Obesity is more likely the cause in some types of cancer than smoking, according to the findings of a study released by a cancer research organization on Wednesday. According to Cancer Research UK, four common cancers – bowel, kidney, ovarian and liver – are more likely to have been caused by being overweight than by smoking tobacco.
Excess weight causes around 1,900 more cases of bowel cancer than smoking in the UK each year, the organization said. The same pattern is true of kidney cancer (1,400 more cases), ovarian cancer (460 more cases) and liver cancer (180 more cases), it said.
Besides these four cancers, nine other types of cancer have also been linked to obesity, said Cancer Research UK. These are breast, pancreatic, esophageal, upper stomach, gallbladder, womb, thyroid, blood and brain cancers.
Scientists have so far identified that obesity causes 13 types of cancer but the mechanisms aren’t fully understood. So further research is needed to find out more about the ways extra body fat can lead to cancer, said Cancer Research UK chief executive Michelle Mitchell.
People who are obese now outnumber smokers two to one in the United Kingdom, according to the study. There are 14.9 million obese adults in the UK, about one-third of the country's adult population.
Cancer Research UK said being overweight or obese increases the chance of cancerous cells being made.
“Extra body fat sends out a signal that can tell cells to divide more often and, similar to smoking, can cause damage that builds up over time and raises the risk of cancer.”