Obesity poses significant dangers to overall health, including an increased risk of developing various types of cancer. It is crucial to understand the link between obesity and cancer to raise awareness and promote proactive measures to mitigate these risks. This article aims to explore the adverse health effects of obesity and cancer development and emphasizes the importance of maintaining a healthy weight to reduce the risk of cancer.

Increased Risk of Cancer in Obese Individuals

Obesity is closely associated with an elevated risk of developing several types of cancer, including breast, colorectal, endometrial, kidney, pancreatic, and liver cancer, among others. The excess weight carried by individuals with obesity can trigger chronic inflammation, hormonal imbalances, and insulin resistance, creating an environment conducive to cancer growth and progression.

“The percentage of cancer cases attributed to excess body weight varied widely across cancer types and was as high as 51% for liver or gallbladder cancer, 49.2% for endometrial cancer in women, 48.8% for liver or gallbladder cancer, and 30.6% for esophageal adenocarcinoma in men.” 

  • Endometrial Cancer: 7 times as likely in people with severe obesity, 
  • Esophageal: 4.8 times as likely in people with severe obesity
  • Gastric Cancer: 2 times as likely in people with obesity
  • Liver Cancer: 2 times as likely in people with obesity or overweight
  • Kidney Cancer: 2 times as likely in people with obesity or overweight
  • Multiple myeloma: 1.1–1.2 times as likely in people with obesity or overweight
  • Meningioma: 1.5 times as likely in people with obesity
  • Pancreatic Cancer: 1.5 times as likely in people with obesity or overweight
  • Colorectal Cancer: 1.3 times as likely in people with obesity
  • Gallbladder Cancer: 1.6 times as likely in people with obesity
  • Breast Cancer: 1.2–1.4 times as likely in people with obesity or overweight
  • Ovarian Cancer: 1.1 times as likely for every 5-unit increase in BMI
  • Thyroid Cancer: 1.3 times as likely in people with obesity

Explaining the Link Between Obesity and Cancer

The link between obesity and cancer can be explained through several mechanisms.

Insulin

Obese individuals commonly have elevated insulin levels in their bloodstream. These increased levels of insulin contribute to the development of type 2 diabetes, which is a known risk factor for cancer. Moreover, higher levels of insulin and insulin-like growth factor-1 (IGF-1) have been associated with the development of cancers such as colon, kidney, prostate, and endometrial cancers.

Inflammation

Chronic inflammation is prevalent in obese individuals, leading to oxidative stress that causes DNA damage and increases the risk of cancer. Additionally, visceral fat, which surrounds organs like the liver and intestines, triggers inflammation. Excessive visceral fat interferes with specific bodily processes, as fat cells release hormones that promote cell growth. Increased cell division raises the likelihood of cancer development. Furthermore, fat tissue can produce proteins that contribute to chronic inflammation and insulin resistance, both of which facilitate cell growth. Uncontrolled cell reproduction significantly raises the risk of cancer, as the more cells divide and replicate, the greater the chances of tumor formation.

Fat Cells

Obesity leads to an accumulation of adipose (fatty) tissue in the body. Fat cells in this tissue produce high levels of estrogen, which has been linked to an increased risk of breast, endometrial, ovarian, and other cancers. Additionally, fat cells release hormones called adipokines, which can either stimulate or inhibit cell growth. Adiponectin, a specific adipokine hormone, plays a role in insulin sensitivity and inflammation management. In obese individuals, adiponectin is less abundant, increasing the risk of cancer development due to the aforementioned factors.

In summary, the connection between obesity and cancer involves various mechanisms. Elevated insulin levels, chronic inflammation caused by oxidative stress and visceral fat, as well as the effects of fat cells and their hormone production, contribute to an increased risk of cancer in obese individuals. Recognizing the detrimental effects of obesity on cancer risk and outcomes is crucial for promoting healthier lifestyles and reducing the burden of obesity-related cancers. Understanding these mechanisms can help emphasize the importance of weight management and adopting a healthy lifestyle to reduce the risk of cancer development.