Here's how obesity increases the risk of 18 types of cancer

Everyone knows Obesity is linked to major non-communicable and life-threatening diseases like Diabetes and heart disease. However, significant studies have shown that being overweight also increases the chance of different types of Cancer. While more conclusive studies are needed in this area, there is no doubt that Obesity is one of the growing concerns within the healthcare sector. Obesity contributes to eight per cent of all Cancer cases, second only to Tobacco use in preventable causes of Cancer.

Dr. Kirti Bhushan, Consultant-Surgical Oncology, SL Raheja Hospital, Mahim says, “Adipose tissue (fat cells) act as an "organ" with the capacity to release chemical mediators, hormones and inflammatory Cytokines that can promote the growth of Cancer cells. All these can contribute to Cancer initiation, development, progression, recurrence, and metastasis.”

Obesity can impact biological mechanisms, which is how it is linked to cancer. One important mechanism is the overproduction of Estrogen by adipose tissue, which leads to an increased risk of developing endometrial, ovarian, and other cancers. Higher Estrogen levels can also stimulate the growth of Hormone Receptor-Positive Breast Cancer cells.

According to Dr. Sharad Sharma, Consultant-Laparoscopic & Bariatric Surgery, Fortis Hiranandani Hospital, Vashi, “The second mechanism results from Insulin Resistance due to increased BMI, which stimulates the production of Insulin called Hyperinsulinemia and prolongs the duration of the action of Insulin-like Growth Factor-1 (IGF-1). These factors lead to the development of colon, renal, prostate, and endometrial cancers.”

Obese people have unnaturally high levels of inflammatory Cytokines, including IL-6, TNFα, and C-reactive protein. This increases chronic inflammatory diseases, including gallstones and Non-Alcoholic Fatty Liver Disease. This damages the cellular DNA and makes people more likely to develop biliary tract, liver, and other malignancies. Additionally, Obese individuals often have increased Insulin levels and Insulin resistance, which can enhance the growth of tumours.

Numerous large-scale population studies have shown that being overweight can increase the incidence of several types of Cancer, including Breast, Colorectal, Pancreatic, Ovarian, Endometrial, Kidney, and Liver Cancer. Further, Estrogen stimulates the endometrium's growth, which can be one of the causes leading to an increase in Endometrial Cancers.

“That’s not all. Being overweight also increases the risk of recurrent Cancer, the risk of morbidities associated with Cancer treatment, and harms a Cancer survivors' quality of life. Also, Obesity has a psychological, emotional and economic impact on a person which is why it is one of the biggest roadblock to a healthy life,” says Dr. Sharma.