Medscape 12th January 2015
As people make their resolutions for 2015, two new studies — which show that curbing alcohol consumption, adding more plant foods to the diet, and losing excess weight can help reduce the risk of developing cancer — serve as a reminder that a healthy lifestyle is important.
The first study, published online January 6 in Cancer Causes & Control, showed that eating a plant-based diet and limiting alcohol intake, both already included in various cancer prevention guidelines, could help cut the risk for obesity-related cancers (about a third of all of cancers).
In a cohort of nearly 3000 adults, the researchers found that restricting alcohol consumption to one drink per day for women and two drinks per day for men was associated with 29% reduced risk for obesity-related cancers. Additionally, the risk was up to 71% lower for the most common site-specific cancers in the United States (breast, prostate, and colorectal).
For individuals who consume starchy vegetables, such as corn, potatoes, and yams, sufficient consumption of nonstarchy legumes, fruits, and vegetables was associated with a reduction in the risk for colorectal cancer.
“These results add to the existing evidence on the potential role of limiting alcohol intake and increasing the intake of plant foods in influencing cancer risk,” said lead author Nour Makarem, a nutrition doctoral student at New York University’s Steinhardt School of Culture, Education, and Human Development. “Therefore, based on these results, dietary advice on cancer should focus on encouraging the consumption of a plant-based diet providing abundant nonstarchy fruits, vegetables, and legumes, and restricting alcohol, if consumed at all, to the recommended levels.”
In 1997, the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) issued cancer prevention guidelines for weight management, diet, and physical activity. These were updated in 2007 and are considered to be the most comprehensive scientific analysis of cancer prevention and causation ever undertaken. Specifically, the guidelines reported that excess body fat is associated with an increased cancer risk and that there is convincing evidence that the consumption of alcohol, red meat, and processed meat elevates cancer risk.
Since that time, numerous studies have reported links between colorectal cancer risk and alcohol, between breast cancer mortality and obesity, between breast cancer relapse and obesity, and between breast cancer risk and red meat.
“It is important to keep in mind that the evidence for the development of the WCRF/AICR guidelines for cancer prevention was based on a comprehensive evaluation of relevant individual scientific studies that addressed one or more foods, food groups, and behaviors in relation to cancer risk,” Makarem told Medscape Medical News. “Therefore, individuals, especially those at high risk of cancer, should be advised to adhere to all cancer prevention guidelines to reduce their risk.”
Pronounced Effect on Cancer Risk
In their study, Makarem and colleagues investigated whether the healthful behaviors outlined in the WCRF/AICR guidelines were associated with the risk for obesity-related cancers, in particular, breast, prostate, and colorectal cancer.
Of the 2983 adults enrolled in the Framingham Offspring cohort from 1991 to 2008, the researchers identified 480 incident obesity-related cancers.