Emma Derbyshire

Capsaicinoids and capsinoids. A potential role for weight management? A systematic review of the evidence.

Capsaicinoids are a group of chemicals found in chilli peppers, with bioactive properties. The purpose of this study is to systematically review research investigating the potential benefits capsaicinoid compounds may have in relation to weight management. Medical databases were searched and 90 trials found, 20 of which were selected for inclusion, involving 563 participants. Three main areas of potential benefit for weight management were found: (1) increased energy expenditure; (2) increased lipid oxidation and (3) reduced appetite. Trial duration, dosage and sized varied, though trials were generally of high quality with a low risk of bias. It was observed that consumption of capsaicinoids increases energy expenditure by approximately 50 kcal/day, and that this would produce clinically significant levels of weight loss in 1-2 years. It was also observed that regular consumption significantly reduced abdominal adipose tissue levels and reduced appetite and energy intake. The mechanism of action is not presently fully understood, although it is well accepted much of the effects are caused by stimulation of the TRPV1 receptor. While capsaicinoids are not a magic bullet for weight loss, the evidence is that they could play a beneficial role, as part of a weight management program.

Habitual micronutrient intake during and after pregnancy in Caucasian Londoners

Micronutrient status is of fundamental importance both upon conception and throughout pregnancy. There is an abundance of literature investigating nutrient intakes during individual trimesters of pregnancy but few studies have investigated baseline intakes of nutrients throughout gestation as a continuum. The current investigation set out to measure habitual micronutrient intakes at weeks 13, 25, 35 of pregnancy and 6 weeks postpartum using a prospective background information questionnaire, 4-7-day weighed food diary and postnatal questionnaire. Seventy-two primiparous, Caucasian Londoners were recruited at the study start with 42 completing the first, second, third trimester and postpartum study stages respectively. Study findings indicated that sodium intakes were significantly higher than UK guidelines throughout and after pregnancy (P < 0.001). Intakes of folate, iron, vitamin D, potassium, iodine and selenium were lower than UK recommendations during and after pregnancy, but to varying levels of statistical significance (P < 0.05). Only 23-38% of women met UK recommendations for folate (300 microg day(-1)) through dietary sources. Similarly, only a small percentage of women met dietary guidelines for iron (19-28%). The findings from the current study indicate that public health interventions may be required to help expectant mothers achieve an optimal diet, particularly after birth when dietary recommendations increase for some micronutrients.

Bioavailability and Potential Uses of Vegetarian Sources of Omega-3 Fatty Acids: A Review of the Literature

Presently alpha-linolenic acid (ALA) is the most widely used vegetarian LC3PUFA, but only marginal amounts are converted into eicosapentaenoic (EPA) and docosahexaenoic acid (DHA); both of which are strongly related to human health. Currently, fish oils represent the most prominent dietary sources of EPA and DHA; however, these are unsuitable for vegetarians. Alternative sources include flaxseed, echium, walnut, and algal oil but their conversion to EPA and DHA must be considered. The present systematic review sets out to collate information from intervention studies examining the bioavailability of alternative vegetarian long chain omega-3 (n-3) polyunsaturated fatty acids (LC3PUFA) sources. Ten key papers published over the last 10 years were identified with seven intervention studies reporting that ALA from nut and seed oils was not converted to DHA at all. Three studies showed that ingestion of micro-algae oil led to significant increases in blood erythrocyte and plasma DHA. Further work is now needed to identify optimal doses of alternative vegetarian LC3PUFAs and how these can be integrated within daily diets. The potential role of algal oils appears to be particularly promising and an area in which further research is warranted.

Enrichment of extruded snack products with coproducts from chestnut mushroom (Agrocybe aegerita) production: interactions between dietary fiber, physicochemical characteristics, and glycemic load.

Mushrooms are a common vegetable product that have also been linked to pharmaceutical and medicinal uses. However, the production of the fruiting bodies of mushrooms results in a large quantity of food waste in the form of spent compost. Hyphae and the base of fruit bodies from Agrocybe aegerita were retrieved from spent mushroom compost and refined as a freeze-dried powder. This fiber-rich ingredient was used in the manufacture of ready-to-eat extruded cereal snack products. Inclusions rates were 0, 5, 10, and 15% w/w replacement levels for wheat flour from a control recipe. Inclusion of mushroom coproduct material (MCM) was significantly correlated to increased product expansion (r = 0.848) and density (r = 0.949) but negatively correlated to water absorption index (WAI; r = -0.928) and water solubility index (WSI; r = -0.729). Fiber content could not be correlated to differences in pasting properties of extruded snacks even though snack products with MCM showed significantly lower final viscosity values compared to the control. The potential glycemic response of foods was significantly lowered by including MCM (p < 0.05) with a negative correlation between fiber content and overall AUC following a standardized in vitro digestion method (r = -0.910). Starch content, WAI, and WSI were positively correlated to AUC of extruded snacks (r = 0.916, 0.851, and 0.878. respectively). The results illustrate a reduction in the potential glycemic response from including 5% (w/w) of MCM in extruded snacks exceeds 20%. Thus, the incorporation of MCM in ready-to-eat snack foods may be of considerable interest to the food industry in trying to regulate the glycemic response of foods.

Changes in Bowel Function: Pregnancy and the Puerperium

Pregnancy is a time when women are susceptible to bowel habit perturbations. The purpose of this study was to provide new baseline data for a range of bowel habit parameters. Prospective 7-day bowel habit diaries were completed during each of the three trimesters of pregnancy and after birth. Sensations of incomplete evacuation and time spent defecating were significantly increased during all three trimesters of pregnancy compared with after birth (P < 0.05). Symptoms of urgency were higher in nonlactating mothers (41% of occasions) compared with lactating women (17% pf occasions) (P=0.07). This study has confirmed the importance of investigating a range of bowel habit parameters during and after pregnancy—investigation of constipation per se may obscure changes in individual bowel habit parameters.

Latest evidence on omega-3 fatty acids and health.

Purpose – There is strong evidence that very long chain omega‐3 polyunsaturated fatty acids (LC3PUFA) are beneficial. The aim of this paper is to review the role of LC3PUFA in health and put this in context with habitual intakes and international recommendations.Design/methodology/approach – A literature review was conducted to locate and summarise relevant published studies and reports.Findings – There is good evidence that LC3PUFA help prevent cardiovascular disease, and may ameliorate inflammatory conditions and mental health issues, as well as supporting cognitive function throughout life. UK dietary surveys show that average fish intakes are well below the recommended two portions per week. Given that the majority of consumers do not eat oily fish, it is reasonable to consider the potential contribution of dietary supplements or fortified foods, although the latter must be sufficiently high in LC3PUFA to merit consideration.Research limitations/implications – Information on LC3PUFA intakes in the UK ...

Habitual caffeine intake in women of childbearing age

BACKGROUND For women, delayed conception and recurrent pregnant loss are just a few of the health implications associated with a caffeine-rich diet (Mol. Hum. Reprod., 11, 357). At present there is a deficit of prospective research measuring current habitual intakes of caffeine in UK women. The purpose of the current study was to collect up-to-date baseline data to assess caffeine intake and knowledge in a group of women (aged 16-45 years). METHODS Seventy Caucasian subjects (mean age 30.4 +/- 8.7 years) were recruited from business offices within the Manchester area. Each participant completed a 3-day food diary and lifestyle questionnaire. RESULTS The mean intake of caffeine was 173.95 mg day(-1) (+/-128.39 mg day(-1)). Eighteen per cent of subjects exceeded caffeine guidelines and consumed 300 mg caffeine or more each day. Subjects consuming over 300 mg day(-1) were more likely to be older (P = 0.016) and smokers (P = 0.000). Individuals given previous advice about caffeine and health, had lower intakes (P = 0.002). CONCLUSIONS Many women are unaware of health perturbations associated with caffeine consumption. A diet abundant in caffeine may result in delayed conception, infertility and increased risk of osteoporosis, cardiovascular disease and cancer later in life. Such information needs to be conveyed to the public sector. Future research is also required to devise specific caffeine guidelines, particularly safe upper limits.

A systematic review of the association between cardiovascular risk factors and regular consumption of oats

Purpose – To review the evidence from high quality human intervention studies that reported links between oat consumption and cardiovascular disease (CVD) risk factors.Design/methodology/approach – Using Medline, a search was made for all randomized controlled trials published between 1990 and 2008 that met defined inclusion criteria. Studies had a minimum duration of 14 days, used oat products rather than purified extracts, and included plasma lipid levels as outcome variables.Findings – A total of 21 eligible studies were located 13 of which reported significant reductions in total cholesterol when oats were consumed, while 14 reported significant reductions in low‐density lipoprotein cholesterol. A few studies found increases in high‐density lipoprotein cholesterol and more favourable cholesterol ratios when oats were consumed.Research limitations/implications – It was not possible to analyse differences in response between health and “at risk” subjects. A meta‐analysis would be a useful step forward, ...

A study to establish whether food-based approaches can improve serum iron levels in child-bearing aged women.

BACKGROUND Iron-deficiency anaemia is particularly prevalent in pregnancy. The present study aimed to determine whether functional bread containing teff flour (i.e. naturally rich in iron) could be an alternative way of improving iron status. However, before testing whether its consumption can improve pregnancy iron status, the bio-availability of iron was determined in a sample of nonpregnant women. METHODS Fifty-eight women (20-50 years) were recruited from the University. Blood samples were taken at baseline to assess iron status and participants were screened to account for other factors affecting iron status. Twenty-four participants (haemoglobin 9.5-14.0g dL(-1) ) were recruited to take part in the intervention and allocated to five groups: (i) control bread (CB); (ii) teff bread (TB); (iii) TB+level 1 phytase (TB+P1); (iv) TB+level 2 phytase (TB+P2); or (v) a supplement containing 10 mg of ferrous sulphate. Venous blood samples were taken before the intervention and after 180-210min, aiming to determine changes in serum iron. RESULTS Consuming three or four slices of TB provided statistically significantly more iron (7.6mg) than CB (5.1mg) (P<0.001). Because participants were fasted, serum iron levels declined in all bread groups (average -1.5μm), although the smallest reduction was observed in the TB+P2 group (-0.3 μm). The area-under-the-curve from baseline to 210min was lower in the TB+P2 (-78.8μmol min L(-1) ) group compared to the other bread interventions, indicating higher levels of iron absorption in this group. CONCLUSIONS The results obtained in the present study show that TB consumption may help to maintain serum iron levels, especially when phytase is added. The findings from the study also demonstrate there may be potential to further improve the bio-availability of iron from non-haem food sources.

Dietary iron intervention using a staple food product for improvement of iron status in female runners

BackgroundAdequate nutrient intake is critically important for achieving optimal sports performance. Like all athletes, female runners require a nutritionally balanced diet to maintain daily activities and a successful training regime. This study investigates the effects of cereal product based dietary iron intervention on iron status of recreational female runners (n=11; 32 ± 7yr; 239 ± 153 minutes exercise/week, of which 161 ± 150 minutes running activity/week; VO2max 38 ± 4 ml/kg/min).MethodsParticipants completed a 6-week dietary intervention study. They were asked to replace their usual bread with iron-rich Teff bread as part of their daily diet. During this period, their dietary habits were assessed by multiple pass 24-hr recalls; iron status was determined by venous blood analysis for serum transferrin, serum transferrin receptor, serum ferritin, total iron-binding capacity and transferrin receptor/ferritin log index.ResultsPre-intervention a cohort of 11 female runners reported inadequate daily dietary iron intake of 10.7 ± 2.7 mg/day, which was associated with overall compromised iron status. Over a third of all participants showed depleted bodily iron stores (serum ferritin < 12 μg/L). Pre-intervention macronutrient assessment revealed adequate energy, protein and fibre intakes, whilst total fat and saturated fat intake was above the recommendations at the expense of carbohydrate intake. A 6-week dietary intervention resulted in significantly higher total iron intakes (18.5 mg/day, P < 0.05) and improved iron tissue supply but not enlarged iron stores. Improvements in heamatological indices were associated with compromised baseline iron status, prolonged intervention period and increase in dietary iron intake.ConclusionDietary iron interventions using a staple cereal product offer an alternative way of improving dietary iron intake and favourable affecting overall iron status in physically active females.