Cranberries! Are they healthy? Let’s find out.
Cranberry juice has been shown to reduce H. pylori infection (1,5,18) and urinary bacteria content in older women (2). Cranberries have a reputation as preventative of urinary infections. While some trials have not found this to be true (3), almost all trials of cranberries on UTI’s have found a significant or almost significant reduction in risk (4).
Cranberry juice may also be beneficial in preventing cardiovascular disease. In one study, cranberry juice decreased carotid-femoral pulse wave velocity, a measure of central aortic stiffness, in people with coronary disease (6). In a study on women with metabolic syndrome decreased oxidized LDL and malondialdehyde levels (7). A study on abdominally obese men found that cranberry juice increased HDL concentrations (8). In another study on men cranberry juice decreased oxidized LDL, ICAM-1, and VCAM-1 levels (9). This same group also observed a decrease in (MMP)-9 levels in those consuming the cranberry juice, suggesting another mechanism of heart healthiness (11). A Finally, a trial on male diabetics noted that drinking cranberry juice reduced the amount of glucose in serum and increased paraoxonase-1 levels (10).
Via reference 11 discussed in the previous paragraph, lower MMP-9 is thought to help decrease cancer risk as well as heart disease risk. In experimental studies on mice, extracts from cranberries have inhibited the growth of several cancers (13). A study in which human gastric cancer cells were xenographed onto mice found that an extract of cranberry juice inhibited tumor proliferation (12). A similar process was done in another study which found that cranberries inhibited breast cancer (15). A study in rats gave the animals the bladder carcinogen OH-BBN, noting that rats given some cranberry juice concentrate developed less cancer (14). Another study on rats given the colonic carcinogen azoxymethane found that cranberry juice inhibited aberrant crypt foci development (16).
And just because I thought it was interesting, a study on rats found that cranberry powder inhibited a number of the inflammatory effects of endotoxin administration (17).
Given this I think there is strong evidence that cranberries will help prevent urinary tract infections and H. pylori infection, moderate evidence that cranberries will help prevent heart disease, and mild evidence that cranberries will help prevent cancer.