London: Deficiency of zinc can adversely impact the essential metabolic functions of most living organisms, finds a new study suggesting that even moderate levels of deficiency of the trace element can be bad for digestion. The findings showed that zinc deficiency in an animal's diet impedes pancreatic digestive activity and results in significant digestive impairment, even at an early stage. In humans, it has been known to increase the levels of inflammation markers and reduce immunocompetence -- the ability of the body to produce a normal immune response following exposure to an antigen. As zinc only exists in small amounts in an organism, it has to be consumed by way of nutrition, the researchers said. The beginning of zinc depletion usually goes unnoticed and without any visible symptoms, but minute changes can be identified in the liver and in the blood. Pancreas, known as the control centre for food digestion and energy homeostasis in the body, pumps zinc into the gastrointestinal tract in order to maintain a consistent zinc level. Conversely, if an organism is depleted of zinc, it reduces its pancreatic zinc excretion to a minimum. "The accumulation of undigested food inside the gastrointestinal tract due to zinc deficiency results in feeling less hungry," said lead author Daniel Brugger of the Chair of Animal Nutrition at Technical University of Munich (TUM) in Germany. "We proved that there is a direct correlation between the amount of digestive enzymes inside the pancreas and zinc levels in the organism as a whole," Brugger added in the paper published in the British Journal of Nutrition. For the purpose of this study, the team fed piglets that had just been weaned on a diet containing different amounts of zinc to develop early-stage zinc deficiency. On the one hand, it was observed that the body tried to absorb zinc more efficiently, while on the other it reduced pancreatic zinc excretion. "Even short intervals of zinc deficiency in the diet should be avoided," Brugger said, adding that particularly older adults need to monitor their zinc intake with foods that are high in zinc like seafood, spinach, pumpkin nuts, cocoa, chocolate and mushrooms.