Lifestyle factors could reduce 27 percent cancer cases in Brazil
Lifestyle risk factors such as smoking, alcohol consumption, overweight and obesity, unhealthy diet and lack of physical activity are associated with a third of all deaths caused by 20 types of cancer in Brazil, according to a new epidemiological study published in the journal Cancer Epidemiology.
Researchers from the Preventive Medicine Department of the University of São Paulo's Medical School in Brazil and the Harvard School of Public Health in Cambridge, Massachusetts used data from the Brazilian Institute of Geography and Statistics 2013 National Health Survey to estimate the prevalence of alcohol consumption, fruit and vegetable consumption, physical activity, and smoking, as well as body mass index.
The researchers also used the institute’s 2008-2009 Household Budget Survey obtain data on the dietary consumption of fiber, calcium, and red and processed meat. The scientists estimated the distribution of lifestyle risk factors by gender and age group.
The researchers considered two exposure scenarios, one with a theoretical minimum risk exposure, assuming the lifestyle risk factors were eliminated in the entire population, and the other with what they termed a plausible reduction in exposure based on policy targets and cancer prevention recommendations.
This plausible scenario would include a 10 percent reduction in alcohol consumption to less than 50 grams per day, a mean body mass index reduction reduction of 1 kilogram per square meter at the population level, dietary calcium consumption of at least 200-399 milligrams per day, and a 30 percent reduction in tobacco use, according to the study abstract.
The researchers concluded that the number of laryngeal, lung, oropharyngeal, esophageal, and colorectal cancer cases could be at least halved by eliminating five lifestyle risk factors, smoking, alcohol consumption, overweight, unhealthy diet, and physical inactivity.
Cancer is one of the main causes of death in Brazil and worldwide. The World Health Organization expects the number of cancer cases in Brazil to rise by 50 percent by 2025, owing mainly to population growth and the aging population. According to the new study, in addition to changes in population structure, the increasing prevalence of lifestyle risk factors may pose additional challenges for controlling the cancer rate in Brazil.
There is a consensus in the scientific literature that the lifestyle factors in question are associated with an increased risk for 20 types of cancer. The researchers calculated a metric for the preventability of cancer, known as the potential impact fraction. This metric is based on the population attributable fraction and estimates the proportional reduction in cancer cases and deaths that would occur if exposure to the lifestyle factors was reduced to a level that corresponds to an ideal exposure scenario.