A NEW STUDY carried out at the University of Gothenburg, Sweden, has found that males who are overweight or obese at age 18 have a higher risk of 17 different cancers later in life. The team previously reported a higher cancer risk in males who had lower aerobic fitness at the time of compulsory conscription for military service at the age of 18. Now, two new studies reveal that high BMI at conscription is linked to even more cancers later in life than poor fitness.
Primary analyses were performed on 1,489,115 males, 78,217 of whom subsequently developed cancer during a mean follow-up of 31 years. Independent of participants’ fitness levels, high BMI at age 18 was linearly associated with a higher risk of lung, head and neck, brain, thyroid, oesophageal, stomach, pancreatic, liver, colon, rectal, kidney, and bladder cancer, as well as malignant melanoma, leukaemia, myeloma, and lymphoma (both Hodgkin and non-Hodgkin).
The link with high BMI was strongest for abdominal cancers, including oesophageal, kidney, and stomach cancers, with a three- or fourfold increased risk for obese males at conscription. A high BMI seemed to explain 15–25% of these cancer cases in Sweden. Interestingly, for several cancer types, the risk was already increased at a BMI of 20.0–22.4, which is within the range of normal weight (18.5–24.9). “This suggests that the current definition of normal weight may be applicable primarily for older adults, while an optimal weight as a young adult is likely to be in a lower range,” commented study author Maria Åberg from the University of Gothenburg.
The researchers also examined the link between high BMI and cancer mortality, and found that males who were overweight or obese were two to three times more likely to die within 5 years of being diagnosed with Hodgkin lymphoma and skin, thyroid, bladder, and prostate cancer, and 1.4–2.0 times more likely to die from cancers of the head and neck, rectum, and kidneys.
Study author Aron Onerup, University of Gothenburg, stated: “Overweight and obesity at a young age seems to increase the risk of developing cancer, and we see links between unhealthy weight and cancer in almost every organ. Given the alarming trend of obesity in childhood and adolescence, this study reinforces the need to deploy strong resources to reverse this trend.”