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Query: dwarfism
Life span extending mutations in growth signaling pathways protect against age-dependent DNA damage in yeast and decrease insulin resistance and cancer in mice. To test their effect in humans, we monitored for 22 years Ecuadorian subjects with mutations in the growth hormone receptor gene leading to severe growth hormone receptor (GHR) and IGF-I deficiencies and combined this information with surveys to identify the cause and age of death for subjects who died before this period. The individuals with GHR deficiency (GHRD) exhibited only one non-lethal malignancy and no cases of diabetes, in contrast to 17% cancer and 5% diabetes prevalence in the controls. A possible explanation for the very low incidence of cancer may be revealed by in vitro studies: serum from GHRD subjects reduced DNA breaks but increased apoptosis in human mammary epithelial cells (HMECs) treated with hydrogen peroxide. We also observed reduced insulin concentrations (1.4 μU/ml vs. 4.4μU/ml in unaffected relatives) and a very low homoeostasis model assessment of insulin resistance (HOMA-IR) index (0.34 vs. 0.96 in unaffected relatives) in GHRD individuals, indicating increased insulin sensitivity, which could explain the absence of diabetes in these subjects. Incubation of HMECs with GHRD serum also resulted in reduced expression of RAS, PKA and TOR, and up-regulation of SOD2, changes that promote cellular protection and life span extension in model organisms. These results provide evidence for a role of evolutionarily conserved pathways in promoting aging and diseases in humans and identify a candidate drug target for healthy life span extension.
Summary Weight loss resulting from an exercise intervention tends to be lower than predicted. Modest weight loss can arise from an increase in energy intake, physiological reductions in resting energy expenditure, an increase in lean tissue or a decrease in non-exercise activity. Lower than expected, weight loss could also arise from weak and invalidated assumptions within predictive models. To investigate these causes, we systematically reviewed studies that monitored compliance to exercise prescriptions and measured exercise-induced change in body composition. Changed body energy stores were calculated to determine the deficit between total daily energy intake and energy expenditures. This information combined with available measurements was used to critically evaluate explanations for low exercise-induced weight loss. We conclude that the small magnitude of weight loss observed from the majority of evaluated exercise interventions is primarily due to low doses of prescribed exercise energy expenditures compounded by a concomitant increase in caloric intake.
Until recently, the majority of cases of diabetes mellitus among children and adolescents were immune-mediated type 1a diabetes. Obesity has led to a dramatic increase in the incidence of type 2 diabetes (T2DM) among children and adolescents over the past 2 decades. Obesity is strongly associated with insulin resistance, which, when coupled with relative insulin deficiency, leads to the development of overt T2DM. Children and adolescents with T2DM may experience the microvascular and macrovascular complications of this disease at younger ages than individuals who develop diabetes in adulthood, including atherosclerotic cardiovascular disease, stroke, myocardial infarction, and sudden death; renal insufficiency and chronic renal failure; limb-threatening neuropathy and vasculopathy; and retinopathy leading to blindness. Health care professionals are advised to perform the appropriate screening in children at risk for T2DM, diagnose the condition as early as possible, and provide rigorous management of the disease.
Deficiency of vitamin D is usually caused by dietary deficiency and/or lack of exposure to sunlight in dark skinned individuals living at northern latitudes. Simple vitamin D deficiency is commonly treated by prescribing a vitamin D containing calcium supplement. This report presents a patient who rejected this approach and instead, after researching alternative treatment options independently, opted to self-treat by consuming UVB-irradiated mushrooms. The beneficial effect of this on the patient's plasma biochemical markers is shown. Further research into the beneficial effect of consuming UVB-irradiated mushrooms is required.
Vitamin B(12) deficiency in infants often produces haematological and neurological deficits, including macrocytic anaemia, neurodevelopmental delay or regression, irritability, weakness, hypotonia, ataxia, apathy, tremor, and seizures. The diagnosis of vitamin B(12) deficiency can be difficult when the typical macrocytic anaemia is absent. We report the case of a 10-month-old female diagnosed with West syndrome associated with vitamin B(12) deficiency but without macrocytic anaemia caused by nutritional inadequacy in the mother. The patient's motor skills and cognitive development were normal until she was 9 months old, when she began to exhibit a series of sudden flexions of the head, trunk, arms, and legs. She was exclusively breast-fed and had received no vitamin supplementation. Results of electroencephalography (EEG) indicated modified hypsarrhythmia and the patient was diagnosed as having West syndrome. Synthetic adrenocorticotropic hormone was administered and although her spasms had resolved, the patient remained apathic and could not sit without assistance. EEG results indicated generalized slow activity. After she was diagnosed as having vitamin B(12) deficiency, parenteral treatment with vitamin B(12) was initiated. Her symptoms resolved and EEG was completely normal. When she was 20 months old she exhibited an age-appropriate developmental and neurological profile. To our knowledge, this is the first report of West syndrome as a presenting symptom of vitamin B(12) deficiency.
Throughout evolution sunlight produced vitamin D in the skin has been critically important for health. Vitamin D, known as the sunshine vitamin, is actually a hormone. Once it is produced in the skin or ingested from the diet it is converted sequentially in the liver and kidneys to its biologically active form 1,25-dihydroxyvitamin D. This hormone interacts with its receptor in the small intestine to increase the efficiency of intestinal calcium and phosphate absorption for the maintenance of the skeleton throughout life. Vitamin D deficiency during the first few years of life results in a flattened pelvis making it difficult for childbirth. Vitamin D deficiency causes osteopenia and osteoporosis increasing risk of fracture. Essentially every tissue and cell in the body has a vitamin D receptor. Therefore vitamin D deficiency has been linked to increased risk for preeclampsia, requiring a Cesarean section for birthing, multiple sclerosis, rheumatoid arthritis, type I diabetes, type II diabetes, heart disease, dementia, deadly cancers and infectious diseases. Therefore sensible sun exposure along with vitamin D supplementation of at least 2000 IU/d for adults and 1000 IU/d for children is essential to maximize their health.
The first infants to experience modern pre- and neonatal care are now in their thirties, an age at which the incidence of cardiometabolic disease is low. However, data from cohorts born preterm prior to the introduction of modern care suggest an increased risk of type 2 diabetes. For young adult cohorts of former very small or very preterm infants, there is accumulating evidence of increased risk factors for later cardiovascular disease, including higher blood pressure, lower lean body mass, impaired glucose regulation, and perhaps a more atherogenic lipid profile. Regarding lifestyle, adults born very small or very preterm undertake less non-conditioning physical activity and may have a lower intake of fruit and milk products. Any intervention reducing risk factors, in particular blood pressure and low physical activity, would have a substantial potential to reduce the lifetime disease burden in small preterm infants. There are now enough data to warrant an expert evaluation of the level of evidence for cardiometabolic disease in individuals born very small or very preterm, which has possible public health implications. Copyright © 2013 Elsevier Ltd. All rights reserved.
Context: Hypovitaminosis D appears to be on the rise in young children, with implications for skeletal and overall health. Objective: The objective of the study was to compare the safety and efficacy of vitamin D2 daily, vitamin D2 weekly, and vitamin D3 daily, combined with supplemental calcium, in raising serum 25-hydroxyvitamin D [25(OH)D] and lowering PTH concentrations. Design: This was a 6-wk randomized controlled trial. Setting: The study was conducted at an urban pediatric clinic in Boston. Subjects: Forty otherwise healthy infants and toddlers with hypovitaminosis D [25(OH)D < 20 ng/ml] participated in the study. Interventions: Participants were assigned to one of three regimens: 2,000 IU oral vitamin D2 daily, 50,000 IU vitamin D2 weekly, or 2,000 IU vitamin D3 daily. Each was also prescribed elemental calcium (50 mg/kg·d). Infants received treatment for 6 wk. Main Outcome Measures: Before and after treatment, serum measurements of 25(OH)D, PTH, calcium, and alkaline phosphatase were taken. Results: All treatments approximately tripled the 25(OH)D concentration. Preplanned comparisons were nonsignificant: daily vitamin D2 vs. weekly vitamin D2 (12% difference in effect, P = 0.66) and daily D2 vs. daily D3 (7%, P = 0.82). The mean serum calcium change was small and similar in the three groups. There was no significant difference in PTH suppression. Conclusions: Short-term vitamin D2 2,000 IU daily, vitamin D2 50,000 IU weekly, or vitamin D3 2,000 IU daily yield equivalent outcomes in the treatment of hypovitaminosis D among young children. Therefore, pediatric providers can individualize the treatment regimen for a given patient to ensure compliance, given that no difference in efficacy or safety was noted among these three common treatment regimens.
To assess the prevalence of eye disease among malnourished children in a rural Ethiopian health center and evaluate correlations between xerophthalmia and grades of malnutrition. A retrospective, cross-sectional survey. An institution-based cross-sectional prospective study was performed at Bushulo Health Center in rural south Ethiopia and included all children age 6 months to 14 years receiving care for malnourishment from June 1st to July 30th, 2008. Data collection involved a combination of interviews with caretakers, ocular examination by a pediatric ophthalmologist and anthropometric measurements. One hundred and seventy-three children (average age at examination 2.9 ± 0.2 years) were treated for malnutrition (97 female, 76 male). One hundred and forty-nine patients had moderate malnutrition (86.03 %) and 24 had severe malnutrition (13.9 %). The following eye diseases were diagnosed--trachoma (12.1 %), blepharitis (13.3 %) and xerophthalmia (20.8 %). Severely malnourished children were more likely to suffer from xerophthalmia than moderately malnourished children (p < 0.0001). When comparing anthropometric measurements to the diagnosis of xerophthalmia, only weight percentile showed significance (p = 0.008). Xerophthalmia is a common global cause of pediatric blindness and is highly correlated with severe malnutrition. Continued efforts are necessary to improve nutrition and outcomes in these patients.
The relationship between diet and attained height was studied in children and adolescents in Southern California. Diet pattern was determined from an extensive food frequency questionnaire in 1765 Caucasian children of 7-18 years, attending state schools (452 m and 443 f) and Seventh-day Adventist schools (427 m and 443 f). The major difference in diet pattern between state and Adventist school children was in meat consumption. The Adventist children were split evenly between three categories of frequency in meat consumption (less than 1/week, 1/week-less than 1/d, and greater than or equal to 1/d), while 92 percent of state school children consumed meat daily. Vegetarians (those consuming meat less than 1/week) differed significantly in the consumption of other major food groups, such as fruit and vegetables. All school and diet subgroups were at or above the 50th percentile of the National Center for Health Statistics. Age-adjusted regression analysis showed that on average Adventist vegetarian children were taller than their meat-consuming classmates (2.5 and 2.0 cm for boys and girls, respectively). These results did not change materially when adjusting for other food groups. Nor did adjustment for parental height and socioeconomic factors in a sub-sample of 518 children. The results indicate that vegetarian children and adolescents on a balanced diet grow at least as tall as children who consume meat.
The development of the male reproductive ducts and external genitalia in vertebrates is dependent on elevated androgen concentrations during embryonic development and the period of postnatal growth. We have observed that a population of juvenile alligators living on Lake Apopka exhibit significantly smaller penis size (24% average decrease) and lower plasma concentrations of testosterone (70% lower concentrations) when compared to animals of similar size on Lake Woodruff. In addition to smaller phalli, no relationship exists between plasma testosterone concentrations and penile size in males from Lake Apopka, whereas a positive relationship exists for males from Lake Woodruff. The alligators on Lake Apopka are known to have elevated concentrations of the antiandrogenic DDT breakdown product p.p'-DDE stored in their fat. We suggest a number of hypotheses that could explain the modification in the phenotype of the juvenile male living in Lake Apopka. These modifications in phenotype include a smaller penis size, lower plasma androgen concentrations, and lack of responsiveness of the penis to the plasma androgens present.
BACKGROUND: Gastrointestinal symptoms that respond to the removal of wheat and/or gluten are becoming more common. Patients who avoid wheat and/or gluten (PWAWG) are a heterogeneous group and predominantly self-diagnosed prior to presenting for clinical evaluation. SPECIFIC AIM: We characterized PWAWGs seen at a tertiary care referral center and compared them to patients with celiac disease (CD) and subjects in the National Health and Nutrition examination survey (NHANES). METHODS: This was a cross-sectional study evaluating patients seen by four gastroenterologists at a CD referral center. Baseline characteristics, laboratory values, and medical comorbidities were compared to CD patients who presented at the same center and subjects enrolled in NHANES. RESULTS: Eighty-four PWAWGs were identified and compared to 585 CD patients and 2,686 NHANES patients. Thirty-two alternative diagnoses were made in 25 (30%) PWAWGs, including small intestinal bacterial overgrowth and fructose/lactose intolerance. When compared to patients with CD, PWAWGs had similar body mass index (BMI, 23.1 vs. 23.5, p = 0.54) and mean hemoglobin value (13.4 vs. 13.3, p = 0.6). When compared to male and female patients in NHANES, BMI, folate, and mean hemoglobin values were lower in PWAWGs. Both male and female PWAWGs had a lower prevalence of hypertension. CONCLUSION: While there are similarities between CD and PWAWGs that could possibly be due to shared HLA haplotypes or an effect of the gluten-free diet, alternative diagnoses are common in these patients. PWAWGs have a similar cardiovascular profile as CD patients in terms of lower BMI and lower prevalence of hypertension.
Background/objectives: To determine the effects of a low-fat plant-based diet program on anthropometric and biochemical measures in a multicenter corporate setting. Subjects/methods: Employees from 10 sites of a major US company with body mass index ⩾25 kg/m2 and/or previous diagnosis of type 2 diabetes were randomized to either follow a low-fat vegan diet, with weekly group support and work cafeteria options available, or make no diet changes for 18 weeks. Dietary intake, body weight, plasma lipid concentrations, blood pressure and glycated hemoglobin (HbA1C) were determined at baseline and 18 weeks. Results: Mean body weight fell 2.9 kg and 0.06 kg in the intervention and control groups, respectively (P<0.001). Total and low-density lipoprotein (LDL) cholesterol fell 8.0 and 8.1 mg/dl in the intervention group and 0.01 and 0.9 mg/dl in the control group (P<0.01). HbA1C fell 0.6 percentage point and 0.08 percentage point in the intervention and control group, respectively (P<0.01). Among study completers, mean changes in body weight were −4.3 kg and −0.08 kg in the intervention and control groups, respectively (P<0.001). Total and LDL cholesterol fell 13.7 and 13.0 mg/dl in the intervention group and 1.3 and 1.7 mg/dl in the control group (P<0.001). HbA1C levels decreased 0.7 percentage point and 0.1 percentage point in the intervention and control group, respectively (P<0.01). Conclusions: An 18-week dietary intervention using a low-fat plant-based diet in a corporate setting improves body weight, plasma lipids, and, in individuals with diabetes, glycemic control.
OBJECTIVE: To test the hypothesis that a low-fat, vegetarian diet reduces dysmenorrhea and premenstrual symptoms by its effect on serum sex-hormone binding globulin concentration and estrogen activity. METHODS: In a crossover design, 33 women followed a low-fat, vegetarian diet for two menstrual cycles. For two additional cycles, they followed their customary diet while taking a supplement placebo pill. Dietary intake, serum sex-hormone binding globulin concentration, body weight, pain duration and intensity, and premenstrual symptoms were assessed during each study phase. RESULTS: Mean (+/- standard deviation [SD]) serum sex-hormone binding globulin concentration was higher during the diet phase (46.7 +/- 23.6 nmol/L) than during the supplement phase (39.3 +/- 19.8 nmol/L, P < .001). Mean (+/- SD) body weight was lower during the diet (66.1 +/- 11.3 kg) compared with the supplement phase (67.9 +/- 12.1 kg, P < .001). Mean dysmenorrhea duration fell significantly from baseline (3.9 +/- 1.7 days) to diet phase (2.7 +/- 1.9 days) compared with change from baseline to supplement phase (3.6 +/- 1.7 days, P < .01). Pain intensity fell significantly during the diet phase, compared with baseline, for the worst, second-worst, and third-worst days, and mean durations of premenstrual concentration, behavioral change, and water retention symptoms were reduced significantly, compared with the supplement phase. CONCLUSION: A low-fat vegetarian diet was associated with increased serum sex-hormone binding globulin concentration and reductions in body weight, dysmenorrhea duration and intensity, and premenstrual symptom duration. The symptom effects might be mediated by dietary influences on estrogen activity.
PURPOSE OF REVIEW: The prevalence of obesity in youth is increasing alarmingly among children and adolescents in the United States. The problem falls disproportionately on African-American and Hispanic children. Many of the metabolic and cardiovascular complications associated with obesity are already present during childhood and are closely linked to the concomitant insulin resistance/hyperinsulinemia and degree of obesity. Moreover, these co-morbidities persist into adulthood. RECENT FINDINGS: The progression from normal glucose tolerance to type 2 diabetes mellitus involves an intermediate stage known as prediabetes or impaired glucose regulation. Prediabetes is characterized by peripheral insulin-resistance and impaired glucose sensitivity of first-phase insulin secretion. On the other hand, in overt type 2 diabetes mellitus beta-cell failure becomes fully manifested. Progression from prediabetes to type 2 diabetes mellitus in youth is characterized by marked weight gain and further reduction in insulin secretion and insulin resistance. SUMMARY: Reverting obesity through lifestyle modification, that involves nutrition education, behavior modification and exercise, is an important step to prevent the progression to diabetes.
PURPOSE: To determine whether a multicomponent nutrition intervention program at a corporate site reduces body weight and improves other cardiovascular risk factors in overweight individuals. DESIGN: Prospective clinical intervention study. SUBJECTS/SETTING: Employees of the Government Employees Insurance Company (GEICO) (N = 113), aged 21 to 65 years, with a body mass index > or =25 kg/m(2) and/or previous diagnosis of type 2 diabetes. INTERVENTION: A 22-week intervention including a low-fat, vegan diet. MEASURES: Changes in body weight, anthropometric measures, blood pressure, lipid profile, and dietary intake. ANALYSIS: Multivariate analyses of variance were calculated for clinical and nutrient measures, followed by univariate analyses of variance, to determine the significance of differences between groups in changes over time. RESULTS: Intervention-group participants experienced greater weight changes compared with control-group participants (mean, -5.1 [SE, .6] kg vs. + .1 [SE, .6] kg, p < .0001), as well as greater changes in waist circumference (mean, -4.7 [SE, .6] cm vs. + .8 [SE, .6] cm, p < .0001) and waistratiohip ratio (mean, -.006 [SE, .003] vs. + .014 [SE, .005], p = .0007). Weight loss of 5% of body weight was more frequently observed in the intervention group (48.5%) compared with the control group (11.1%) (chi(2)[1, N = 113] = 16.99, p < .0001). CONCLUSIONS: Among individuals volunteering for a 22-week worksite research study, an intervention using a low-fat, vegan diet effectively reduced body weight and waist circumference.
Vitamin D deficiency is the most common nutritional deficiency and likely the most common medical condition in the world. The major cause of vitamin D deficiency has been the lack of appreciation that the body requires 5- to 10-fold higher intakes than is currently recommended by health agencies. There is now overwhelming and compelling scientific and epidemiologic data suggesting that the human body requires a blood level of 25(OH)D above 30 ng/mL for maximum health. To increase the blood level to the minimum 30 ng/mL requires the ingestion of at least 1000 IU of vitamin D per day for adults. In general, there is no downside to increasing either a child's or adult's vitamin D intake. Copyright 2010 Elsevier Inc. All rights reserved.
Vitamin A deficiency (VAD) has been recognized as a public-health issue in developing countries. Economic constraints, sociocultural limitations, insufficient dietary intake, and poor absorption leading to depleted vitamin A stores in the body have been regarded as potential determinants of the prevalence of VAD in South Asian developing countries. VAD is exacerbated by lack of education, poor sanitation, absence of new legislation and enforcement of existing food laws, and week monitoring and surveillance system. Several recent estimates confirmed higher morbidly and mortality rate among children and pregnant and non-pregnant women of childbearing age. Xerophthalmia is the leading cause of preventable childhood blindness with its earliest manifestations as night blindness and Bitot's spots, followed by blinding keratomalacia, all of which are the ocular manifestations of VAD. Children need additional vitamin A because they do not consume enough in their normal diet. There are three general ways for improving vitamin A status: supplementation, fortification, and dietary diversification. These approaches have not solved the problem in South Asian countries to the desired extent because of poor governmental support and supervision of vitamin A supplementation twice a year. An extensive review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science, and Google Scholar. All abstracts and full-text articles were examined, and the most relevant articles were selected for screening and inclusion in this review. Conclusively, high prevalence of VAD in South Asian developing countries leads to increased morbidity and mortality among infants, children, and pregnant women. Therefore, stern efforts are needed to address this issue of public-health significance at local and international level in lower- and middle-income countries of South Asia.
The marked age-related decline in serum dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) has suggested that a deficiency of these steroids may be causally related to the development of a series of diseases that are generally associated with aging. Postulated consequences of low DHEA levels include insulin resistance, obesity, cardiovascular disease, cancer, reduction of the immune defence system as well as psychosocial problems such as depression and a general deterioration in the sensation of well-being and cognitive function. Clinically, the spectrum of women that would benefit from DHEA therapy is not clearly defined and nor is the dosage of hormone treatment. Whether DHEA therapy could be prescribed as a general anti-aging therapy or could be an alternative treatment for women suffering from androgen deficiency syndrome remains uncertain across studies. The lack of definitive evidence for biological mechanisms and the presence of only a few studies that address these emerging issues of DHEA therapy in postmenopausal women might encourage a new critical analysis of the available literature, evidencing current limits and incongruities.
Background & Aims Asymptomatic diverticulosis is commonly attributed to constipation secondary to a low-fiber diet, although evidence for this mechanism is limited. We examined the associations between constipation and low dietary fiber intake with risk of asymptomatic diverticulosis. Methods We performed a cross sectional study, analyzing data from 539 individuals with diverticulosis and 1569 without (controls). Participants underwent colonoscopy and assessment of diet, physical activity and bowel habits. Our analysis was limited our analysis to participants with no knowledge of their diverticular disease, to reduce the risk of biased responses. Results Constipation was not associated with an increased risk of diverticulosis. Participants with less frequent bowel movements (BM: <7/wk) had reduced odds of diverticulosis compared to those with regular (7/wk) BM (odds ratio [OR] 0.56, 95% confidence interval [CI], 0.40–0.80). Those reporting hard stools also had a reduced odds (OR, 0.75; 95% CI, 0.55–1.02). There was no association between diverticulosis and straining (OR, 0.85; 95% CI, 0.59–1.22) or incomplete BM (OR, 0.85; 95% CI, 0.61–1.20). We found no association between dietary fiber intake and diverticulosis (OR, 0.96; 95% CI, 0.71–1.30) in comparing the highest quartile to the lowest (mean intake 25 versus 8 g/day). Conclusions In our cross-sectional, colonoscopy-based study, neither constipation nor a low-fiber diet was associated with an increased risk of diverticulosis.
We report on the case of an infant who was hospitalized because of failure to thrive, megaloblastic anemia, and delayed psychomotor development. He was 10 months old and had been exclusively breast-fed by his vegan mother. Investigations showed vitamin B(12) deficiency with hematocytopenia and pervasive developmental disorders as well as vitamin K and vitamin D deficiencies. The infant's mother presented the same deficiencies. Introduction of vitamin supplementation normalized the biological disorders, and the infant showed weight gain and neurological improvement. This case highlights that a vegan diet during pregnancy followed by exclusive breast-feeding can induce nutritional deficiencies in the newborn, with clinical consequences. Detecting mother and child vitamin deficiencies and preventing them is essential.
Previously used standards for the diagnosis of precocious puberty in girls no longer appear to be appropriate in the USA, in that a significant number of girls are being seen in paediatricians' offices with breast budding before 8 years of age. The timing of menarche, however, has changed little over the past few decades. Early maturing girls are more likely to become obese in adolescence and adulthood than normal or late maturing girls. Early maturing white girls are heavier at the onset of puberty, but this is not the case for African-American girls or boys of either race. Boys and girls with premature pubarche may be more hyperinsulinaemic than normal children, and girls with premature pubarche more likely to develop functional ovarian and adrenal hyperandrogenism. Early menarche is preceded by prepubertal hyperinsulinaemia. It is proposed that pubertal onset, although not necessarily the tempo of puberty, is influenced by hyperinsulinaemia and insulin resistance. If this hypothesis is correct, insulin resistance may be more prevalent in US children than previously recognized. An advance in timing of onset of puberty has not been noted in other countries, although it is likely that this phenomenon may become more prevalent as other countries adopt a more American lifestyle and diet.
We examined effects of fiber on stool output, since this is one of the primary mediating variables for the hypothesized relationship between fiber and disease. Total neutral detergent fiber in the dietary fiber source was predictive of stool weight but not frequency. Substantial individual differences in stool output remained when dietary factors were controlled. Personality measures were used to predict stool weight and frequency independently of diet, and accounted for about as much variance in stool output as did dietary fiber. These results suggest that personality factors predispose some persons to low stool output. These individuals may benefit particularly from dietary fiber.
Cutaneous synthesis of vitamin D by exposure to UVB is the principal source of vitamin D in the human body. Our current clothing habits and reduced time spent outdoors put us at risk of many insufficiency-related diseases that are associated with calcaemic and non-calcaemic functions of vitamin D. Populations with traditional lifestyles having lifelong, year-round exposure to tropical sunlight might provide us with information on optimal vitamin D status from an evolutionary perspective. We measured the sum of serum 25-hydroxyvitamin D₂ and D₃ (25(OH)D) concentrations of thirty-five pastoral Maasai (34 (SD 10) years, 43 % male) and twenty-five Hadzabe hunter-gatherers (35 (SD 12) years, 84 % male) living in Tanzania. They have skin type VI, have a moderate degree of clothing, spend the major part of the day outdoors, but avoid direct exposure to sunlight when possible. Their 25(OH)D concentrations were measured by liquid chromatography-MS/MS. The mean serum 25(OH)D concentrations of Maasai and Hadzabe were 119 (range 58-167) and 109 (range 71-171) nmol/l, respectively. These concentrations were not related to age, sex or BMI. People with traditional lifestyles, living in the cradle of mankind, have a mean circulating 25(OH)D concentration of 115 nmol/l. Whether this concentration is optimal under the conditions of the current Western lifestyle is uncertain, and should as a possible target be investigated with concomitant appreciation of other important factors in Ca homeostasis that we have changed since the agricultural revolution.
Mild iodine deficiency is a recognised problem in Australia and New Zealand. However, iodine excess can cause hypothyroidism in some infants. We highlight two cases which illustrate the risks of excess dietary iodine intake during pregnancy and breastfeeding. They also describe a cultural practice of consuming seaweed soup to promote breast milk supply. Although most attention recently has been on the inadequacy of iodine in Australian diets, the reverse situation should not be overlooked. Neither feast nor famine is desirable. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).