Overweight children have an increased risk of cancer in adulthood.

Abstract

The new findings come from the BMI Epidemiology Study Gothenburg, a population-based cohort including the body mass index (BMI) during development and diagnostic data from high-quality Swedish registers for 36,565 men born between 1945 and 1961. Scientists analyzed the BMI of the included individuals at the age of 8 years and again at the age of 20 years and followed up their cancer diagnoses from the age of 20 years and for approximately 40 years thereafter. A nearly 40% excess relative risk remained even for the group of boys who were overweight at the age of 8 years but had a normal weight at the age of 20 years in comparison with the group with normal weights at both ages. According to Dr Célind, the results show that preventive measures against obesity-related cancer should start early in childhood. Obesity-related cancers, many of which are on the rise in industrialized countries, include cancers of the mouth, liver, gallbladder, pancreas, colon, thyroid, skin (malignant melanoma), and blood. Although the association between a high BMI in adulthood and an increased risk of obesityrelated cancer was already known, the risk associated with a high BMI during childhood and puberty has not been detailed in previous studies. “Prior studies have shown that people who are obese in middle age or older adulthood have a higher risk of cancer in the following years. Based on these studies and other evidence, expert groups have concluded that obesity in adulthood increases the risk of 13 types of cancer,” says Elizabeth A. Platz, ScD, MPH, a professor at the Department of Epidemiology of the Johns Hopkins Bloomberg School of Public Health and the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins in Baltimore, Maryland, who was not involved with the study. “The study by Célind and his colleagues is important because they were able to study whether overweight at a much earlier age—boyhood—also may be associated with a higher risk of obesity-associated cancer decades later into middle age. This study provides evidence that boys who are overweight may have an increased risk of obesity-associated cancers in adulthood, and that this increased risk is not lowered, even if later in early adulthood weight is in the normal range.”