D-mannose is a natural substance available in dietary supplement form. A type of sugar found in a number of fruits (including cranberries), D-mannose is typically touted as a natural remedy for urinary tract infections and bladder infections.
D-mannose is thought to keep bacteria from sticking to the walls of the urinary tract, which is why it's used to prevent and treat urinary tract infections.
In addition, D-mannose is sometimes used to treat a condition called carbohydrate-deficient glycoprotein syndrome. A type of genetic disorder, carbohydrate-deficient glycoprotein syndrome interferes with the body's ability to properly break down and produce mannose (a sugar molecule that plays a key role in metabolism).
Proponents claim that use of D-mannose can help improve liver function, regulate blood sugar levels, and protect against blood clotting in patients with carbohydrate-deficient glycoprotein syndrome.
To date, research on the health effects of D-mannose is very limited. However, there's some evidence that D-mannose shows promise for protection against urinary tract infections.
In a laboratory study published in the journal PLoS One in 2008, for instance, scientists demonstrated that D-mannose can help stop Escherichia coli (the type of bacteria that causes the vast majority of urinary tract infections) from sticking to cells found in the urinary tract. Although the study's authors suggest that D-mannose may help prevent urinary tract infections, it should be noted that there is currently a lack of clinical trials testing the use of D-mannose supplements against urinary tract infections (or any other health condition).
Alternatives to D-Mannose
If you're seeking a natural remedy for the prevention or treatment of urinary tract infections, several other dietary supplements may be of some benefit. For instance, some research suggests that drinking cranberry juice may decrease incidence of urinary tract infections.
Like D-mannose, certain compounds found in cranberry (including proanthocyanins, a type of antioxidant) may help prevent bacteria from adhering to the walls of the urinary tract. When using cranberry juice to prevent urinary tract infections, opt for the unsweetened variety to limit your sugar intake.
For more help in fighting urinary tract infections, make sure to drink plenty of water on a regular basis. By doing so, you'll increase the likelihood that bacteria will be flushed from your urinary tract before infection sets in.
Is It Safe?
Little is known about the safety of long-term use of D-mannose supplements. However, there's some concern that D-mannose supplements can trigger a number of side effects (such as bloating). When taken in excess doses, D-mannose may lead to kidney damage.
Since D-mannose may alter your blood sugar levels, it's crucial for diabetes patients to take caution when using D-mannose supplements.
It's also important to note that self-treating any condition with D-mannose supplements, and avoiding or delaying standard care, may have serious health consequences. For example, if a urinary tract infection isn't properly treated with antibiotics, the infection may spread to the kidneys even though a person's symptoms initially improve.
If you're considering the use of D-mannose supplements for a health problem, make sure to talk to your doctor before starting your supplement regimen.
Where to Find It
Widely available for purchase online, D-mannose supplements are sold in many natural-foods stores and in stores specializing in dietary supplements. D-mannose is typically available in powder, capsule, and tablet form.
Wellens A, Garofalo C, Nguyen H, Van Gerven N, Slättegård R, Hernalsteens JP, Wyns L, Oscarson S, De Greve H, Hultgren S, Bouckaert J. "Intervening with urinary tract infections using anti-adhesives based on the crystal structure of the FimH-oligomannose-3 complex." PLoS One. 2008 Apr 30;3(4):e2040.