The Acute Effect of Coffee Consumption on Stomach, Self-reported Gastrointestinal Symptoms and Stress.

The Acute Effect of Coffee Consumption on Salivary Gastrin, Alpha-amylase and Cortisol Concentrations, on Self-reported Gastrointestinal Symptoms, on Self-reported Psychometric Assessments and on Blood Pressure.

This study investigated the acute effect of the consumption of four different kinds of coffee (hot and cold instant coffee, cold espresso and hot filter coffee) with the same caffeine content on salivary gastrin, cortisol and alpha-amylase concentrations, on self-reported gastrointestinal symptoms and on psychometric assessments in healthy individuals.

Coffee consumption is very common in Greece. Many of the consumers support that certain types of coffee and especially instant coffee cause gastrointestinal symptoms in healthy individuals. Up to now, few studies have investigated the relationship between coffee consumption, gastrointestinal symptoms and stress in healthy individuals with conflicting results.Coffee consumption is related with increased gastric acid and gastrin secretion, however it does not seem to affect stomach or stomach walls. Stress, which characterizes modern lifestyle, also is found to increase gastric acid and gastrin secretion and seems to be exclusively responsible for gastrointestinal symptoms.

Inclusion Criteria:

• Stable body weight for at least 1 month prior to study enrollment.

Exclusion Criteria:

• If one volunteer consumed breakfast more than three days a week, their daily caffeine intake was over 500 mg caffeine, was taking medication, their psychological state was strongly influenced by some exogenous factor (e.g. moving to a new house, new job, divorce e.t.c.), was on hypocaloric diet for weight loss, was smoking more than five cigarettes a day, was an athlete with very vigorous physical activity (> 4 hours vigorous exercise a day), had a history of gastrointestinal disorders (e.g. gastroesophageal reflux disease (GERD), irritable bowel syndrome, diarrhea, ulcers e.t.c.), depression, diabetes, kidney disease, hypertension, blood disorders, liver disease, unregulated hyper - or hypothyroidism, arrhythmia, heart disease, cancer, vascular disease, recent surgery, or severe psychiatric disorders was automatically excluded from the study.