Warning to men who were fat in their teens or 20s as scientists discover ‘it increases risk of dying from prostate cancer by almost a third’

Being fat as a teenager or in your 20s raises the risk of dying from prostate cancer by almost a third, research found.

Carrying excess weight between the age of 17 and 29 substantially increased both the risk of developing an aggressive form of the disease and dying from it, a major study showed.

Obesity leads to elevated concentrations of insulin-like growth factor-1 (IGF-1), a hormone that is involved in cell growth and development, which scientists believe can trigger the disease.

Whereas people cannot change risk factors such as age and family history, experts suggest this shows that keeping a healthy weight is something men can control to reduce their chances of developing prostate cancer.

Prostate cancer is the most common cancer in men in the UK, with around 52,000 cases a year and the second most common cause of cancer death, with almost 12,000 deaths a year. It kills around 32,000 men each year in the US, with another 225,000 being diagnosed.

Although many prostate cancers are slow-growing and may not cause harm during someone’s lifetime, others are more aggressive, spreading quickly outside the prostate and are harder to treat.

Scientists wanted to examine if obesity was a risk factor for different strains of the disease.

Researchers analysed data on 258,477 men in Sweden whose weight had been measured at least three times between the ages of 17 and 60, from 1963 to 2019.

During that time, some 23,348 participants were diagnosed with prostate cancer and 4,790 men died from it, with an average age of 70 at diagnosis, according to the findings presented at the European Congress on Obesity.

They found weight gain was greatest earlier in life among the study group, with an average of 1.6lb a year at 17 to 29 years, 0.75lb at 30 to 44 years and 0.5lb between 45 to 60 years.

Those who gained 1.1lb a year had a 10 and 29 per cent higher risk of developing and dying from aggressive prostate cancer, respectively, compared to those who maintained a healthy weight.

Further analysis showed this was being driven by weight gain while younger, with those who gained 2.2lb a year between 17 and 29 – totalling 21lbs – having a 13 per cent increased risk of aggressive disease and a 27 per cent increased risk of dying from it.

Dr Marisa da Silva, of Lund University, Sweden, said the findings suggest preventing weight gain in young adulthood may reduce the risk of aggressive and fatal prostate cancer.

‘Knowing more about the factors that cause prostate cancer is key to preventing it.

‘The only well-established risk factors, such as increasing age, a family history of the disease and several genetic markers, are not modifiable, making it vital to identify risk factors that can be changed.’

She added: ‘Previous research has implicated elevated concentrations of insulin-like growth factor-1 (IGF-1), a hormone that is involved in cell growth and development, with an increased risk of prostate cancer.

‘Levels of this hormone are raised in people with obesity and a steep increase in weight may fuel this elevation and the development of the cancer.

‘We do not know if it is the weight gain itself or the long duration of being heavier that is the main driver of the association that we see.

‘Nevertheless, one must gain weight to become heavier, so preventing a steep increase in weight in young men is imperative for the prevention of prostate cancer.’

Simon Grieveson, assistant director of research at Prostate Cancer UK, said: ‘Several studies have indicated a possible correlation between being overweight and aggressive prostate cancer, and this study builds on those by suggesting that weight gain earlier in life is associated with an increased risk of dying from the disease.

‘While these results are intriguing, more research is needed to fully understand the biological link between obesity and prostate cancer — and, most importantly, how we can use this information to improve outcomes for men.’