What Happens If You Drink a Lot of Cranberry Juice? Side Effects

Medically Reviewed on 12/23/2021
What Happens If You Drink a Lot of Cranberry Juice
Although cranberry juice is safe in moderation, drinking too much can cause side effects such as upset stomach, diarrhea, and blood sugar spikes

Although cranberry juice is safe to consume in moderation, drinking too much can cause side effects such as upset stomach, diarrhea, and blood sugar spikes. 

In the past, it was believed that cranberry juice can slow the growth of bacteria and therefore is useful in treating urinary tract infections. However, recent studies have shown that although cranberry juice may help prevent bacteria from sticking to the urinary tract wall, it doesn’t do enough to make a significant difference.

Cranberry juice is high in salicylic acid, which may alleviate swelling and blood clots in the body. Therefore, it may do more for boosting heart health than urinary tract health.

Who should exercise caution when drinking cranberry juice?

Cranberry juice should be used with caution if you have the following conditions:

  • Diabetes: Sweetened cranberry juice can cause blood sugar spikes due to the presence of added sugar.
  • Kidney stones: Cranberry juice is high in oxalates, which can lead to kidney stones.
  • Pregnancy and breastfeeding: Since there isn’t much information regarding the safety of drinking cranberry juice while pregnant, most experts recommend avoiding cranberry juice if you are pregnant or breastfeeding.
  • Aspirin allergy: Aspirin is similar to salicylic acid. Since cranberry juice contains a significant amount of salicylic acid, it is best to avoid drinking it if you are allergic to aspirin.
  • Blood thinner medications: Some studies report that cranberries can react negatively with blood thinners such as warfarin.

Cranberry juice may interact with the following medications:

If you are taking these medications, consult your doctor about how much cranberry juice is safe to consume.


According to the USDA, there is no difference between a “portion” and a “serving.” See Answer

What are the health benefits of cranberry juice?

Although there are side effects to drinking excessive amounts, cranberry juice is loaded with vitamin C and is good for you in moderation:

  • Acts as a powerful antioxidant: Antioxidants prevent free radicals from damaging your cells and can protect against chronic diseases such as heart disease and cancer.
  • Boosts immune system: Vitamin C in cranberry juice helps fight bacterial and viral infections. According to one study, cranberries can eliminate norovirus—a common cause of foodborne illness.
  • Improves heart health: Studies report that cranberry juice can reduce blood pressure and body mass index, which can contribute to heart health.
Table: Nutritional value of unsweetened cranberry juice per 100 grams
Nutrient Amount
Water 87.1 grams
Energy 46 kcal
Protein 0.39 grams
Total fat 0.13 grams
Carbohydrates 12.2 grams
Fiber 0.1 grams
Sugar 12.1 grams
Calcium 8 mg
Iron 0.25 mg
Magnesium 6 mg
Phosphorus 13 mg
Potassium 77 mg
Sodium 2 mg
Zinc 0.1 mg
Copper 0.055 mg
Selenium 0.1 µg
Vitamin C 9.3 mg
Thiamin 0.009 mg
Riboflavin 0.018 mg
Niacin 0.091 mg
Vitamin B6 0.052 mg
Vitamin A 45 IU
Vitamin E 1.2 mg
Vitamin K 5.1 µg

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Medically Reviewed on 12/23/2021
Image Source: iStock Images