If your doctor came in and handed you a sugar to deal with your UTI, you might look at her a bit cross-eyed. After all, sugar tends to make bacteria grow, not shrink.
But not all sugars are created equal. One particular one, D-mannose, can be quite helpful (as opposed to his useless brother, L-mannose-organic chemistry geeks click here for pictures of the two).
What D-mannose has been claimed to do is bind with bacteria trying to set up shop in the urinary canal and move the bacteria on out. But (courtesy of Alan Gaby) I now know there are proteins called Tamm-Horsfall proteins that act in the kidneys like D-mannose and require high mannose concentrations to function. They also seem to be involved with calcium processing, and low levels of these proteins can increase risks of kidney stones.
So, how well does this D-mannose fellow stack up? In a head-to-head trial of D-mannose versus nitrofurantoin (aka macrobid), the D-mannose patients had fewer recurring UTIs. Both groups did far better than the control group, and the difference between the two medications wasn’t significant.
What was significant was that the patients the took D-mannose had far fewer side effects.
So, here is an over-the-counter supplement outperforming a prescription medication with fewer side effects. Unfortunately, I doubt anyone will be switching prescriptions, because D-mannose cannot be patented and won’t be aggressively marketed like its prescription opponent.
Here’s the study link.