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Nocturnal Admission The human body does not digest food well in the night, even if lunch is at 3am By Dara Colwell EATING CAN BE PROBLEMATIC for night workers, who statistically suffer from higher rates of gastrointestinal problems than those who work during the day. The reason stems from the body's circadian rhythm, or internal biological clock, which regulates the sleep/wake cycle, body temperature, digestive secretions and hormone production. Simply put, it is hard for the body to digest food at night. Geared by millions of years of evolution, our digestive rhythms anticipate meals at their traditional times, not at the twilight hours. Without sleep, the central nervous system becomes more active, inhibiting the pancreas from producing adequate insulin, the hormone the body needs to digest glucose. The graveyard shift is also hard on the heart. Researchers have found that the nerve and chemical messages that control the heart's activity stick closely to a 24-hour pattern. Cortisol, a stimulant hormone that drives the nerve systems that keep the heart rate, digestive system, breathing and other functions running at a faster pace during the day, is lower at night. The level of Cortisol levels do not shift with a worker's nighttime schedule. A study by Ichiro Kawachi found that American nurses who worked rotating shifts for six years or more had a 51 percent risk of coronary heart disease. And what's more, too little sleep, in a period as short as a week, can lead to the deterioration in overnight levels of cortisol. This affects the body's metabolism and hormone levels by mimicking the effects of aging. [ San Jose | Metroactive Central | Archives ]