Diet and risk of Type II diabetes: the role of types of fat and carbohydrate

Abstract

The prevalence of Type II (non-insulin-dependent) diabetes mellitus is increasing rapidly in the United States [1] and worldwide [2]. Prevalence of diabetes in adults in the world is estimated to reach 5.4 % and the number of adults with diabetes to reach 300 million worldwide in the year 2025 [2]. The toll of diabetes on health and the economy is enormous and will continue to rise. Because there is no currently available cure for diabetes, primary prevention through diet and lifestyle modification is of paramount importance.Although diet and nutrition are widely believed to play an important part in the development of Type II diabetes, specific dietary factors have not been clearly defined. Much controversy exists about the relation between the amount and types of dietary fat and carbohydrate and the risk of diabetes. Prevailing dietary recommendations promote low-fat, high-carbohydrate diets for the prevention of diabetes, heart disease, and other chronic diseases [3,4]. However, neither dietary fats nor carbohydrates are homogeneous molecules and it is now increasingly appreciated that different types of fat and carbohydrate have different effects on glucose homeostasis and insulin sensitivity. We review in detail the current evidence regarding the association between types of fat and carbohydrates and insulin resistance and Type II diabetes. We specifically discuss the roles of major types of fat, trans-fatty acids and n-3 fatty acids, as well as different types of carbohydrate and fiber, in the development of insulin resistance and Type II diabetes.We searched the Medline database for epidemiologic investigations of the associations between dietary fat and carbohydrate and the risk of developing hyperglycaemia and Type II diabetes. We also carefully examined the cited references in the articles Diabetologia (2001) AbstractAlthough diet and nutrition are widely believed to play an important part in the development of Type II (non-insulin-dependent) diabetes mellitus, specific dietary factors have not been clearly defined. Much controversy exists about the relations between the amount and types of dietary fat and carbohydrate and the risk of diabetes. In this article, we review in detail the current evidence regarding the associations between different types of fats and carbohydrates and insulin resistance and Type II diabetes. Our findings indicate that a higher intake of polyunsaturated fat and possibly long-chain n-3 fatty acids could be beneficial, whereas a higher intake of saturated fat and trans-fat could adversely affect glucose metabolism and insulin resistance. In dietary practice, exchanging nonhydrogenated polyunsaturated fat for saturated and trans-fatty acids could appreciably reduce risk of Type II diabetes. In addition, a low-glycaemic index diet with a higher amount of fiber and minimally processed whole grain products reduces glycaemic and insulinaemic responses and lowers the risk of Type II diabetes. Dietary recommendations to prevent Type II diabetes should focus more on the quality of...

High-fibre, low-fat diet predicts long-term weight loss and decreased type 2 diabetes risk: the Finnish Diabetes Prevention Study

“…Type of fat (namely, high saturated and trans-fatty acid and low unsaturated fatty acid intake), rather than total fat intake, has in several studies been associated with increased diabetes risk [48]. In our study the total and saturated fat intakes were highly correlated (r=0.81) and the intake of mono-unsaturated fat remained relatively stable throughout the study.…”

The Pro12Ala polymorphism of the PPAR-γ2 gene affects associations of fish intake and marine n−3 fatty acids with glucose metabolism

“…Although the controversy in earlier data concerning marine fatty acids and glucose metabolism (Salomaa et al, 1990;Feskens et al, 1991Feskens et al, , 1995Borkman et al, 1993;Adler et al, 1994;Vessby et al, 1994aVessby et al, , b, 2001Pan et al, 1995;Marshall et al, 1997;Baur et al, 1998;Gustafsson et al, 1998;Bjerregaard et al, 2000;Ekblond et al, 2000;Mori et al, 2000;Hu et al, 2001;Salmeró n et al, 2001;Dewailly et al, 2001a, b;van Dam et al, 2002;Wang et al, 2003;Harding et al, 2004;Thorsdottir et al, 2004) may be partly explained by different doses and durations of supplementation in intervention studies, and by different background diets between the study populations, inclusion of subjects with different PPARG Pro12Ala genotypes could also influence the outcome of the study. That PPARG genotype may affect the associations of dietary fat composition with insulin concentrations (Luan et al, 2001) and serum triacylglycerol response to fish oil supplementation (Lindi et al, 2003) was suggested previously.…”

“…Especially, long-chain nÀ3 polyunsaturated fatty acids have been found to be associated with enhanced glucose metabolism (Feskens et al, 1991;Adler et al, 1994;Feskens et al, 1995;Baur et al, 1998;Ekblond et al, 2000;Hu et al, 2001;Salmeró n et al, 2001;Thorsdottir et al, 2004) and to lower serum free fatty acid (FFA) concentrations (Gustafsson et al, 1998), although there are also contradictory results (Salomaa et al, 1990;Borkman et al, 1993;Vessby et al, 1994aVessby et al, , b, 2001Pan et al, 1995;Marshall et al, 1997;Bjerregaard et al, 2000;Mori et al, 2000;Dewailly et al, 2001a, b;van Dam et al, 2002;Wang et al, 2003;Harding et al, 2004). It is not known whether some of the discrepancies in previous results could be attributed to differences in the genetic background of the subjects.…”

Food consumption and the incidence of type II diabetes mellitus

“…High fat intake may contribute to the development of diabetes via obesity. Findings of several studies suggest that higher intake of polyunsaturated fat and possibly long-chain n-3 fatty acids could be beneficial in prevention of type II diabetes, whereas higher intake of saturated fat and trans-fat may be detrimental (Hu et al, 2001b). Other dietary factors that have been related to reduced risk of type II diabetes include coffee (van Dam & Feskens, 2002;Tuomilehto et al, 2004), dairy products , and vitamin D (Baynes et al, 1997).…”