Can Cranberry Juice Stop or Prevent Recurrent UTIs in Women?

A urinary tract infection (UTI) refers to both upper and lower urinary tract infections. Typical symptoms of UTI include painful and frequent urination, feeling the urge to urinate despite having an empty bladder, blood in urine, and lower abdominal pain.

Among women who get UTIs, the chances of it returning are fairly common. An interesting way women can tackle recurrent UTIs is through drinking cranberry juice.

Dr Teo discusses this while answering some other commonly asked questions.

What is a recurrent UTI?

A recurrent UTI is a UTI that keeps coming back. It is defined as a UTI that has occurred at least twice in 6 months or thrice in 12 months. After the first infection, 30 – 44% of women will have another one in 6 months, and half will have a 3^rd. The most common causative pathogen is Escherichia coli (E. coli), followed by Proteus, Klebsiella, Pseudomonas, Serratia and Enterococci.

What causes recurrent UTIs in women?

The proven causes associated with recurrent UTIs in women are:

• Frequent intercourse (≥3 times per week)
• New or multiple sex partners
• Spermicide use, which disrupts the healthy flora in the vagina, allowing the invasion of harmful bacteria
• Incomplete urination (i.e. residual bladder urine volume ≥150mL)
• Comorbidities e.g. cystocele (protrusion of the bladder into the vagina), kidney stones, and immune-weakening conditions like diabetes, HIV and chemotherapy
• Having a UTI before 15 years old
• First-degree female relatives with recurrent UTIs ≥5 times
• Urinary catheterisation and deteriorate functional status in elderly institutionalised women
• Oestrogen deficiency in menopause as it changes the vaginal flora and pH, causing vaginal atrophy and increased risk of infections

Does cranberry juice help prevent recurrent UTIs?

Generally, the majority of studies suggest that cranberry helps with preventing and treating recurrent UTIs in women. In 2021, a review concluded that cranberry significantly reduced the risk of recurrent UTIs in women by 32%.

The American Urological Association (AUA) and the European Association of Urology (EAU) recommend cranberry as non-antibiotic treatment in preventing recurrent UTIs.

However, not all cranberry juices can stop or prevent recurrent UTIs in women. In order for cranberry juice to help prevent stop or prevent recurrent UTIs, it needs to contain enough of a compound called proanthocyanidin (PAC).

How can cranberry juice help with UTIs?

PAC is a plant-based compound that grants cranberry the ability to prevent recurrent UTIs. In fact, it is present in many fruits and vegetables. In cranberry, it exists as a unique A-type PAC that can decrease bacterial (specifically E. coli) adhesion to the epithelial cells of our urinary tracts.

The minimum amount of PACs required to reduce the risk of UTIs is 36mg daily. Studies have found that only soluble PACs exert the anti-adherence effect. As a result, a cranberry juice extract and a whole cranberry blended product aren't equally effective. Cranberry juice extracts have a higher soluble PAC, and therefore have a greater effect in reducing the risk of recurrent UTIs.

When cranberry juice extracts are consumed, soluble PACs will be absorbed into the bloodstream and passed into the urine. These PACs in urine interfere with the adherence of bacteria to the cells. The bacteria cannot grow, so no infection occurs. This proposed mechanism is called competitive inhibition.

Another reason why cranberries may help stop or prevent recurrent UTIs are due to their anti-inflammatory effect. This can allow cranberries to help relieve the inflammation caused by UTIs, thereby suppressing the reproduction of bacteria in the urinary tract and preventing the disease from becoming severe.

Do other cranberry products help with recurrent UTIs?

Cranberry juice is 35% more effective than cranberry capsules or tablets in preventing recurrent UTIs. It is reasoned that since cranberry juice is a liquid, it can help flush out bacteria from the urinary tract. The juice might also have a synergistic effect caused by additives or other unknown substances.

Until studies are more conclusive as to the reasons why cranberry can help stop or prevent recurrent UTIs, it is best to stick to cranberry juice and to avoid other cranberry products in the quest against recurrent UTIs.

However, do take note of the sugar and calories that cranberry juices have. It is also important to note that cranberry products should be avoided if you are taking the blood-thinning medication warfarin because they can interact with warfarin and result in internal bleeding.

What are some other home remedies for recurrent UTIs?

These lifestyle modifications may help in preventing recurrent UTIs in women:

• Drink plenty of water. Water helps to dilute your urine and flush out bacteria from the urinary tract.
• Wash the skin around the anus and genital area.
• Urinate as soon as you feel the urge, usually every 2 – 3 hours.

Some examples of natural therapeutics in preventing recurrent UTIs in women include:

• Herbal diuretics like goldenrod, lovage, parsley, and stinging nettle. They may increase urine volume and help in flushing out bacteria.
• Herbs with antimicrobial properties. Examples are bearberry, juniper leaf, Oregon grape, and goldenseal. They may directly kill microbes or stop them from adhering to epithelial cells.
• D-mannose is a sugar commonly found in plants, fruits/berries, and is synthesised by our bodies. It helps by stopping E. coli adhesion to epithelial cells.
• Probiotics (Lactobacilli) help establish normal ecology of the vagina and urinary tract pH. They are great in preventing recurrent UTIs in women who have a disturbed balance of the vaginal flora due to long-term antibiotics, post-menstruation and menopause.

When should I see a doctor for my recurrent UTI?

It's a good idea to seek medical attention if you think you might have a recurrent UTI, especially if your symptoms are:

• Suggestive of an upper UTI infection, including a high fever (≥38°C ), flanks or back pain, shivering or chills, feeling ill, confused, agitated, and restlessness.
• Severe or getting worse
• Not improving after a few days
• Recurring frequently

Your doctor might conduct further tests to rule out other possible causes of your symptoms. Antibiotics may be prescribed to treat the infection. It is best to consult your doctor if you suspect you have a recurrent UTI.