Published Science

In a town in northern Sweden, 3.3% of the 15-year-old adolescents were vegans in 1996. This study describes the process of becoming a vegan among adolescents and interprets the informants' descriptions by constructing categories, which later on were related to relevant theories. Group interviews were conducted with three vegans and in-depth interviews were performed with three other vegan adolescents. The methodology was grounded theory and the adolescents' perceptions were analyzed in the framework of symbolic interactionism. Three types of vegans were identified: the Conformed Vegan, the Organized Vegan, and the Individualistic Vegan. The decision to become a vegan was reported to be influenced by perceived internal reasons such as ethics, health, distaste for meat, and preference for vegetarian food. In addition, friends, family, school, media, and music influenced the decision to become a vegan. The perceived consequences of becoming a vegan were positive as well as negative and differed between the three types of vegans. Veganism as a new type of status passage with specific characteristics was illustrated. No modifications or new properties were discovered that add to the theory of status passage which indicates that the general model is applicable also in a vegan context.

OBJECTIVE: Hearing impairment is a multifaceted condition with medical and social aspects. If the neuropsychiatric impact of deafness on children has been investigated by researchers from a variety of fields and backgrounds, their conclusion is that children with hearing impairment follow many different developmental pathways. The aim of this paper is to examine the relationships between hearing impairment and mental health and the effect of impaired communication on family development. METHOD: From a review of the literature, the authors examine the relationships between hearing impairment and mental disorders in children and adolescents in terms of prevalence, clinical features and etiological factors. The fami-ly dynamics and the parents-child interactions were also explored. RESULTS: The assessment of psychiatric disorders in hearing-impaired children sets some methodological pro-blems. Accurate evaluation is hampered by the immature language exhi-bited by many hearing-impaired children and by the difficulties that may be encountered in establishing rapport if the child does not understand the examiner's verbal exchanges. Several authors point out the lack of communication skills and experiences with hearing-impaired children on the part of many examiners. In addition, delays have been observed for the development of social maturity in hearing-impaired children and the parents' descriptions may reflect their own worries, rather than the emotional-behavioral functioning of the child. The measurement of psychiatric symptoms is then compromised insofar as many of the assessment procedures are highly verbal and were standardized for normal-hearing children. These difficulties may explain that the pre-valence rates of mental disorders in hearing-impaired children and adolescents found in the literature vary from 15% to 60%. If autism and deafness may both confound each others' dia-gnosis, several studies also point out the high comorbidity observed between these 2 conditions. The significance of this association remains unclear. Many of the authors conclude that hearing impairment is unlikely to be an etiological factor in autism. However, auditory impairment may be a marker for brain damage in autism. Although some studies showed high rates of depression and anxiety disorders, particularly social phobias, in deaf and hard-of-hearing children and adolescents, most of the studies conclude that the prevalence of affective disorders in hearing-impaired children and adolescents is comparable with estimates of prevalence for hearing young people. A number of studies have suggested that deaf children show greater degrees of impulsivity than hearing children. However, it seems that this background of greater impulsivity does not lead to higher rates of attention-deficit/hyperactivity disorder (ADHD) among deaf children. Using standardized instruments to estimate the prevalence of ADHD in this population, recent studies conclude that deaf children with hereditary deafness are not at greater risk of developing ADHD but that children with acquired deafness are, and that this difference is probably related to the medical conditions and family climates distinguishing these two groups. Psychotic disorders are no more common among hearing-impaired young people than among young people with normal hearing. However, some recent studies showed that the presentation of schizophrenia can differ in deaf people because of the high frequency of visual hallucinations observed in them. Lastly, if primitive personality has been described as being more prevalent among hearing-impaired children and adolescents, most of the studies found a normal range of emotional-behavioral functioning in them. In summary, if varying incidences of emotional disturbances and behavioral problems have been reported for hearing-impaired children and adolescents, except autism, it seems that children with hearing impairment experience the same range of mental health problems as hearing children. A variety of demographic, medical and educational factors were investigated as possible etiological factors for the psychiatric disorders observed in hearing-impaired children. Factors such as medical conditions, degree of deafness, communication ability and social deprivation may play a role. However, many studies also emphasize that a number of other variables, including educational methods, parental adaptation and parental support, may have an impact, positive or negative, on the development of the hearing-impaired child. By this way, numerous investigations have shown that deaf children of deaf parents attain better emotional and cognitive development than do deaf children of hearing parents. CONCLUSION: A number of questions remain about the neuropsychiatric and psychosocial aspects of hearing-impairment in children. For instance, few studies have been conducted to examine the impact of the different methods of communication and education on the psychosocial adjustment of deaf children. However, this review clearly show that appropriate and effective management can occur only when the mental health professionals are know-ledgeable and sensitive to the unique characteristics and experiences of hearing-impaired children and adolescents.

Although much is known about genetic variation in human and African great ape (chimpanzee, bonobo, and gorilla) genomes, substantially less is known about variation in gene-expression profiles within and among these species. This information is necessary ...

BACKGROUND: It is not clear whether varying the protein-to-carbohydrate ratio of weight-loss diets benefits body composition or metabolism. OBJECTIVE: The objective was to compare the effects of 2 weight-loss diets differing in protein-to-carbohydrate ratio on body composition, glucose and lipid metabolism, and markers of bone turnover. DESIGN: A parallel design included either a high-protein diet of meat, poultry, and dairy foods (HP diet: 27% of energy as protein, 44% as carbohydrate, and 29% as fat) or a standard-protein diet low in those foods (SP diet: 16% of energy as protein, 57% as carbohydrate, and 27% as fat) during 12 wk of energy restriction (6-6.3 MJ/d) and 4 wk of energy balance ( approximately 8.2 MJ/d). Fifty-seven overweight volunteers with fasting insulin concentrations > 12 mU/L completed the study. RESULTS: Weight loss (7.9 +/- 0.5 kg) and total fat loss (6.9 +/- 0.4 kg) did not differ between diet groups. In women, total lean mass was significantly (P = 0.02) better preserved with the HP diet (-0.1 +/- 0.3 kg) than with the SP diet (-1.5 +/- 0.3 kg). Those fed the HP diet had significantly (P < 0.03) less glycemic response at weeks 0 and 16 than did those fed the SP diet. After weight loss, the glycemic response decreased significantly (P < 0.05) more in the HP diet group. The reduction in serum triacylglycerol concentrations was significantly (P

OBJECTIVE: The aim of this study was to evaluate the prevalence of fibromyalgia (FM) in patients with diabetes mellitus (DM). SUBJECTS: The study included 100 consecutive unselected patients with DM attending our diabetes clinic. Patients were divided into two groups: 45 patients with type 1 diabetes and 55 patients with type 2 diabetes. A group of 50 healthy hospital staff members served as controls. The FM was diagnosed according to the 1990 American College of Rheumatology criteria. Counts of 18 tender points were performed by thumb palpation and assessed by dolorimeter. Routine biochemical tests and levels of HbA(1c) were recorded in each patient. RESULTS: The main outcome measure was the association of FM with DM. Fibromyalgia was diagnosed in 17 patients (17%) with DM and in only one (2%) healthy control ( P=0.008). No differences in patients were noted in the prevalence of FM between type 1 and type 2 diabetes (18.5% vs 15.5%, respectively). Patients with both FM and DM had significantly higher levels of HbA(1c) than DM patients without FM (9.2+/-1.1% vs 6.4+/-1.5%) ( P

Recently, it has been shown that endoplasmic reticulum (ER) stress causes apoptosis. However, the mechanism of the ER stress-dependent pathway is not fully understood. In human neuroblastoma SH-SY5Y cells, we detected a caspase-12-like protein that has a molecular mass (approximately 60 kDa) similar to that of mouse caspase-12. Thapsigargin, an inhibitor of ER-associated Ca(2+)-ATPase, induced the degradation of caspase-12-like protein. In addition, the degradation of caspases-9 and -3, cleavage of poly(ADP-ribose) polymerase, DNA fragmentation, and cell death were also observed. Pretreatment with phorbol-12-myristate-13-acetate, which induces the expression of antiapoptotic Bcl-2, inhibited thapsigargin-induced degradation of caspases-9 and -3, but not caspase-12-like protein degradation. A caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp(OCH(3))-CH(2)F, inhibited the degradation of caspase-12-like protein, but not that of caspases-9 and -3. These results suggest that thapsigargin may induce the activation of both ER- and mitochondria-dependent pathways in human SH-SY5Y cells.

Objective: To survey the attitudes of Australian medical students to determine their views about the relative attractiveness of psychiatry as a career compared with other specialities, and against findings from a North American study. Method: We surveyed 655 first-year medical students attending six Australian Universities. Results: Responses indicated that Australian medical students view psychiatry as distinctly less ÔattractiveÕ than other career options, as reported in the North American sample. In comparison with other disciplines, psychiatry was regarded as more interesting and intellectually challenging, but also as lacking a scientific foundation, not being enjoyable and failing to draw on training experiences. Conclusion: Our findings suggest that psychiatry has an image problem that is widespread, reflecting community perceptions and the specialist interests of medical students on recruitment. If psychiatry is to improve its ÔattractivenessÕ as a career option, identified image problems need to be corrected and medical student selection processes re-considered.

PURPOSE: The ketogenic diet (KD) is an effective treatment for intractable epilepsy. However, little is known about its underlying mechanisms. METHODS: In this study, in vivo extracellular field responses to angular bundle stimulation were recorded in the dentate gyrus of Sprague-Dawley rats fed one of three diets: ketogenic calorie-restricted (KCR), normal calorie-restricted (NCR), or normal ad libitum (NAL). Input/output curves and paired-pulse relations were used to assess network excitability. A maximal dentate activation (MDA) protocol was used to measure electrographic seizure threshold and duration. RESULTS: Animals fed calorie-restricted (CR) diets exhibited greater paired-pulse inhibition, an elevated MDA threshold, and an absence of spreading depression-like events compared with ad libitum-fed controls. In the MDA model of epileptogenesis, the rate of increase in electrographic seizure duration after repeated stimuli was markedly reduced in KCR-fed animals compared with NCR- and NAL-fed controls. CONCLUSIONS: These data suggest that CR, by itself, can be anticonvulsant, and treatment with a KCR diet may be both anticonvulsant and antiepileptogenic.

Synthetic crystalline lycopene is a nutritional supplement to increase dietary intake of lycopene, an antioxidant carotenoid. Its potential oral developmental toxicity was studied in rats and rabbits. Each study included 3 control groups (water and matrix for Lycopene 10 CWD or LycoVit 10%), 3 Lycopene 10 CWD groups [500, 1500 and 3000 (rats)/2000 (rabbits) mg/kg/day] and 1 LycoVit 10% group [3000 mg/kg/day (rats)/2000 (rabbits)]. The high dosages were at maximum achievable concentrations and dosage volumes (15 and 10 ml/kg for rats and rabbits, respectively) of the highly viscous test material suspensions. Dosages were administered on gestation days (GDs) 6 through 19 (rats) or GDs 6 through 28 (rabbits). Endpoints evaluated included viability, body weight, feed consumption, necropsy observations [GD 20 (rats)/GD 29 (rabbits)], uterine contents and fetal viability, gender, body weight and morphology (skeletons double-stained). Feed consumption and weight gain were essentially unaffected in rats and rabbits, despite intubation problems in both species and reduced gastrointestinal motility and mortality in rabbits attributable to the physical properties of the gels. Neither Lycopene 10 CWD nor LycoVit 10% caused direct maternal or developmental toxicity in rats or rabbits at dosages as high as 3000 or 2000 mg/kg/day, respectively.

Objective:To describe the lifestyle characteristics and nutrient intakes of the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).Design:Cohort of men and women recruited through general practices or by post to include a high proportion of non meat-eaters. Dietary, anthropometric and lifestyle data were collected at baseline and four diet groups were defined.Setting:United Kingdom.Participants:In total, 65 429 men and women aged 20 to 97 years, comprising 33 883 meat-eaters, 10 110 fish-eaters, 18 840 lacto-ovo vegetarians and 2596 vegans.Results:Nutrient intakes and lifestyle factors differed across the diet groups, with striking differences between meat-eaters and vegans, and fish-eaters and vegetarians usually having intermediate values. Mean fat intake in each diet group was below the UK dietary reference value of 33% of total energy intake. The mean intake of saturated fatty acids in vegans was approximately 5% of energy, less than half the mean intake among meat-eaters (10–11%). Vegans had the highest intakes of fibre, vitamin B1, folate, vitamin C, vitamin E, magnesium and iron, and the lowest intakes of retinol, vitamin B12, vitamin D, calcium and zinc.Conclusions:The EPIC–Oxford cohort includes 31 546 non meat-eaters and is one of the largest studies of vegetarians in the world. The average nutrient intakes in the whole cohort are close to those currently recommended for good health. Comparisons of the diet groups show wide ranges in the intakes of major nutrients such as saturated fat and dietary fibre. Such variation should increase the ability of the study to detect associations of diet with major cancers and causes of death.

INTRODUCTION: The present investigation aimed at identifying differences in muscle structural composition, substrate selection, and performance capacity in highly trained endurance athletes as a consequence of consuming a high-fat or a low-fat diet. METHODS: Eleven duathletes ingested high-fat (53% fat; HF) or high-carbohydrate diets (17% fat; LF) for 5 wk in a randomized crossover design. RESULTS: In m. vastus lateralis, oxidative capacity estimated as volume of mitochondria per volume of muscle fiber (HF: 9.86 +/- 0.36 vs LF: 9.79 +/- 0.52%, mean +/- SE) was not different after the two diet periods. Intramyocellular lipid (IMCL) was significantly increased after HF compared with LF (1.54 +/- 0.27% vs 0.69 +/- 0.09%, P = 0.0076). Glycogen content was lower after HF than after LF, but this difference was not statistically significant (487.8 +/- 38.2 vs 534.4 +/- 32.6 mmol x kg-1 dry weight, P = 0.2454). Maximal power and [OV0312]O(2max) (63.6 +/- 0.9 vs 63.9 +/- 1.2 mL O(2) x min-1 x kg-1 on HF and LF) during an incremental exercise test to exhaustion were not different between the two diet periods. Total work output during a 20-min all-out time trial (298 +/- 6 vs 297 +/- 7 W) on a bicycle ergometer as well as half-marathon running time (80 min 12 s +/- 86 s vs 80 min 24 s +/- 82 s) were not different between HF and LF. Blood lactate concentrations and respiratory exchange ratios (RER) were significantly lower after HF than after LF at rest and during all submaximal exercise loads. CONCLUSIONS: Muscle glycogen stores were maintained after a 5-wk high-fat diet period whereas IMCL content was more than doubled. Endurance performance capacity was maintained at moderate to high-exercise intensities with a significantly larger contribution of lipids to total energy turnover.

AIM: This review identifies deficits in current educational efforts for the primary prevention of cardiovascular disease. DATA SYNTHESIS: Essential fatty acids in the foods we eat have a subtle but powerful influence on hundreds of different processes in the life and death of humans, understanding of which has been delayed by two attitudes in the biomedical community. One involves a bias towards expensive curative/treatment interventions that neglect prevention of initial nutritional causes of disease and death, and the other involves careless logic in interpreting evidence of causes of disease and death. Both attitudes interfere with translation of published science of essential fatty acids into effective prevention of cardiovascular deaths, a situation made worse by a widespread wish for simple descriptions of complex interactions in disease. Some clinical signs and risk factors may be only shadows of true causal factors. For example, attention to cholesterol ignored important evidence that nutritional imbalances in expenditure/intake of energy and in omega-3/omega-6 essential fatty acids cause cardiovascular disease. Balancing the few percentage of daily calories in omega-3/omega-6 nutrients is not a question of obesity or blood cholesterol. Effective prevention through education will require targeting the causal risk factors that are known beyond the shadow of a doubt, but seldom discussed by health professionals and the public. CONCLUSIONS: Death from coronary heart disease comes from acute ischemia and arrhythmia, often following long-term chronic inflammatory vascular damage that predisposes to acute fatal thrombosis and arrhythmia. The three processes involve excessive self-healing actions of natural n-6 autacoids (auto = self, akos = healing) produced from tissue essential fatty acids that come only from foods. Readily corrected nutritional imbalances in expenditure/intake of energy and in omega-3/omega-6 essential fatty acids are causal risk factors with plausible mechanisms contributing to fatal events which can be prevented.

AIM: This review identifies deficits in current educational efforts for the primary prevention of cardiovascular disease. DATA SYNTHESIS: Essential fatty acids in the foods we eat have a subtle but powerful influence on hundreds of different processes in the life and death of humans, understanding of which has been delayed by two attitudes in the biomedical community. One involves a bias towards expensive curative/treatment interventions that neglect prevention of initial nutritional causes of disease and death, and the other involves careless logic in interpreting evidence of causes of disease and death. Both attitudes interfere with translation of published science of essential fatty acids into effective prevention of cardiovascular deaths, a situation made worse by a widespread wish for simple descriptions of complex interactions in disease. Some clinical signs and risk factors may be only shadows of true causal factors. For example, attention to cholesterol ignored important evidence that nutritional imbalances in expenditure/intake of energy and in omega-3/omega-6 essential fatty acids cause cardiovascular disease. Balancing the few percentage of daily calories in omega-3/omega-6 nutrients is not a question of obesity or blood cholesterol. Effective prevention through education will require targeting the causal risk factors that are known beyond the shadow of a doubt, but seldom discussed by health professionals and the public. CONCLUSIONS: Death from coronary heart disease comes from acute ischemia and arrhythmia, often following long-term chronic inflammatory vascular damage that predisposes to acute fatal thrombosis and arrhythmia. The three processes involve excessive self-healing actions of natural n-6 autacoids (auto = self, akos = healing) produced from tissue essential fatty acids that come only from foods. Readily corrected nutritional imbalances in expenditure/intake of energy and in omega-3/omega-6 essential fatty acids are causal risk factors with plausible mechanisms contributing to fatal events which can be prevented.

BACKGROUND: Food Photographs and standard portion sizes have been used with adults to assess portion size when recording dietary intake. The effectiveness of these methods may be reduced when memory/recall is required and children may have problems using these techniques. METHODS: Adults (47) and children (37) were recruited from amongst university personnel, their children and children's friends to assess portion sizes of nine self-served amounts of selected food items using food photographs and standard descriptions of portion sizes. Portion sizes were estimated directly after self-serving and three - 4 days later. RESULTS: Substantial differences in the estimate of portion sizes were observed for most foods regardless of the method used or the age of the subjects, median difference range: -52-100%. For children there were greater errors using both methods than for adults. Significant differences were found between the two methods of estimating weight. The food atlas provided higher median estimated weights for the majority of the food items. There were very few differences in the estimation of portion sizes between the two testing periods. CONCLUSION: The findings would suggest that either an alternative method or a modification of the methods used here for estimating portion sizes in young subjects, for example standard food portion sizes for children of different ages such as those that are being developed by the Food Standards Agency, would be more appropriate.

PURPOSE: To determine both the efficacy of and compliance with the ketogenic diet in the adolescent population. METHODS: A retrospective study of 45 patients, aged 12-19 years, consecutively enrolled in a ketogenic diet program from 1994 to 2002, was performed. Thirty-seven patients were from The Johns Hopkins Medical Institutions; eight were from The University of Texas at Houston. Charts were reviewed, and patients were contacted by telephone. RESULTS: Six months after diet initiation, 28 (62%) of 45 remained on the ketogenic diet, with six (21%) of 28 having 50-90% seizure reduction, and eight (29%) of 28 having >90%. At 12 months, 20 (44%) of 45 remained on the diet, with seven (35%) of 20 having 50-90% seizure reduction and six (30%) of 20 achieving >90% efficacy. Only 22% discontinued the diet for perceived restrictiveness. The mean diet duration was 1.2 years. Patients with multiple seizure types did best, whereas gender, prior seizure frequency, diet ratio, and age did not influence outcome. Patients dependent on parents for daily care were more likely to remain on the diet at 6 months, but had less efficacy. Weight loss (60%) and menstrual dysfunction (45% of female subjects) were the most commonly reported side effects. CONCLUSIONS: The ketogenic diet is as well tolerated and efficacious for adolescents with epilepsy as for the general childhood population.

Although a salted diet appears to be a sine qua non for the development of essential hypertension, low-salt diets often have a modest or even negligible impact on the blood pressure of hypertensives; this suggests that salt, perhaps often acting in concert with other aspects of a modern, rich diet, may set in place certain metabolic vicious cycles that sustain blood pressure elevation even when dietary salt is eliminated. Therapeutic fasting is known to lower elevated blood pressure - presumably in large part because it minimizes insulin secretion - and may have the potential to break some of these vicious cycles. Goldhamer has recently reported that a regimen comprised of a water-only fast of moderate duration, followed by a transition to a low-fat, low-salt, whole-food vegan diet, achieves dramatic reductions in the blood pressure of hypertensives, such that the large majority of patients can be restored to normotensive status, in the absence of any drug therapy. Although long-term follow-up of these subjects has been sporadic, the available data suggest that these large reductions is blood pressure can be conserved in patients who remain compliant with the follow-up diet - in other words, a 'cure' for hypertension may be feasible. If a protein-sparing modified fast can be shown to be virtually as effective as a total fast for achieving these benefits, it may be possible to implement this regimen safely on an outpatient basis. The ability of therapeutic fasts to break metabolic vicious cycles may also contribute to the efficacy of fasting in the treatment of type 2 diabetes and autoimmune disorders. As a general principle, if a metabolic disorder is susceptible to prevention - but not reversal - by a specific diet, and therapeutic fasting has a temporary favorable impact on this disorder, then a more definitive therapy may consist of a therapeutic fast, followed up by the protective diet as a maintenance regimen.

This paper is concerned with the psychopathological processes that account for the persistence of severe eating disorders. Two separate but interrelated lines of argument are developed. One is that the leading evidence-based theory of the maintenance of eating disorders, the cognitive behavioural theory of bulimia nervosa, should be extended in its focus to embrace four additional maintaining mechanisms. Specifically, we propose that in certain patients one or more of four additional maintaining processes interact with the core eating disorder maintaining mechanisms and that when this occurs it is an obstacle to change. The additional maintaining processes concern the influence of clinical perfectionism, core low self-esteem, mood intolerance and interpersonal difficulties. The second line of argument is that in the case of eating disorders shared, but distinctive, clinical features tend to be maintained by similar psychopathological processes. Accordingly, we suggest that common mechanisms are involved in the persistence of bulimia nervosa, anorexia nervosa and the atypical eating disorders. Together, these two lines of argument lead us to propose a new transdiagnostic theory of the maintenance of the full range of eating disorders, a theory which embraces a broader range of maintaining mechanisms than the current theory concerning bulimia nervosa. In the final sections of the paper we describe a transdiagnostic treatment derived from the new theory, and we consider in principle the broader relevance of transdiagnostic theories of maintenance.

OBJECTIVE: To test the hypothesis that older men who consumed a vegetarian (lacto-ovo) diet would develop a lower iron status compared with older men who consumed a beef-containing diet during a period of resistive training (RT). DESIGN: Experimental, repeated measures study. SUBJECTS: Twenty-one healthy men aged 59 to 78 years, with a BMI range of 24 to 33 kg/m(2), completed the study. INTERVENTION: All men consumed a vegetarian diet for 2 weeks (baseline). After this, the men were randomly assigned to one of two dietary groups. Eleven men consumed a beef-containing diet, and 10 men continued to consume a vegetarian diet for 12 weeks. During this time all subjects participated in RT three days per week, designated as RT1 to RT12. MAIN OUTCOME MEASURES: Serum ferritin and serum iron concentrations, transferrin saturation, transferrin receptor, total iron binding capacity, and selected hematological variables, as well as selected nutrient intakes and estimated iron bioavailability from three-day diet records, were determined at baseline, RT5, and RT12. STATISTICAL ANALYSES: A general linear model repeated-measures ANOVA was used to examine the effects of group, time, and group x time interactions for iron status and dietary data. RESULTS: Total iron intake was not different between the two groups; however, the beef group had a three to four times greater intake of bioavailable iron (P<.01) than the vegetarian group. Serum iron, total iron binding capacity, transferrin saturation, and transferrin receptor were not significantly different between the beef and vegetarian groups, or changed over time with RT. Serum ferritin decreased over time in both the beef and vegetarian groups during RT (P<.01). Re-introduction of beef into the diets of the beef group increased hemoglobin concentration and hematocrit compared with the vegetarian group during the 12 weeks of RT (group x time, P

Calcium balance is decreased by an increased intake of purified proteins, although the effects of common dietary sources of protein (like meat) on calcium economy remain controversial. We compared the effects of several weeks of controlled high and low meat diets on body calcium retention, using sensitive radiotracer and whole body scintillation counting methodology. Healthy postmenopausal women (n = 15) consumed diets with similar calcium content (approximately 600 mg), but either low or high in meat (12 vs. 20% of energy as protein) for 8 wk each, in a randomized crossover design. After 4 wk of equilibration of each diet, calcium retention was measured by extrinsically labeling the 2-d menu with (47)Ca, followed by whole body scintillation counting for 28 d. Urinary and blood indicators of bone metabolism were also determined for each diet. Calcium retention was not different during the high and low meat dietary periods (d 28, mean +/- pooled SD: 17.1 and 15.6%, +/-0.6%, respectively; P = 0.09). An initially higher renal acid excretion in subjects consuming the high meat compared with the low meat diet decreased significantly with time. The diets did not affect urinary calcium loss or indicators of bone metabolism. In conclusion, under controlled conditions, a high meat compared with a low meat diet for 8 wk did not affect calcium retention or biomarkers of bone metabolism in healthy postmenopausal women. Calcium retention is not reduced when subjects consume a high protein diet from common dietary sources such as meat.

The 2002 ISSFAL Meeting arranged a special evening discussion with professional dietitians about diet-tissue-disease relationships involving essential fatty acids and eicosanoids. The balance of eicosanoid precursors in human tissues differs widely, reflecting voluntary dietary choices among different groups worldwide. An empirical quantitative diet-tissue relationship fits these diverse values as well as other research reports on essential fatty acid metabolism. Information for dietitians and nutritionists about essential fatty acids and eicosanoids is also given in two distance learning web sites, http://ods.od.nih.gov/eicosanoids/ and http:// efaeducation.nih.gov/, which facilitate dietitian education and diet counseling. These sites also have an innovative, interactive diet planning software program with the empirical equation embedded in it to help evaluate personal food choices in the context of the diet-tissue-disease relationship and other widely recommended dietary advice.

Non-occlusal, buccal tooth microwear variability has been studied in 68 fossil humans from Europe and the Near East. The microwear patterns observed suggest that a major shift in human dietary habits and food processing techniques might have taken place in the transition from the Middle to the Late Pleistocene populations. Differences in microwear density, average length, and orientation of striations indicate that Middle Pleistocene humans had more abrasive dietary habits than Late Pleistocene populations. Both dietary and cultural factors might be responsible for the differences observed. In addition, the Middle Paleolithic Neanderthal specimens studied show a highly heterogeneous pattern of microwear when compared to the other samples considered, which is inconsistent with a hypothesis of all Neanderthals having a strictly carnivorous diet. The high density of striations observed in the buccal surfaces of several Neanderthal teeth might be indicative of the inclusion of plant foods in their diet. The buccal microwear variability observed in the Neanderthals is compatible with an overall exploitation of both plant and meat foods on the basis of food availability. A preliminary analysis of the relationship between buccal microwear density and climatic conditions prevailing in Europe during the Late Pleistocene has been attempted. Cold climatic conditions, as indicated by oxygen isotope stage data, seem to be responsible for higher densities of microwear features, whereas warmer periods could correspond to a reduced pattern of scratch density. Such a relationship would be indicative of less abrasive dietary habits, perhaps more meat dependent, during warmer periods.

Oxidative injury induces cellular and nuclear damage that leads to apoptotic cell death. Agents or antioxidants that can inhibit production of reactive oxygen species can prevent apoptosis. We tested the hypothesis that flavonoids can inhibit H(2)O(2)-induced apoptosis in human umbilical vein endothelial cells. A 30-min pulse treatment with 0.25 mmol/L H(2)O(2) decreased endothelial cell viability within 24 h by approximately 40% (P < 0.05) with distinct nuclear condensation and DNA fragmentation. In the H(2)O(2) apoptosis model, the addition of 50 micro mol/L of the flavanol (-)epigallocatechin gallate and the flavonol quercetin, which have in vitro radical scavenging activity, partially (P < 0.05) restored cell viability with a reduction in H(2)O(2)-induced apoptotic DNA damage. In contrast, the flavones, luteolin and apigenin, at the nontoxic dose of 50 micro mol/L, intensified cell loss (P

The ketogenic diet (KD) is a high-fat, low-carbohydrate, adequate-protein diet that has been used for more than eight decades for the treatment of refractory epilepsy in children. Despite this long history, the mechanisms by which the KD exerts its anti-seizure action are not fully understood. Questions remain regarding several aspects of KD action, including its effects on brain biochemistry and energetics, neuronal membrane function and cellular network behavior. With the explosion of the KD use in the last 10 years, it is now imperative that we understand these factors in greater detail, in order to optimize the formulation, administration and fine-tuning of the diet. This review discusses what is known and what remains to be learned about the KD, with emphasis on clinical questions that can be approached in the laboratory. We encourage scientists with a primary interest in nutritional neuroscience to join with those of us in the epilepsy research community to address these urgent questions, for the benefit of children ravaged by intractable seizures.

Objectives To compare the effects of a low-carbohydrate (LC) diet with those of a low-fat (LF) diet on weight loss and serum lipids in overweight adolescents. Design A randomized, controlled 12-week trial. Setting Atherosclerosis prevention referral center. Methods Random, nonblinded assignment of participants referred for weight management. The study group (LC) (n = 16) was instructed to consume <20 g of carbohydrate per day for 2 weeks, then <40 g/day for 10 weeks, and to eat LC foods according to hunger. The control group (LF) (n = 14) was instructed to consume <30% of energy from fat. Diet composition and weight were monitored and recorded every 2 weeks. Serum lipid profiles were obtained at the start of the study and after 12 weeks. Results The LC group lost more weight (mean, 9.9 ± 9.3 kg vs 4.1 ± 4.9 kg, P < .05) and had improvement in non-HDL cholesterol levels (P < .05). There was improvement in LDL cholesterol levels (P

Metabolomics or the large-scale phytochemical analysis of plants is reviewed in relation to functional genomics and systems biology. A historical account of the introduction and evolution of metabolite profiling into today's modern comprehensive metabolomics approach is provided. Many of the technologies used in metabolomics, including optical spectroscopy, nuclear magnetic resonance, and mass spectrometry are surveyed. The critical role of bioinformatics and various methods of data visualization are summarized and the future role of metabolomics in plant science assessed.

Claims about the merits or risks of carbohydrate (CHO) vs. protein for weight loss diets are extensive, yet the ideal ratio of dietary carbohydrate to protein for adult health and weight management remains unknown. This study examined the efficacy of two weight loss diets with modified CHO/protein ratios to change body composition and blood lipids in adult women. Women (n = 24; 45 to 56 y old) with body mass indices >26 kg/m(2) were assigned to either a CHO Group consuming a diet with a CHO/protein ratio of 3.5 (68 g protein/d) or a Protein Group with a ratio of 1.4 (125 g protein/d). Diets were isoenergetic, providing 7100 kJ/d, and similar amounts of fat ( approximately 50 g/d). After consuming the diets for 10 wk, the CHO Group lost 6.96 +/- 1.36 kg body weight and the Protein Group lost 7.53 +/- 1.44 kg. Weight loss in the Protein Group was partitioned to a significantly higher loss of fat/lean (6.3 +/- 1.2 g/g) compared with the CHO Group (3.8 +/- 0.9). Both groups had significant reductions in serum cholesterol ( approximately 10%), whereas the Protein Group also had significant reductions in triacylglycerols (TAG) (21%) and the ratio of TAG/HDL cholesterol (23%). Women in the CHO Group had higher insulin responses to meals and postprandial hypoglycemia, whereas women in the Protein Group reported greater satiety. This study demonstrates that increasing the proportion of protein to carbohydrate in the diet of adult women has positive effects on body composition, blood lipids, glucose homeostasis and satiety during weight loss.

Objective: To evaluate literature relating to cardiac QT prolongation and the use of antipsychotic drugs. Method: Literature searches of EMBASE, Medline, PsychLIT were performed in December 2001 and reference sections of retrieved papers scrutinized for further relevant reports. Results: The Cardiac QTc interval is difficult to measure precisely or accurately but appears to be a useful predictor of risk of dysrhythmia (specifically torsade de pointes) and sudden death. It is less clear that drug-induced QTc prolongation gives rise to similar risks but data are emerging, linking antipsychotic use to increased cardiac mortality. Many antipsychotics have been clearly associated with QTc prolongation. Methodological considerations arguably preclude assuming that any antipsychotic is free of the risk of QTc prolongation and dysrhythmia. Conclusion: Available data do not allow assessment of relative or absolute risk of dysrhythmia or sudden death engendered by antipsychotics but caution is advised. Risk of dysrhythmia can very probably be reduced by careful prescribing of antipsychotics in low doses in simple drug regimens which avoid metabolic interactions. Electrocardiographic monitoring may also help to reduce risk but review by specialist cardiologist may be necessary.

A pilot prospective follow-up study of the role of the ketogenic diet was carried out on 30 children, aged between 4 and 10 years, with autistic behavior. The diet was applied for 6 months, with continuous administration for 4 weeks, interrupted by 2-week diet-free intervals. Seven patients could not tolerate the diet, whereas five other patients adhered to the diet for 1 to 2 months and then discontinued it. Of the remaining group who adhered to the diet, 18 of 30 children (60%), improvement was recorded in several parameters and in accordance with the Childhood Autism Rating Scale. Significant improvement (> 12 units of the Childhood Autism Rating Scale) was recorded in two patients (pre-Scale: 35.00 +/- 1.41[mean +/- SD]), average improvement (> 8-12 units) in eight patients (pre-Scale: 41.88 +/- 3.14[mean +/- SD]), and minor improvement (2-8 units) in eight patients (pre-Scale: 45.25 +/- 2.76 [mean +/- SD]). Although these data are very preliminary, there is some evidence that the ketogenic diet may be used in autistic behavior as an additional or alternative therapy.

Mucus is a water-insoluble gel secreted by the gastrointestinal tract. It exists as a protective gel layer adherent to the epithelial surface of the stomach, small intestine and colon. The mucus gel is composed of 1-10 % (w/v) mucin glycoprotein in a plasma-like fluid. Since the mucus gel is predominantly water, standard histological techniques dehydrate the mucus, making visualisation of the functional barrier difficult. Specialist techniques have been developed to enable visualisation of the intact mucus layer. A simple histological method using snap-frozen tissue, sectioned with a cryostat and stained with modified periodic acid-Schiffs/Alcian blue in mucus-preserving conditions will be described. A second powerful in vivo animal model is described which enables measurement of mucus secretion over time. The use of these two methods has allowed the characterisation of the normal mucus layer in the colon and the determination of how it is affected by disease and dietary intervention, in particular the effect of dietary fibre, and evidence that fibre deficiency results in colonic mucosal fragility is presented.

The colon is subjected to a myriad of potentially damaging agents that may reside within the lumen for 1-2 d. Its first line of defence against these agents is the protective mucus bilayer that lines the entire colonic mucosa. This bilayer acts as a physical barrier to mucosal aggressors and also reduces shear stress to the mucosa. These actions are dependent on the unstimulated ('resting') colonic mucus thickness, and also on the rate that this layer can be replenished. The colonic mucus layer is altered in a number of colonic diseases that have been linked to a deficiency of fibre in the diet. The action of fibre intake on colonic mucus thickness and secretion is unknown. Using an in vivo rat model it has been demonstrated that: (1). fibre deficiency leads to a decreased protective potential of the mucus layer (e.g. the mean resting mucus thickness of the fibre-deficient group (429 microm) was significantly lower than its respective control (579 microm; P< 0-001), as was its total mucus secretion over 6 h (270 microm v. 541 microm; P

The title of this presentation is derived from a national bestseller that defines the moment when an idea, trend, or social behavior crosses a threshold, "tips," and becomes widely disseminated. Three key tipping-point factors are discussed in the context of medical nutrition education. The Law of Few has to do with the essentiality of role models in directing educational curricula and clinical programs. The Stickiness Factor describes the quality and the content of the message that enable the information to have prolonged meaning. The Power of Context refers to the conditions and risk factors that are directly affected by diet and nutrition. Examples of these key factors are provided with a look to the future of medical nutrition education.

Encephalization, and its relationship to potential selective forces, have been a focus of many studies of primate adaptation. It has been argued that gut size may constrain brain mass because these two types of "expensive tissue" (among others) compete in their metabolic requirements (Aiello and Wheeler [1995] Curr. Anthropol. 36:199-221). Following from the inverse correlation of gut size with diet quality, the expensive tissue hypothesis predicts that differences in diet quality are positively correlated with differences in brain mass, once the correlation of each variable with body mass is taken into account. We tested this prediction using both nonphylogenetic and phylogenetic methods. The results of both methods are consistent with predictions made by the expensive tissue hypothesis. We also discuss several examples of independent contrasts that are consistent with the hypothesis (e.g., Colobinae vs. Cercopithecinae), as well as some that are not (e.g., Tarsius vs. anthropoidea). Overall, the results indicate that improved diet quality, by allowing reduction in relative gut mass, is one mechanism involved in increased encephalization.

Encephalization, and its relationship to potential selective forces, have been a focus of many studies of primate adaptation. It has been argued that gut size may constrain brain mass because these two types of "expensive tissue" (among others) compete in their metabolic requirements (Aiello and Wheeler [1995] Curr. Anthropol. 36:199-221). Following from the inverse correlation of gut size with diet quality, the expensive tissue hypothesis predicts that differences in diet quality are positively correlated with differences in brain mass, once the correlation of each variable with body mass is taken into account. We tested this prediction using both nonphylogenetic and phylogenetic methods. The results of both methods are consistent with predictions made by the expensive tissue hypothesis. We also discuss several examples of independent contrasts that are consistent with the hypothesis (e.g., Colobinae vs. Cercopithecinae), as well as some that are not (e.g., Tarsius vs. anthropoidea). Overall, the results indicate that improved diet quality, by allowing reduction in relative gut mass, is one mechanism involved in increased encephalization.

Amino acids interact with glucose metabolism both as carbon substrates and by recycling glucose carbon via alanine and glutamine; however, the effect of protein intake on glucose homeostasis during weight loss remains unknown. This study tests the hypothesis that a moderate increase in dietary protein with a corresponding reduction of carbohydrates (CHO) stabilizes fasting and postprandial blood glucose and insulin during weight loss. Adult women (n = 24; >15% above ideal body weight) were assigned to either a Protein Group [protein: 1.6 g/(kg. d); CHO 55%]. Diets were equal in energy (7100 kJ/d) and fat (50 g/d). After 10 wk, the Protein Group lost 7.53 +/- 1.44 kg and the CHO Group lost 6.96 +/- 1.36 kg. Plasma amino acids, glucose and insulin were determined after a 12-h fast and 2 h after a 1.67 MJ test meal containing either 39 g CHO, 33 g protein and 13 g fat (Protein Group) or 57 g CHO, 12 g protein and 14 g fat (CHO Group). After 10 wk, subjects in the CHO Group had lower fasting (4.34 +/- 0.10 vs 4.89 +/- 0.11 mmol/L) and postprandial blood glucose (3.77 +/- 0.14 vs. 4.33 +/- 0.15 mmol/L) and an elevated insulin response to meals (207 +/- 21 vs. 75 +/- 18 pmol/L). This study demonstrates that consumption of a diet with increased protein and a reduced CHO/protein ratio stabilizes blood glucose during nonabsorptive periods and reduces the postprandial insulin response.

Iron-deficiency anemia has been shown to alter body mineral concentrations and activities of iron- and non-iron-containing enzymes, especially those with antioxidant functions. These effects, however, have been less studied in nonanemic iron-depleted individuals. Thus, this study assessed indices of selenium status in 12 college-aged females with adequate iron stores and 15 college-aged females with low iron stores before and after iron therapy. Blood samples were drawn at baseline for both groups and following iron supplementation in the low-iron-stores group. Hematocrit, hemoglobin, and serum ferritin concentrations of the low iron- stores group were significantly lower than those of the control group. The serum transferrin receptor-to-serum ferritin ratio in the low-iron stores group was significantly greater than that of the control group. Serum selenium and glutathione peroxidase concentrations of the low-iron-stores group were not significantly different from those of the controls. Iron supplementation significantly increased hemoglobin, hematocrit, and serum ferritin concentrations and significantly decreased the serum transferrin receptor concentration and serum transferrin receptor:serum ferritin ratio in the low-iron-stores group posttreatment compared to pretreatment. Serum selenium and glutathione peroxidase concentrations did not differ significantly from pretreatment to posttreatment in the low-iron-stores group. Results of this study indicate that low iron stores without anemia are not associated with impaired selenium status in college-aged females.

Rats carrying one copy of the fa allele are predisposed to diet-induced metabolic disturbances which contribute to hyperinsulinemia, obesity and dyslipidemia. To investigate the role of dietary carbohydrate and fat in the development of these conditions, we fed 6-week old male heterozygous (fa/+) lean rats carbohydrate-free diets containing primarily saturated fat either ad libitum or pair-fed. These diets were compared to standard chow and to a high saturated fat mixed diet containing 10% energy from sucrose for 4 weeks. The carbohydrate-free diet resulted in significantly lower circulating glucose levels compared to all other groups (p = 0.006). Weight gain was negligible in the carbohydrate free groups compared to standard diet and 10% sucrose diet (p = 0.03). This was reflected in energy efficiency which was markedly reduced (90%) in the carbohydrate-free groups compared to the other groups (p = 0.04). Corresponding changes were noted in fat pad mass. The subscapular and epididymal fat pads were increased 42% and 44%, respectively, in animals consuming the 10% sucrose diet compared to all other groups (p < 0.01). Comparable changes in fatty acid synthase (FAS) mRNA were observed in response to the carbohydrate-free diet, which resulted in a 53% decrease in adipocyte FAS mRNA (p

BACKGROUND: Hypertriglyceridemia is associated with increased risk of cardiovascular disease. Until recently, the importance of hepatic de novo lipogenesis (DNL) in contributing to hypertriglyceridemia was difficult to assess because of methodologic limitations. OBJECTIVE: We evaluated the extent of the contribution by DNL to different conditions associated with hypertriglyceridemia. DESIGN: After 5 d of an isoenergetic high-fat, low-carbohydrate diet, fasting DNL was measured in normoinsulinemic (or= 115 pmol/L) obese (n = 8) subjects. Fasting DNL was measured after a low-fat, high-carbohydrate diet in normoinsulinemic lean (n = 5) and hyperinsulinemic obese (n = 5) subjects. Mass isotopomer distribution analysis was used to measure the fraction of newly synthesized fatty acids in VLDL-triacylglycerol. RESULTS: With the high-fat, low-carbohydrate diet, hyperinsulinemic obese subjects had a 3.7-5.3-fold higher fractional DNL (8.5 +/- 0.7%) than did normoinsulinemic lean (1.6 +/- 0.5%) or obese (2.3 +/- 0.3%) subjects. With the low-fat, high-carbohydrate diet, normoinsulinemic lean and hyperinsulinemic obese subjects had similarly high fractional DNL (13 +/- 5.1% and 12.8 +/- 1.4%, respectively). Compared with baseline, consumption of the high-fat, low-carbohydrate diet did not affect triacylglycerol concentrations. However, after the low-fat, high-carbohydrate diet, triacylglycerols increased significantly and DNL was 5-6-fold higher than in normoinsulinemic subjects consuming a high-fat diet. The increase in triacylglycerol after the low-fat, high-carbohydrate diet was correlated with fractional DNL (P

Debate about the optimum balance of macronutrients for adult weight maintenance or weight loss continues to expand. Often this debate centers on the relative merits or risks of carbohydrates vs. fats; however, there is increasing interest in the optimal level of dietary protein for weight loss. Diets with a reduced ratio of carbohydrates/protein are reported to be beneficial for weight loss, although diet studies appear to lack a fundamental hypothesis to support higher protein intakes. Presently, needs for dietary proteins are established by the recommended daily allowance (RDA) as the minimum level of protein necessary to maintain nitrogen balance. The RDA define the primary use of amino acids as substrates for synthesis of body proteins. There is emerging evidence that additional metabolic roles for some amino acids require plasma and intracellular levels above minimum needs for protein synthesis. The branched-chain amino acid leucine is an example of an amino acid with numerous metabolic roles that function in proportion with cellular concentration. This review provides an overview of the current understanding of metabolic roles of leucine and proposes a metabolic framework to evaluate the merits of a higher protein diet for weight loss.

Background Despite the popularity of the low-carbohydrate, high-protein, high-fat (Atkins) diet, no randomized, controlled trials have evaluated its efficacy. Methods We conducted a one-year, multicenter, controlled trial involving 63 obese men and women who were randomly assigned to either a low-carbohydrate, high-protein, high-fat diet or a low-calorie, high-carbohydrate, low-fat (conventional) diet. Professional contact was minimal to replicate the approach used by most dieters. Results Subjects on the low-carbohydrate diet had lost more weight than subjects on the conventional diet at 3 months (mean [±SD], –6.8±5.0 vs. –2.7±3.7 percent of body weight; P=0.001) and 6 months (–7.0±6.5 vs. –3.2±5.6 percent of body weight, P=0.02), but the difference at 12 months was not significant (–4.4±6.7 vs. –2.5±6.3 percent of body weight, P=0.26). After three months, no significant differences were found between the groups in total or low-density lipoprotein cholesterol concentrations. The increase in high-density ...