Should you drink cranberry juice when sick?

Cranberry juice is a popular beverage that is often touted as having various health benefits. One common claim is that drinking cranberry juice can help treat or prevent infections, especially urinary tract infections (UTIs). But is there any truth to this? Let’s take a closer look at what the research says.

What are the proposed benefits of cranberry juice?

Cranberries contain certain active compounds, including proanthocyanidins, flavonoids, and anthocyanins, that may offer some antimicrobial and anti-inflammatory benefits. Some key proposed benefits of cranberry juice include:

  • Preventing bacteria from adhering to the urinary tract: Proanthocyanidins may prevent E. coli bacteria from sticking to the cells lining the urinary tract, which may prevent infection.
  • Treating UTIs: Regularly drinking cranberry juice may help clear up mild UTIs by stopping the growth of infection-causing bacteria.
  • Preventing recurrent UTIs: For those prone to chronic UTIs, regular cranberry juice consumption may help prevent repeat infections by stopping bacteria from taking hold.
  • Supporting overall immunity: The antioxidant and anti-inflammatory compounds in cranberries may support overall immune health.

What does the research say?

A substantial amount of research has been conducted to evaluate the effectiveness of cranberry juice and cranberry extracts for preventing and treating UTIs. Here is a summary of some of the key findings:

Preventing UTIs

  • A 2011 review of 13 studies found that cranberry juice significantly reduced the risk of UTIs over a 12 month period, particularly for women with recurrent UTIs.
  • A 2016 review looked at 24 studies with nearly 5,000 participants. Researchers concluded that cranberry products significantly reduced the incidence of UTIs compared to placebo, water, or no treatment.
  • The most recent Cochrane review analyzed 36 studies with over 4,500 participants. They concluded that cranberry products reduced the risk of UTIs by 26% compared to placebo or no treatment.

Treating UTIs

  • A 2012 study found that drinking an 8 oz serving of cranberry juice twice daily for 6 months significantly decreased UTI symptoms compared to placebo.
  • However, a 2011 review found that most trials did not show a significant difference in UTI cure rates between those given cranberry juice versus placebo.
  • Researchers concluded that cranberry juice is less effective for treating active infections, and it should not replace antibiotics for a UTI.

Preventing recurrence of UTIs

  • In a 2004 study, women who had experienced at least 2 UTIs in the past year took either cranberry capsules or placebo for 6 months. The cranberry group had significantly fewer recurrences – 16% vs. 33% for placebo.
  • A 2016 study had women with a history of recurrent UTIs drink 240ml of cranberry lingonberry juice or a placebo for 6 months. About 25% of the cranberry juice group had a UTI compared to about 45% of the placebo group.

Overall, the bulk of research indicates that regular consumption of cranberry juice or cranberry extracts may be beneficial for preventing UTIs in certain high-risk populations. However, evidence for its effectiveness at treating active infections is weaker.

Potential risks and side effects

For most healthy individuals, cranberry juice is very safe with minimal risks. However, there are some potential side effects and considerations to keep in mind:

  • Drug interactions: Cranberries contain significant amounts of salicylic acid, which can interact with blood thinners like warfarin. Cranberry juice should be avoided by those on blood thinning medications unless approved by their physician.
  • Gastrointestinal distress: Drinking large amounts of cranberry juice can potentially cause nausea, vomiting, diarrhea, or stomach pain. Start with small servings and increase gradually.
  • Calorie content: Many commercial cranberry juice cocktails have added sugars and are high in calories. Consume diluted or low-sugar varieties in moderation.
  • Kidney stones: The oxalate content of cranberries may increase risk of kidney stones in those predisposed. Individuals with kidney stones should exercise caution and speak to their healthcare provider before consuming large amounts regularly.

Dosage recommendations

Most studies that have found benefits used cranberry juice in doses of around 8-10 oz (240-300 ml) taken once or twice daily. Higher doses may be more effective. Clinical trials have used varying cranberry products and dosages, including:

  • 8-16 oz of cranberry juice cocktail
  • 15-30 mL of concentrated cranberry juice
  • 500-1,000 mg dried cranberry extract capsules
  • 36-72 mg proanthocyanidin tablets

For urinary tract health, aim for approximately 300 ml (10 oz) of cranberry juice containing at least 25% cranberry juice or 36 mg of proanthocyanidins daily. This appears to be sufficient for most people to get benefits.

When to avoid cranberry juice

While cranberry juice is usually very safe, there are some situations where it’s better to avoid it or get medical guidance first:

  • If you take blood thinning medications like warfarin – cranberry juice can interact and change the effectiveness
  • If you have a history of calcium oxalate kidney stones – the oxalates in cranberries may increase risk
  • If you take antibiotics for a UTI – some antibiotics interact with cranberry, so check with your doctor first
  • If you have iron deficiency anemia – compounds in cranberries can inhibit iron absorption
  • If you have salicylate sensitivity – cranberries contain salicylic acid

Pregnant and breastfeeding women should exercise caution and limit intake to normal food amounts, not mega-doses. And for children, dilute cranberry juice with water and offer age-appropriate portions.

Cranberry capsules vs. juice – which is better?

Both cranberry juice and cranberry capsules/extracts have shown effectiveness for UTI prevention in studies. Some key differences include:

Cranberry Juice Cranberry Capsules
  • Contains various active compounds like proanthocyanidins, anthocyanins, flavonoids
  • Lower concentration of active ingredients
  • Must be consumed consistently
  • May add calories or sugar
  • More affordable and accessible
  • Standardized dose in each capsule
  • Higher concentration of active compounds
  • More convenient dosing
  • Fewer calories and no sugar
  • More expensive

For most people, drinking a daily glass of cranberry juice can provide benefits at a reasonable cost. But cranberry capsules may be preferred for those watching calories/sugar, needing convenience, or desiring a more potent standardized dose.

Does cranberry juice work for other infections?

Most research has focused specifically on the urinary tract. There is some preliminary evidence that cranberries may have benefits for other types of infections as well:

  • Respiratory tract infections: Compounds in cranberries may inhibit the flu virus and reduce symptoms of bronchitis. A few small studies found cranberry juice reduced cold and flu symptoms.
  • Gastrointestinal infections: Cranberries contain compounds that may inhibit H. pylori bacteria, which causes stomach ulcers. A couple small studies found benefit for reducing H. pylori infections when taken alongside antibiotics.
  • Periodontal disease: The anti-inflammatory effects of cranberries may reduce gum inflammation and prevent bacteria from adhering to teeth. A handful of studies show promising results, but more research is needed.

While findings are preliminary, adding cranberry juice to your diet when sick with respiratory, stomach, or gum infections has minimal risks and may provide some additional benefits. But always see a doctor for proper treatment of significant infections rather than self-treating with cranberry juice alone.

Best practices for drinking cranberry juice

Here are some tips for incorporating cranberry juice to maximize benefits and minimize risks:

  • Choose pure or diluted cranberry juice with minimal added sugars
  • Drink approximately 8-10 oz daily for UTI prevention
  • Gradually increase intake to avoid gastrointestinal distress
  • Rinse your mouth after drinking pure cranberry juice to prevent damage to tooth enamel
  • Avoid large amounts if taking blood thinners or you have a history of kidney stones
  • Always consult your physician if taking antibiotics for a UTI
  • Rotate cranberry juice with other berry juices to vary antioxidant intake
  • Select organic brands when possible to minimize pesticide exposure

Cranberry juice can also be used to make smoothies, juice blends, salad dressings, sauces, and more to take advantage of its potential benefits in a tastier form.

Should children drink cranberry juice?

There is limited safety data on giving cranberry juice to children. Potential benefits and risks include:

Potential benefits

  • May prevent recurrent UTIs
  • Contains antioxidants like vitamin C
  • May support overall immunity

Potential risks

  • Added sugars could promote cavities
  • Oxalates could increase kidney stone risk
  • Iron absorption may be inhibited
  • Could cause loose stool or diarrhea

Here are some recommendations for giving cranberry juice to kids:

  • Always dilute 100% cranberry juice with water
  • Limit to 4-8 oz diluted juice per day for young kids
  • Only give to children prone to UTIs or with physician guidance
  • Brush teeth after drinking to prevent enamel erosion
  • Avoid juice cocktails with added sugars
  • Provide water to stay hydrated and limit excess calories

Children should avoid cranberry supplements without medical supervision. If your child experiences recurrent UTIs, speak to their pediatrician about appropriate prevention and treatment.


Research indicates drinking cranberry juice regularly may help prevent UTIs, especially for women suffering from recurrent infections. The proclaimed benefits for treating active infections are less certain. While generally very safe, exercise some caution with cranberry juice if you have kidney stones, take blood thinners, or eat an iron-poor diet. Always speak with your doctor if using cranberry juice to treat a UTI instead of taking prescribed antibiotics. Moderation and dilution are key for children. Overall, incorporating cranberry juice in your diet can be a tasty way to take advantage of its unique health protective compounds.

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