Obesity increases the risk of stomach cancer: Understanding the link between excess weight and digestive health |

Obesity has long been linked to an increased risk of chronic diseases such as heart disease, diabetes, and various cancers. Recent research, however, has revealed a lesser-known but serious connection between obesity and stomach cancer (gastric cancer). Excess body fat can trigger hormonal changes, inflammation, and metabolic imbalances that may increase the likelihood of cancerous growth in the stomach lining. This emerging evidence highlights that maintaining a healthy body weight is not just about physical appearance or fitness; it plays a crucial role in protecting long-term digestive health and preventing serious, potentially life-threatening conditions like gastric cancer.

Stomach cancer, also known as gastric cancer, develops when malignant cells form in the lining of the stomach. It often begins in the mucosal layer, the innermost lining of the stomach, and can spread to deeper tissues and other parts of the body over time.While stomach cancer is less common than other cancers, it remains one of the leading causes of cancer-related deaths worldwide, primarily because it’s often diagnosed in later stages when symptoms become noticeable.Common symptoms include:

These symptoms are often mistaken for ordinary digestive issues, leading to delayed detection, particularly among people who are overweight or obese.

According to a study published in Obesity and the Risk of Gastrointestinal Cancers on PMC, excess adiposity is strongly linked to a higher risk of several gastrointestinal cancers, including stomach cancer. The research highlights that metabolic changes caused by obesity, such as chronic inflammation, insulin resistance, and hormonal imbalance, can promote tumour growth in the digestive tract, emphasising the need for effective weight management in cancer prevention.1. Chronic inflammation and cell damageExcess body fat, especially around the abdomen, triggers chronic low-grade inflammation throughout the body. This inflammatory state releases cytokines and other molecules that can damage stomach cells, alter the stomach’s environment, and encourage the development of cancerous growths. Over time, these inflammatory changes can make the stomach lining more susceptible to cell mutations and tumour formation.2. Hormonal changes and insulin resistanceObesity disrupts the body’s hormonal balance, particularly increasing levels of insulin, oestrogen, and leptin, all of which have been linked to cancer cell proliferation. High insulin and insulin-like growth factors can stimulate cell growth in the stomach lining, promoting abnormal or uncontrolled cell division. This hormonal environment creates a setting where cancer can take root and spread more easily.3. Fatty tissue and oxidative stressAdipose (fat) tissue isn’t just a passive storage site; it’s an active metabolic organ. In obese individuals, this tissue produces excessive reactive oxygen species (ROS), leading to oxidative stress. Oxidative stress damages DNA in gastric cells and reduces the body’s ability to repair genetic errors, a key step in the cancer development process.4. Connection with Gastroesophageal Reflux Disease (GERD)Obesity, particularly abdominal obesity, increases pressure on the stomach and the lower oesophageal sphincter, which can lead to acid reflux or GERD (Gastroesophageal Reflux Disease).Chronic acid reflux irritates the lining of the stomach and oesophagus, causing conditions like Barrett’s oesophagus, which is a known precancerous stage. Thus, obesity doesn’t just impact stomach acid levels but also sets the stage for gastric and oesophageal cancers.5. Influence on gut microbiota and H. pylori infectionResearch suggests that obesity can alter gut microbiota composition, disrupting the balance of healthy bacteria in the digestive system. This imbalance may worsen infections such as Helicobacter pylori (H. pylori), a bacterium strongly linked to stomach cancer. Obese individuals might experience more severe inflammation and a slower healing response, making it easier for chronic infections to cause cellular damage in the stomach lining.

While genetics and infections can play a role in stomach cancer, lifestyle choices remain a major factor within your control. Here are key steps to help reduce your risk:1. Maintain a healthy weightAdopting a balanced diet and regular physical activity helps reduce body fat and lower inflammation levels in the body. Aim for a BMI between 18.5 and 24.9, but also keep an eye on waist circumference.2. Eat an antioxidant-rich dietInclude plenty of fruits, vegetables, and whole grains in your meals. Foods rich in vitamin C, beta-carotene, and polyphenols can protect stomach cells from oxidative damage.3. Limit processed and red meatsDiets high in processed, smoked, or salted foods have been linked to a higher risk of stomach cancer. Replace them with lean proteins like fish, legumes, and poultry.4. Reduce alcohol and quit smokingBoth smoking and excessive alcohol consumption irritate the stomach lining and amplify cancer risk, especially when combined with obesity.5. Get screened for H. pyloriIf you experience chronic indigestion or have a family history of stomach issues, ask your doctor about H. pylori testing. Treating this infection early can drastically lower your cancer risk.Disclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult a healthcare professional before making any changes to your diet, medication, or lifestyle.Also read | Stomach pain warning signs: When persistent discomfort could point to appendicitis, gallstones, or pancreatitis