Next time you’re coming down with a UTI and consider heroically peeling yourself out of bed to purchase a bottle of cranberry juice — maybe don’t bother.
This Vox analysis of one study on cranberry juice and UTIs illuminates the ways that the food industry perpetuates health myths to improve sales. In this case, Ocean Spray funded and co-authored a very legitimate-seeming study that yielded the following conclusion: “Consumption of a cranberry juice beverage lowered the number of clinical urinary tract infection episodes in women with a recent history of urinary tract infection.” The juice company then touted this result as evidence supporting the longstanding myth that cranberry juice helps ward off UTIs.
However, there are many holes in this study. For one thing, Ocean Spray broadened the definition of UTI to “symptomatic UTIs.” That means they measured the effect of cranberry juice on women who complained of having UTI-like symptoms, but whose urine samples didn’t actually prove they had the infection.
The active ingredient in cranberries that is believed to stop UTI bacteria is actually only found in cranberry capsules — not the highly diluted juice that Ocean Spray offers. Which isn’t to say that we should stop enjoying the delicious tart beverage that is cranberry juice. Just don’t expect it to do much for your urinary tract other than, you know, helping you generate pee.