Cancer

Colorectal cancer accounts for approximately 10% of cancer deaths in the United States, and is the second leading cause of cancer death. Dietary fiber from plant foods may reduce risk for colorectal cancer since fiber binds bile acids, reduces time stool sits in the colon, increases stool bulk, and ferments fatty acids that may be protective. In this study, the diets of 3057 people diagnosed with colorectal adenoma (growths) of the distal colon were compared to controls with no diagnoses. Both fruit and vegetables were somewhat protective, but the strongest protection came from fruit. Those who consumed the most fruit (about 5.7 servings/day) had 25% less risk of colorectal adenoma compared to those who ate the smallest amounts of fruit (about 1.2 servings/day). These results were not completely related to fiber content, suggesting that other nutrients in fruit also play a protective role against cancer development.

Millen AE, Subar AF, Graubard BI, Peters U, Hayes RB, Weissfeld JL, Yokochi LA, Ziegler RG. Fruit and vegetable intake and prevalence of colorectal adenoma in a cancer screening trial. American Journal of Clinical Nutrition 2007;86:1754-64.

In another study, a diet high in fruit and low in meat was found to reduce risk for colorectal adenomas. Of 725 individuals undergoing colonoscopy, 203 had colorectal adenoma(s) versus 522 controls. Compared to those consuming a high fruit and low meat diet, those eating a high vegetable and moderate meat diet had 2.17 times increased odds of developing colorectal adenomas, and those eating a high meat diet had 1.7 times increased odds of having had colorectal adenomas. This study suggests that a diet high in fruit consumption and low in meat consumption may be protective against the development of colorectal adenomas, even when compared with a group that consumes a large amount of vegetables.

Austin GL, Adair LS, Galanko JA, Martin CF, Satia JA, Sandler RS. A diet high in fruits and low in meat reduces the risk of colorectal adenomas. The Journal of Nutrition 2008;137:999-1004.

Eating more fruits, vegetables, and whole grains while limiting fat is a protective pattern against ovarian cancer. Of 48,835 postmenopausal women in the Women’s Health Initiative, 19,541 ate 20% less fat, and more fruits, vegetables, and grains compared to 29,294 women who followed a typical American diet. Ovarian cancer risk was lower in the intervention group than in the control group, and risk continued to decrease as these women continued eating more fruits, vegetables, and whole grains. Overall, a diet that includes fruits, vegetables, and whole grains in place of fat may reduce the incidence of ovarian cancer among postmenopausal women.

Prentice RL, et al. Low-fat dietary pattern and cancer incidence in the women’s health initiative dietary modification randomized controlled trial. Journal of the National Cancer Institute 2007;99:1534-1543.

Fruit and vegetables rich in antioxidants are thought to be protective against renal cell cancer. Of 47,828 men in the Health Professional Follow-up Study, 116 men developed renal cell cancer over 14 years. Those eating more than 6 servings of fruits and vegetables per day had about half of the risk of renal cell cancer than those consuming fewer than 3 servings/day! Vitamin C was associated with this decreased risk, but other factors (antioxidants, phytochemicals, etc.) were also at work, which suggests that consuming whole fruit is the ideal way to consume produce.

Lee JE, Giovannucci E, Smith-Warner SA, Spiegelman D, Willett WC, Curhan GC. Intakes of fruits, vegetables, vitamins A, C, and E, and carotenoids and risk of renal cell cancer. Cancer Epidemiology Biomarkers and Prevention 2006;15(12):2445-2452.

In 472,081 participants aged 50-71 years in the National Institutes of Health(NIH) – AARP Diet and Health Study, intake of several botanical subgroups were significantly associated with decreased lung cancer risk in men. In particular, rosaceae (e.g. pears), convolvulaceae (e.g. sweet potato), and umbelliferae (e.g. carrot) were found to have significant, negative associations with cancer risk. Indeed, these results suggest a protective role of fruits and vegetables against lung cancer, especially specific plant groups that includes pears.

Wright ME, Park Y, Subar AF, Freedman ND, Albanes D, Hollenbeck A, Leitzmann Mf, Schatzkin A. Intakes of fruit, vegetables, and specific botanical groups in relation to lung cancer risk in the NIH-AARP Diet and Health Study. American Journal of Epidemiology 2008;168(9):1024-34.

Another study that observed 521,457 participants at 23 centers in 10 European countries as part of the European Prospective Investigation into Cancer and Nutrition (EPIC) study found that increasing fruit intake, especially pears and apples, may be protective against lung cancer risk in the overall population and those who smoke! This effect is attributed to nutrient-density of the fruits, vitamin C, fiber, antioxidants, etc., and their wide availabilities. Again, as the consumption of fruit increased, risk for lung cancer decreased in the observed participants. Consume more pears and you’ll be eating more vitamin C, fiber, and antioxidants that that may protect against lung cancer.

Linseisen J, et al. Fruit and vegetable consumption and lung cancer risk: updated information from the European Prospective Investigation into Cancer and Nutrition (EPIC). International Journal of Cancer 2007;121:1103-1114.