Low carbohydrate diets in family practice: what can we learn from an internet-based support group

The Active Low-Carber Forums (ALCF) is an on-line support group started in 2000 which currently has more than 86,000 members. Data collected from posts to the forum and from an on-line survey were used to determine the behavior and attitudes of people on low carbohydrate diets. Members were asked to complete a voluntary 27-item questionnaire over the internet. Our major findings are as follows: survey respondents, like the membership at large, were mostly women and mostly significantly overweight, a significant number intending to and, in many cases, succeeding at losing more than 100 lbs. The great majority of members of ALCF identify themselves as following the Atkins diet or some variation of it. Although individual posts on the forum and in the narrative part of our survey are critical of professional help, we found that more than half of respondents saw a physician before or during dieting and, of those who did, about half received support from the physician. Another 28 % found the physician initially neutral but supportive after positive results were produced. Using the same criteria as the National Weight Registry (without follow-up) – 30 lbs or more lost and maintained for more than one year – it was found that more than 1400 people had successfully used low carb methods. In terms of food consumed, the perception of more than half of respondents were that they ate less than before the diet and whereas high protein, high fat sources replaced carbohydrate to some extent, the major change indicated by survey-takers is a large increase in green vegetables and a large decrease in fruit intake. Government or health agencies were not sources of information for dieters in this group and a collection of narrative comments indicates a high level of satisfaction, indeed enthusiasm for low carbohydrate dieting. The results provide both a tabulation of the perceived behavior of a significant number of dieters using low carbohydrate strategies as well as a collection of narratives that provide a human perspective on what it is like to be on such a diet. An important conclusion for the family physician is that it becomes possible to identify a diet that is used by many people where the primary principle is replacement of starch and sugar-containing foods with non-starchy vegetables, with little addition of fat or protein. Used by many people who identify themselves as being on the Atkins diet, such a strategy provides the advantages of carbohydrate-restricted diets but is less iconoclastic than the popular perception and therefore more acceptable to traditional nutritionists. It is reasonable for family practitioners to turn this observation into a recommendation for patients for weight control and other health problems

Interrelations of platelet aggregation and secretion.

A B S T R A C T The mechanism of stimulus-response coupling in human platelets was investigated with a new instrument that simultaneously monitors aggregation and secretion in the same sample of plateletrich plasma. When platelets were stimulated by high concentrations of ADP, secretion began only after aggregation was almost complete. With lower concentrations of ADP or with epinephrine, biphasic aggregation was observed, and secretion began simultaneously with, or slightly after, the second phase of aggregation. When platelets were stimulated with high concentrations of y-thrombin or A23187, secretion and aggregation began essentially together. With very low concentrations of y-thrombin or A23187, biphasic aggregation was observed with secretion paralleling the second phase. At every concentration of collagen, secretion and aggregation appeared to be parallel events. Under every condition where the beginning of secretion lagged behind aggregation, secretion was dependent upon aggregation and was inhibited by indomethacin; this is referred to as aggregation-mediated platelet activation. When secretion began at the same time as aggregation, it also occurred in the absence of aggregation and was not blocked by indomethacin; this is referred to as directly induced platelet activation. These observations are -consistent with a simple model of platelet stimulusresponse coupling that includes two mechanisms for activation; aggregation-mediated activation is inhibited by indomethacin, while direct activation does not depend upon aggregation and is not inhibited by indomethacin. Secretion and second wave aggregation appear to be parallel events, with little evidence for second wave aggregation being a consequence of secretion as usually described

The scale, governance, and sustainability of central places in pre-Hispanic Mesoamerica

Examinations of the variation and relative successes or failures of past large-scale societies have long involved attempts to reconcile efforts at generalization and the identification of specific factors with explanatory value for regional trajectories. Although historical particulars are critical to understanding individual cases, there are both scholarly and policy rationales for drawing broader implications regarding the growing corpus of cross-cultural data germane to understanding variability in the constitution of human societies, past and present. Archaeologists have recently highlighted how successes and failures in communal-resource management can be studied over the long term through the material record to both engage and enhance transdisciplinary research on cooperation and collective action. In this article we consider frameworks that have been traditionally employed in studies of the rise, diversity, and fall of preindustrial urban aggregations. We suggest that a comparative theoretical perspective that foregrounds collective-action problems, unaligned individual and group interests, and the social mechanisms that promote or hamper cooperation advances our understanding of variability in these early cooperative arrangements. We apply such a perspective to an examination of pre-Hispanic Mesoamerican urban centers to demonstrate tendencies for more collective systems to be larger and longer lasting than less collective ones, likely reflecting greater sustainability in the face of the ecological and cultural perturbations specific to the region and era.Accepted manuscrip

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

AbstractThe 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

Physiogenomic analysis of weight loss induced by dietary carbohydrate restriction

BACKGROUND: Diets that restrict carbohydrate (CHO) have proven to be a successful dietary treatment of obesity for many people, but the degree of weight loss varies across individuals. The extent to which genetic factors associate with the magnitude of weight loss induced by CHO restriction is unknown. We examined associations among polymorphisms in candidate genes and weight loss in order to understand the physiological factors influencing body weight responses to CHO restriction. METHODS: We screened for genetic associations with weight loss in 86 healthy adults who were instructed to restrict CHO to a level that induced a small level of ketosis (CHO ~10% of total energy). A total of 27 single nucleotide polymorphisms (SNPs) were selected from 15 candidate genes involved in fat digestion/metabolism, intracellular glucose metabolism, lipoprotein remodeling, and appetite regulation. Multiple linear regression was used to rank the SNPs according to probability of association, and the most significant associations were analyzed in greater detail. RESULTS: Mean weight loss was 6.4 kg. SNPs in the gastric lipase (LIPF), hepatic glycogen synthase (GYS2), cholesteryl ester transfer protein (CETP) and galanin (GAL) genes were significantly associated with weight loss. CONCLUSION: A strong association between weight loss induced by dietary CHO restriction and variability in genes regulating fat digestion, hepatic glucose metabolism, intravascular lipoprotein remodeling, and appetite were detected. These discoveries could provide clues to important physiologic adaptations underlying the body mass response to CHO restriction

Real-Time In Vivo Imaging of Early Mucosal Changes during Ischemia-Reperfusion in Human Jejunum

BACKGROUND AND STUDY AIMS: Small intestinal ischemia-reperfusion (IR) is a frequent, potentially life threatening phenomenon. There is a lack of non-invasive diagnostic modalities. For many intestinal diseases, visualizing the intestinal mucosa using endoscopy is gold standard. However, limited knowledge exists on small intestinal IR-induced, early mucosal changes. The aims of this study were to investigate endoscopic changes in human jejunum exposed to IR, and to study concordance between endoscopic appearance and histology. PATIENTS AND METHODS: In 23 patients a part of jejunum, to be removed for surgical reasons, was isolated and selectively exposed to ischemia with 0, 30 or 120 minutes of reperfusion. In 3 patients, a videocapsule was inserted in the isolated segment before exposure to IR, to visualize the mucosa. Endoscopic view at several time points was related to histology (Heamatoxylin & Eosin) obtained from 20 patients. RESULTS: Ischemia was characterized by loss of villous structure, mucosal whitening and appearance of punctate lesions. This was related to appearance of subepithelial spaces and breaches in the epithelial lining in the histological view. Early during reperfusion, the lumen filled with IR-damaged, shed cells and VCE showed mucosal erosions, hemorrhage and intraluminal debris. At 60 minutes of reperfusion, the only remaining signs of IR were loss of villous structure and small erosions, indicating rapid mucosal healing. CONCLUSIONS: This study shows a unique, real-time in vivo endoscopic view of early mucosal changes during IR of the human small intestine. Future studies should evaluate its usefulness in diagnosis of patients suspected of IR