根据英国的研究，人体的胃和小肠到了晚上会产生一种化学物质（TFF2蛋白质）以修复破裂之处。当一个人晚上睡眠不足时，久而久之会减少这种物质的产生，因而增加胃溃疡的患病几率，并刺激胃癌基因的生长。专家表示，睡眠不好以及作息不规律会导致植物神经调节功能紊乱，因为肠胃都是在神经调节下运作的。因此，熬夜会影响肠胃消化吸收，长期以来，癌变的可能性就会大幅上升。
专家表示，早就有研究表明，癌症的发生与睡眠有密切的关系。美国斯坦福大学医学研究中心的科学家们研究证明，睡眠与不眠之间的循环周期会对某些激素的分泌产生影响，而人体组织中的各项生命活动都受到特定激素指数的调控。夜间，人体会产生一种褪黑激素，它拥有的抗氧化性能可保护脱氧核糖核酸（DNA）不受氧化物的损害，同时也能抑制雌激素的产生，而这种雌激素会促使肿瘤的生长和发展。
此外，身体还有一种激素－－可的松（Cortisone）会对肿瘤细胞产生影响。这种激素分泌量高的时间是在凌晨，而白天则会下降。它能够对人体的免疫力系统产生巨大的影响，也影响到人体对肿瘤的抵抗。因此，可的松的分泌规律一旦遭到破坏，就会导致机体组织免疫 系统被破坏，也导致肿瘤细胞极容易生长。
Staying up late increases the chances of stomach cancer
According to the research done in England, the stomach and small intestine will produce a chemical substance (TFF2 protein) at night to repair any rupture there can be found. When a person is lack of sleep, the production of this substance will gradually reduce and the risk of gastric ulcer will increase.
This will in turn stimulate the growth of gastric cancer genes. Experts pointed out that poor quality sleep and irregular daily routine can lead to autonomic dysfunction as the gastrointestinal tract operates under the regulation of the nerve. Hence, staying up late will affect the gastrointestinal digestion and absorption.
The possibility of cancer will increase substantially over a period of time.
Experts also said that studies have long shown that the occurrence of cancer is closely related to sleep. The scientists at the Stanford University Medical Research Centre have proven that the cycle between sleep and sleeplessness will affect the secretion of certain hormones as well as the biological activities in human tissues, which are regulated by these specific hormones.
During the night, the body will produce melatonin which has antioxidant properties that can protect the deoxyribonucleic acid (DNA) from being destroyed. It can also inhibit the production of estrogen which causes the growth and development of tumour.
In addition, there is a hormone in the body, cortisone, which has an impact on tumour cells. The secretion of cortisone is particularly vigorous in the small hours of the morning, however, it will drastically slow down during the day. This has a significant impact on the body’s immune system, and it affects one’s resistance to cancer. Therefore, once the secretion of cortisone is disrupted, it will cause the destruction of the body immune system and lead to the growth of tumour cells