Causes and Risk Factors of Acid Reflux (GERD)
Causes of acid reflux (GERD):
1) Failure of lower oesophageal sphincter
This is the major cause of GERD. Lower oesophageal sphincter (LES) is a ring of muscle between the oesophagus and stomach. When a person swallows, the LES relaxes to allow food and liquid to travel into the stomach, and closes to retain the contents in the stomach for digestion. GERD develops when the LES is weak or relaxed inappropriately, thereby allowing the gastric acid and stomach contents such as food, enzymes and bile to flow backwards into the oesophagus.
Inappropriate relaxation of LES is the cause of acid reflux
2) Hiatal hernia
The oesophagus is a passage that joins the mouth to the stomach, passing through the chest cavity to the abdominal cavity via a hole in the diaphragm known as oesophageal hiatus. Hiatal hernia is a condition where the upper part of the stomach (normally located in the abdominal cavity) pushes or protrudes through the oesophageal hiatus into the chest cavity. This causes gastric acid to flow upwards into the oesophagus, resulting in an inflammation in the lining of the oesophagus and symptoms of GERD to surface.
3) Other conditions that can increase the risk of GERD are:
Being overweight and obese can provoke the onset and affect the severity of GERD. Researchers found that people who are overweight (BMI of 25 to 30) are almost twice as likely to develop GERD as those of normal weight. Likewise, people who are obese (BMI greater than 30) are almost triple the risk. Excess fat in the abdomen compresses the stomach and increases its internal pressure, which may overwhelm the LES and become one of the causes of acid reflux.
Hormonal changes associated with pregnancy cause the slowing down of digestive system and muscles that push food down the esophagus. LES is also weakened temporarily during pregnancy. The growing uterus pushes on the stomach, and sometimes forces gastric acid up into the esophagus. For most cases, GERD symptoms improve after the baby is born.
Smokers are much more likely to have GERD than non-smokers. Nicotine, a key component of tobacco, is known to relax LES, causing acid to surge into and damage esophagus. Smoking also prompts the stomach to produce more gastric acid, increasing the risk of gastric juices being back flowed into the esophagus.
- Alcohol consumption
Alcohol consumption, especially in large quantities, increases the risk of GERD. Alcohol may damage esophageal and gastric mucosa. In addition, drinking alcohol also make the stomach to produce more acid than usual, exacerbating acid reflux.
- Dry mouth
Dry mouth is associated with acid reflux. Saliva is an important part of digestive process and the alkaline nature of saliva helps to counteract acid in the esophagus. Dry mouse could hamper the process of food being adequately soaked with the saliva which is alkaline and neutralizes any gastric acid backflow into the esophagus.
People with asthma are twice as likely to have GERD compared to those who do not have asthma. The exact relationship between asthma and GERD is ambiguous.
- Diabetes and delayed stomach emptying
According to a study published in the World Journal of Gastroenterology (2008), GERD occurs in about 40% of people with diabetes. GERD is found to be more common in people with diabetes and neuropathy (nerve damage), a common complication of diabetes, compared to people without neuropathy.
- Connective tissue disorders, such as scleroderma
People with scleroderma usually have GERD. Scleroderma is an autoimmune disease that causes hardening and thickening of skin and sometimes other organs of the body. With scleroderma, the immune system triggers the body into producing too much collagen (primary protein found in connective tissue). This excess collagen will be deposited within the skin and other organs, including the muscle of the esophagus, leading to their hardening and thickening. This in turn causes dysfunction of the lower part of the esophagus, including the area around the LES. Thus, the LES could no longer close tightly to contain acid in the stomach, allowing reflux to happen.
- Poor diet
Poor diet could cause or worsen the GERD symptoms. Examples of these foods are:
Fatty food can cause LES to relax, leading to more gastric acid to backflow into the esophagus.
Spicy and tangy foods:
Spicy and tangy foods, such as garlic and onions may provoke GERD symptoms in some people.
Highly acidic food, such as tomatoes and citrus fruits can cause or worsen GERD symptoms.
Chocolate contains methylxanthine, an ingredient that has been shown to relax the smooth muscle in the LES and boost reflux.