Rumination syndrome the syndrome in mentally healthy patients appeared thereafter. At first, adult rumination was described and treated as a benign condition. It is now described as otherwise. While the base of patients to examine has gradually increased as more and more people come forward with their symptoms, awareness of the condition by the medical community and the general public is still limited. The chewing of cud by animals such as cows, goats, and giraffes is considered normal behavior. These animals are known as ruminants. Such behavior, though termed rumination, is not related to human rumination syndrome, but is ordinary. Involuntary rumination,
Chewing gum researchers noted that no improvement could be found for verbal fluency, which is in accordance with previous studies. This finding suggests that the effect of chewing gum is domain specific. The cognitive improvements after a period of chewing gum have been demonstrated to last for 15–20 minutes and decline afterwards. Sugar-free gum sweetened with xylitol has been shown to reduce cavities and plaque. The sweetener sorbitol has the same benefit, but is only about one-third as effective as xylitol. Other sugar substitutes, such as maltitol, aspartame and acesulfame K, have also been found to not cause tooth decay. Xylitol is