A collaborative meta-analysis of more than a quarter million cases of cancer around the globe finds clearer association between obesity and several types of cancer. The findings are reported in the latest issue of The Lancet.
Following on from findings reported by the World Cancer Research fund last year, the study reveals that risk is increased not only in common cancers such as breast, bowel and kidney, but also in less common cancers such as blood cancers (myeloma and leukaemia) and melanoma (a form of skin cancer). Dr. Andrew Renehan and colleagues from the University of Manchester and Christie Hospital, did a meta-analysis (a combined analysis of 221 previous studies), looking at over 250,000 cases of cancer, to determine the risk of cancer associated with a 5kg/m2 increase in body mass index (BMI). The researchers found in men, a 5kg/m2 increase in BMI raised the risk of oesophageal adenocarcinoma by 52%, thyroid cancer by 33%, and colon and kidney cancers each by 24%. In women, a BMI increase of 5kg/m2 increased the risk of endometrial (59%), gallbladder (59%), oesophageal adenocarcinoma (51%) and kidney (34%) cancers. They also noted weaker, but significant, positive associations between increased BMI and rectal cancer and malignant melanoma in men; postmenopausal breast, pancreatic, thyroid, and colon cancers in women; and leukaemia, multiple myeloma, and non-Hodgkin’s lymphoma in both sexes.
Researchers from the National Institute of Environmental Medicine in Sweden added, “The number of deaths per year attributable to obesity is about 30000 in the UK and ten times that in the USA, where obesity has been estimated to have overtaken smoking in 2005 as the main preventable cause of illness and premature death.”
Last week we brought you news of the proposed law in Mississippi that would ban restaurants from serving obese people. As reported, the intent was to bring attention to the obesity epidemic rather than to truly pass legislation. As study after study comes out about the risks of obesity, we wonder if further public education is truly enough. It’s not that we take the Mississippi legislation seriously. What we mean is this: are we really dealing with a lack of education? Sometimes we scratch our heads about where the confusion comes in. Sure, we take issue with some of the nutritional “guidelines” offered by government agencies and certain organizations. But does anyone truly believe that a Big Mac is healthy? Do our children’s nutrition textbooks idealize pizza and ice cream? What’s really going on here?
Hmmm. No single, simple answer, we realize. Individuals operating more out of denial than lack of information? Doctors afraid (or tired) of dispensing tough love (not all doctors, we know)? The pharmaceutical industry and phony side of the supplement industry sending the message that a pill can replace individual effort? Political games that subsidize empty calories for WIC Programs and the farming of grains galore? School lunches that too often are bland, nutrient deficient fast food look-a-likes? Yes, we’re flying our curmudgeonly flag today. We see news like this, and actually give a you-know-what. But what now?
What do researchers responding to this study suggest? See for yourself. In their associated statement, the researchers at Sweden’s National Institute of Environmental Medicine offered the following advice:
Efforts will be needed to increase education on diet and physical activity, train health professionals, restrict advertisements of high-calorie and low-nutrient foods, limit access to unhealthy foods in schools and workplaces, levy taxes on sugary drinks and other foods high in calories, fat, or sugar, lower the prices of health foods, and promote physical activity in schools and workplaces. National cancer plans should include all these factors to reduce obesity, and thus decrease cancer incidence and increase survival.