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Background and Aims: The positive and negative health effects of dietary carbohydrates are of interest to both researchers and consumers.Methods: International experts on carbohydrate research held a scientific summit in Stresa, Italy, in June 2013 to discuss controversies surrounding the utility of the glycemic index (GI), glycemic load (GL) and glycemic response (GR).Results: The outcome was a scientific consensus statement which recognized the importance of postprandial glycemia in overall health, and the GI as a valid and reproducible method of classifying carbohydrate foods for this purpose. There was consensus that diets low in GI and GL were relevant to the prevention and management of diabetes and coronary heart disease, and probably obesity. Moderate to weak associations were observed for selected cancers. The group affirmed that diets low in GI and GL should always be considered in the context of diets otherwise understood as healthy, complementing additional ways of characterizing carbohydrate foods, such as fiber and whole grain content. Diets of low GI and GL were considered particularly important in individuals with insulin resistance.Conclusions: Given the high prevalence of diabetes and pre-diabetes worldwide and the consistency of the scientific evidence reviewed, the expert panel confirmed an urgent need to communicate information on GI and GL to the general public and health professionals, through channels such as national dietary guidelines, food composition tables and food labels. [ABSTRACT FROM AUTHOR]

BACKGROUND: Consumption of 3 g oat [beta]-glucan/d is considered sufficient to lower serum LDL cholesterol, but some studies have shown no effect. LDL cholesterol lowering by oat [beta]-glucan may depend on viscosity, which is controlled by the molecular weight (MW) and amount of oat [beta]-glucan solubilized in the intestine (C). OBJECTIVES: Our 2 primary objectives were to determine whether consumption of 3 g high-MW oat [beta]-glucan/d would reduce LDL cholesterol and whether LDL cholesterol lowering was related to the log(MW x C) of oat [beta]-glucan. DESIGN: In a double-blind, parallel-design, multicenter clinical trial, subjects with LDL cholesterol >=3.0 and <=5.0 mmol/L (n = 786 screened, n = 400 ineligible, n = 19 refused, n = 367 enrolled, and n = 345 completed) were randomly assigned to receive cereal containing wheat fiber (n = 87) or 3 g high-MW (2,210,000 g/mol, n = 86), 4 g medium-MW (850,000 g/mol, n = 67), 3 g medium-MW (530,000 g/mol, n = 64), or 4 g low-MW (210,000 g/mol, n = 63) oat [beta]-glucan/d (divided doses, twice daily) for 4 wk. RESULTS: LDL cholesterol was significantly less with 3 g high-MW, 4 g medium-MW, and 3 g medium-MW oat [beta]-glucan cereals than with the wheat-fiber cereal by 0.21 (5.5%; 95% CI: -0.11, -0.30; P = 0.002), 0.26 (6.5%; 95% CI: -0.14, -0.37; P = 0.0007), and 0.19 (4.7%; 95% CI: -0.08, -0.30; P = 0.01) mmol/L, respectively. However, the effect of 4 g low-MW oat [beta]-glucan/d (0.10 mmol/L) was not significant (2.3%; 95% CI: 0.02, -0.20). By analysis of covariance, log(MW x C) was a significant determinant of LDL cholesterol (P = 0.003). Treatment effects were not significantly influenced by age, sex, study center, or baseline LDL cholesterol. CONCLUSIONS: The physicochemical properties of oat [beta]-glucan should be considered when assessing the cholesterol-lowering ability of oat-containing products; an extruded breakfast cereal containing 3 g oat [beta]-glucan/d with a high-MW (2,210,000 g/mol) or a medium-MW (530,000 g/mol) lowered LDL cholesterol similarly by ~=0.2 mmol/L (5%), but efficacy was reduced by 50% when MW was reduced to 210,000 g/mol. This trial was registered at www.clinicaltrials.gov as NCT00981981. Copyright © 2010 American Society for Nutrition [ABSTRACT FROM AUTHOR]

Prospective evidence on the extent to which serum lipid concentrations in older persons respond to dietary modification is scarce. It is not clear whether such behavioral changes are relevant in the context of more commonly initiated treatments with lipid-lowering drugs. We therefore examined whether individual changes in the consumption of dietary fatty acids or main food sources were associated with changes in the serum lipid profile of older Australians. A total of 903 participants (> or =49 y) in the Blue Mountains Eye Study had complete data on fasting lipids and dietary intake from a validated FFQ at baseline (1992-1994) and 5- and 10-y follow-up examinations. Decreasing consumption of SFA and butter during the 10-y period were associated with moderate decreases in serum total cholesterol independently of initiation of lipid-lowering drug treatment [adjusted estimates were 0.018 +/- 0.007 mmol/(L x % energy (%en) from SFA (P = 0.01) and 0.055 +/- 0.015 mmol/(L x 5 g butter) (P = 0.0003), respectively]. Increased consumption of (n-3) fatty acids and fish was independently related to modest increases in serum HDL-cholesterol [0.067 +/- 0.026 mmol/(L x %en from (n-3) fatty acids) (P = 0.01) and 0.010 +/- 0.004 mmol/(L x 20 g fish) (P = 0.02)] and decreases in log-transformed serum triglyceride concentrations [P = 0.02 for (n-3) fatty acids and P = 0.02 for fish intake]. Hence, 10-y changes in the intake of dietary fatty acids and their food sources appear to have contributed to concurrent improvements in the serum lipid profile of older Australians, independent of concomitantly initiated lipid-lowering drug treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: High-glycemic index diets have been linked to greater risk of cardiovascular disease and type 2 diabetes. Postprandial glycemia within the normal range may promote oxidative stress and inflammatory processes underlying the development of disease. OBJECTIVE: We explored acute differences in the activation of the inflammatory marker nuclear factor-kappaB after consumption of 2 carbohydrate meals matched for macronutrient and micronutrient composition but differing in glycemic index. DESIGN: After an overnight fast, 10 young, lean healthy subjects were fed in random order 3 meals providing 50 g of available carbohydrate as glucose, white bread, or pasta. Venous blood samples were collected at 0, 1, 2, and 3 h, and nuclear proteins were extracted from mononuclear cells. Changes in nuclear factor-kappaB-p65 proteins were detected by Western blotting. Acute changes in other markers of oxidative stress (nitrotyrosine and soluble intercellular adhesion molecule-1) were also assessed. RESULTS: The maximum increase in nuclear factor-kappaB activation was similar after the bread meal [mean (+/-SEM) area under the curve: 69 +/- 16% optical density x h] and the glucose challenge (75 +/- 9% optical density x h), but was 3 times higher than after the pasta meal (23 +/- 5% optical density x h) (P < 0.05). Similarly, changes in nitrotyrosine, but not soluble intercellular adhesion molecule-1, were higher after glucose and bread than after pasta (P = 0.01 at 2 h). CONCLUSIONS: The findings suggest that high-normal physiologic increases in blood glucose after meals aggravate inflammatory processes in lean, young adults. This mechanism may help to explain relations between carbohydrates, glycemic index, and the risk of chronic disease. Copyright © 2008 American Society for Nutrition [ABSTRACT FROM AUTHOR]

BACKGROUND: The concentration of sialic acid in brain gangliosides and glycoproteins has been linked to learning ability in animal studies. Human milk is a rich source of sialic acid-containing oligosaccharides and is a potential source of exogenous sialic acid. OBJECTIVE: The aim of the study was to compare the sialic acid concentration in the brain frontal cortex of breastfed and formula-fed infants. DESIGN: Twenty-five samples of frontal cortex derived from infants who died of sudden infant death syndrome were analyzed. Twelve infants were breastfed, 10 infants were formula-fed, and 1 infant was mixed-fed; the feeding status of the remaining 2 infants was unknown. Ganglioside-bound and protein-bound sialic acid were determined by HPLC. Ganglioside ceramide fatty acids were also analyzed to determine the relation between sialic acid and long-chain polyunsaturated fatty acids. RESULTS: After adjustment for sex with age at death as a covariate, ganglioside-bound and protein-bound sialic acid concentrations were 32% and 22% higher, respectively, in the frontal cortex gray matter of breastfed infants than in that of formula-fed infants (P < 0.01). Protein-bound sialic acid increased with age in both groups (P = 0.02). In breastfed but not in formula-fed infants, ganglioside-bound sialic acid correlated significantly with ganglioside ceramide docosahexaenoic acid and total n-3 fatty acids. CONCLUSIONS: Higher brain ganglioside and glycoprotein sialic acid concentrations in infants fed human milk suggests increased synaptogenesis and differences in neurodevelopment. Copyright © 2003 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

In rats, prolonged feeding of high glycemic index (GI) starch results in basal hyperinsulinemia and an elevated insulin response to an intravenous glucose tolerance test (IVGTT). The aim of this study was to assess hepatic and peripheral insulin resistance (IR) using euglycemic hyperinsulinemic clamps. Insulin sensitivity, epididymal fat deposition and fasting leptin concentrations were compared in rats fed isocalorically a low or high GI diet for 7 wk (45% carbohydrate, 35% fat and 20% protein as energy) or a high fat diet (20% carbohydrate, 59% fat and 21% protein as energy) for 4 wk so that final body weights were similar. At the end of the study, high GI rats had higher basal leptin concentration and epididymal fat mass than the low GI group, despite comparable body weights. High GI and high fat feeding both resulted in the higher insulin response during IVGTT, but impaired glucose tolerance was seen only in rats fed high fat. The GI of the diet did not affect basal and clamp glucose uptake or hepatic glucose output, but high fat feeding induced both peripheral and hepatic IR. The findings suggest that hypersecretion of insulin without IR may be one mechanism for increased fat deposition in rats fed high GI diets. [ABSTRACT FROM AUTHOR]