Obesity in Adolescence Is a Major Risk Factor for 17 Types of Cancer

Obesity in Adolescence Is a Major Risk Factor

Ranking fourth among the risk factors for death, obesity and overweight are associated with numerous diseases. A recent study reveals that young individuals with a high body mass index (BMI) during adolescence face a three- to four-times higher risk of developing certain types of cancer in adulthood. The authors emphasize the urgency of reversing this trend. Meanwhile, the World Health Organization (WHO) predicts that obesity will surpass smoking as a “preventable risk factor” in the coming years.

Overweight and obesity are among the risk factors associated with many chronic diseases. However, a study suggests that they could play a role in the development of 17 cancers, starting at the end of adolescence. Conducted exclusively among men, these findings underscore the importance of taking new actions to combat sedentary behavior as obesity cases continue to rise globally.

Nearly two-thirds of adults and one in three children in the WHO European Region are overweight or obese, and these rates continue to rise,” warned the World Health Organization (WHO) in a 2022 report. The WHO goes so far as to warn that “obesity could surpass smoking as the primary preventable cancer risk” in the coming decades, estimating that thirteen cancers are linked to obesity. This major public health issue is something the global authority aims to prevent by establishing “healthy environments.” This involves combating sedentary behavior, especially induced by screen time, promoting a healthy and balanced diet, and increasing physical activity.

Cancers Affecting All Organs

A new study by researchers from the University of Gothenburg confirms the role of obesity and a high body mass index (BMI) more broadly in health and, notably, in the risk of cancer. The analysis involves a staggering 1.4 million men who underwent conscription examinations between 1968 and 2005, when they were aged 16 to 25. Of these, nearly 80,000 developed cancer during an average follow-up of 31 years. Published in the journal Obesity, these research findings suggest that a high BMI at the age of 18, the end of adolescence, is linked to an increased risk of several cancers in adulthood, more so than having poor fitness at this young age.

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,” explains Aron Onerup from the University of Gothenburg, the principal author of the study, in a statement.

During these studies, researchers observed a higher risk of lung, head, neck, brain, thyroid, esophagus, stomach, pancreas, liver, colon, rectum, kidney, bladder, as well as melanoma, leukemia, myeloma, and non-Hodgkin lymphoma cancers in participants with a high BMI at an average age of 18. It’s important to note that a BMI over 25 was considered high, encompassing both overweight and obesity.

In the Future, Over Half of Cancer Cases Could Be Linked to a High BMI

Researchers specify that this association was even stronger for esophageal, stomach, and kidney cancers, reporting a three to four times higher risk for men in obesity at the age of 18. However, it should be noted that a BMI considered normal, between 20 and 22.4, was also associated with a high risk of head, neck, esophageal, stomach, pancreatic, liver, kidney, melanoma, and non-Hodgkin lymphoma cancers.

This surprising finding is explained by scientists, who state that “the current definition of normal weight may apply mainly to older adults, while the optimal weight for a young adult is probably in a lower range.” As for prostate cancer, the risk was higher in participants who were neither overweight nor obese.

In 30 years, the researchers expect an increase in the proportion of cancer cases linked to youth overweight and obesity, calculated based on overweight and obesity in today’s 18-year-old men in Sweden. For cancer of the stomach, the proportion rises to 32% and for cancer of the esophagus to 37%. Based on the current prevalence of youth overweight and obesity in the United States, more than one in two cases of these two cancers could be linked to high BMI in the late teenage years in 30 years,” concludes the study.