Study finds being overweight is likely to cause cancer


A QIMR Berghofer study has found people who are overweight could reduce their risk of dying from cancer later in life by up to 30 per cent, by shedding some kilograms and maintaining a healthy body mass index (BMI).

The study also found that by reducing BMI by five points, an overweight person can cut their risk of developing any form of cancer by retirement age by 10 per cent.

Senior author and head of QIMR Berghofer’s Statistical Genetics research group, Associate Professor Stuart MacGregor, said the Mendelian randomisation study specifically looked at genetic markers related to BMI to explore the relationship between obesity and cancers.

“We found the risk of developing any form of cancer by age 65 escalated with every extra five-unit-point increase in BMI,” Associate Professor MacGregor said.

“The strength of this study is that it lets us extrapolate what the relationship is between BMI and cancer risk. By examining how genetic predisposition to obesity was related to cancers, we could also explore how other people who were overweight – due to lifestyle and other factors – were also at higher risk.

Associate Professor MacGregor said it was important for people to realise they could change their cancer risk because only a third of weight gain was attributable to a person’s genetics while two thirds was due to lifestyle and environment.

“We also observed that people who were genetically predisposed to being overweight had a higher risk of developing aggressive cancers that could result in death,” he said.

“This study adds to the growing evidence that obesity causes cancer, and might explain why all cancer rates have increased as populations have become heavier.

“These findings also provide evidence that cancer prevention strategies targeting weight control ought to be continued, given the high prevalence of obesity in many western countries.”

The World Health Organization (WHO) guideline for ideal weight is a BMI of 18.5 to 24.9.

“While some studies have shown a high BMI may help prevent some types of breast cancer, the risk of developing the vast majority of cancers seems to be made worse by excess weight,” Associate Professor MacGregor said.

“Worryingly, excess weight has the biggest impact on some of the most aggressive and deadly cancers such as those of the oesophagus and endometrium.

“Our study raises some important issues for public health and highlights the need for more research into whether this BMI-cancer relationship varies by different forms of weight gain (fat, muscle mass, etc.).

“To do that we will need larger genetic studies to identify genes that may cause different types of fat. This will be an interesting direction to take this work further.”

The Mendelian randomisation study examined genetic data from more than 46,000 Caucasian British participants in the UK Biobank project who were aged between 40 and 69 and who had developed any kind of cancer, and compared it to data from more than 390,000 cancer-free participants in the same cohort.

The study was funded by the National Health and Medical Research Council and the findings have been published in the British Journal of Cancer.

Quick facts:

  • The study results were similar for males and females, and smokers and non-smokers.
  • The Australian Institute of Health and Welfare (AIHW) says one in every two Australians will be diagnosed with cancer by age 85.
  • The Australian Institute of Health and Welfare defines people with a body mass index between 20 and 25 as being of healthy weight, while those between 25 and 30 are classified as overweight and those with a BMI of 30 and over are considered obese.
  • According to the Australian Bureau of Statistics, in 2015 almost two-thirds (63%) of Australians aged 18 and over were overweight or obese.
Community Health & Wellness Science & Research

QIMR Berghofer Medical Research Institute :
PO Royal Brisbane Hospital, Brisbane, QLD, 4029, Brisbane
07 3845 3752
QIMR Berghofer Medical Research Institute
Showing 10+ recent articles for this business
Researchers find new clues to what drives ADHD 01 November 2019 | New Australian and Taiwanese research has for the first time pinpointed where in the brain the communication process breaks down for people with chronic attention deficit hyperactivity disorder (ADHD) – a... More information...
Researchers find why some Parkinson’s patients develop harmful addictive behaviours 27 October 2019 | A QIMR Berghofer study has discovered how the medications given to people with Parkinson’s disease cause some patients to develop addictive behaviours such as problem gambling, binge eating, hypersexuality and... More information...
Australian researchers recruit for world's largest skin cancer study 17 September 2019 | Queensland researchers have launched the world’s largest ever genetic study of skin cancer and are calling on more than 20,000 Australians to take part. More information...
Scientists discover promising new lead in Crohn's disease 17 September 2019 | QIMR Berghofer researchers have identified a key driver of the aggressive gut disorder, Crohn’s disease, a finding that could eventually lead to new treatments for the often-debilitating condition. More information...
Australian researchers find 45 new genetic causes of non-melanoma skin cancers 06 August 2019 | An Australian study has discovered 45 new genetic variants that put people at a greater risk of developing the most common form of skin cancers, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). More information...
Daily coffee doesn’t affect cancer risk 18 July 2019 | Drinking coffee does not change a person’s risk of being diagnosed with or dying from cancer, a new QIMR Berghofer study has found. More information...
Australian researchers help identify first genes linked to anorexia nervosa 16 July 2019 | QIMR Berghofer researchers have played a vital role in helping identify the first eight genes associated with the eating disorder anorexia nervosa. More information...
Being born prematurely changes sleep brain activity and could affect future brain heath 26 June 2019 | A new study has shed light on how being born extremely early can change an infant’s brain activity during sleep, with flow-on effects for brain development two years later. More information...
More genetic evidence of what puts people at risk of breast and other cancers 18 June 2019 | A new international study has discovered that 94 genetic variants, about which little has been known until now, increase a person’s risk of developing breast, ovarian, prostate and pancreatic cancers. More information...
Chronic liver disease on the rise in Queensland 13 June 2019 | A new study by QIMR Berghofer and Princess Alexandra Hospital has found a significant increase in the number of Queenslanders being admitted to hospital for treatment of chronic liver disease, and the rates are... More information...

comments powered by Disqus

All articles submitted by third parties or written by My Sunshine Coast come under our Disclaimer / Terms of Service