Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements.

Abstract

"The negative impact of consuming sugar-sweetened beverages on weight and other health outcomes has been increasingly recognized; therefore, many people have turned to high-intensity sweeteners like aspartame, sucralose, and saccharin as a way to reduce the risk of these consequences. However, accumulating evidence suggests that frequent consumers of these sugar substitutes may also be at increased risk of excessive weight gain, metabolic syndrome, type 2 diabetes, and cardiovascular disease. This paper discusses these findings and considers the hypothesis that consuming sweet-tasting but noncaloric or reduced-calorie food and beverages interferes with learned responses that normally contribute to glucose and energy homeostasis. Because of this interference, frequent consumption of high-intensity sweeteners may have the counterintuitive effect of inducing metabolic derangements."

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Endocrine-Disrupting Chemicals: Associated Disorders and Mechanisms of Action

Abstract

"The incidence and/or prevalence of health problems associated with endocrine-disruption have increased. Many chemicals have endocrine-disrupting properties, including bisphenol A, some organochlorines, polybrominated flame retardants, perfluorinated substances, alkylphenols, phthalates, pesticides, polycyclic aromatic hydrocarbons, alkylphenols, solvents, and some household products including some cleaning products, air fresheners, hair dyes, cosmetics, and sunscreens. Even some metals were shown to have endocrine-disrupting properties. Many observations suggesting that endocrine disruptors do contribute to cancer, diabetes, obesity, the metabolic syndrome, and infertility are listed in this paper. An overview is presented of mechanisms contributing to endocrine disruption. Endocrine disruptors can act through classical nuclear receptors, but also through estrogen-related receptors, membrane-bound estrogen-receptors, and interaction with targets in the cytosol resulting in activation of the Src/Ras/Erk pathway or modulation of nitric oxide. In addition, changes in metabolism of endogenous hormones, cross-talk between genomic and nongenomic pathways, cross talk with estrogen receptors after binding on other receptors, interference with feedback regulation and neuroendocrine cells, changes in DNA methylation or histone modifications, and genomic instability by interference with the spindle figure can play a role. Also it was found that effects of receptor activation can differ in function of the ligand."

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The diet-heart hypothesis: a critique.

Abstract

"The low-fat "diet-heart hypothesis" has been controversial for nearly 100 years. The low-fat-high-carbohydrate diet, promulgated vigorously by the National Cholesterol Education Program, National Institutes of Health, and American Heart Association since the Lipid Research Clinics-Primary Prevention Program in 1984, and earlier by the U.S. Department of Agriculture food pyramid, may well have played an unintended role in the current epidemics of obesity, lipid abnormalities, type II diabetes, and metabolic syndromes. This diet can no longer be defended by appeal to the authority of prestigious medical organizations or by rejecting clinical experience and a growing medical literature suggesting that the much-maligned low-carbohydrate-high-protein diet may have a salutary effect on the epidemics in question."

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Limited effect of dietary saturated fat on plasma saturated fat in the context of a low carbohydrate diet.

Abstract

"We recently showed that a hypocaloric carbohydrate restricted diet (CRD) had two striking effects: (1) a reduction in plasma saturated fatty acids (SFA) despite higher intake than a low fat diet, and (2) a decrease in inflammation despite a significant increase in arachidonic acid (ARA). Here we extend these findings in 8 weight stable men who were fed two 6-week CRD (12%en carbohydrate) varying in quality of fat. One CRD emphasized SFA (CRD-SFA, 86 g/d SFA) and the other, unsaturated fat (CRD-UFA, 47 g SFA/d). All foods were provided to subjects. Both CRD decreased serum triacylglycerol (TAG) and insulin, and increased LDL-C particle size. The CRD-UFA significantly decreased plasma TAG SFA (27.48 ± 2.89 mol%) compared to baseline (31.06 ± 4.26 mol%). Plasma TAG SFA, however, remained unchanged in the CRD-SFA (33.14 ± 3.49 mol%) despite a doubling in SFA intake. Both CRD significantly reduced plasma palmitoleic acid (16:1n-7) indicating decreased de novo lipogenesis. CRD-SFA significantly increased plasma phospholipid ARA content, while CRD-UFA significantly increased EPA and DHA. Urine 8-iso PGF(2α), a free radical-catalyzed product of ARA, was significantly lower than baseline following CRD-UFA (-32%). There was a significant inverse correlation between changes in urine 8-iso PGF(2α) and PL ARA on both CRD (r = -0.82 CRD-SFA; r = -0.62 CRD-UFA). These findings are consistent with the concept that dietary saturated fat is efficiently metabolized in the presence of low carbohydrate, and that a CRD results in better preservation of plasma ARA."

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