Facing the increasing prevalence of type 2 diabetes worldwide in the past few decades, one may ask what is wrong with humans. Geneticists tell us that the human genome has not changed markedly in such a short time. Therefore, something must be happening in our environment or diet. As a matter of fact, dietary pattern is known to be closely linked to the development of type 2 diabetes. The increasing prevalence of type 2 diabetes following worldwide food fortification with niacin suggests that type 2 diabetes may involve excessive niacin intake.
A research article to be published on December 7, 2009 in the World Journal of Gastroenterology addresses the association between nicotinamide overload and type 2 diabetes. The study revealed that diabetic patients have a slow nicotinamide metabolism and thus require a longer time to clear up excess nicotinamide metabolites within the body. High nicotinamide intake may lead to an increase the generation of reactive oxygen species, and subsequent oxidative stress and insulin resistance, both being the major features of type 2 diabetes. Liver is the main organ responsible for nicotinamide detoxification. This study found that liver-injury-inducing drugs may reduce nicotinamide detoxification and thus impair glucose tolerance. Most interestingly and importantly, this study demonstrates that sweating is an effective way for expelling excess nicotinamide from the body. The findings from this study may help explain a wide variety of well-documented but poorly understood phenomena in diabetes, such as lifestyle-triggered diabetes, liver-disease-related abnormal glucose metabolism, post-burn insulin resistance, and seasonal diabetes.