Cancer toll of obesity crisis revealed in shock study

In the largest study of its kind, experts say overweight and obese people are at an increased risk of 10 of the commonest cancers.

They warn the toll will only grow if the nation’s weight problems worsen at the same rate, triggering more than 3,500 additional cases every year.

The findings are the latest to link obesity with serious illness, with triggers already well established with diabetes and heart disease.

The research published today in The Lancet medical journal looked at more than five million adults in the UK who were followed for seven years.

Nearly 170,000 people developed one of 22 cancers examined. An increased body mass index (BMI) was linked with 17 cancers, with the strongest links on cancers of the uterus, gall bladder and kidney.

Study leader Krishnan Bhaskaran, of the London School of Hygiene and Tropical Medicine, said: “The number of people who are overweight or obese is rapidly increasing both in the UK and worldwide. Our results show that if these trends continue, we can also expect to see substantially more cancers as a result.”

Around 64 per cent of adults in England are overweight or obese with a BMI of 25 or more.

The study team found each increase in BMI of five was linked with a 62 per cent higher risk of cancer of the uterus, a 31 per cent risk of gall bladder cancer, and a 25 per cent risk of kidney cancer. Risks of developing cancers of the cervix and thyroid, as well as leukaemia, rose by around 10 per cent.

There were further links with liver, colon, ovarian and breast cancers but the effects varied according to factors among them sex and menopausal status.

The researchers estimate excess weight could account for 41 per cent of cancers of the uterus and 10 per cent of gall bladder, kidney, liver and colon cancers.

And they warn a population-wide increase of 8-10lb in weight, which would occur every 12 years based on recent trends, would lead to an extra 3,800 cases of the 10 commonest cancers in the UK each year.

Dr Bhaskaran added: “There was a lot of variation in the effects of BMI on different cancers. For example, risk of cancer of the uterus increased substantially at higher body mass index; for other cancers, we saw more modest increases in risk, or no effect at all.

“This variation tells us that BMI must affect cancer risk through a number of different processes depending on the cancer type.”

Tom Stansfeld, of the charity Cancer Research UK, said the study had uncovered “new and stronger links” between obesity and cancer.

“Although the relationship between cancer and obesity is complex, it’s clear that carrying excess weight increases your risk of developing cancer,” he said.

“Keeping a healthy weight reduces cancer risk, and the best way to do this is through eating a healthy, balanced diet and exercising regularly.”