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The Effect of Diet on Urine pH for Interstitial Cystitis

Updated: Aug 11, 2022

Did you know that the foods and beverages you consume have a direct effect on your bladder symptoms?

The human body is an amazing thing. It has the ability to break down the nutrients in food and use them as energy, building blocks of muscle, for storage, and many other functions.

We have two systems in our bodies that break down nutrients for these functions: the gastrointestinal (GI) tract and the urinary tract. In this post, I’m going to review the anatomy of the urinary tract as well as how what you eat directly impacts your IC symptoms.

The job of the urinary system is to filter blood and create urine to be removed from the body as waste. The system consists of the kidneys, ureters, bladder, and urethra.

As I mentioned earlier, the body breaks down nutrients via the GI tract and the urinary tract. After the body absorbs the nutrients that it needs to survive, it leaves waste products behind in the form of urine and stool.

The kidneys and urinary system help the body eliminate liquid waste called urea. Urea is produced when foods containing protein (think animal sources like meat or plant sources like nuts and beans) are broken down in the body. Urea is carried through the bloodstream to the kidneys, where it is removed along with water and various other wastes in the form of urine and eventually excreted from the body.

In addition to creating urine, the kidneys help keep chemicals, such as potassium and sodium, and water in balance. They also help regular blood pressure and control the production of red blood cells. The urinary tract is truly a work of art!

In interstitial cystitis (IC), it is theorized that the pH of urine plays a role in symptoms. Let’s first review what pH is. The pH scale is used to measure the acid and alkaline present in various fluids, in this case, urine. A pH of 7 is neutral, anything below 7 is acidic and anything above 7 is basic, or alkaline.

According the the American Association For Clinical Chemistry, a normal urine pH ranges between 4.5 and 8. Urine pH can be measured by a test called a urinalysis. This test involves urinating into a sterile cup (called a “clean-catch) to reduce the chance of bacteria affecting the urine sample. If a urinalysis is performed in a medical setting, a doctor will visually examine the sample, conduct a dipstick test, and can even look at the sample under a microscope.

Urine pH is extremely complex and can be changed affected by diet and medical conditions. What a person consumes on a daily basis can affect his or her urine pH (we will get into this later). Medical conditions that can cause urine to measure alkaline include diabetic ketoacidosis, dehydration, acidosis, starvation, kidney stones, and diarrhea. Acidic urine can be caused by kidney failure, respiratory alkalosis, and urinary tract infection, among various other conditions.

It is theorized that a diet high in high-acid foods and beverages can cause an increase in symptoms. In fact, many practitioners recommend following an alkaline diet. However, this causes some controversy in the IC community. Even Barbara Shorter, a fellow Registered dietitian and Interstitial Cystitis Association (ICA) Medical Advisory Board member, says, “There is some controversy here, but we don’t have any proof that it’s the acid or the alkaline that makes a difference in the bladder.” Currently, the ICA does not support the alkaline diet theory.

You may be wondering, “Should I be restricting acidic foods?” Well, the answer to this question is a bit complicated. This is because the effect of food on your urine can be very different from the acidity of the food itself - that is because of the way our body digests and metabolizes foods and beverages. For example, orange or lemon juice are acidic (low pH) that once metabolized, produce alkaline urine. Another example is meat, fish and chicken. These items are alkaline but produce acidic urine.

So what causes an acid to go in and come out of the body as alkaline? It’s your body! Like I said earlier, our bodies are truly amazing. They have a built-in system for controlling pH - it can actually automatically correct the pH of the blood if it sees fit. The acidity of a food or beverage that goes into our body has almost no relationship to what happens to it once inside.

So why do so many people think people with IC should avoid all foods high in acid? Well, this is pretty much the result of people over-simplifying the common IC trigger foods. However, it is a common misconception. There are many foods high in acid that people with IC can tolerate.

Also, the acidity of urine does not necessarily cause an increase in symptoms. Or at least we don’t have any research to support this theory (even with the amount of people who feel their symptoms increase when their urine is acidic). There was a study conducted at the University of British Columbia that aimed to test this theory. Participants of this study were diagnosed with IC and either had their own highly acidic urine re-inserted into their bladder or had a neutralized solution inserted. The researchers found that the acidity of the urine did not seem to play a difference in symptoms.

In conclusion, diet does play a role in the pH of the body, but a eating an acidic food does not mean that urine produced will also be acidic. The common misconception of avoiding all foods with acid is likely the result of over-simplifying the IC diet. It is important to know that each person with IC has their own unique dietary triggers that should be tested via an elimination diet.

Want individualized guidance in learning your IC triggers? Check out my Road To Remission program here!


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