Vitamin K Linked to Lower Cancer Rates

HEIDELBERG, GermanyDietary intake of vitamin K was associated with a reduced risk of cancer in a recent German Cancer Research Center study (Am J Clin Nutr. 2010 Mar 24). Specifically, researchers found vitamin K2, or menaquinone, which study participants mostly consumed from cheese, was associated with a reduced risk of incident and fatal cancer. Men fared better than women, with a greater reduced risk for prostate and lung cancers with higher vitamin K intake.

In the prospective EPIC-Heidelberg (European Prospective Investigation into Cancer and NutritionHeidelberg) cohort study, researchers studied 24,340 participants aged 35 to 64 years who were free of cancer at enrollment from 1994 to 1998. The participants were observed for cancer incidence and mortality through 2008. Dietary vitamin K intake was estimated from food-frequency questionnaires completed at baseline.

During a median follow-up time of less than 10 years, 1,755 incident cancer cases occurred, of which 458 were fatal. Dietary intake of menaquinones was nonsignificantly inversely associated with overall cancer incidence (P = 0.08), and the association was stronger for cancer mortality (P= 0.03). Cancer risk reduction with increasing intake of menaquinones was more pronounced in men than in women, mainly driven by significant inverse associations with prostate (P = 0.03) and lung cancer (P = 0.002). They found no association with phylloquinone (vitamin K1) intake.

Researchers noted anticarcinogenic activities of vitamin K have previously been observed in animal and cell studies. Both forms of vitamin K have shown to inhibit the growth of cancer cell lines in past studies.