For up to a million women in the U.S., enjoying a piece of pepperoni pizza has painful consequences. They have a chronic bladder condition called interstitial cystitis that causes severe pelvic pain. Spicy food such as citrus, caffeine, tea (even green tea), sodas, tomatoes and alcohol can cause their symptoms (pain and an urgent need to frequently urinate) to flare up and intensify. It was thought that the spike in their symptoms was triggered when digesting the foods produced chemicals in the urine that irritated the bladder.

However, researchers from Northwestern University's Feinberg School of Medicine believe the colon, irritated by the spicy food, is to blame.
This idea opens up new treatment possibilities for interstitial cystitis, or painful bladder syndrome (PBS), a condition that primarily affects women (only 10 percent of sufferers are men.) During a flare up, the pelvic pain is so intense some women administer anesthetic lidocaine directly into their bladders via a catheter to get relief. Patients typically also feel an urgent need to urinate up to 50 times a day and are afraid to leave their homes in case they can't find a bathroom.

"This disease has a devastating effect on people's lives," said David Klumpp, principal investigator and assistant professor of urology at the Feinberg School. "It affects people's relationships with family and friends." Klumpp said some women who suffer from this become so depressed, they attempt suicide.

The researchers believe the colon's central role in the pain is caused by the wiring of pelvic organ nerves. Nerves from this region, the bladder, colon and prostate, are bunched together like telephone wires and plug into the same region of the spinal cord near the tailbone.

People with interstitial cystitis have bladder nerves that are constantly transmitting pain signals to the spinal cord. And when the colon is irritated by pepperoni pizza or another type of food, colon nerves also send a pain signal to the same area on the spinal chord intensifying the pain.

Klumpp noted. "Pepperoni pizza does nothing to most people other than heartburn, but when you give it to a person with an inflamed bladder, that will cause their symptoms to flare because the nerves from the bladder and bowel are converging on the same part of the spinal cord."

Oral therapy with quercetin supplement has been shown to provide significant symptomatic improvement in patients with interstitial cystitis.
References:
1. D. Klumpp, C. Rudick. The pepperoni pizza hypothesis. Northwestern University. October 2008.
2. Katske F, Shoskes DA, Sender M, Poliakin R, Gagliano K, Rajfer J. Treatment of interstitial cystitis with a quercetin supplement. Tech Urol. 2001 Mar;7(1):44-6. PMID: 11272677.
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