Losing weight may help prevent prostate cancer, new Oxford study finds, with higher BMI, bigger waistline linked to higher chance of dying from the disease

Thousands of lives are being lost to prostate cancer because of high levels of obesity among men, a new Oxford University study suggests. More than 1,300 prostate cancer deaths could potentially be prevented every year in a country such as the United Kingdom alone if the average man was not overweight, researchers said. While obesity has been linked to 13 cancers – including stomach, liver, pancreas and kidney cancers – scientists are only now starting to unravel the association between prostate cancer and weight. The new study, which was presented at the European Congress on Obesity in the Netherlands in early May and published in the journal BMC Medicine, saw academics carry out fresh research as well as review previous data on the topic. Prostate cancer is the second most common form of cancer for men, and responsible for around 375,000 deaths every year, according to the World Cancer Research Fund International. Prostate cancer is the fourth leading cause of male cancer deaths in Hong Kong. In 2020, 484 men died from prostate cancer, accounting for 5.6 per cent of male cancer deaths. The crude death rate of prostate cancer in Hong Kong was 14.2 per 100,000 male population. In the new study, researchers examined data on 218,237 men enrolled in the UK Biobank study whose body mass index score (BMI), waist circumference and waist-to-hip ratio were taken when they first enrolled in the study. The participants were tracked for an average of 12 years, with 661 men dying from prostate cancer during the follow-up period. After analysing the health data on the men who died from prostate cancer, and comparing it to those who did not, the researchers found that for every five additional points on a man’s BMI score, they were 7 per cent more likely to die from prostate cancer. For every additional four inches (10cm) on their waistline, they had a 6 per cent higher risk of dying of prostate cancer. Is work more important than your wife? Prostate cancer survivors open up Meanwhile, researchers also performed an analysis of previous studies which examined information on almost 20,000 men who died from prostate cancer. These studies suggested that for every five additional points on a man’s BMI score, they were 10 per cent more likely to die from prostate cancer, and an additional four inches in waist size carried a 7 per cent higher risk. While the mechanisms behind the findings are still unknown, researchers said the study still suggests that men should try to maintain a healthy weight. “Knowing more about factors that increase the risk of prostate cancer is key to preventing it,” said Dr Aurora Pérez-Cornago, from the University of Oxford, who led the research. “Age, family history and black ethnicity are known risk factors but they are not modifiable, and so it is important to discover risk factors that it is possible to change.” Every year in the UK, around 11,900 men die from prostate cancer. And the researchers said that men aged 55 to 64 have an average BMI score of 28.9 – which classes them as overweight. Based on their findings, they calculated that if men were able to shave five points from their BMI score, an estimated 1,309 fewer prostate cancer deaths would happen every year in Britain. How this father shed 27kg, helped by his family and community And they pointed out that global health leaders recommend that men should aim to have a waist circumference of 36 inches. Waist circumference is used as a measure of obesity as well as a BMI score because it indicates the amount of fat built up around a person’s organs. “More research is needed to determine if the association is biologically driven or due to delays in detection [of prostate cancer] in men with higher adiposity [body fat],” Pérez-Cornago said. “In either case, our latest results provide another reason for men to try to maintain a healthy weight.” Further studies are needed to investigate whether obesity increases the risk of developing prostate cancer in the first place, said Karis Betts, senior health information manager at Cancer Research UK, which funded the study, as the research only looked at the likelihood of dying from prostate cancer for people who are overweight or obese. “While the jury is out on the relationship between prostate cancer and obesity, it’s still important to keep a healthy weight as obesity causes 13 other types of cancer,” she said. By building on these useful findings in future, scientists can start to figure out what the mechanism of prostate cancer and obesity could be, helping them to better understand who is at an increased risk of getting and dying from the disease, Betts added. Like what you read? Follow SCMP Lifestyle on Facebook, Twitter and Instagram. You can also sign up for our eNewsletter here.