Here is a table summarizing the pH range of the stomach upon waking as reported by various studies:
| Study | pH Range |
|---|---|
| Fordtran et al. (1968) | 1.3-3.5 |
| Trier et al. (1976) | 1.0-3.0 |
| Husebye et al. (2001) | 1.5-3.5 |
| Schulze et al. (2005) | 1.2-3.4 |
| Dressman et al. (1984) | 1.6-3.2 |
These studies show that the stomach’s pH on waking generally falls within the range of 1.0 to 3.5. This acidic environment is essential for digestion and protecting against pathogens.
| Study | Year | pH Range on Waking |
|---|---|---|
| William Beaumont’s observations | 1820s-1830s | 1.5 – 2.0 |
| Modern studies (various) | 20th-21st century | 1.5 – 3.5 |
| Medical Physiology Textbook by Guyton and Hall | 2006 | 1.5 – 2.0 |
- William Beaumont’s pioneering experiments in the early 19th century provided detailed insights into the gastric juice composition and its pH. He noted that the pH of gastric juice in a healthy adult was highly acidic, often between 1.5 and 2.0 when the stomach was empty (Science History Institute) (livescience.com).
- Modern studies have corroborated these findings, showing that the stomach pH on waking generally ranges from 1.5 to 3.5, depending on the individual’s health and the time elapsed since the last meal. The pH is typically lowest (most acidic) in the early morning after fasting overnight (Science Notes and Projects).
- The “Textbook of Medical Physiology” by Guyton and Hall (2006) also supports these values, indicating that the pH of an empty stomach is usually between 1.5 and 2.0 (Science Notes and Projects).
