PCRM Experts Tackle Cancer and Obesity in Three New Journal Reports
Race and Cancer Survival
A new study by PCRM’s Hope R. Ferdowsian, M.D., M.P.H., and Neal D. Barnard, M.D., and featured in the July issue of Ethnicity and Disease explores the interplay of race and ethnicity with cancer mortality, finding that simple diet changes could help reduce racial disparities.
The report analyzed data from 25 previously published papers and reports. It shows that African-American men are more likely than white men to be diagnosed with prostate cancer and to die from it. While African-American women are less likely to be diagnosed with breast cancer, compared with white women, they are more likely to die of the disease.
The report explains that the typical high-fat, meat-based Western diet contributes to the development and progression of breast and prostate cancers. Many studies have shown that low-fat, high-fiber, and plant-based diets reduce the risk of these types of cancer for everyone. However, those who are disproportionately affected may see even greater benefits from adopting this diet than the general population.
Ferdowsian HR, Barnard ND. The role of diet in breast and cancer prevention and survival. Ethnicity and Disease. 2007;17:S218-22.
Vegan Diets Best for Long-Term Weight Loss
It is well established that overweight people who start a vegetarian or vegan diet lose weight. A new controlled study shows that vegan diets, especially when paired with group support, also help keep weight from coming back over the long term.
The study participants were 64 overweight, postmenopausal women who were randomly assigned to either a low-fat vegan diet or a more conventional low-fat diet following the National Cholesterol Education Program guidelines. And within each diet group, some participants were offered extended group support, while others were not. No meals were provided and no calorie restrictions were placed on either group.
The vegan group lost a median of 11 pounds at one year, compared with four pounds for the control group. At the two-year mark, the vegan group had lost approximately seven pounds from baseline, compared with approximately two pounds for the control group. Regardless of diet assignment, participants who were offered group support meetings lost more weight over the course of the study than those who did not.
The study, published in the September issue of Obesity, was authored by PCRM nutrition scientist Gabrielle M. Turner-McGrievy, M.S., R.D., PCRM president Neal D. Barnard, M.D., and Anthony R. Scialli, M.D., of Georgetown University.
Turner-McGrievy G, Barnard, ND, Scialli, AR. A two-year randomized weight loss trial comparing a vegan diet to a more moderate low-fat diet. Obesity. 2007;15-9:1-6.
Effect of Diet on Prostate Cancer
Men who increase consumption of vegetarian foods and avoid foods that feed tumor growth, such as dairy products and meat, may significantly increase survival after prostate cancer diagnosis, say the authors of a new study appearing as the lead article in the September issue of Nutrition Reviews.
The paper looked at the findings of eight observational studies and 17 intervention studies on the effect of a plant-based diet on prostate cancer. The data showed that adoption of a plant-based diet may slow disease progression and improve prognosis. In prospective studies of prostate cancer patients, a diet high in saturated fat is associated with a threefold higher risk of cancer progression and death, compared with a diet low in saturated fat. Specific foods may also play a role, according to the paper. For example, a slowing of prostate cancer progression was observed in patients who consumed flaxseed or lycopene-containing foods, such as tomatoes. Soy or isoflavone supplements also were reported to improve prostate cancer prognosis.
PCRM nutrition consultant Susan E. Berkow, Ph.D., C.N.S., who is also on the faculty at George Mason University, wrote the paper along with PCRM president Neal Barnard, M.D., and Gordon Saxe, M.D., Ph.D., of the University of California, San Diego.
Berkow, S, Barnard N, Saxe, G, Ankerberg-Nobis, T. Diet and survival after prostate cancer diagnosis. Nutrition Reviews. 2007;65-9;391-493.