David C. K. Roberts

Dietary and Supplement Treatment of Iron Deficiency Results in Improvements in General Health and Fatigue in Australian Women of Childbearing Age

Objective: To examine the effects of iron deficiency and its treatment by iron supplementation or a high iron diet on fatigue and general health measures in women of childbearing age. Design: Randomised controlled trial to compare supplement and dietary treatment of iron deficiency. Subjects: 44 iron deficient (serum ferritin <15 μg/L or serum ferritin 15–20 μg/L, plus two of the following: serum iron <10 μmol/L, total iron binding capacity >68 μmol/L or transferrin saturation <15%) and 22 iron replete (hemoglobin ≥120 g/L and serum ferritin >20 μg/L) women 18 to 50 years of age were matched for age and parity. Interventions: Iron deficient women were randomly allocated to either iron supplementation or a high iron diet for 12 weeks. Measures of Outcome: Iron deficient and iron replete participants had iron studies performed and completed the Piper Fatigue Scale (PFS) and the SF-36 general health and well-being questionnaire at baseline (T0), following the 12 week intervention (T1) and again after a six-month non-intervention phase (T2). The SF-36 includes measures of physical (PCS) and mental (MCS) health and vitality (VT). Results: MCS and VT scores were lower and PFS scores were higher for iron deficient women (diet and supplement groups) than iron replete women at baseline. Both intervention groups showed similar improvements in MCS, VT and PFS scores during the intervention phase, but mean increases in serum ferritin were greater in the supplement than the diet group. PCS scores were not related to iron status. Conclusions: Treatment of iron deficiency with either supplementation or a high iron diet results in improved mental health and decreased fatigue among women of childbearing age.

Iron deficiency, general health and fatigue: Results from the Australian Longitudinal Study on Women's Health

Associations between self-reported ‘low iron’, general health and well-being, vitality and tiredness in women, were examined using physical (PCS) and mental (MCS) component summary and vitality (VT) scores from the MOS short-form survey (SF-36). 14,762 young (18–23 years) and 14,072 mid-age (45–50 years) women, randomly selected from the national health insurance commission (Medicare) database, completed a baseline mailed self-report questionnaire and 12,328 mid-age women completed a follow-up questionnaire 2 years later. Young and mid-age women who reported (ever) having had ‘low iron’ reported significantly lower mean PCS, MCS and VT scores, and greater prevalence of ‘constant tiredness’ at baseline than women with no history of iron deficiency [Differences: young PCS = −2.2, MCS = −4.8, VT = −8.7; constant tiredness: 67% vs. 45%; mid-age PCS = −1.4, MCS = −3.1, VT = −5.9; constant tiredness: 63% vs. 48%]. After adjusting for number of children, chronic conditions, symptoms and socio-demographic variables, mean PCS, MCS and VT scores for mid-age women at follow-up were significantly lower for women who reported recent iron deficiency (in the last 2 years) than for women who reported past iron deficiency or no history of iron deficiency [Means: PCS – recent = 46.6, past = 47.8, never = 47.7; MCS – recent = 45.4, past = 46.9, never = 47.4; VT – recent = 54.8, past = 57.6, never = 58.6]. The adjusted mean change in PCS, MCS and VT scores between baseline and follow-up were also significantly lower among mid-age women who reported iron deficiency only in the last 2 years (i.e. recent iron deficiency) [Mean change: PCS = −3.2; MCS = −2.1; VT = −4.2]. The results suggest that iron deficiency is associated with decreased general health and well-being and increased fatigue.

Calcium absorption measured by stable calcium isotopes (42Ca & 44Ca) among northern Chinese adolescents with low vitamin D status

An adequate calcium intake and vitamin-D status is important for bone mineralization in adolescents. In Northern China, calcium intake and plasma vitamin-D level of adolescents is low due to low consumption of dairy foods and inadequate sunshine exposure. True fractional calcium absorption (TFCA) in Chinese adolescents has never been performed. This study aims to evaluate nutritional adaptation namely, TFCA and urinary calcium excretion among Chinese adolescents in northern China.

Stages of Change and Reduction of Dietary Fat: Effect of Knowledge and Attitudes in an Australian University Population

Abstract This survey focused on the use of the stages of change model of behavior change in reducing dietary fat intake while identifying attitudinal variables that might be relevant in the decision to change ones dietary habits. Knowledge of dietary fat and reported fat intake were also examined. Data were obtained using a cross-sectional survey of 1081 university employees. The Precontemplation stage comprised the largest group of respondents (33%) while the Contemplation stage was the smallest group, containing only 6% of respondents. Twelve percent of respondents were in the Preparation stage while the Action and Maintenance groups comprised 22% and 27% of the total population, respectively. Two one-way multivariate analyses of variance were used to compare male and female respondents across the five stages of change on knowledge, dietary fat intake, benefits, and barriers. Dietary fat intake and barriers to reducing fat intake decreased significantly across the stages of change while the benefits to change increased significantly across the stages. The results of our study confirm differences in stages of change in fat intake and indicate the need for taking these phases of change into account in nutrition advice.

The effectiveness of nutrition counselling by Australian General Practitioners.

Objective:To determine whether General Practitioners (GPs) consider or provide nutrition counselling for hypertension, diabetes, lipid disorders, ischaemic heart disease (IHD), overweight or obesity, and whether GPs include assessment of the patients usual diet, assessment of the patients readiness to change their diet, provision and discussion of nutrition leaflets when counselling.Design:A self-completed questionnaire.Setting:New South Wales, Australia.Subjects:A total of 399 GPs were surveyed using a division mailing list.Methods:Questionnaires were distributed in May 2004 with two reminders provided at four-weekly intervals.Results:Of the 399 GPs, 28 no longer practiced at the address while nine were on extended leave. Of the remaining 362, 50% responded, 5% declining to participate, while 163 (45%) completed the questionnaire. GPs were less likely to strongly agree to consider nutrition for hypertension (37%), IHD (61%) and overweight (68%), than diabetes (86%), lipid disorders (82%) and obesity (83%). They were also less likely to strongly agree to provide nutrition for hypertension (22%), IHD (46%) and overweight (45%), than diabetes (79%), lipid disorders (71%) and obesity (68%). In total, 97% of GPs provided some nutrition counselling, with 66% ‘often’ assessing the patients diet and 59% ‘often’ assessing the patients readiness to change their diet. In total, 45% were unaware of stage of change behaviour theory. A total of 85% used nutrition leaflets and 59% ‘often’ discussed these with their patients.Conclusions:Determining what are the barriers to nutrition counselling for hypertension, IHD and overweight is urgently needed. Educating GPs on stage of change behaviour theory could increase the efficacy of the counselling provided.

A31P nuclear magnetic resonance investigation of acyl group transfer from phosphatidylcholine to yield lysophosphatidylcholine in human plasma

Abstract31P nuclear magnetic resonance (NMR) spectroscopy was used to measure the rate of acyl transfer from phosphatidylcholine (lecithin, PC) in whole plasma and in high density lipoprotein (HDL). Spectral deconvolution was used to resolve overlapping resonances in the31P NMR spectra of the phospholipids. Mean values of the acyl group transfer rates from PC in plasma and HDL were 36 μmol L−1h−1 and 19 μmol L−1h−1, respectively. The reciprocal nature of the decrease in the spectral peak intensities of PC, compared to the increase in the intensities of the lysolecithin (lysoPC) peaks, suggested a substrate/product relationship consistent with the action of lecithin:cholesterol acyltransferase (LCAT), the enzyme responsible for the esterification of free cholesterol in plasma. LCAT involvement was confirmed by measuring the cholesterol esterification rate based on the13C NMR spectra obtained on lipid extracts from plasma that had been incubated at 37°C. Within experimental error, the rate of lysoPC formation in plasma was shown to be equal to that of cholesteryl ester formation.

Meat meal replacement in diets for silver perch, Bidyanus bidyanus: effect on growth, protein and lipid composition.

Abstract Fish meal is currently the major protein source in fish feeds. However rising costs and decreasing availability of fish meal are placing pressure on the aquaculture industry to find suitable alternative sources of protein. The replacement of fish meal and fish oil in aquaculture diets may have a negative impact on the n-3 polyunsaturated fatty acid (PUFA) content of the final fish flesh. The goal of this study was to investigate the effects on production and composition especially lipid fatty acids of juvenile silver perch, Bidyanus bidyanus, by replacing dietary fish meal with meat meal. Silver perch were fed one of five diets with similar content of protein and digestible energy (DE) but different amounts of fish meal and lamb meal or ProvineR (a speciality high protein meat meal) for a period of 65 days in 10,000-L tanks. Water temperature ranged between 24.3 and 26.7°C, and aerated recirculated fresh water was filtered through a rapid rate sand filter before being supplied to experimental tanks at a flow rate of 17 L/minute. Fish growth was reduced when diets contained less than 13% fish meal and more than 9% ProvineR. No significant differences (P> 0.05) were detected in the moisture, protein, and total fat content of the silver perchfed the experimental diets. With respect to lipid composition, there were also no differences in saturated, monounsaturated, and n-6 PUFA among fish fed the experimental diets. The 27% fish meal diet produced fish with significantly (P< 0.05) higher amounts of the longer chain n-3 PUFA than fish fed the diets with meat meal. Meat meal diets produced comparable growth, similar amounts of total fat and saturated fat, but significantly lower amounts of the n-3 PUFA.

Virus specific and polyclonal responses following challenge with influenza in immunised mice fed fish oil, linseed oil or beef tallow

Experiments were conducted to determine the effect of diets containing fish oil (providing long chain n-3 fatty acids), linseed oil (providing the shorter chain n-3 fatty acid, alpha linolenic acid) or beef tallow (control diet) and different doses or routes of immunisation (oral, intra-peritoneal or sub-cutaneous) on immunity to influenza virus in mice. Between diet groups there was no difference in virus clearance or influenza virus specific antibody (serum immunoglobulin (Ig) G, lung IgG, lung IgA) for each route of immunisation. Between immunisation routes, intra-peritoneal immunisation was associated with the highest lung IgG after challenge while sub-cutaneous immunisation was associated with poorer virus clearance. Immunised mice fed linseed oil cleared more virus than non-immunised controls regardless of immunisation route. There was no difference in virus clearance or influenza specific antibody response between fish oil and beef tallow fed mice at each oral vaccine dose. Even at the lowest immunisation dose, with little antibody present, virus load was significantly lower than non-immunised controls suggesting a major contribution from cell mediated immunity. Total (polyclonal) lung IgG was higher in orally immunised and non immunised beef tallow fed mice and total lung IgA was higher in orally immunised beef tallow fed mice although these differences were not associated with a difference in virus clearance. Splenocytes from orally immunised and non-immunised mice fed fish oil had higher proliferative responses to Concanavalin A. The present experiments demonstrate that fish and linseed oil diets do not impair influenza virus clearance in mice immunised by mucosal routes.