Lesley MacDonald-Wicks

Micronutrient intakes during pregnancy in developed countries: Systematic Review and Meta-Analysis

Micronutrient status during pregnancy influences maternal and fetal health, birth outcomes, and the risk of chronic disease in offspring. Research reporting dietary intake during pregnancy in nationally representative population samples, however, is limited. This review summarizes the micronutrient intakes of pregnant women from developed countries and compares them with relevant national recommendations. A systematic search without date limits was conducted. All studies reporting the micronutrient intakes of pregnant women were considered, irrespective of design. Two authors independently identified studies for inclusion and assessed methodological quality. Nutritional adequacy was summarized, with confounding factors considered. Meta-analysis data are reported for developed countries collectively, by geographical region, and by dietary methodology. Pregnant women in developed countries are at risk of suboptimal micronutrient intakes. Folate, iron, and vitamin D intakes were consistently below nutrient recommendations in each geographical region, and calcium intakes in Japan were below the Japanese recommendations and the average intake levels in other developed countries. Research examining the implications of potential nutrient insufficiency on maternal and offspring health outcomes is needed along with improvements in the quality of dietary intake reporting.

Systematic review and meta-analysis of energy and macronutrient intakes during pregnancy in developed countries

Research reporting diet during pregnancy in nationally representative samples is limited. This review summarizes the dietary intakes of pregnant women in developed countries and compares them with national recommendations. A systematic search without date limits was conducted. All studies reporting the macronutrient intakes of pregnant women were considered, irrespective of design. Two authors independently identified the studies to be included and assessed the methodological quality. Nutritional adequacy was summarized, with confounding factors considered. Meta-analysis data are reported for developed countries collectively, by geographical region, and by dietary methodology. Energy and macronutrient intakes of pregnant women do not match national recommendations. Energy and fiber intakes were consistently below recommendations, while total fat and saturated fat intakes were generally above recommendations and carbohydrate and polyunsaturated fat intakes were below to borderline low compared with recommendations. A mismatch between dietary practices and macronutrient recommendations in pregnant women is widespread and not well quantified. The implications of these practices are unknown until further research compares maternal diet with short-term and long-term maternal and offspring health outcomes.

Dietary balance during pregnancy is associated with fetal adiposity and fat distribution

BACKGROUND The prenatal environment can induce permanent changes in offspring phenotype. Thinness at birth is associated with adult risk of cardiometabolic disease. OBJECTIVE The objective was to investigate the association between maternal nutrition during pregnancy and intrauterine development of fetal body composition. DESIGN We used prospective data from 179 Australian women with singleton pregnancies from the Women and Their Childrens Health Study. A validated food-frequency questionnaire was used at 18-24 wk and 36-40 wk of gestation to quantify maternal diet during the previous 3 mo of pregnancy. Fetal body-composition measurements were ascertained from abdominal and midthigh sites by ultrasound performed at 19, 25, 30, and 36 wk. The subcutaneous fat area at each site was calculated by subtracting the lean/visceral area from the total area. RESULTS In linear mixed-model regressions, maternal intakes of protein (b = -0.13; P = 0.04) and starch (b = 0.10; P = 0.02) and the protein:carbohydrate ratio (b = -3.61; P = 0.02) were associated with the percentage of abdominal fat, whereas SFA (b = 0.27; P = 0.04) and PUFA (b = -0.48; P = 0.03) were associated with the percentage of midthigh fat. Response surfaces for fetal adiposity were maximized at different macronutrient intakes. Abdominal fat was highest with low protein intakes (<16% of energy), and midthigh fat was highest at intermediate protein (18-21% of energy), high fat (>40% of energy), and low carbohydrate (<40% of energy) intakes. CONCLUSION Fetal body composition may be modifiable via nutritional intervention in the mother and thus may play an important role in influencing the offsprings risk of future disease.

Normal growth in cystic fibrosis associated with a specialised centre

OBJECTIVE To assess the impact of lifetime continuous care within the John Hunter Hospital cystic fibrosis (CF) clinics on growth and lung function. DESIGN A cross sectional survey of variables affecting nutritional status in CF was undertaken for 1993 and 1997. Data were retrieved from medical records and grouped into 5 year age bands. MAIN OUTCOME MEASURES Change in height z-score, weight centile, and forced expiratory volume in one second (FEV1) between patient cohorts receiving specialised care for different lengths of time. RESULTS Improved mean height z-score (−0.880 v −0.047) and weight centile (28.3% v 48.1%) for the 10–15 year age group in 1997, who had received continuous lifetime care within the clinic, compared with the same age group in 1993, for whom continuous medical care started at an older age. There was no corresponding improvement in FEV1, as an indicator of lung function, in this group (81.6% predicted v89.5% predicted). CONCLUSIONS This study suggests that lifetime continuous care within a specialised CF centre is associated with improved growth but not improved lung function.

Disparities exist between National food group recommendations and the dietary intakes of women

BackgroundPreconception and pregnancy dietary intakes can influence the health of future generations. In this study we compared the food intakes of reproductive-aged women by pregnancy status, to current Australian recommendations.MethodsData are from the Australian Longitudinal Study on Womens Health, younger cohort aged 25-30 years in 2003, with self-reported status as pregnant (n = 606), trying to conceive (n = 454), given birth in the last 12 months (n = 829) or other (n = 5597). Diet was assessed using a validated 74-item food frequency questionnaire. Food group servings and nutrient intakes were compared to the Australian Guide to Healthy Eating (AGHE) and Australian Nutrient Reference Values (NRVs).ResultsNo women met all AGHE food group recommendations. Highest adherence rates [mean (95% CI) servings/day] were for meat [85%, 1.9(1.8-1.9)], fruit [44%, 2.1(2.1-2.2)] and dairy [35%, 1.8(1.8-1.9)], with < 14% meeting remaining recommendations. Women who achieved NRVs (folate, iron, calcium, zinc, fibre) for pregnancy, breastfeeding and adult life stages were 1.5%, 3.3% and 13.7%, respectively. Compared to AGHE, women consumed more servings of fruit (4.9 vs 4.0;P = 0.034) and dairy (3.4 vs 2.0;P = 0.006) to achieve pregnancy NRVs; more dairy (2.9 vs 2.0;P = 0.001), less fruit (3.9 vs 5.0;P < .001) and vegetables (3.4 vs 7.0;P < .001) to achieve breastfeeding NRVs; more fruit (3.6 vs 3.0;P < .001), dairy (2.5 vs 2.0;P < .001), meat (1.8 vs 1.5;P = 0.015), less vegetables (3.6 vs 5.0;P < .001) to achieve adult NRVs.ConclusionsThe AGHE does not align with contemporary diets of Australian women or enable them to meet all NRVs. Current tools to guide food consumption by women during pregnancy require revision.

Investigation of the association between dietary intake, disease severity and airway inflammation in asthma.

Dietary intake is an important modifiable risk factor for asthma and may be related to disease severity and inflammation, through the effects of intake of anti‐oxidant‐rich foods and pro‐inflammatory nutrients. This study aimed to examine dietary intake in asthma in relation to asthma severity, lung function, inhaled corticosteroid use, leptin levels and inflammation.

Consumption of an n-3 polyunsaturated fatty acid-enriched dip modulates plasma lipid profile in subjects with diabetes type II

Objective:Recent developments in micro-emulsification technology have allowed the fortification of foods with long-chain n-3 polyunsaturated fatty acid (PUFA) without the undesirable fish odour/taste and with reasonable shelf life. The effects of supplementing the diets of people with diabetes type II with a hummus-based dip enriched with long-chain n-3PUFA on plasma fatty acid composition and lipid levels were examined.Design:A pre- and post-intervention study.Setting:This study was conducted at the University of Newcastle, Australia.Subjects:Participants were recruited via advertisements on the University of Newcastle notice boards and in the local newspapers. Following initial response to study advertisements, information statements were mailed out to 29 potential participants. Thirteen participants were eligible and consented to participate in the trial. There were no dropouts as all the 13 participants completed 6-week intervention trial.Methods:Free-living male and female subjects with diabetes type II (n=13) consumed the n-3PUFA-enriched dip for a period of 6 weeks. Fasting blood samples were collected pre- and post-intervention for analyses of fatty acids and plasma lipids.Results:Following 6 weeks of consuming the enriched dip, all the long-chain n-3PUFA (20:5n-3, 22:5n-3 and 22:6n-3) were significantly (P<0.05) elevated in the plasma lipids. This represented an increase in 20:5n-3 content by 117%, an increase in 22:5n-3 content by 15% and an increase in 22:6n-3 content by 80% over the baseline values before dip consumption. A significant reduction (P<0.05) in the plasma triglyceride levels from 1.93 (1.08–2.09) mmol/l at baseline to 1.27 (0.93–2.22) mmol/l after 6 weeks was also apparent following the consumption of the n-3PUFA-enriched dip. Plasma cholesterol was unchanged; however, low-density lipoprotein (LDL)-cholesterol (2.46±0.21 versus 2.72±0.22 mmol/l, P<0.034) and high-density lipoprotein (HDL)-cholesterol (1.16±0.09 versus 1.22±0.09 mmol/l, P<0.042) were significantly increased following the dietary intervention.Conclusions:These results demonstrate that n-3PUFA are readily bioavailable from the fortified dip matrix and alter the plasma lipid profile.Sponsorship:This study was conducted without a dedicated fund source.

Vitamin E supplementation in the mitigation of carbon tetrachloride induced oxidative stress in rats.

Oxidative stress is implicated in the pathophysiology of a number of chronic diseases including atherosclerosis, diabetes, cataracts and accelerated aging. The aim of this study was to elucidate the protective role of vitamin E supplementation when oxidative stress is induced by CCl4 administration, using the rat as a model. Rats were fed diets for four weeks either with or without dl-alpha-tocopherol acetate supplementation. Half of the rats (n = 9) from each of the diet groups were then challenged with CCl4 at the completion of the four week diet period. Plasma levels of 8-iso-PGF(2alpha), antioxidant micronutrients and antioxidant enzyme activities were measured to examine changes in oxidative stress subsequent to the supplementation of dl-alpha-tocopherol in the diet. Plasma alpha-tocopherol (vitamin E) concentrations were higher for the groups supplemented with dl-alpha-tocopherol acetate, however the supplemented diet group that was subsequently challenged with CCl4 had significantly lower (p <0.001) plasma alpha-tocopherol concentration than the dl-alpha-tocopherol acetate diet group that was not challenged with CCl4. Total plasma 8-iso-PGF(2alpha) concentration was elevated in diet groups challenged with CCl4, however, the concentration was significantly lower (p <0.001) when the diet was supplemented with dl-alpha-tocopherol acetate. The antioxidant enzymes were not influenced by either dietary alpha-tocopherol manipulation or by the inducement of oxidative stress with CCl4. Plasma concentrations of trans-retinol (vitamin A) were reduced by CCl4 administration in both the dl-alpha-tocopherol acetate supplemented and unsupplemented diet groups. The results of this study indicate that dl-alpha-tocopherol acetate supplementation was protective of lipid peroxidation when oxidative stress is induced by a pro-oxidant challenge such as CCl4.

Incorporation of n−3 fatty acids into plasma and liver lipids of rats: Importance of background dietary fat

The health benefits of long-chain n−3 PUFA (20∶5n−3 and 22∶6n−3) depend on the extent of incorporation of these FA into plasma and tissue lipids. This study aimed to investigate the effect of the background dietary fat (saturated, monounsaturated, or n−6 polyunsaturated) on the quantitative incorporation of dietary 18∶3n−3 and its elongated and desaturated products into the plasma and the liver lipids of rats. Female weanling Wistar rats (n=54) were randomly assigned to six diet groups (n=9). The fat added to the semipurified diets was tallow (SFA), tallow plus linseed oil (SFA-LNA), sunola oil (MUFA), sunola oil plus linseed oil (MUFA-LNA), sunflower oil (PUFA), or sunflower oil plus linseed oil (PUFA-LNA). At the completion of the 4-wk feeding period, quantitative FA analysis of the liver and plasma was undertaken by GC. The inclusion of linseed oil in the rat diets increased the level of 18∶3n−3, 20∶5n−3, and, to a smaller degree, 22∶6n−3 in plasma and liver lipids regardless of the background dietary fat. The extent of incorporation of 18∶3n−3, 20∶5n−3, and 22∶5n−3 followed the order SFA-LNA>MUFA-LNA>PUFA-LNA. Levels of 22∶6n−3 were increased to a similar extent regardless of the type of major fat in the rat diets. This indicates that the background diet affects the incorporation in liver and plasma FA pools of the n−3 PUFA with the exception of 22∶6n−3 and therefore the background diet has the potential to influence the already established health benefits of long-chain n−3 fatty acids.

A systematic review of the effect of oral glucocorticoids on energy intake, appetite, and body weight in humans

Obesity is a serious risk factor for chronic disease, and commonly prescribed oral glucocorticoids (OCS) may be contributing to the prevalence of obesity. The objective of this review was to assess the impact of OCS on obesity in humans through effects on body weight (BW), energy intake, appetite, and body composition. An electronic search of English language peer-reviewed studies from 1973 up to March 2012 was conducted using Medline, CINAHL, EMBASE, and Cochrane databases. Original studies that addressed the effects of OCS on appetite, energy intake, BW, or body composition in adults were considered eligible. Data from 21 studies with objectively measured outcomes were extracted and assessed for quality using standardized tools. The publication year varied from 1986 to 2013, and the sample size, from 6 to 189. Energy intake was measured in 6 studies; BW, in 19 studies; energy expenditure, in 3 studies; body composition, in 6 studies; and appetite was evaluated in 3 studies. Short-term oral glucocorticoid therapy may result in small increases in energy intake but does not appear to result in increased BW, possibly due to an increase in energy expenditure. Long-term therapy may result in clinically significant weight gain. Within-subject variation due to metabolism and physical activity levels confounds the relationship. A dose-response relationship of oral glucocorticoid therapy on energy intake, appetite, BW, or body composition was not found. Additional well-designed, double-blind, placebo-controlled clinical trials that use standardized doses of OCS and assess the effects on appetite, energy intake, BW, and composition are strongly justified to confirm the findings of this review.