Obesity has already been linked with a number of health conditions. A new study adds cancer to the list, noting that excess body weight led to around 481,000 new cancer cases in 2012.
Carried out by researchers from the International Agency for Research on Cancer, a World Health Organization arm, the study estimated that about 3.6 percent of all cases of cancer in the world are attributable to excess body weight, most of which are recorded in Europe and North America.
The researchers hypothesized that a high body mass index (which coincides with excess body fat and weight) triggers cancer by altering hormone, glucose and insulin levels and increasing chronic inflammation in the body.
While everyone tipping the scale more than they should have to be worried, the ladies have greater cause for concern because 5.4 percent of obesity-related cancer cases worldwide are in women.
Men, on the other hand, only registered around 1.9 percent of obesity-related cases of cancer around the world.
Published in The Lancet Oncology Wednesday, the study listed the countries most affected by obesity-related cancers. For men, the Czech Republic, Jordan, the United Kingdom and Malta were the worst offenders. In women, Barbados, the Czech Republic, and Puerto Rico have to watch out.
The United States is one of the biggest contributors to obesity-related cancer cases with 3.5 percent and 9.5 percent of cases linked to excessive body weight in men and women, respectively.
"Overall, we see that while the number of cancer cases associated with overweight and obesity remains highest in richer countries, similar effects are already visible in parts of the developing world," said [pdf] Dr. Isabelle Soerjomataram, the project's principal investigator and one of the study's lead authors.
Though percentages are low, the resulting number is still high because of the sheer size of the population. Take China, for instance. Overall, only 1.6 percent of cancer cases in the country are attributed to obesity. However, given China's large population, 1.6 percent still translates to around 50,000 cases of obesity-related cancers in men and women.
"These findings emphasize the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer," wrote the researchers.
The study received funding support from the World Cancer Research Fund International, the Australian National Health and Medical Research Council, the U.S. National Institutes of Health, and the European Commission.
