Obesity double the risk of cancer, a Study has warmed.
The research, led by the France-based International Agency for Research on Cancer (IARC) looked at how genetic measures of body weight affected cancer risk.
It focused on seven forms of the disease – the six named above and breast cancer – which are thought to cause 80 per cent of obesity-related cancers.
For many of them, the risk increase was around double what it had previously been thought to be, and for two it was multiplied by more than four times.
Previous estimates had been based on measures of someone’s height-to-weight ratio – their BMI – while the new predictions were based on genetic markers of obesity.
These sections of DNA, the scientists said, gave a more accurate picture of obesity over someone’s lifetime rather than at a single point in time.
And they showed the risk for kidney cancer, for example, rose from a 30 per cent increase to a 59 per cent increase.
It’s important to note the figures are for relative risk, so an increase on the risk a healthy weight person has, and do not suggest that 59 per cent of obese people get kidney cancer.
The risk rose from 50 per cent to 106 per cent for endometrial cancer, from six per cent to 13 per cent for ovarian cancer and from 48 per cent to 110 per cent for cancer of the oesophagus.
For pancreatic cancer the obesity risk increase changed from 10 per cent to 47 per cent, and for bowel cancer it rocketed from five per cent to 44 per cent.
‘Our analysis of genetic data for six of eight obesity-linked cancers indicated that the cancer burden associated with BMI may be considerably underestimated,’ the researchers, led by Dr Daniela Mariosa, wrote.
They added: ‘These estimates would also make excessive body fatness the second most important cause of cancer in high-income countries, after tobacco.’
Obesity is known to make people more likely to get 13 types of cancer.
These include breast, bowel, womb, oesophageal, pancreatic, kidney, liver, stomach, gallbladder, ovarian, thyroid and brain cancers, as well as myeloma.
Chief executive of the NHS, Simon Stevens, said: ‘While cancer survival is at a record high, many people don’t yet realise that obesity causes cancer.
‘And now there is evidence that it’s a graver danger than first thought.
‘If we continue to pile on the pounds, we’re heading for thousands more avoidable cancer deaths every year.