Blueberries have been used as a food and medicine for centuries for a wide range of ailments from preventing cataracts to treating constipation. Blueberries are high in fiber, and they also contain vitamin C and other antioxidants. As with cranberries, some people use blueberries to help prevent bladder infections and maintain bladder health. However, as with any supplement, consult with your doctor before taking blueberries for medicinal reasons.
About Bladder Health
Your bladder is responsible for storing urine and, when full, it eliminates the urine from your body through a tube called the urethra. Sometimes bacteria enter the urethra and get into your bladder where they can cause infections, called urinary tract infections, or UTIs. Some self-care approaches you can use to help you lower your risk of bladder infections include drinking lots of fluids to cleanse bacteria from your bladder, urinating frequently and taking supplements such as blueberry.
How Blueberry Works
According to a 1991 article in the "The New England Journal of Medicine," adhesion of Escherichia coli -- the most common bacteria to cause bladder infections -- on the bladder wall allows them to survive cleansing methods and to absorb nutrients, so they can grow and cause infection. Blueberries contain certain substances that inhibit E. coli from attaching to the lining of the bladder. So, when the bladder is emptied, the bacteria are flushed out and infection may be avoided.
Effectiveness
A laboratory study published in the "The New England Journal of Medicine" in 1991 found that blueberry juice blocked the adhesion properties of E. coli. An earlier study published in the "The Journal of Infectious Disease" in 1979 showed that substances that blocked the adherence of bacteria to the cells lining the bladder prevented the development of bladder infections in mice. Studies have not yet been done, though, to verify if blueberry can help prevent bladder infections in humans.
Considerations
Blueberries are generally safe for most people, but if you have diabetes, you must monitor your blood levels closely, as blueberries may lower your blood sugar levels. Also, blueberries may affect blood sugar control during and after surgery, so avoid blueberries for at least two weeks before any scheduled surgery.
References
- MedlinePlus: Blueberry
- "The New England Journal of Medicine"; Anti-Escherichia Coli Adhesin Activity of Cranberry and Blueberry Juices; Itzhak Ofek, Ph.D., et al.; May 1991
- "The Journal of Infectious Disease"; Prevention of Colonization of the Urinary Tract of Mice With Escherichia Coli by Blocking of Bacterial Adherence With Methyl A-D-Mannopyranoside; M. Aronson, et al.; March 1979
