Health Hazards of Drinking Too Much Cranberry Juice

Cranberry juice benefits for female health is well-known, such as helping prevent UTIs, but what about the cranberry juice side effects that come with consuming too much of the popular drink? Drinking too much cranberry juice may lead to stomach upset or negative interactions with certain drugs.

Cranberries are native to the United States, and can be consumed not only as a juice, but also as oral capsules, teas and of course the fruit itself, which can be added to salads and mixed into several recipes. The University of Rochester recommends consuming no more than 10 ounces of cranberry juice per day.

While cranberry juice has many benefits, drinking too much of it can induce unpleasant side effects. According to the National Institutes of Health (NIH), large amounts of cranberry juice can trigger an upset stomach. Moreover, an excess of cranberry juice may, over time, heighten the risk of kidney stones.

Cranberry juice, taken in large doses, can also alter levels of warfarin, a blood thinning drug. A February 2012 review in Clinics expounds on the interaction between cranberry juice and certain drugs, explaining that flavonoids, a major component of cranberries, affect certain drug-metabolizing enzymes and inhibitors.

Read more: What are the Health Benefits of Cranberry Pills?

Perhaps the most well-known of the cranberry juice benefits for female health is that it can help prevent UTIs. However, according to The University of Rochester, the evidence is not definitive. An article in the Cleveland Clinic gets to the bottom of what cranberry juice can do for those afflicted with a UTI.

According to urologist Courtenay Moore MD, quoted in the Cleveland Clinic article, cranberries contain an active ingredient that prevents bacteria, particularly E. coli, from sticking to the bladder wall. Yet several studies show that cranberry juice doesn't contain enough of this ingredient to actually prevent the bacteria from adhering to the urinary tract.

While cranberry juice may not help, it doesn't hurt either, at least when taken in normal doses. If you're looking to prevent UTIs, Cleveland Clinic recommends taking certain precautions, such as urinating after sex, developing good bowel habits and balancing the "good" bacteria, such as those from probiotics, with the bad.

Read more: Why Drinking Juice Isn't Nearly As Healthy As Eating Whole Fruit

The fruit juice we know and love today came to be during the second world war, when scientists were commissioned to develop a product that would provide vitamin C to soldiers overseas, says an article in The Guardian. While fruit juice has mostly been considered a healthy option, evidence has proved otherwise.

The USDA recommends eating whole fruit rather than drinking fruit juice for the best nutritional value, such as dietary fiber intake.

Susan Jebb, a government advisor and head of the diet and obesity research group at the Medical Research Council's Human Nutrition Research unit at Cambridge University who was quoted in The Guardian article, says that fruit juice contains a large amount of sugar — 100 grams of cranberry juice contains about 12 grams of sugar, according to NutritionValue.org.

Fruit juice, says Jebb, also gets absorbed very fast, so your body can't distinguish it from other types of sugary drinks such as soda. The bottom line: stick to eating whole fruits.