When a patient experiences bladder symptoms, most assume that they have a urinary tract infection. Many, however, are stunned to learn that urine testing has found no infection. So what else can trigger these urinary symptoms? The bladder, like any other part of the body, can be injured, usually the result of chemical exposure.
Acid
When we think about diet induced flares, the worst irritant appears to be acid. From the citric acid found in citrus drinks and sodas, ascorbic acid found in vitamin C to acetic acid found in vinegar, acids are undeniably painful in quantity. Patients with wounds in their bladder (i.e. Hunner’s lesions) learn very quickly that foods high in acid can cause agonizing flares that slowly resolve as the bladder slowly heals the damaged tissue.
When you think about a cup of coffee or tea, it’s not the caffeine that injures the bladder wall. Rather, it’s the acids. Coffee can be very high in chlorogenic acid which are created when coffee beans are roasted in hot metal drums. Teas, particularly green teas, are also quite acidic. Caffeine, on the otherhand, does’t directly damage the bladder, it stimulates nerves and, for many, a reliable bowel movement in the morning. Drinking excessive caffeine, however, could traumatize sensitive nerves, especially with long-term consumption.
Chemotherapy
Cancer patients often struggle with symptoms similar to IC because their bladders are being irritated by the toxins that occur when some chemotherapeutic medications (i.e. cyclophosphamide, ifosfamideare) are metabolized and produce acrolein. Acrolein is so damaging that the bladder can bleed. These patients may also struggle with severe bladder pain, frequency and urgency. Patients are encouraged to drink plenty of water to dilute their urine. There is a medication (Mesna) which can break that toxin down into a bladder friendly substance. The challenge is that many oncologists disregard complaints of bladder irritation.
Ketamine
Ketamine has gained popularity as a recreational drug that is well known for damaging the bladder, resulting in ketamine cystitis. Acting like an industrial solvent, long-term use can cause such severe damage to the bladder, ureters and kidneys that bladder removal may be required. Learn more at: ketaminecystitis.org
Medications
Some antibiotics, high dose vitamin C or potassium products could irritate the bladder. Even products developed for bladder health, such as a urinary antiseptic (UroBlue), could injure/irritate the bladder wall. Methenamine, for example, is commonly prescribed to IC and UTI patients though it’s only use is to make urine so toxic that bacteria can’t grow. Methanamine is broken down into formaldehyde, a chemical well known for irritating some bladders. Methenamine products are not suggested as a treatment for IC in our national AUA guidelines.
Artificial Sweeteners
Aspartame (aka Nutrasweet) is found in many modern foods, where it is used as an artificial sweetener used to reduce sugar intake. In the IC community, it is well known for irritating the bladder likely because it is metabolized into methanol, formic acid and formaldehyde, all of which are caustic chemicals and potential irritants.
While aspartame advocates and the US FDA states that the levels should be safe (as long as someone doesn’t overconsume them), the International Agency for Research on Cancer (IARC) has labelled aspartame as “possibly carcinogenic to humans.” The World Health Organization does not suggest the use of any non-sugar sweeteners given their proven risk of obesity, diabetes, cardovascular disease and adverse pregnancy outcomes. (3)
Chinese Herbs
A new case study from China shares the story of a 77 year old man who developed symptoms suggestive of interstitial cystitis. They were later connected with a chinese herb, known as Kampo, which the patient had taken for just 35 days. A cystoscopy revealed that his bladder had thickened, with significant inflammation that improved once we stopped the herbal prep.
Chinese herbs present significant challenges for new patients who may hear that they work. A bottled product with labels identifying the ingredients are preferred over “on the fly” herbal preparations. Some herbalists are known for creating custom formulations by grabbing a varying amounts of herbs and placing them in jars, without disclosing what the herb is and what it does. One patient in my support group had an agonizingly painful flare after visiting a chinese herbalist. Please don’t accept any herbal product that is not properly labelled and the ingredients are not disclosed. Better yet, take the time to research the ingredients before buying and trying the product.
Alcohol
Every spill alcohol onto a wound? It hurts, badly. The same is true for the bladder. As millions of IC patients can attest, alcohol is a well known bladder irritant and trigger of IC flares. But, alcohol does far more damage. It causes dehydration, which then concentrates your urine, irritating your bladder lining and causing more frequency and urgency. Alcohol can impair signals from your bladder to your brain, resulting in incontinence. Alcohol also can relax the muscles of your bladder, also resulting in incontinence. Thankfully, in 2026, you can now find many, excellent dealcoholized beers, wines and champagnes. In many cases, you’d never know they are alcohol free. Guiness, for example, tastes great.
Sodium & Potassium
One of the earliest forms of torture was rubbing salt into open wounds. If present in high quantities in urine, both sodium and potassium can penetrate more deeply into the bladder wall, where they can trigger bladder pain, urgency and smooth muscle contractions. This is why the potassium sensitivity test was developed. If a potassium solution triggered bladder pain, this was a defacto diagnosis that the bladder wall was injured. Thus, many patients with a vulnerable bladder wall avoid foods high in salt and/or potassium.
A Patient Success Story
IC patient Helen lives a very healthy lifestyle. She’s slim, fit, exercises regularly and eats vegan. Yet, a recent sonagram for a suspected hernia revealed that she had signs of significant fatty liver disease. Fatty liver disease is strongly associated with alcohol, which she had not drunk in more than 40 years. It can also be the result eating excessive sugars and carbohydrates. Her doctor, however, said that given her lifestyle, her diet shouldn’t be playing a negative role in her health. He asked “are you taking anything else?” This is where the mystery was solved.
Helen had struggled with constipation since childhood. In 1978, her doctor suggested that she take Senna and cascara sagrada, both herbs known for stimulating bowel movements. She had used them daily for more than 40 years. What she did not know is that neither one is suggested for use longer than seven days. When used for extended periods of time, both have been linked to liver damage. She stopped using them immediately.
Here’s where her story gets interesting. After stopping the stimulant laxatives, her bladder symptoms improved dramatically. Why? One possibility is that both herbs are well known for causing dehydration, resulting in more concentrated and potentially irritating urine. Her story is a stark reminder that even physicians may not understand the risks of some herbs. When in doubt, research it more carefully.
A Patient Tragedy
One of the most remarkable patient stories in my career was a woman who was bed bound, drinking a pot of coffee and a six pack of diet soda a day. She was also using opiate pain medication frequently. Her husband called our office, desperate for any suggestions on how to help his wife. I had the chance to speak with her twice, stunned when she said “I’d rather have my coffee and my pain meds than nothing at all.” She was clearly addicted to both caffeine and pain medication. Worse, there was no interest in learning about her bladder and the things that she could do to help herself. She reminds me of another patient with a similar addiction who was finally able to quit and her bladder symptoms improved dramatically in just a few months. There are times when we all must confront and change addictions and/or bad habits.
Conclusion
Chemical injury is not a disease. It is, in fact, tissue that has been injured. Your job is to help your bladder heal by protecting and soothing it. This means that you must avoid things that could injure it further. You may argue that just one cup of coffee a day should do no harm but the harsh reality is that it could be causing just enough damage to prevent healing or, worse, prevent bladder treatments from actually working.
There is no treatment that can counteract the physical damage caused by coffee, soda or any other major irritant daily. As Dr. Anthony Schaeffer explained years ago during a national IC meeting, the stem cells that are trying to grow and repair the bladder wall are often destroyed by that simple one cup of coffee, setting that patients healing back atleast two weeks. And, if that coffee is drunk daily, it may be physically impossible for the bladder to heal. This is why we always suggest that patients avoid these strong triggers for several months just to give the bladder wall an opportunity to calm and heal.
References
- Czarnecka K, et al. Aspartame-True or False? Narrative Review of Safety Analysis of General Use in Products. Nutrients. 2021 Jun 7;13(6):1957. doi: 10.3390/nu13061957. PMID: 34200310; PMCID: PMC8227014.
- IARC. Aspartame hazard and risk assessment results released. July 14, 2023. https://www.iarc.who.int/news-events/aspartame-hazard-and-risk-assessment-results-released/
- World Health Organization (2023). Use of non-sugar sweeteners: WHO guideline summary. World Health Organization. https://iris.who.int/handle/10665/375565. License: CC BY-NC-SA 3.0 IGO
