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SEAMEO-TROPMED Regional Center for Community Nutrition University of Indonesia

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

Dr. Umi Fahmida

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 21st – 22nd, 2017

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

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 1.7-1.8% Rao et al. (1983) India Wheat-based 3.5 – 4.0% “ India Rice-based 8.3 – 10.3% “ 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 + 100 g fresh fruit 4.8% “ Thailand Rice + 60 g fish 21.6% “

**Data used by WHO/FAO (2004) to develop algorithm for Fe bioavailability

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 2,985 642 21.5 Cambodia 2,477 210 8.5 Indonesia 2,777 182 6.6 Lao PDR 2,451 219 8.9 Malaysia 2,916 535 18.3 Myanmar 2,571 428 16.6 Philippines 2,570 388 15.1 Thailand 2,784 351 12.6 Timor-Leste 2,131 246 11.5 Viet Nam 2,745 575 20.9 South-Eastern Asia 2,716 332 12.2

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 7.9 1550 19.4 5.8 17.5 28 Thailand ESEASP 8.5 1218 14.2 12.6 37.8 29.8 Myanmar ESEASP 9.2 1500 16.1 9.7 23.5 27 Timor-Leste ESEASP 7.5 1326 17.5 10.6 31.9 30.1 Cambodia ESEASP 8.4 1307 15.4 9.3 27.6 29.3 Singapore HIGHIN 11.1 1592 14.1 17.1 38.7 24.6 Lao PDR ESEASP 8.9 1426 15.9 7.4 23.4 27.8 Malaysia ESEASP 10.1 1364 13.3 17.6 44.1 27 Viet Nam ESEASP 11.7 1540 13 14.3 39.1 24.4 Brunei Darussalam HIGHIN 12.1 1658 13.6 20.2 43 23.5 Philippines ESEASP 9.1 1142 12.4 15.1 39.8 29.7

Data from Wessells KR, Brown 2012 PLoS ONE 7(ii): e50568

1 Fractional Zn absorption calculated from Miller equation

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 Korea1 China2

Zinc intake (mg/day) 10.1 10.6 (8.5 – 13.3) Iron intake (mg/day) 15.2 21.2 (16.8 – 27.1) Calcium intake (mg/day) 426.5 338.1 (240.9 – 471.8) Phytate intake (mg/day) 1,677 1,189 (823 – 1,603) Phytate : calcium molar ratio

0.22 (0.14 – 0.31)

Phytate : iron molar ratio 4.88 (3.28 – 6.61) Phytate : zinc molar ratio 15.9 11.1 (8.1 – 14.2) Phy:Zn molar ratio >15 (%) 23.1 Phy:Fe molar ratio >1 (%) 95.4 Phy:Ca molar ratio >0.24 (%) 43.7

1 From: Kwun and Kwon, Biological Trace Element Research, vol 75: 29-41 (2000) 2 From: Ma et al, European Journal of Clinical Nutrition, vol 61: 368-374 (2007)

Data at national level but also available by life stage group

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 96.9 24.2 20.4 96.2

Frequency/week In median (10th – 90th 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

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.

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%

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

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

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Thank You Terima Kasih