Red wine can be a common trigger for heartburn, the burning sensation felt in the chest or throat when stomach acid backs up into the esophagus. This uncomfortable symptom is a sign of acid reflux, medically known as gastroesophageal reflux (GER). The properties of red wine interact with the digestive system, making the backup of stomach contents more likely to occur.
The Physiological Mechanism
The primary mechanism by which red wine encourages acid reflux involves the lower esophageal sphincter (LES). This ring of muscle acts like a one-way valve, sealing off the stomach from the esophagus to prevent acidic stomach contents from flowing upward. Alcohol, which includes the ethanol content in red wine, acts as a smooth muscle relaxant.
When the LES muscle relaxes, it temporarily loses its seal, creating a pathway for stomach acid to escape into the esophagus. This involuntary opening allows the reflux of gastric juices, which irritates the sensitive lining of the esophagus and causes the characteristic burning feeling of heartburn. Alcohol consumption can also directly irritate the lining of the esophagus, increasing sensitivity to any acid that does reflux.
The amount of time the esophagus is exposed to stomach acid, known as “percent reflux time,” increases after consuming moderate amounts of red wine with a meal. This extended exposure time means the esophageal lining is subjected to the burning acid for longer periods, which can increase the severity and duration of the heartburn. Even in healthy individuals, this mechanism is observed, suggesting that the relaxant effect of alcohol is a significant factor in acid reflux.
Chemical Components That Increase Risk
Beyond the muscle-relaxing effect of ethanol, red wine contains chemical components that further aggravate the digestive system and contribute to heartburn. Red wine is naturally an acidic beverage, typically falling within a pH range of 3.0 to 4.0. Introducing this acidity into the stomach increases the overall acid load, making reflux more likely to cause discomfort.
The concentration of ethanol also plays a role in the intensity of the LES relaxation effect. Ethanol has been shown to irritate the tissues in the esophagus and may stimulate the stomach to produce more acid. This combination of increased acid production and a relaxed sphincter creates a greater chance for acid to flow back up.
Other compounds found in red wine, such as tannins, can be a factor for some sensitive individuals. Tannins are polyphenols that give red wine its color and astringent mouthfeel. They are often highly concentrated alongside histamines, which are also present in red wine and can be significantly higher than in white wine.
Histamines are compounds that stimulate the production of gastric acid in the stomach, which can lead to an overproduction that overwhelms the LES. Red wine is fermented with the grape skins, which is why it has higher levels of both histamines and tannins. These compounds may exacerbate digestive irritation or trigger acid production in those who are particularly sensitive.
Strategies for Prevention
Individuals who enjoy red wine but wish to minimize the risk of heartburn can adopt practical consumption strategies. One effective method is to avoid drinking red wine close to bedtime. Alcohol relaxes the LES, and lying down removes the benefit of gravity, which helps keep stomach contents contained. It is recommended to finish the last glass at least two to three hours before lying down for the night.
Pacing and moderation are important, as drinking slowly and limiting the total quantity allows the body time to process the alcohol’s effects. Consuming red wine with a meal, rather than on an empty stomach, helps buffer the acid and slow the rate of alcohol absorption. Pairing the wine with neutral or low-acidity foods is better than pairing it with common reflux triggers like tomato-based sauces or high-fat foods.
Remaining upright for a few hours after drinking helps the LES maintain its function against the force of stomach acid. Sipping water alongside the wine can help dilute the acid in the stomach and keep the esophagus hydrated. These conscious habits allow for the enjoyment of red wine while reducing the likelihood of a heartburn flare-up.