Causes of Excess Stomach Acid and Acid Reflux, and How to Improve Them Through Lifestyle

Acid Reflux Is a Lifestyle Disease of Modern Living

Heartburn after a meal, something sour rising up to your throat, a cough that starts when you lie down. People troubled by the symptoms of gastroesophageal reflux disease (GERD) are not unusual in Japan either, and plenty of them have lived with it for years while leaning on over-the-counter stomach remedies. It used to be regarded as a condition more common in the West, but against a backdrop of a more Westernized diet, rising obesity rates, and an increasingly stressful society, it has been pointed out that more people in Japan now report it as well.

Many people keep taking antacids on the assumption that "there is simply too much acid," but in most cases the amount of stomach acid itself is normal and the problem lies in the mechanism that allows acid to flow back into the esophagus. Real improvement calls for understanding how reflux happens and taking a fresh look at daily habits.

How Acid Reflux Happens - the Role of the Lower Esophageal Sphincter

At the junction between the esophagus and the stomach sits a ring-shaped muscle called the lower esophageal sphincter (LES). Normally the LES opens only when food passes through and stays closed the rest of the time, preventing acid from flowing back. Reflux esophagitis develops when this LES function declines and stomach acid escapes upward into the esophagus.

The main factors behind declining LES function are hiatal hernia (part of the stomach pushing past the diaphragm into the chest cavity), obesity (raised abdominal pressure), loss of muscle strength with age, and relaxation of the LES caused by particular foods or medications. Unlike the stomach lining, which protects itself with mucus and bicarbonate ions, the esophageal lining has little equipment for withstanding strong acid. Repeated exposure to refluxed acid therefore leads to inflammation, erosion, and ulcers.

Foods and Drinks That Make Reflux Worse

Certain foods and drinks relax the LES or increase acid secretion, making reflux worse. The items clinicians raise again and again as aggravating factors are the following.

Chocolate contains theobromine, which relaxes the LES. Coffee (caffeine) stimulates acid secretion and relaxes the LES. Alcohol relaxes the LES and slows esophageal peristalsis at the same time. Citrus fruits and tomatoes are highly acidic and directly irritate an inflamed esophageal lining. Fatty meals delay gastric emptying and encourage LES relaxation. Carbonated drinks raise the pressure inside the stomach and trigger reflux.

That said, reactions to these foods vary a great deal from person to person. Not everyone gets worse on the same foods, so keeping a food diary to pin down your own trigger foods matters. For approaches to improving eating habits without adding stress, the separate article on the subject is also worth reading.

How Posture and Body Position Affect Reflux

Gravity is a powerful ally against reflux. Standing or sitting, gravity keeps acid down in the stomach, but once you lie down that help disappears and reflux becomes easier. Lying down straight after eating is one of the biggest risk factors for reflux esophagitis.

To prevent reflux while you sleep, leave at least 3 hours between dinner and bedtime. Raise the head end of the bed by 15 to 20 cm (tilt the bed itself rather than piling up pillows). Lying on your left side puts the LES above the surface of the stomach contents, given the anatomy of the stomach, so there is less reflux than lying on your right.

Daytime posture matters too. A hunched-forward posture raises abdominal pressure and invites reflux. Keep your back straight during desk work, and avoid tasks that bend you forward (cleaning, gardening) right after eating. Cinching the abdomen with a belt or a corset also makes reflux worse.

Stress and Stomach Acid

Saying "stress is making my stomach hurt" is not just a figure of speech. Stress affects how the stomach and esophagus work by way of the autonomic nervous system, and it is thought to push esophageal sensation in particular toward hypersensitivity. How much the volume of acid secretion itself changes is not consistent from person to person, but most people who struggle with symptoms recognize the part where the same amount of reflux comes to feel far more intense.

Stress also weakens esophageal peristalsis (the movement that pushes refluxed acid back down into the stomach) and reduces saliva production. Saliva is mildly alkaline and neutralizes acid that has come up into the esophagus, so less saliva under stress means the esophagus stays exposed to acid for longer. The effects of chronic stress on the body are covered in detail in a separate article.

Types of Drug Treatment and Their Caveats

The mainstay of drug treatment for reflux esophagitis is the proton pump inhibitor (PPI). PPIs block the proton pumps in the parietal cells of the stomach and strongly suppress acid secretion. Omeprazole, lansoprazole, and esomeprazole are typical examples, and for many people heartburn eases within a few days to a few weeks.

Long-term PPI use, however, carries risks. Stomach acid is needed to absorb calcium, magnesium, iron, and vitamin B12, so suppressing acid over a long period may cause poor absorption of these nutrients. A higher risk of osteoporosis, changes in the gut microbiome, and a higher risk of Clostridioides difficile infection have also been reported.

A PPI is not a drug that cures but a drug that suppresses, and symptoms often return once you stop taking it. That is precisely why it is important to work on daily habits alongside drug treatment, aiming in the end for a state where you do not depend on medication. If you want to relearn stomach and bowel health, including how to live with medication, it is worth getting the overall picture from books on digestive health care.

Concrete Lifestyle Steps That Reduce Reflux

On the food side, cut the size of each meal and eat more often (5 to 6 small meals a day). Hold deep-fried and fatty dishes to one item per meal, and cut down on the amount of oil you cook with in the first place. Go easy on fluids during meals and drink between them instead. Chewing gum promotes saliva production, which helps neutralize acid in the esophagus (avoid mint flavors, which relax the LES).

Weight management matters as well. It has long been noted that the more weight people put on, the more of them complain of heartburn, and conversely there are plenty of people whose symptoms ease after losing a few kilograms. Abdominal obesity (the visceral fat type) in particular pushes abdominal pressure up directly, so tracking changes in your waist circumference rather than the number on the scale makes the effect easier to see. On improving your intestinal environment, the article on gut health is worth reading alongside this one.

When to See a Doctor, and What Tests Are Used

Seeing a gastroenterologist is recommended if any of the following apply: heartburn twice a week or more that continues for 4 weeks or longer, no improvement with over-the-counter antacids, difficulty swallowing (a sense that food is sticking in your throat), accompanying weight loss, or vomiting of blood or black stools.

In gastroenterology, upper gastrointestinal endoscopy (a gastroscope) is used to look directly at the state of the esophageal lining, checking for erosion or ulcers and for Barrett's esophagus (a state in which the squamous epithelium of the lower esophagus has been replaced by columnar epithelium resembling that of the stomach or intestine, a risk factor for esophageal cancer). Even when endoscopy finds nothing abnormal, 24-hour pH monitoring can quantify how much acid the esophagus is exposed to.