fredag 17 oktober 2014

Glycemic index: overview of implications in health and disease


The glycemic index concept is an extension of the fiber hypothesis, suggesting that fiber consumption reduces the rate of nutrient influx from the gut. Theglycemic index has particular relevance to those chronic Western diseases associated with central obesity and insulin resistance. Early studies showed that starchy carbohydrate foods have very different effects on postprandial blood glucose and insulin responses in healthy and diabetic subjects, depending on the rate of digestion. A range of factors associated with food consumption was later shown to alter the rate of glucose absorption and subsequent glycemia and insulinemia. At this stage, systematic documentation of the differences that exist among carbohydrate foods was considered essential. The resulting glycemic indexclassification of foods provided a numeric physiologic classification of relevant carbohydrate foods in the prevention and treatment of diseases such as diabetes. Since then, low-glycemic-index diets have been shown to lower urinary C-peptide excretion in healthy subjects, improve glycemic control in diabetic subjects, and reduce serum lipids in hyperlipidemic subjects. Furthermore, consumption of low-glycemicindex diets has been associated with higher HDL-cholesterol concentrations and, in large cohort studies, with decreased risk of developing diabetes and cardiovascular disease. Case-control studies have also shown positive associations between dietary glycemic index and the risk of colon and breast cancers. Despite inconsistencies in the data, sufficient, positive findings have emerged to suggest that the dietary glycemic index is of potential importance in the treatment and prevention of chronic diseases.

David JA Jenkins, Cyril WC Kendall, Livia SA Augustin, Silvia Franceschi, Maryam Hamidi, Augustine Marchie, Alexandra L Jenkins, and Mette Axelsen
Glycemic index: overview of implications in health and disease
Am J Clin Nutr 2002 76: 1 266S-273S

söndag 12 oktober 2014

Metabolic reprogramming induced by ketone bodies diminishes pancreatic cancer cachexia


Thus, our studies demonstrate that the cachectic phenotype is in part due to metabolic alterations in tumor cells, which can be reverted by a ketogenic diet, causing reduced tumor growth and inhibition of muscle and body weight loss

torsdag 9 oktober 2014

Biomarkers of essential fat... [Cancer Epidemiol Biomarkers Prev. 1996] - PubMed - NCBI

These data suggest that linoleic acid consumption may increase prostate cancer risk, which is consistent with results from animal experiments. Linoleic acid is found in vegetable oils used in cooking and in cereals, snack foods, and baked goods. Our data failed to demonstrate consistently a protective effect of marine omega-3 fatty acids on prostate cancer.

The association of fatty acids with prostate cancer risk - PubMed - NCBI

Results are consistent with other studies showing that linoleic and total omega-6 fatty acids increase risk of prostate cancer. Contrary to animal studies, alpha-linolenic acid was also positively associated with risk. Further research will be required to clarify the role of these fatty acids in human prostate cancer.

A Prospective Study of Trans-Fatty Acid Levels in Blood and Risk of Prostate Cancer

Blood levels of all the trans-fatty acids examined were unrelated to total prostate cancer risk. When results were divided according to tumor aggressiveness, blood levels of 18:1n-9t, all the 18:2t examined, and total trans-fatty acids were positively associated to nonaggressive tumors. The relative risks (95% confidence intervals; P trend) comparing top with bottom quintile trans-fatty acid levels were 2.16 (1.12-4.17; 0.11) for 18:1n-9t, 1.97 (1.03-3.75; 0.01) for total 18:2t, and 2.21 (1.14-4.29; 0.06) for total trans-fatty acids. None of the trans fats examined was associated with aggressive prostate tumors.
Conclusion: Blood levels of trans isomers of oleic and linoleic acids are associated with an increased risk of nonaggressive prostate tumors. As this type of tumors represents a large proportion of prostate cancer detected using prostate-specific antigen screening, these findings may have implications for the prevention of prostate cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(1):95–101)

The Secret to Heart Health Is Avoiding Sugar | Marcelle Pick, OB-GYN N.P.

onsdag 8 oktober 2014

Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base - Nutrition


The inability of current recommendations to control the epidemic of diabetes, the specific failure of the prevailing low-fat diets to improve obesity, cardiovascular risk, or general health and the persistent reports of some serious side effects of commonly prescribed diabetic medications, in combination with the continued success of low-carbohydrate diets in the treatment of diabetes and metabolic syndrome without significant side effects, point to the need for a reappraisal of dietary guidelines. The benefits of carbohydrate restriction in diabetes are immediate and well documented. Concerns about the efficacy and safety are long term and conjectural rather than data driven. Dietary carbohydrate restriction reliably reduces high blood glucose, does not require weight loss (although is still best for weight loss), and leads to the reduction or elimination of medication. It has never shown side effects comparable with those seen in many drugs. Here we present 12 points of evidence supporting the use of low-carbohydrate diets as the first approach to treating type 2 diabetes and as the most effective adjunct to pharmacology in type 1. They represent the best-documented, least controversial results. The insistence on long-term randomized controlled trials as the only kind of data that will be accepted is without precedent in science. The seriousness of diabetes requires that we evaluate all of the evidence that is available. The 12 points are sufficiently compelling that we feel that the burden of proof rests with those who are opposed.