The risk of cancer increases considerably if a person gains weight before the age of 40 with the risk of endometrial cancer increasing by 70 percent, according to an international study, headed by researchers from University of Bergen, Norway.
“Obesity is an established risk factor for several cancers,” said Professor Tone Bjørge, University of Bergen. “In this study, we have focused on the degree, timing and duration of overweight and obesity in relation to cancer risk.”
For the study, ‘BMI and weight changes and risk of obesity-related cancers: a pooled European cohort study’, published in International Journal of Epidemiology, the researchers wanted to find out how adult overweight and obesity increase the risk of different types of cancer. They included adults with two or more measurements, obtained at least three years apart, and before a possible cancer diagnosis. On average, the individuals were followed for about 18 years.
The researchers used data for 220,000 individuals from the Me-Can study, with participants from Norway, Sweden and Austria. Data from health examinations, including information on height and weight, were linked to data from national cancer registries.
In total, 27,881 individuals were diagnosed with cancer during follow-up, of which 9,761 (35 percent) were obesity-related. Participants with obesity at the first and second health examination had the highest risk of developing obesity-related cancer, compared to participants with normal BMI.
The study showed that if you were overweight before age 40, the risk of developing cancer increases by:
- 70 percent for endometrial cancer
- 58 percent for male renal-cell cancer
- 29 percent for male colon cancer
- 15 percent for all obesity-related cancers (both sexes)
“The risk increased by 64 percent for male participants and 48 percent for females,” concluded Bjørge. “Our key message is that preventing weight gain may be an important public health strategy to reduce the cancer risk.”