The role of diet on nutrient bioavailability: Issues for habitual diets of Asian countries

Transcription

1 The role of diet on nutrient bioavailability: Issues for habitual diets of Asian countries Dr. Umi Fahmida SEAMEO-TROPMED Regional Center for Community Nutrition University of Indonesia Southeast Asian Ministers of Education Organization Regional Center for Food and Nutrition (SEAMEO RECFON) Pusat Kajian Gizi Regional Universitas Indonesia (PKGR-UI) Global Harmonization of Methodological Approaches to Nutrient Intake Recommendations Rome, Sep 21 st 22 nd,

2 Tools to estimate bioavailability in the Asian region** Isotope data measuring bioavailability in whole diets Consensus needed across countries on which data to use FAO Food Balance Sheets (210 countries) Per capita values for supply of 95 food commodities (g/d); energy, protein, fat per capita Other nutrients can also be calculated (e.g. Zn & phytate) WHO/FAO GEMS/Food cluster diets*(183 countries) Data standardized into 13 cluster diets Number & percent of children & adults consuming each commodity Mean + SD as g/kg BW/day of food/food grp for children & adults Use NFCS data from FAO/WHO GIFT platform Mean daily intakes by life stage group of: standardized food groups (g/d); nutrients; antinutrients Food sources of nutrients (as %) ; phytate Fe & phytate:zn molar ratios; FAZ from Miller equation

3 Iron absorption data from isotopic studies of habitual diets across countries in S & SE Asia** Country Type of diet Fe absorption (as %) Author India Millet-based % Rao et al. (1983) India Wheat-based % India Rice-based % Myanmar Rice-based 1.7% Aung et al. (1976) Myanmar Rice + 15 g fish 5.5% Myanmar Rice + 40g fish 10.1% Thailand Basal Rice-based 1.9% Hallberg et al. (1974; 1977) Thailand Rice-based g fresh fruit 4.8% Thailand Rice + 60 g fish 21.6% **Data used by WHO/FAO (2004) to develop algorithm for Fe bioavailability

4 Food Balance Sheet data: Energy from animal source foods (ASF) in Southeast Asian countries Area Energy (kcal/d) Energy from ASF (kcal/d) %Energy from ASF Brunei Darussalam 2, Cambodia 2, Indonesia 2, Lao PDR 2, Malaysia 2, Myanmar 2, Philippines 2, Thailand 2, Timor-Leste 2, Viet Nam 2, South-Eastern Asia 2,

5 Mean per capita phytate: Zn molar ratios and fractional absorption (as %) from available food supply based on food balance sheet data (2005) for selected Southeast Asian countries Countries GBD Region Code Zinc (mg) Phytate (mg) Phytate : zinc molar ratio % of energy from animal source foods % of zinc from animal source foods Estimated fractional absorption (as %) 1 Indonesia ESEASP Thailand ESEASP Myanmar ESEASP Timor-Leste ESEASP Cambodia ESEASP Singapore HIGHIN Lao PDR ESEASP Malaysia ESEASP Viet Nam ESEASP Brunei Darussalam HIGHIN Philippines ESEASP Fractional Zn absorption calculated from Miller equation Data from Wessells KR, Brown 2012 PLoS ONE 7(ii): e50568

6 Use of National Food Consumption data from South Korea and China: Intakes and molar ratios of zinc, iron, calcium and phytate in South Korea and China* Indicators South Korea 1 China 2 Zinc intake (mg/day) ( ) Iron intake (mg/day) ( ) Calcium intake (mg/day) ( ) Phytate intake (mg/day) 1,677 1,189 (823 1,603) Phytate : calcium molar 0.22 ( ) ratio Phytate : iron molar ratio 4.88 ( ) Phytate : zinc molar ratio ( ) Phy:Zn molar ratio >15 (%) 23.1 Phy:Fe molar ratio >1 (%) 95.4 Phy:Ca molar ratio >0.24 (%) 43.7 Data at national level but also available by life stage group 1 From: Kwun and Kwon, Biological Trace Element Research, vol 75: (2000) 2 From: Ma et al, European Journal of Clinical Nutrition, vol 61: (2007)

7 Use of NFCS data: Example from Indonesia (pregnant women) Source: Basic Health Survey 2010 Cellular animal protein Vit C containing foods Orange/yellow fruits & veg Green leafy veg Percent consumers Frequency/week In median (10 th 90 th percentiles) 5 (2-9) 0 (0-1) 0 (0-1) 4 (2-7) Median portion size (g/day) Meat = 94 Fish = 95 Poultry = 91 Organ meat = 71 Fruit = 96 Veg = 34 Fruit = 106 Veg = 59 DGLV = 109

8 Estimating calcium bioavailability in Asian diets Dietary calcium content of greater importance than bioavailability especially in Asia where intake of dairy products often very low. Calcium poorly absorbed from foods rich in oxalic acid (spinach, sweet potatoes, rhubarb, and beans) or phytic acid (unleavened bread, raw beans, seeds, nuts, grains, and soy isolates). Calcium absorption from dried beans is about half that from milk and about one-tenth from spinach. Data on Ca absorption from specific foods are limited so effects of absorption modifiers have not been quantified Hence bioavailability has not been considered in setting the calcium dietary requirements in the region.

9 Estimating iron bioavailability in Asian diets Diets in Southeast Asia very complex so not possible to estimate bioavailability for all habitual diets via isotope techniques Development of algorithms an attractive approach, although more work is needed to quantify effect of various components in Asian diets affecting iron bioavailability. Consensus on analytical methods for tannin needed, whereas new phytate database by FAO/INFOODS/IZiNCG will permit estimates of phytate:fe molar ratios from NFCS data In the meantime, it is reasonable to assume, based on available scientific data, that bioavailability of iron in Southeast Asia is in the range of 5% to 10%. eg. Malaysia 10%, Philippine 8.5%

10 Estimating zinc bioavailability in Asian diets Estimates of fractional Zn absorption (FAZ) available for FBS food supply data New phytate database by FAO/INFOODS/IZiNCG will permit estimates of phytate:zn molar ratios from NFCS dietary data at the individual level Fractional Zn absorption (as %) can be calculated on individual-level NFCS data by lifestage group using updated Miller equation Zn WHO/FAO algorithm needs to be updated taking into account phytate:zn molar ratios from NFCS data at the individual level and estimates for FAZ across region

11 Implications of variations in Asian diets on global harmonization of bioavailability adjustments 1. Iron: Bioavailability from isotope studies difficult to estimate due to complexity of diets in SEA countries Algorithms: helpful but could be revised based on additional data from NFC surveys such as: Phytate:Fe molar ratios; % Fe from flesh foods; heme & non hem Fe intakes 2. Zinc: FBS data provides opportunity to estimate fractional absorbable zinc, but does not allow breakdown by specific life-stage groups NFC surveys based on intake data by life-stage group could be used to estimate (i) phytate:zn molar ratios; (ii) FAZ; (iii) revise WHO/FAO algorithm for Zn 3. Calcium: Insufficient data to quantify effects of absorption modifiers bioavailability not considered for Ca dietary requirements in SEA 11

12 Thank You Terima Kasih 12