For years, we ve been hearing about how the obesity epidemic will pose an ever-greater public health threat if we don t somehow manage to slow it down. Obesity puts one at risk for diabetes, debilitating arthritis and other chronic ills. And according to a new study published in The Lancet Oncology, excess body weight is associated with about 3.6 percent of cancers worldwide about 481,000 new cancer cases each year.
Researchers from the International Agency for Research on Cancer (IARC) led by Dr. Melinda Arnold used data from 2012 on cancer incidence and mortality from 184 countries to create a model to determine the percentage of cancers associated with excess body weight. In women, excess body weight was associated with 5.4 percent of cancers (the majority being endometrial and postmenopausal breast cancers) and in men excess body weight was associated with almost 2 percent of cancers (mostly colon and kidney cancers).
The proportion of cancers associated with excess body weight was higher in developed countries 8 percent in women and 3 percent in men compared to developing countries 1.5 percent in women and 0.3 percent in men. North America had the highest proportion of obesity-related cancers 111,000, - while sub-Saharan Africa had the least 7300.
According to Dr. Arnold, Our findings add support for a global effort to address the rising trends in obesity. The global prevalence of obesity in adults has doubled since 1980. If this trend continues it will certainly boost the future burden of cancer, particularly in South America and North Africa, where the largest increases in the rate of obesity have been seen over the last 30 years.
However, Dr. Benjamin Cairns from the University of Oxford makes an interesting point in an accompanying editorial. He says, If 3.6% of all cancers are associated with high BMI, that is nearly half a million cancers, but this number is large mainly because the world population is large. Global health resources specifically for cancer prevention are not so large, and the resources targeted at obesity must be balanced against those for other important causes of cancer, particularly infections and tobacco use, which are each associated with much larger proportions of cases.
ACSH s Dr. Gil Ross had this comment: The smaller burden of obesity-related cancers in the underdeveloped world is obviously due to their shorter life expectancies cancer is largely a disease of older individuals and of course their lower levels of obesity. And I fully agree with Dr. Cairns that fighting the non-obesity-related causes of cancer hepatitis B and C, HIV, HPV, and especially smoking must take precedence over the obesity-related. Sadly, the toll of cigarettes in those regions will be rapidly increasing as the tobacco companies, restricted in their recruitment of new smokers in North America and Europe and the effective cessation methods of harm reduction now spreading there, aim more and more of their resources at Africans and Asians.