Cranberry

Cranberry: what was it used for?

A food first. The assessment report records that Native Americans ate wild cranberries for centuries in pemmican, crushed berries with fat and dried meat, though there is no recorded medicinal use among the tribes of Massachusetts; other peoples in Canada made a tea of the branches for pleurisy and poulticed wounds with the fruit, and First Nations people in Quebec applied crushed cranberries to sores. Seventeenth-century writers gave it for blood disorders, stomach ailments, fevers, and scurvy, and in 1905 the raw fruit was still a domestic poultice for erysipelas, swollen glands, ulcers, and tonsillitis.

Cranberry: what does modern science say?

The European Medicines Agency’s herbal committee accepts the fruit as a traditional herbal medicine, “exclusively based upon long-standing use,” to relieve the symptoms of mild recurrent lower urinary tract infections in women, such as burning or frequent urination, and to prevent recurrent uncomplicated lower urinary tract infections in women, in both cases after a doctor has excluded serious conditions (monograph of 2022). Its assessment report names the proanthocyanidins, chiefly chains of four or five epicatechin units, and the anthocyanin pigments among the constituents, with high levels of vitamin C. The Cochrane reviews of 2023 divide the two uses. For prevention, fifty studies in 8,857 participants support cranberry products in reducing symptomatic, culture-verified infections in women with recurrent infections, in children, and in people susceptible after medical interventions, but not in the elderly, in people with bladder-emptying problems, or in pregnancy. For treatment, the review found no randomised trials at all, and so “no good quality evidence to suggest that it is effective for the treatment of UTIs.”

Cranberry: what did the older authorities say?

Huron H. Smith, Ethnobotany of the Ojibwe Indians (1932)

Of the small cranberry, Vaccinium oxycoccus, which the Ojibwe called by a name meaning ‘swamp berry bush,’ Smith recorded “A tea for a person who is slightly ill with nausea,” and that white men had used its bitter, astringent leaves in diarrhoea and diabetes and for purifying the blood.