The link between coffee and upset stomach can be related to caffeine and heartburn. The caffeine in coffee may stimulate production of stomach acids, causing heartburn. Heartburn can then cause upset stomach. Caffeine is a stimulant that increases heart rate which can be directly linked to nausea.
Coffee is available in caffeinated, half-caffeinated, and decaffeinated forms. Decaffeinated coffee has less caffeine than other types, but two to four milligrams (mg) of caffeine remains even after processing to remove caffeine. Half-caffeinated coffee typically has about 50 mg to 60 mg, and caffeinated contains about 100 mg to 120 mg.
Sensitivity to oral stimulants is one common cause of the coffee and upset stomach link. The caffeine in coffee can cause heart rate to increase, leading to nausea, dizziness, and irritability. Drinking coffee that is lower in caffeine may help reduce the side effect. Replacing coffee with tea may further lower caffeine intake, and any stomach problems associated with it.
People who are not sensitive to caffeine may also suffer from the coffee and an upset stomach connection. Caffeine overdose occurs when too much caffeine is consumed in a short period. Often referred to as coffee jitters, caffeine overdose is not typically life threatening but it can take hours for stimulation and nausea to go away.
Coffee also causes production of stomach acids which can lead to upset stomach. Stomach acids are typically produced when food is eaten, to start the digestive process. If no food is in the stomach, acids can cause irritation and upset stomach. Therefore, eating food while drinking a cup of coffee may counteract the feeling of nausea.
Some brands or styles of coffee are more acidic than others. Low acid varieties may not stimulate the release of as much stomach acid. Brewing with hot water may produce more acidic coffee. Cold-brewing is a viable alternative, but tends to take longer than hot-brewing. Using cold water to make coffee involves steeping coffee grounds in cold water for three to four hours, or overnight before straining them from the beverage.
Coffee allergy may be another source of the connection between coffee and upset stomach. Coffee contains tannins. Moderate symptoms of a tannin allergy include upset stomach. Pesticides and herbicides used during the growing phase are also linked to allergic reactions.
If coffee and upset stomach is a problem, alternatives to traditional coffee are available. Tea and soy coffee are two that are widely available in many grocery markets throughout the world. Before skipping coffee for good, other causes of upset stomach, like dairy or caffeine sensitivity, can be ruled out.
