Calories in Cranberry juice, not fortified, from concentrate

What makes cranberry juice so powerful?

Cranberry juice is famous for its association with urinary tract health, but the underlying chemistry is often misunderstood. The effect is not about making urine more acidic, as was once commonly believed. Instead, it comes from a specific class of flavonoids called A-type proanthocyanidins (PACs). These compounds possess an unusual double-linkage structure that is rare in most other foods. When consumed, these PACs act as a chemical shield. They bind to the tiny, hair-like appendages (fimbriae) on the surface of Escherichia coli bacteria, which are the primary culprits behind urinary tract infections. By altering the shape and function of these fimbriae, the PACs prevent the bacteria from adhering to the lining of the urinary tract. Unable to stick, the bacteria are simply flushed out by normal urination. This anti-adhesion mechanism is highly specific to the A-type linkage; the more common B-type proanthocyanidins found in foods like chocolate or apples do not have the same effect. Because cranberries are exceptionally tart, juice from concentrate is often diluted or sweetened, but even the unsweetened versions retain these distinctive, bacteria-repelling phytochemicals.