Mayo study links increased vitamin K intake to lower non-Hodgkin lymphoma risk
In one of several noteworthy presentations at the 101st Annual Meeting of the American Association for Cancer Research, held in Washington, DC, it was reported that a higher intake of vitamin K is associated with a reduced risk of non-Hodgkin's lymphoma, an immune system cancer that is the most common blood malignancy in the United States.
In research funded by the National Cancer Institute, cancer epidemiologist James Cerhan, MD, PhD and his colleagues at the Mayo Comprehensive Cancer Center compared 603 newly diagnosed non-Hodgkin lymphoma patients to 1,007 men and women who did not have cancer. Dietary questionnaire responses were analyzed for vitamin K intake from food and supplements.
The investigators found an association between a lower risk of non-Hodgkin lymphoma and increased consumption of vitamin K. For those whose intake of the vitamin was among the top 25 percent of participants at over 108 micrograms per day, the risk of the disease was 45 percent lower than those whose intake was among the lowest fourth at less than 39 micrograms per day. Adjustment of the analysis for age and other factors failed to modify the association. When vitamin K from supplements was examined, intake of the vitamin was also shown to be protective up to a certain level, above which increased intake offered no additional benefit, suggesting that it is not necessary to supplement with high doses for protection to occur.
Vitamin K is well known for its role in blood coagulation; however, an ability of the vitamin to inhibit inflammatory cytokines and involvement in cell cycle arrest and cell death pathways could help explain the benefit suggested by the current study's outcome.
"Whether the protective effect we observed is due to vitamin K intake, or some other dietary or lifestyle exposure, cannot be definitely assessed in this study," Dr Cerhan remarked. "But these findings add to a lot of other data that support a diet that includes plenty of green leafy vegetables in order to prevent many cancers as well as other diseases."
"These results are provocative, since they are the first work we have done on the connection between vitamin K and Non-Hodgkin lymphoma, and this is a fairly strong protective effect," he noted. "However, as with all new findings, this will need to be replicated in other studies."
Nutritional supplements with demonstrated activity against lymphoma cells include curcumin, genistein from soy extract, vitamins A, C, D, and E, green tea, resveratrol, ginger, fish oil, and garlic. These supplements can be used to complement conventional drugs, and they can be closely monitored for effectiveness with a range of blood tests and diagnostic procedures described in this protocol.
Non-Hodgkin's lymphoma describes all lymphoma types without Reed-Sternberg cells (Coffey J et al 2003; Jimenez-Zepeda VH et al 1998). NHL develops as a result of malignant B and T lymphocytes (white blood cells). B-cell lymphomas are more common and account for over 85 percent of NHL cases (Coffey J et al 2003).
New cases of Hodgkin’s lymphoma represent less than 1 percent of all cancer cases in the United States. By contrast, non-Hodgkin’s lymphoma is the fifth most common cancer after lung, breast, colorectal, and prostate cancers (Groves FD et al 2000). Moreover, NHL is among the top five causes of cancer-related death (Fisher SG et al 2004; Hauke RJ et al 2000) and is the leading cause of cancer death in males aged 15-54 (Mohammad RM et al 2003). Lymphoma patients should consult their physicians before using any nutritional supplements while receiving conventional medical treatment. In addition, lymphoma patients using nutritional supplements should enlist their physicians in ensuring the use of blood tests and diagnostic procedures that are essential in monitoring the effectiveness of any adjuvant therapy for lymphoma.
In experimental studies, vitamin C has improved the effectiveness of chemotherapy in inducing lymphoma cell death (Chen Q et al 2005; Nagy B et a