Vitamin K protective against non Hodgkin lymphoma.
Non-Hodgkin's lymphomas (Prevention)
Vitamin K (Health aspects)
Cerhan J et al. 2010. Vitamin K intake and risk of non-Hodgkin
lymphoma (NHL). Poster presentation, 101st Annual Meeting of the
American Association for Cancer Research (AACR). Apr 17-21, Washington
This study from the Mayo clinic is a first to examine a link between vitamin K and risk of non Hodgkin lymphoma (NHL). Their findings indicate that people who have higher intakes of vitamin K from their diet have a lower risk of developing NHL.
While studying the link between diet and NHL risk, they became interested in a potential role for vitamin K. Well known for its essential role in blood clotting, it also appears to be important in other biological processes including inhibition of inflammatory cytokines thought to play a role in NHL as well as pathways involved in cell cycle arrest and cell death.
The Mayo study enrolled 603 patients (average age 61, 57% male) who were newly diagnosed with NHL as well as 1007 matched cancer free control participants (average age 60, 53%%o male). Participants answered a food questionnaire about their usual intake of over 120 food items two years prior to their cancer diagnosis or enrolment into the study (controls). They also answered questions about use of a variety of supplements. Vitamin K intake was estimated from this data. The median intake of vitamin K from diet among controls was 63.5 [micro]g/ day; 16% used a multivitamin supplement that included vitamin K.
Results showed that the risk of developing NHL was approximately 45% lower for participants who had vitamin K intakes in the top quartile of intake in the study (>108 [micro]g/day), compared with participants who had intakes in the bottom quartile (<39 ug/day). This association remained after accounting for other factors such as age, sex, education, obesity, smoking, alcohol use and intake of foods with high amounts of antioxidants. The lead author considers these results provocative since it is the first work they have done on the connection between vitamin K and NHL, and shows a strong protective effect. However as with all new findings this will need to be replicated in other studies.
While there was a clear trend showing that a greater intake of vitamin K from dietary sources was associated with a lower risk of NHL, the use of vitamin K supplements presented a slightly different picture. Increasing intake of vitamin K from supplements did protect against NHL but reached a point where the highest intake offered no reduction in risk. The significance of this finding is unclear but suggests that taking high doses of supplements is unlikely to be helpful.
People taking certain oral anticoagulants or seizure medications should closely follow their physician's dietary recommendations with respect to vitamin K intake, since vitamin K can interfere with these drugs.