The Root Cause of Acid Reflux: Valve Dysfunction

What causes acid reflux? At its core, acid reflux occurs when stomach contents flow backward into the esophagus—and often into the respiratory system—leading to a wide range of symptoms, from heartburn to chronic cough, post-nasal drip, sinusitis, asthma, shortness of breath, and even hearing loss and tinnitus. Identifying the underlying factors behind this backward flow is essential for creating a meaningful and effective healing plan.

At the root of this condition is a muscular valve called the lower esophageal sphincter (LES), which acts as a protective barrier between the stomach and esophagus. The LES is designed to stay closed except when swallowing, keeping acidic stomach contents where they belong. When it doesn’t function properly, even briefly, those contents can escape upward, potentially causing damage to both digestive and respiratory tissues.

What causes the LES to weaken or relax? Many of the contributing factors are common parts of everyday life—such as food choices, physical habits, medications, and even the timing of meals—and are explored below.

LES Relaxation: A Leading Cause of Acid Reflux

The LES plays a vital role in preventing reflux. It protects the esophagus from the stomach’s highly acidic contents as well as from digestive enzymes like pepsin, which can be particularly damaging outside the stomach.

In people who experience reflux, the LES may open inappropriately. This may happen due to a loss of muscle tone or because of pressure building in the stomach that forces the valve open. The good news is that LES dysfunction is often reversible. Once the triggers are identified and removed, LES function can frequently return to normal.

Below are four key areas that contribute to LES relaxation and reflux. While not every item affects every person the same way, understanding common causes can be a powerful step toward healing.

Triggers That Relax or Overwhelm the LES

Food

Certain foods are known to weaken the LES or slow down digestion, both of which make reflux more likely. High-fat foods, including fried or heavily processed items, can delay stomach emptying and stimulate hormonal changes that relax the LES.

Chocolate is another common trigger—it contains both caffeine and theobromine, compounds that reduce LES tone. Processed meats are often high in fat, salt, and chemical additives, which together burden the digestive system and irritate the gut lining.

Common examples include:
• Fried foods
• Fast food
• High-fat meals (buttery, creamy, or greasy dishes)
• Processed meats (such as bacon, sausage, deli meats)
• Chocolate

Beverages

Drinks can have just as much impact as solid foods. Beverages that contain caffeine or alcohol tend to reduce LES tone, while acidic drinks like citrus juices can irritate the esophageal lining.

Carbonated drinks increase the volume of gas in the stomach, raising internal pressure and pushing contents toward the esophagus. Some energy drinks are especially problematic, as they often combine acidity, caffeine, and carbonation.

Common examples include:
• Alcohol
• Carbonated beverages (soda, sparkling water)
• Citrus juices (orange, grapefruit, pineapple)
• Energy drinks
• Coffee and black or green tea

Medications and Supplements

Many commonly used medications—and even some over-the-counter supplements—can contribute to reflux. Some drugs relax smooth muscle tissue, including the LES. Others may slow digestion or irritate the esophagus directly.

Even helpful supplements like B vitamins or joint formulas can provoke symptoms when taken improperly. Nicotine, though not a medication, is one of the most potent substances that reduces LES tone and delays esophageal healing.

Common examples include:
• Nicotine (from tobacco products)
• ACE inhibitors (used to treat high blood pressure)
• Chondroitin and glucosamine (used for joint support)
• B-complex vitamins
• Antibiotics (especially broad-spectrum types)
• Corticosteroids (such as prednisone)

Lifestyle Habits

How and when we eat, as well as how we move, can strongly influence reflux risk. Large meals increase stomach volume and pressure, making it easier for acid to escape. Lying down shortly after eating removes the benefit of gravity and makes reflux more likely.

Weight gain, especially around the abdomen, increases internal pressure on the LES. Certain forms of physical activity—such as bending, crunching, or straining the abdomen—can also trigger reflux if done too soon after a meal.

Common contributors include:
• Eating close to bedtime
• Snacking late in the evening
• Overeating or consuming large meals
• Obesity or central weight gain
• Exercising too soon after eating

Conclusion: Understanding the Causes of Acid Reflux Is the First Step

Identifying what drives reflux is the foundation of lasting relief. While symptoms may vary, the common thread is often a compromised LES—affected by foods, medications, physical habits, or a combination of these factors.

Because each person’s reflux profile is unique, what triggers symptoms in one individual may not affect another. Paying attention to patterns and recognizing personal sensitivities is important.

Acid reflux does not have to be permanent. When LES dysfunction is at the root of the problem, the valve often regains normal tone and function once contributing factors are addressed. Restoring LES function is a crucial step toward healing.

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For more information about diagnosis and treatment of acid reflux, see two companion books on Amazon: Dr. Koufman’s Acid Reflux Diet and Dropping Acid: The Reflux Diet Cookbook & Cure. If you would like to receive personalized guidance and strategies for lasting relief, consider scheduling an online consultation.