Obesity may be to blame for cancer surge in under-50s – the chickens have come home to roost

Well, the chickens have come home to roost. By that I mean we’re now paying a very high price for the ­epidemic of obesity, with soaring ­cancer rates.

And while cancer is traditionally seen in older people, these new ­cancers are in a younger age group. The number of people under 50 being diagnosed with cancer has risen 24% in two decades, which experts say is probably linked to the usual suspects, rocketing obesity levels, cheap junk food and inactivity.

The stats are frightening. About 35,000 under-50s are now developing cancer every year, that’s almost 100 young women and men a day.

We don’t fully understand the reasons for the rise but poor diet, physical inactivity and obesity are likely to be among the factors behind the surge in cancer rates among young people in the UK, higher than any other age group. The second biggest rise was among the under-25s at 16% meaning that almost half the cancer growth rate is among the under-50s.

Professor Charles Swanton of Cancer Research UK says clues are emerging about why cancer may be becoming a young person’s disease.

“Increased exposure to known as well as unknown cancer risk factors, changes to lifestyles and diets over time, and rising obesity may all contribute to the uptick in early-onset cancer,” he said. “Genetics, improvements in diagnosis and screening and the microbiome could also play a role,” he added.

Britain has one of the highest obesity rates in Europe, with two in three adults in the UK overweight or obese. Mind you, the surge in early- onset cancer is a global problem. Worldwide the number of under-50s affected has climbed by almost 80%. A recent review of registry records from 44 countries found the incidence of early-onset cancers was rising rapidly for bowel and 13 other types, many of which affect the digestive system.

Dr Aparna Parikh, an associate professor of medicine at Harvard Medical School and an oncologist at Massachusetts General Hospital, said the boom in cases was complex, but added it was likely to be “driven by various factors, including diet, the environment, and features of the microbiome”.

Swanton offers practical advice while researchers race to unlock more answers. There are many ways people could reduce their risk.

“Around four in 10 cancer cases are preventable, and there are steps people can take to help reduce their cancer risk,” he said. “Not smoking, keeping a healthy weight, being safe in the sun and cutting down on alcohol all makes a big difference.”