Addressing the obesity epidemic has become even more critical now that numerous other cancers have been linked to being overweight.
A new study published in The Lancet Regional Health – Europe found obesity may be associated with 18 more cancers than scientists previously thought. Conducted by researchers in Sweden as part of the Obesity and Disease Development Sweden (ODDS) pooled cohort study, the findings could shake up the way the medical community views the relationship between body mass index (BMI) and cancer risk.
Obesity has long been recognized as a significant risk factor for several serious health conditions. It is a major contributor to a wide range of conditions, including cardiovascular diseases like hypertension, coronary artery disease, and heart failure, as well as metabolic disorders such as type 2 diabetes and metabolic syndrome. It also increases the likelihood of developing sleep apnea, osteoarthritis, liver disease, and mental health issues like depression, in addition to many different cancers.
The 2016 International Agency for Research on Cancer (IARC) report identified 13 cancers as being linked to obesity, including breast, liver, kidney, and colon cancer. And since that time, research has continued to explore the full extent of obesity’s impact on cancer development.
The Swedish study analyzed data from over 4.1 million individuals across 50 years, starting in 1963 and continuing through 2019. This large dataset allowed researchers to investigate over 100 cancer forms and subtypes, focusing on the impact of BMI on cancer development. The research took into account variables such as age, sex, smoking habits, education level, and other factors known to influence cancer risk.
In this cohort, the average BMI was 24 kg/m² for women and 22.5 kg/m² for men. Researchers used Cox regression models to estimate the hazard ratios (HRs) for cancer risk based on BMI, adjusted for confounding factors. These models helped identify associations between BMI and cancer types that had previously not been recognized as linked to obesity.
Ultimately, 18 potential obesity-related cancers that had not been previously established as obesity-linked were found. The study also confirmed the established 13 cancers recognized by the IARC. These newly associated cancers accounted for 15% of all cancer cases within the study population.
For women, cancers of the cervix, vulva, head and neck (specifically squamous cell carcinoma), and nodular melanoma were identified as being linked to obesity. In men, cancers of the penis, head and neck (adenocarcinoma), and malignant melanoma showed similar associations. Additionally, for both men and women, obesity was linked to cancers of the small intestine, biliary tract, oral cavity, adrenal glands, connective tissue, parathyroid glands, pituitary glands, and hematological cancers such as lymphoid and myeloid neoplasms.
Men appeared to have a slightly stronger association between BMI and the risk of malignant melanoma and lymphoid neoplasms than women. Meanwhile, women had a higher relative risk of developing obesity-related cancers of the reproductive organs. The team also found that specific subtypes of certain cancers were more strongly associated with BMI than others. For example, squamous cell carcinoma in the head and neck region had a stronger link to obesity than adenocarcinoma in the same area.
As the world grapples with rising obesity rates as well as rising numbers of obesity-related diseases, especially type 2 diabetes, the medical community is increasingly focusing on preventive care and education to reduce the burden of obesity-related diseases. With 18 more cancers now potentially linked to obesity, the need for effective weight management strategies has become more critical than ever before.
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Research identifies 31 additional cancers potentially linked to obesity
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