the infections can be prevented.
However, there is no evidence of effectiveness for such dietary supplements. Only a higher amount of proanthocyanidins has a noticeable effect on the bladder and urinary tract. The European Food Safety Authority forbade any health claims made for such capsules, syrups, juices, powders, etc., to state that they promote bladder health. The manufacturers are now adding vitamins such as vitamin C or vitamin B 6 or minerals such as zinc or selenium to the products, which have permitted health claims for such advertising. However, these vitamins and minerals have nothing to do with the effects of the proanthocyanidins active in the cranberries.
Cranberries are a healthy and versatile food. You can use the dried berries in a similar way to raisins, in yogurt as in rice dishes and muesli, in desserts and fruit salads, in cookies such as cakes. Fresh cranberries taste tart and sour and are suitable for game dishes and meat. Cranberry sauce can be used in a similar way to cranberry sauce in Germany.
Effects to prevent urinary tract infections by drinking cranberry juice cannot be proven in humans. But one thing is clear: the juice contains a high content of vitamin C, which can be used to combat vitamin deficiency, plus vitamins A and B, a good dose of iron (important for blood formation) and other minerals. Tannins (which pull together and promote digestion) and soluble fiber promote the health of the stomach and intestines.
Since cranberries taste slightly acidic, the manufacturers of the berry juices usually add sugar, water and additional flavors. It is best to make the juice yourself from fresh fruits in a juice machine.
Cranberries and environmental protection
The vast majority of cranberries that we buy in the store come from the United States. You have come a long way. Except for proven sustainable cultivation, their production is ecologically harmful. Cultivation areas are endangered and highly sensitive ecosystems, that is, peatlands. In the wet harvest, the growing areas are completely flooded. Pesticides against fungal attack, the washing out of toxins in the groundwater during harvesting and the damage to the moor ecosystem are anything but ecologically justifiable.
It is better if you can create a "moor garden", that is, have a low-lime and acidic soil that you keep moist to grow cranberries yourself or to use such organic quality berries from local production. By the way, blueberries contain a similar amount of vitamins and minerals; the cranberry is even closely related to the cranberry - and here in Germany they get these organic berries.
The studies on cranberries against infections of the urinary tract and bladder show a positive tendency, but are "mixed" in that they are based on different dosages, products, extracts, etc. - with hardly comparable experimental arrangements. In some cases, the examinations were methodologically weak, and they even came to different conclusions - a study in humans also showed no increased immunity to infections that went beyond the placebo effect.
There are still pending standardized studies that could provide evidence as to whether, how, why and to what extent cranberries work against urinary tract infections. However, there is limited evidence of a heart-protecting effect of the berries due to their antioxidant capacity and their lipoprotein profile.
There is no question that the berries show a strong phenolic bioactivity that contributes to human health. The high proportion of minerals and vitamins is also not up for discussion - this resembles blueberries or cranberries. Cranberries can be clearly recommended for a balanced diet. (Dr. Utz Anhalt)
Author and source information
This text corresponds to the requirements of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
Dr. phil. Utz Anhalt, Barbara Schindewolf-Lensch
- Bühring, Ursel: Practical textbook of modern herbal medicine: basics - application - therapy, Karl F. Haug, 2014
- Blumenberg, Jeffrey B et al .: Cranberries and Their Bioactive Constituents in Human Health, Advances in Nutrition, Volume 4, Issue 6, November 2013, pages 618-632, Published online November 6, 2013, PubMed
- Manisha Juthani-Mehta, Peter H. Van Ness, Luann Bianco, et al .: Effect of Cranberry Capsules on Bacteriuria Plus Pyuria Among Older Women in Nursing Homes; in: JAMA, Volume 316, Issue 18, 2016, jamanetwork.com
- Jepson, R. G .; Williams, G .; Craig, J.C .: Cranberries for preventing urinary tract infections; in: Cochrane Database of Systematic Reviews 2012, Issue 10, October 2012, cochrane.org
- Darren M. Lynch: Cranberry for Prevention of Urinary Tract Infections; in: Americcan Family Physician, Volume 70, Issue 11, December 2004, aafp.org
- Ioanna Mantzourani, et al .: Comparative Susceptibility Study Against Pathogens Using Fermented Cranberry Juice and Antibiotics; in: Frontiers in Microbiology, Volume 10, 2019, frontiersin.org
- R. Raz, B. Chazan, M. Dan: Cranberry Juice and Urinary Tract Infection; in: Clinical Infectious Diseases, Volume 38, Issue 10, May 15, 2004, academic.oup.com
- Shaomin Zhao, Haiyan Liu, Liwei Gu: American cranberries and health benefits - an evolving story of 25 years; in: Science of Food and Agriculture (published January 9, 2018), onlinelibrary.wiley.com