August 9, 2011
Garlic and grape seed supplementation associated with fewer blood cancers

An article published online on July 29, 2011 in the journal Cancer Epidemiology, Biomarkers & Prevention reveals a link between increased use of garlic, grape and multivitamin supplements and a lower risk of hematologic malignancies, including Hodgkin andnon-Hodgkin lymphomas, leukemia and myeloma.

Researchers from Fred Hutchinson Cancer Research Center and the University of Washington in Seattle examined data from 66,227 men and women aged 50 to 76 enrolled in the VITamins And Lifestyle (VITAL) study, which was created to evaluate the impact of dietary supplement use on cancer risk. Responses to questionnaires completed by the participants between 2000 and 2002 were used to estimate ten year average daily dose of each supplemental vitamin, mineral or specialty supplement consumed prior to enrollment.

Five hundred eighty-eight hematologic malignancies were identified among the study subjects through December, 2008 via cancer registry data. Among those who reported using garlic supplements for at least four days a week over three or more years, there was a 45 percent lower adjusted risk of a hematologic cancer compared to those who reported no use. For grape seed extract, the risk was 43 percent lower in those who reported ever using the supplement compared to nonusers. Daily use of multivitamin supplements for at least eight years was associated with a non-significant 20 percent lower risk of hematologic malignancies in comparison with no use.

Possible mechanisms for garlic include modulation of carcinogen metabolism, protection against DNA damage, improved antioxidant defenses and DNA repair, and increased programmed cell death of cancer cells. Grape seed is an additional source of antioxidants, and possesses anti-inflammatory properties.

"This is the first cohort study to suggest a possible role of these supplements in the chemoprevention of hematologic malignancies," the authors announce. "Our findings suggest a possible role of these supplements in the chemoprevention of hematologic malignancies, but further, controlled studies will need to confirm these findings."

Lymphoma There are two types of lymphoma (Hansmann ML et al 1996): Hodgkin's lymphoma, also known as Hodgkin's disease (HD) Non-Hodgkin's lymphoma (NHL). Hodgkin's lymphoma begins in the lymph nodes and is characterized by the presence of Reed-Sternberg cells, which are large, cancerous cells that increase in number with disease progression (Harris NL 1999; Kuppers R et al 2002). Evidence suggests that B lymphocytes (B-cells), the infection- and tumor-fighting cells that produce antibodies, produce Reed-Sternberg cells (Brauninger A et al 1999; Harris NL 1999; Kuppers R et al 2002). However, T lymphocytes (T-cells) have also been implicated in rare cases (Kuppers R et al 2002). 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). Nutritional supplements with demonstrated activity against lymphoma cells include: Curcumin Soy extract Vitamins A, C, D, and E Green tea Resveratrol Ginger Fish oils Garlic Resveratrol, a naturally occurring substance found in grapes, blocks the growth of lymphoma cells and also increases their rate of cell death (Bruno R et al 2003; Park JW et al 2001). Resveratrol sensitizes chemotherapy-resistant lymphoma cells to treatment with paclitaxel-based chemotherapy (Jazirehi AR et al 2004). Resveratrol also reduces the production of growth factors such as VEGF and IL-8, and theoretically should be beneficial in reducing the ability of lymphoma cells to spread to other organs (Dulak J 2005). Garlic extracts can induce death in lymphoma cells (Arditti FD et al 2005; Scharfenberg K et al 1990). Indeed, in a recent study, conjugation of a garlic extract to the antibody rituximab (which targets lymphoma cells) led to the death of these cells (Arditti FD et al 2005).