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close this bookFood and Nutrition Bulletin Volume 19, Number 3, 1998 (UNU, 1998, 102 pages)
close this folderDietary fat in developing countries
View the document(introductory text...)
View the documentIntroduction
View the documentConsumption pattern of dietary fats in Chile
View the documentSummary and recommendations
View the documentReferences

(introductory text...)

Joyce Beare-Rogers, Ghafoorunissa, Onno Korver, Gérard Rocquelin, Kalayan Sundram, and Ricardo Uauy

The authors are members of IUNS Committee 1/4. Joyce Beare-Rogers is a nutrition consultant in Nepean, Canada. Ghafoorunissa is affiliated with the National Institute of Nutrition in Hyderabad, India. Onno Korver is with Unilever Research in Vlaardingen, Netherlands. Gérard Rocquelin is affiliated with the Tropical Nutrition Unit of ORSTOM in Montpellier, France. Kalayan Sundram is with the Palm Oil Research Institute of Malaysia in Kuala Lumpur. Ricardo Uauy is the director of the Institute of Nutrition and Food Chemistry in the University of Chile in Santiago.

Mention of the names of firms and commercial products does not imply endorsement by the United Nations University.

Introduction

Dietary fat encompasses all the sources of lipids in foods, including those in plant and animal cellular membranes, as well as the readily recognized fats and oils. Fat is an important contributor of energy, which may be in short supply in some developing countries. As noted in the Food and Agriculture Organization/World Health Organization (FAO/WHO) report on fats and oils in human nutrition, there is a great disparity in the supply of this dietary component [1]. Data in 1990 from national food-balance sheets showed that the availability of total fat in developing countries was 49 g per person per day, equivalent to 440 kcal. Corresponding figures from national food-balance sheets for developed countries were 128 g of fat or 1,150 kcal per person per day. Within the two large economic groups, intake in individual countries varied from less than 20 g of fat (180 kcal) per person per day in Bangladesh, Cambodia, and Rwanda to more than 170 g (1,530 kcal) in Belgium, Denmark, Ireland, and Luxembourg. The difference between these two groups of countries in the supply of a major energy source was eight- to nine-fold.

The percentage of energy content provided by fat in breastmilk from well-nourished women is expected to be 40% to 55% during the first six months and to decrease thereafter. According to FAO/WHO, the percentage of energy provided by fat should be at least 15% in adults and 20% in women of reproductive age [1]. On this basis, a minimum level of fat in a diet might be considered to be 20% of energy.

Globally, cardiovascular disease is the major cause of death [2]. This underscores the importance of dietary fat, a modifiable risk factor for cardiovascular disease. There is overwhelming evidence linking elevated plasma levels of total cholesterol and its principal carrier, low-density lipoprotein (LDL), to cardiovascular disease [3]. Over the past decades, diets designed for industrialized countries to reduce total fat and cholesterol and replace saturated fatty acids with polyunsaturated fatty acids have contained a large amount of linoleic acid. Subsequent studies have shown that large amounts of linoleic acid (>10 en % [energy percent]) can reduce not only LDL but also high-density lipoprotein (HDL) cholesterol. Apart from the effects on lipoproteins, dietary fatty acids modify platelet aggregation, vascular reactivity, and immune functions through their effects on the synthesis of eicosanoids in platelets and endothelial cells of the arterial wall. High intakes of n-6 fatty acids and saturated fatty acids increase platelet aggregation. Whereas the n-3 eicosapentaenoic and docosahexaenoic acids decrease platelet aggregation and bleeding time, they lower triacylglycerol and have hypolipidaemic, vasodilatory, anti-inflammatory, and hypotensive effects, as compared to n-6 arachidonic acid. In many developing countries, plant foods supply most of the essential fatty acids, and the ratio of n-6 to n-3 is the ratio of linoleic acid to (a-linolenic acid. There are developing countries where fish supply eicosapentaenoic acid and docosahexaenoic acid. The balance between linoleic acid and a-linolenic acid should be maintained in developing countries at an n-6/n-3 ratio of 5:1 to 10:1. Saturated fatty acids do not contribute equally to hypercholesterolaemia or hyperaggregability of platelets, and further, their effects can vary with dietary levels of cholesterol and polyunsaturated fatty acids [4, 5].

This report describes the dietary fat consumed in two developing countries, Chile and India. Corresponding data were not available from impoverished countries in Africa. Other topics discussed are the nature of complementary foods for the young, the response of blood lipoproteins to saturated and trans fatty acids, and the role of vegetable oils in supplying vitamin A and carotenoids. It is assumed that the safety considerations of fatty foods intended for human consumption have been addressed through good manufacturing practices.

Consumption pattern of dietary fats in Chile

Chile, a country of 14.5 million, has experienced rapid economic growth and dramatic improvements in human and social development indices during the last two decades. Infant mortality presently stands at 12 per 1,000, illiteracy is less than 5%, and access to basic educational and health services is nearly universal. Poverty is decreasing markedly, and the per capita gross national product is growing at 6% to 7% per year. Unemployment is close to 5%, and projected inflation is less than 6% [6]. The nutritional status of children has improved; less than 1% of children are below 2 SDs in weight-for-age, and 5% are below 2 SDs in height-forage. Mean per capita energy availability is close to 3,000 kcal per day, or 109% of the estimated need.

Chile's economic progress has been fuelled by exports amounting to 33% of the gross national product. Local oil production is based mostly on imported seeds and semi-refined oils. An exception in terms of manufactured products is the fish meal and fish oil industry. It is well developed in terms of overall production and quality; these products are technologically advanced and successfully compete in the international market.

Chile consumes both vegetable and animal fats and oils. Of the vegetable oils, soya bean oil, which is either imported from Argentina and Bolivia as such or produced from imported soya beans, is the most important contributor to the dietary fat supply. Rapeseed oil of the low-erucic-acid variety is the second most common vegetable oil consumed in Chile. It is also imported, although there is a limited local production. Sunflower oil is almost totally imported from Argentina and Brazil; more recently, imported canola oil has been introduced. There is a small consumption of olive oil locally produced and imported [7]. Animal fats are predominantly derived from beef and pork; a small proportion is obtained from sheep tallow. Fish oil products with different degrees of processing are highly consumed in Chile. Table 1 provides detailed information on estimated fat consumption in Chile for 1995 [8].

The improvement in the economic status of the country has been coupled to a change in the pattern of consumption of fats and oils. Over the past 20 years, there has been a steady rise in human consumption of oils and a decrease in the consumption of solid fats of animal origin, including butter. The consumption of margarine and solid vegetable fats (shortenings) has changed relatively little. The increased availability and use of liquid oils can be directly linked to the improvement in local buying capacity. In 1975 the per capita gross national product was US$2,800, whereas in 1995 it was US$4,800 in constant dollars [9]. The greatest use of liquid oils is for frying foods; they have replaced animal tallow and vegetable shortenings for this purpose. This trend has coincided with an increase in local consumption of fast foods and snacks. There has been an explosive growth of foreign and local fast-food chains promoted by aggressive advertising campaigns. Figure 1 illustrates the changes in the distribution of the types of fats consumed in Chile from 1975 to 1995 [8]. The estimated yearly per capita consumption of fats for 1995, 16.7 kg, is slightly above the average world per capita consumption of 15.2 kg for the same year.

Chile has a strong fishing tradition, although the local population does not consume a lot of fish or marine foods. Most of the fish catch in Chile serves as raw material for the production of fish meal and fish oil, and only a small percentage is used in canning. Pelagic fish, such as sardines, anchovies, and mackerel, constitute the main varieties caught along the long Chilean coastline [10]. There are over 50 fish meal factories distributed along the coast, which produce fish meal for export as well as internal consumption. Chile is the world's second largest producer of fish meal and fish oil, surpassed only by Peru. Table 2 shows recent information on the main world producers of fish oil. Within Chile fish oil is used in human foods and animal feeds and in the manufacturing of industrial products such as paints, varnishes, and leather tannery. Table 3 summarizes the main uses of fish oil in Chile; human consumption represents 36% of the total [11].

TABLE 1. Estimated fat consumption in Chile in 1995

Fat

Consumption (x 1,000 metric tons)

Fish oil

91.7

Soya bean oil

77,5

Rapeseed oil

23.5

Sunflower oil

14.4

Butter

6.3

Tallow

5.7

Lard

0.15

Other oils (olive, canola, etc.)

0.05

Total consumption

219.3


FIG. 1. Changes in distribution of types of fats consumed in Chile from 1975 to 1995 (a)


FIG. 1. Changes in distribution of types of fats consumed in Chile from 1975 to 1995 (b)

Human consumption of fish oil is largely in food products that are hydrogenated to various degrees to secure stability and prevent rancidity. Refined, deodorized, partially hydrogenated fish oil is mixed with vegetable oils of different origins to produce a low-cost vegetable oil. These are generically called "combined oils" (containing up to 30% fish oil) and are sold by bulk in large metal drums. The commercial distribution to low-income consumers occurs in small grocery shops, which dispense the combined oil in small amounts according to the income of the customer. These combined oils are also packaged in one-litre or one-half-litre individual bottles under various trade names. Bottled oil is destined to replace oil in large metal drums, since local food regulations now prohibit the large containers. The combined oils are organoleptically satisfactory and acceptable, despite the non-standardized, variable fatty acid composition. The composition will change according to the source of the fish oil and vegetable oil used in the combination and the degree of hydrogenation. Combined oils do not constitute a good source of long chain n-3 fatty acids, since partial hydrogenation significantly reduces the content of eicosapentaenoic acid and docosahexaenoic acid to less than 2% of the total fat. These fatty acids are reduced mostly to isomeric mono- and di-enes by partial hydrogenation [12].

TABLE 2. Main producers of fish oil (x 1,000 metric tons)

Country

Year


1990

1992

1994

Peru

185

244

488

Chile

130

148

286

Denmark

77

115

138

United States

126

82

110

Norway

50

110

100

Iceland

73

76

90

Japan

418

104

84

South Africa

11

16

12

TABLE 3. Uses offish oil in Chile in 1994

Use

Consumption (x 1,000 metric tons)

Industrial uses (paints, varnishes, etc.)

8

Aquaculture (salmon, trout)

15

Poultry feed

9

Human food

102

Pet food

1

Export

151

Total

286

A significant proportion of fish oil in Chile is used in the manufacture of fat spreads for direct human consumption and solid fats used in processed foods (shortenings). Fish oil must be intensely hydrogenated to achieve a stable solid fat. The high-melting-point fats are very resistant to oxidation, do not become rancid with time, and are easy to handle in food processing, adding texture and flavour. The relatively low cost of hydrogenated fish oils as compared with vegetable oils makes them economical for use in margarine and industrial shortening. Up to 53% of the fat consumed in Chile is hydrogenated; of this 90% is hydrogenated fish oil [13]. Of the total margarine and shortening consumed in Chile, 80% and 95%, respectively, contain some proportion of hydrogenated fish oil [12]. The estimated consumption of fish oil in Chile, partially hydrogenated in combined oils or fully hydrogenated in margarine and shortening, is close to 7 kg per person per year. However, it must be emphasized that because of hydrogenation, most of the eicosapentaenoic acid and docosahexaenoic acid is lost. Therefore these products must be blended with vegetable oil to assure the presence of essential fatty acids.

The sources of n-6 and n-3 fatty acids in the Chilean diet are those described above, basically linked to the vegetable oils used. Nevertheless, additional sources of essential fatty acids, especially long-chain essential fatty acids, are present in pork, poultry, and eggs, since the animal feeds contain partially refined fish oil or free fatty acids as by-products of the fish oil used for human consumption. These free fatty acids are sold as a low-cost energy supplement for use during the early stages of poultry and pork production. To prevent the meat or eggs from having a fishy smell, the supplements are discontinued when the animals are close to completing their growth cycle, before they are sent to market. Because of this feeding practice, pork and poultry are important sources of n-3 fatty acids in Chile; the nutritional health impact of these non-traditional n-3 sources has not been fully studied. Figure 2 summarizes the n-3 fatty acid composition of beef, pork, chicken, and eggs in Chile [14].

Lipids in infant nutrition have been historically considered solely part of the exchangeable dietary energy supply. The main consideration was the amount of fat that could be tolerated and digested by infants and young children. The significance of the composition of the dietary fat has received little attention. Presently, there is a growing interest in the quality of the dietary lipid supply in early childhood as a major determinant of growth, development, and long-term health. Thus the selection of dietary lipid supply during the first years of life is now considered of greater significance (see next section). Lipids serve as structural components of all tissues and are indispensable for the synthesis of cell and plasma membranes. The brain, retina, and other neural tissues are particularly rich in long-chain poly-unsaturated fatty acids. These lipids have been shown to affect neural development and function.


FIG. 2. Content of n-3 fatty acids in meat and eggs consumed in Chile. Abbreviations: DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; PUFA, polyunsaturated fatty acids

Information on the fatty acid composition of human milk from developing and developed regions of the world is summarized in figure 3 and contrasted with recent data obtained in Chile. It should be noted that milk from mothers in China and Nigeria and low-income mothers in Chile has significantly higher total n-3 and also higher docosahexaenoic acid (22:6 n-3) than milk from mothers in the United States and Germany. It is tempting to hypothesize that in Chile the consumption of docosahexaenoic acid-rich eggs, pork, and poultry may contribute to the high docosahexaenoic acid content of human milk. In addition, the small proportion of intact n-3 long-chain polyunsaturated fatty acids in the combined oil, which contains fish oil, may contribute to the overall supply of docosahexaenoic acid; the estimated total daily intake of docosahexaenoic acid and eicosapentaenoic acid may amount to 750 mg. Non-breastfed infants receive commercial formula, which usually provides the same n-6 and n-3 essential fatty acids that are found in breastmilk, but no long-chain polyunsaturated fatty acids, since new formulations that contain these have not yet been introduced in Chile (R. Uauy and P. Mena, personal communication, 1997). Older infants and even young infants of low socio-economic status fed powdered milk receive no long-chain n-3 and small amounts of n-6 from dairy fat. Cow's milk is also quite low in n-3 (18:3) and n-6 (18:2) essential fatty acid precursors. Human milk in developing countries may represent the only way to secure appropriate n-6 and n-3 fatty acids in the right amount and balance; modern commercial formula is simply not affordable by most of the population. Unmodified cow's milk is a poor source of essential fatty acids and provides virtually no n-3 fatty acids.


FIG. 3. Content of n-3 fatty acids in breastmilk of mothers in Chile and other countries

In most developed countries, fats included in foods, even those given to young children, are products of one or many industrial processes. In the 1970s, hydrogenated fish oil was used in Chile for low-cost formula. When the fat was exclusively from hydrogenated fish oil and was fed to children recovering from malnutrition, faecal fat loss was as high as 20%; when this fat was mixed with equal parts of hydrogenated vegetable oil, fat loss was reduced to about 5%. In addition, the concern about the large amount of trans fatty acids formed during hydrogenation offish oil posed two other potential problems: it may induce essential fatty acid deficiency and alter lipoprotein metabolism.

Trans fatty acids do not serve as substrates for synthesis of long-chain polyunsaturated fatty acids (n-6 20:4 and n-3 22:6), and thus more essential fatty acid precursors are needed [15]. The extent of essential fatty acid deficiency in developing countries is virtually unknown, especially since the clinical manifestations occur only in extreme deficiency. Thus this problem may go unreported, despite the potential effects on the development of the neural system. The other issue relative to the use of hydrogenated fats with large amounts of trans fatty acids is the effect they have on cholesterol and lipoprotein metabolism. High-trans diets increase LDL cholesterol, reduce HDL cholesterol, and possibly increase lipoprotein (a) [16]. All of these changes increase atherogenicity. Despite the urgency in improving the energy supply of infants in developing countries, we should avoid inducing problems in later life. The low price and long shelf life of hydrogenated products do not justify the risk of possible long-term effects of this type of fat [17].

Another example of safety concerns with fats used in developing countries is the need to avoid the use of high-erucic-acid rapeseed oil. If its use is not monitored, toxicity from erucic acid may occur, and this is difficult to diagnose clinically. If rapeseed oil is to be used, it should be derived from genetically selected low-erucic-acid varieties. Canada produces these varieties and markets them as canola oil. Unfortunately, cross pollination may lead to the production of phenotypes with an increasing level of erucic acid, and therefore certified seeds should be purchased. These may have a high cost, and farmers in developing countries may not use them unless forced to do so by appropriate quality control measures.

A critical safety issue is the stability of oils in terms of peroxidation. Highly unsaturated oils, such as processed fish oil used in human foods and as animal feed, require substantial amounts of synthetic antioxidants to preserve their structure and prevent rancidity [18]. The Chilean legislature has authorized the use of up to 0.01% BHT, BHA, TBHQ, and propyl or octyl gal-late as total antioxidants. This is in accordance with the Codex Alimentarius, despite some concerns about the safety of synthetic antioxidants, which have led some countries to restrict the use of BHA. A specific issue in the use of processed fish oil for animal feed is the concern about the safety of ethoxyquine, which is utilized as an antioxidant in the product. This is a highly efficient antioxidant and anticombustion agent but is prohibited for use in foods for humans. The consumption of poultry or other animals fed fish meal or fish oil containing ethoxyquine has not been addressed by present regulatory efforts. Research is under way to find alternative antioxidants to replace ethoxyquine at reasonable prices.

Finally, there maybe safety problems in the dispensing of oils. Large metal containers used to reduce costs in developing countries may facilitate adulteration of products and promote peroxidation because of the large volume and the long time before all the product is sold. Bottled oil ready for consumer purchases is undoubtedly safer but is also more expensive. Soft plastic (polyvinylchloride) containers using phthalic acid as a plasticizer can also create safety problems, since this agent is fat soluble and a known carcinogen. Rigid plastic or glass bottles are preferable. Brick containers have recently been introduced in some countries.

In Chile the recent food safety regulations promulgated in 1997 follow FAO/WHO Codex Alimentarius directives in terms of quality control, technical specifications, safety of sources, use of additives and anti-oxidants, labelling, and nutritional claims.

Dietary fats in India

The major nutritional problem of India, a country of 940 million, is chronic energy deficiency associated with low fat intake [19]. The urban affluent and middle-income groups are increasing in number, with a corresponding increase in the prevalence of obesity, diabetes, and coronary heart disease in that segment of the population [20]. Fat intake in India is income dependent and highly skewed [21, 22].

The vegetable oils used in cooking represent 80% of the visible fat consumed in India [23]. Despite a yearly increase of 15% to 20% in the production of vegetable oil during the last few years, India has a shortage of oils. The average annual per capita consumption is 8 kg, as compared with 16 kg for the world and more than 40 kg for developed countries [24]. For many decades, 60% of the oil consumed was groundnut oil, followed by rapeseed and mustard seed oil, which accounted for 15%. The production of these seed oils has almost tripled [25].

A single oil is generally chosen for cooking, especially in rural areas. Groundnut oil predominates in the western and southern states, whereas mustard seed oil predominates in the northern and eastern states. In Karnataka and South Maharashtra, safflower oil is preferred. Sesame oil is produced and used all over India, but mostly as a second rather than the main oil. Coconut oil is popular in Kerala [26]. Sunflower and rice bran oils have been introduced, and sunflower oil has become popular. Palm oil, used over the last 15 years, is available through the public distribution system and is likely to become an important indigenous oil because of the introduction of palm cultivation [24]. Vegetable ghee (vanaspati), popular in the northern states, is used in confectionery, bakery, and ready-to-eat foods. Ghee, made from milk in the home or purchased, contributes to the high intake of fat in the urban affluent and middle-income groups [27].

Invisible fat in animal and plant foods was once poorly analysed because structural and tightly bound lipids were not extracted. More recent data on the fat content and fatty acid composition of Indian foods are shown in table 4 [28, 29]. Although cereal and millet contain only 1% to 3% fat, of which linoleic is a major fatty acid, as bulk items in the Indian diet they contribute significantly to the total fat intake. The fatty acids in commonly occurring visible fats vary according to the source. In safflower, sunflower, soya bean, and cottonseed oils, linoleic acid constitutes more than half of the total fatty acids. In sesame, rice bran, groundnut, and mustard oils, linoleic acid accounts for 20% to 40% of the total fatty acids; in palm oil it accounts for about 10%. Coconut and palm kernel oils have a high proportion of short- and medium-chain-length saturated fatty acids. Rapeseed, mustard, and soya bean oils contain n-3 linolenic acid and the first two also have long-chain eicosanoic (20:1) and erucic acids (22:1). Ghee, which has the fatty acids of milk fat, is high in saturated fatty acids, of which 40% are of short or medium chain length. Vanaspati contains long-chain saturated fatty acids and up to 55% trans fatty acids.

Dietary data from national surveys [19, 21] of the rural poor (an estimated 80% of the population) show that the average daily intake of cereal and millet is about 500 g, whereas the intake of visible fats and oils is less than 10 g per person. By using data on invisible fat and fatty acids in Indian foods [28, 29] and information on dietary intake of the rural population [21], it has been found that cereal and millet alone furnish about 70% of the total invisible fat in the diet. Pulses, milk, fresh coconut, whole oil seeds, and spices constitute the rest [28]. The daily intake of cereal, millet, pulses, and milk contains an average of about 16 g (7 en %) fat, 5 g (2 en %) linoleic acid, and 0.6 g (0.2 en %) n-3 linolenic acid. Thus, invisible fat from cereal and pulses alone furnishes two thirds of the requirement for linoleic acid [28]. Diets of urban high-income groups are low in cereal (200-300 g per person per day) but contain more legumes, pulses, vegetables, and milk (and also, for non-vegetarians, eggs and animal foods) [22]. Therefore, the invisible fat contributes 30 g (12 en %) to the diet [28]. The average daily intake of visible fat in the urban population is about 13 g in slum dwellers, 23 g in industrial labourers and low-income groups, 35 g in middle-income groups, and 46 g in high-income groups [22], but it is much higher in the top affluent group [31]. In the rural population, the lower limit of visible fat in Indian diets is about 20 g per person per day [28, 32]. Since chronic energy deficiency is a major problem in low-income groups, increasing dietary fat could help to remedy this situation.

In the urban high-income group, a daily intake of about 50 g per person (18 en %) would be the upper limit of visible fat (e.g., oil, ghee, vanaspati, and butter) [28, 32]. It was estimated that one third of all the fat in India was consumed by the 5% of the population who constituted the urban rich [26]. This segment of the population, which has a high prevalence of obesity and cardiovascular disease, could lower the consumption of fat and ease the pressure on the supply of edible oil elsewhere in the country.

During pregnancy and lactation, when the requirements of total fats and essential fatty acids are high, the invisible fat of cereals, pulses, and milk in Indian diets can meet 42% and 30% of the recommended level for linoleic acid of 3 en % as proposed by FAO/WHO [33] (4.5 en % in pregnancy and 6 en % in lactation). To furnish the additional amounts of linoleic acid recommended, the visible fat intake should be about 30 g in pregnant women and 45 g in lactating women [28, 32].

TABLE 4. Invisible fat and fatty acids in Indian foods (g/100 g food)a

Food

Botanical name

Fat

16:0

18:0

18:1

18:2 n-6

18:3 n-3

18:2 n-6/18:3 n-3 ratio

Cereals and millets

Rice

Oryza sativa

1.7

0.40

0.05

0.4

0.5

0.01

41

Wheat

Triticum aestivum

2.9

0.40

0.10

0.3

1.1

0.17

6

Maize

Zea mays

4.8

0.70

0.20

1.1

2.2

0.05

47

Jowar

Sorghum vulgare

3.3

0.50

0.07

1.0

1.5

0.05

32

Ragi

Eleusine coracana

1.5

0.30

0.02

0.7

0.3

0.05

5

Bajra

Pennisetum typhoideum

5,5

1.00

0.24

1.2

2.2

0.13

17

Legumes and pulses

Black gram

Phaseolus mungo Roxb

1.7

0.20

0.05

0.20

0.1

0.70

0.2

Rajmah

Phaseolus vulgaris

2.2

0.30

0.04

0.20

0.5

0.70

0.7

Cowpea

Vigna catjang

2.9

0.60

0.10

0.20

0.8

0.50

1.7

Green gram

Phaesolus aureus Roxb

1.7

0.40

0.05

0.50

0.6

0.20

3.0

Red gram

Cajanus cajan

2.2

0.40

0.08

0.10

1.0

0.10

8.0

Lentil

Lens esculenta

2.0

0.20

0.04

0.40

0.8

0.16

5.0

Bengal gram

deer arietinum

6.9

0.50

0.07

1.20

3.5

0.20

17.0

Pea

Pisum sativum

2.1

0.20

0.06

0.40

0.8

0.15

5.0

Soya bean

Glycine max. Merr

20.0

1.40

0.8

5.40

10.4

1.40

7.0

Vegetables

Beansb


0.2

0.04

0.007

0.009

0.07

0.04

2.0

Green leafy vegetablesc


0.4

0.05

0.007

0.025

0.04

0.15

0.3

Otherd


0.2

0.03

0.008

0.016

0.06

0.03

2.0

Potato

Solarium tuberosum

0.6

0.15

0.002

0.150

0.08

0.06

5.0

Condiments and spices

Dry chili

Capsicum annuum

17

2.20

0.34

1.8

9.1

0.26

35.0

Cumin seed

Caminum cyminum

9

0.30

0.08

4.7

2.1

0.48

4.0

Coriander seed

Coriandrum sativum

20

0.60

0.10

12.5

3.0

0.02

129

Fenugreek seed

Trigonella foenumgraecum

10

0.90

0.30

1.5

3.4

1.90

1.8

Nuts and oil seeds

Coconut

Cocos nuifera

40

8.0

4.0

3.2

0.6

-

-

Groundnut

Arachis hypogaea

40

3.5

1.7

21.0

10.0

0.2

50

Sesame

Sesamum indicum

40

4.0

1.6

18.0

16.0

0.4

40

Mustard

Brassica nigra

40

0.4

0.2

5.0

5.0

3.5

1.4

Source: ref. 30, with permission.
a. Mean of 3 pooled market samples.
b. Mean of 3 different types.
c. Mean of 14 different types.
d. Mean of 5 different types.

In meeting the energy needs of children over two years of age by cereal-pulse diets, excess bulk is a problem. To prevent this, diets should contain a minimum of 25 en % fat. Widespread dietary energy deficiency in young children of low-income groups was attributed to an insufficient quantity of food [34], but re-examination of the intakes of energy and fat by preschool children belonging to different socio-economic groups in both rural and urban areas showed that increased energy intake was closely associated with increased intake of visible fat [35]. The data also showed that when the intake of visible fat was 15 en %, the energy intake was judged to be adequate [36]. These observations reinforce the importance of increasing the energy density of diets for young children.

In diets of the rural poor, invisible fat furnishes about 5 g of saturated fatty acids, 4 g of monounsaturated fatty acids, 8 g of n-6 linoleic acid, and 0.3 g of n-3 linolenic acid; the ratios of polyunsaturated fatty acids to saturated fatty acids and n-6 to n-3 are about 1 and 13, respectively. In the urban high-income group, invisible fat furnishes about 13 g of saturated fatty acids, 6 g of monounsaturated fatty acids, 4 g of linoleic acid, and 0.6 g of n-3 linolenic acid; the ratios of polyunsaturated fatty acids to saturated fatty acids and n-6 to n-3 are 0.3 and 6, respectively [28].

Estimates of the various fatty acids in the total diet indicate that the levels of linoleic acid are generally adequate because of its high levels in cereals and many vegetable oils (table 5). The levels of n-3 linolenic acid, however, are low. To correct the quality of fat in Indian diets, n-3 polyunsaturated fatty acids should be increased [39]. Saturated and/or trans fatty acids are often needed in food products where a solid or semi-solid fat is desired. On their own, saturated fatty acids could fulfil the same functional requirements. Therefore, in countries where the consumption of trans fatty acids is high, solid fat formulations could be based on saturated fatty acids. In the high-income group, use of oils such as safflower, sunflower, sesame, or groundnut oil provides high ratios of n-6 to n-3 [30]. The levels of n-3 linolenic acid will be in the desirable range only when mustard, rapeseed, or soya bean oils are used [39]. Analyses of commonly consumed fish in India indicate that fish with high fat (>5 g/100 g), medium fat (1-5 g/100 g), and low fat (<1 g/100 g), respectively, furnish an average of about 1.2,0.4, and 0.1 g of long-chain n-3 polyunsaturated fatty acids per 100 g of muscle [40]. The use of any single oil does not ensure the quality of fat (individual fatty acid levels, polyunsaturated fatty acids/saturated fatty acids, and n-6/n-3 ratios), as recommended for the prevention of cardiovascular disease [39].

The habitual diets of Indians contain a number of factors that are known to reduce the risk of coronary heart disease [3], including low fat intake (except in urban high-income and affluent groups, whose fat intake may exceed 30 en %), provision of essential fatty acids by invisible fat, high fibre, and provision of more than 60% of total energy intake by complex carbohydrates [19, 20]. Indian diets are also rich in spices and condiments, which may have antioxidant properties.

A series of metabolic studies was conducted in Indian subjects to determine the possible atherogenic effects of changing the cooking fat from groundnut oil to palmolein [30], ghee, canola oil [41], or mustard oil. The results showed that canola oil decreased LDL cholesterol, and mustard oil, with its high level of erucic acid, increased LDL cholesterol and triacylglycerol.

Improvements to the dietary fat in India could best be accomplished by:

» using oils with moderate levels of linoleic acid, such as groundnut, rice bran, or sesame oil;

» adding an oil or fat with a low level of linoleic acid, such as palm oil, to an oil with a high level of linoleic acid, such as safflower, sunflower, cottonseed, or soya bean oil;

» using a preferred oil along with mustard oil to increase the n-3 fatty acid content and moderate the intake of erucic acid from the mustard oil;

» combining soya bean oil with palm oil in equal proportions;

» using oils with minor components, such as antioxidants, which contribute to their nutritional benefits;

» consuming foods rich in n-3 linolenic acid, such as some vegetable oils and green leafy vegetables, and (for non-vegetarians) eating fish.

Since the requirements for n-3 polyunsaturated fatty acids increase with increased intake of n-6 polyunsaturated fatty acids, it is important to moderate linoleic acid and to increase the intake of n-3 polyunsaturated fatty acids. Use of more than one source of oil gives the added advantage of providing a greater variety of the minor components in the diet.

Fats and essential fatty acids in complementary foods for infants

Complementary foods are introduced when breastmilk can no longer satisfy all of the nutritional needs of an infant. Up to four months of age, a full-term infant fed by a well-nourished mother obtains sufficient energy and nutrients from maternal milk, the fat of which supplies 40% to 55% of the total energy and all of the n-6 and n-3 polyunsaturated fatty acids needed for growth and development [1]. As traditionally prepared in many developing countries, complementary foods have low energy and nutritional values [42, 43] and are often introduced earlier than the recommended age of four to six months. The prevailing situation in developing countries is that the fat content of breastmilk is too low and the wrong complementary foods are introduced too early. According to Butte [44], energy requirements may be 13% to 20% lower than those recommended by FAO/WHO/UNU [45], and breastmilk would be adequate up to six months if milk consumption reached at least 714 g/day up to two months and at least 784 g/day in three- to five-month-old infants [46]. Many infants under four months of age receive food supplements (fig. 4). There has been a consensus that complementary foods which would reduce breastmilk consumption should not be used before four months of age, and preferably should be used only after six months of age [47, 48].

Staple complementary foods are usually based on locally cultivated cereal crops, such as rice, millet, wheat, corn, and teff; roots and tubers, such as cassava, yam, taro, potato, and sweet potato; or starchy fruits, such as banana, plantain, and breadfruit. Other foods of various origins and fat contents are occasionally added to the complementary foods [42,43]. The complementary food, which is generally high in carbohydrate and low in fat, is fed to infants as a gruel of low energy density and nutritional value. In French-speaking African countries, such as Senegal and the Congo, the energy density of complementary foods has further decreased since 1994, with the devaluation of the currency and the poorer economic status of households [49]. Consequently, fat, essential fatty acids, and fat-soluble vitamins could be even more inadequate in these foods.

TABLE 5. Fat and essential fatty acid content (g/100 g edible portion) of main traditional complementary foods in developing countries


Data source


FAOa

Ref. 38 or unpublished data of the authors




Essential fatty acid content

Food

Mean fat content

Mean fat content (range)

18:2 n-6

18:3 n-3

Staple complementary foods

Cereals


Rice

0.1-2.7

0.65 (0.5-1.0)

031c

0.01c


Barley

1.2-2.1

2.10 (1.80-2.25)

1.15

0.11


Maize

0.1-7.5

2.82 (1.56-3.90)

1.41

0.03


Sorghum

1.7-3.7

3.20 (0.10-5.80)

1.01

0.07


Wheat

1.0-2.4

0.90-2.30b

-

-


Oats

6.3-7.8

7.10 (6.80-7.50)

2.74

0.12


Teff (Ethiopian millet)

0.7-3.5

-

-

-


Millet

0.3-6.3

3.90 (2.00-5.00)

1.77

0.13

Roots and tubers


Cassava

0.1-4.3

0.23 (0.20-0.35)

-

-


Yam

0.1-0.6

0.13 (0.10-0.20)

~0

0


Taro

0.1-0.4

0.25 (0.10-0.40)

-

-


Potato

0.1

0.10 (0.04-0.17)

0.03

0.02


Sweet potato

0.2-0.8

0.60 (0.40-1.00)

-

-

Starchy fruits


Banana

0.1-0.4

0.18 (0.10-0.38)

0.04

0.03


Plantain

0.3

-

-

-

Occasional complementary foods

Broad bean

1.5

-

-

-

Kidney bean

0.5

0.60

-

-

Lima bean

1.4

1.40 (1.10-1.60)

0.56

0.25

Mung bean (green gram)

0.8-1.0

1.10 (0.90-1.40)

-

-

Mungo bean (black gram)

0.6-2.6

1.20 (1.00-1.60)

0.14

0.57

African locust bean

22.9

-

-

-

Cow pea

0.9-2.0

1.40 (1.10-1.60)

0.44

0.26

Chick pea

5.3

3.40 (1.60-5.18)

-

-

Pigeon pea

1.3-3.0

1.40 (1.20-1.70)

-

-

Amaranth leaf

0.9

-

-

-

Gombo-okra leaf

0.3-1.0

-

-

-

Cassava leaf

0.2-2.9

1.64c

0.26c

0.67c

Spinach leaf

0.1-0.3

0.30 (0.20-0.41)

0.03

0.13

Soya bean flour

13.7-19.2

20.60 (19.80-22.10)

10.70

1.40

Pumpkin seed

41.5-53.7

50.64c

32.10c

0.05c

Shea-butter seed

48.0-50.0

-

-

-

Sesame seed

26.2-57.9

50.40 (48.40-52.80)

18.70

0.67

Roasted peanut

31.4-52.3

49.40 (48.10-50.90)

14.30

0.54

Vegetable oil

99.9

99.9

d

d

Condensed sweetened milk

-

8.8 (8.4-9.0)

0.18

0.07

Sweetening agent

Sugar

0.0

0.0

0.0

0.0

a. In cases of multiple values, we reported the lowest and the highest means. See ref. 37.
b. See ref. 38.
c. Unpublished data of the authors.
d. Developing countries produce mainly peanut, palm, palm kernel, coconut, and soya bean oils of varying essential fatty acid compositions.


FIG. 4. Percentage breastfeeding + food supplements by infants 0 to 4 months of age in developing countries. Source: ref. 47 and unpublished data

The concentrations of fat and essential fatty acids of staple and occasional complementary foods fed to infants in most developing countries of Asia, Africa, and Latin America vary with the sampling, the analytical methodology, and the source of data collected for food composition tables (table 5). Food from tubers, roots, and starchy fruits, all low-fat products, becomes even lower in fat when mixed with water in preparing gruel. The actual fat level in complementary foods is highly variable and is probably well below that of human milk.

Data on the content of essential fatty acids are relatively scanty and also vary greatly. Improved information would have to come from fatty acid analyses of the traditional gruels used in rural and urban areas of each developing country. Tubers, roots, and starchy fruits are low in total fat and in essential fatty acids, but most cereals contain significant amounts of linoleic acid (18:2 n-6), and some, such as barley, oats, and millet, also have linolenic acid (18:3 n-3). Oilseeds are high in linoleic acid, and some of them have linolenic acid. These foods of vegetable origin lack the long-chain derivatives of linoleic and linolenic acids.

Table 6 lists examples of transitional foods of improved nutritional value and energy density, known as "weaning flours", that are prepared in small-scale production units. Sometimes imported sugar or skimmed milk is added. Two of the 22 transitional foods contain vegetable oils. The energy densities of these transitional foods are within a rather narrow range (342-444 kcal/100 g). Their fat content, although higher than that of traditional complementary foods, varies greatly (0.9-10.2 g/100 g), yet the fat content of gruel remains well below that of breastmilk from even malnourished mothers [50]. These features aggravate a deficiency of fat and essential fatty acids. The essential fatty acids in transitional foods are provided by cereals and legumes, and the long-chain polyunsaturated fatty acids are provided by eggs, dried meat, and yeast.

It is generally agreed that fat should not be restricted in the diet of infants and that it should constitute 40% to 55% of their energy intake. On the basis of the estimated fat content (28 g/L or 252 kcal/L) and energy density (0.59 kcal/g) of human milk in developing countries, fat provides 41% of energy [46]. When the fat content of human milk is low, the importance of complementary foods becomes more crucial. As shown in table 7, the energy supplied by milk fat is adequate for infants from 0 to 2 months of age, but at older ages there is a need for additional fat to supply 40% of the infant's energy intake from fat. The additional daily amount of fat required would be 6 g at 3 to 5 months of age, 12 g at 6 to 8 months, and 20 g at 9 to 11 months. Supplying this amount of fat with the complementary foods that are currently available would require the infant to consume an excessive bulk of food. Alternatively, enrichment of complementary foods with fat or addition of high-fat foods could enhance their nutritional value. Such enhancement would be necessary if fat were expected to provide 55% of the infant's dietary energy, because if maternal milk provided only 41 % of energy and the fat content of the complementary food were not enhanced, the infant would have to consume an impossibly large amount of complementary food.

Some nutritionists consider that it might be sufficient, and more realistic for conditions in developing countries, for infants to obtain 30% instead of 40% to 55% of their energy from fat [46]. If this were so, infants aged 0 to 5 months would obtain enough energy from milk fat, and older infants would require 4 to 10 g of complementary fat daily, according to age. The important question is whether infants who obtain 30% of their energy from fat are adequately nourished.

TABLE 6. Energy density and fat content of locally processed transitional foods in developing countries

Country

Name of product

Main ingredients

Energy density (kcal/100g)

Fat content





g/100 g

% of total energy value

Algeria

Superamine

Wheat, chickpea, lentil, VMC, sugar, skimmed milk

414

4.5

9.8

Benin

Ouando1

Maize, sorghum, rice, sugar

401

3.1

7.0


Ouando 2

Maize, sorghum, kidney bean, peanut, sugar

366

4.0

9.8

Burkina Faso

Misola

Millet, soya bean, peanut, sugar, salt

430

11.5

24.1

Burundi

Musalac

Maize, sorghum, soya bean, sugar, skim milk, VMC

417

7.6

16.4

Cameroon

Boussiri

Maize, egg

410

0.9

2.0

Cape Verde

MICAF

Wheat, maize, bean

434

5.5

11.4

Congo

Vitafort

Maize or cassava, soya bean, sugar, VMC

342

5.8

15.3


Maiso

Soya bean, maize, sugar, VMC

427

7.2

15.2

Guinea

Yéolac

Maize, sorghum, soya bean, sugar, milk

430

8.1

17.0

Morocco

Actamine

Wheat, soya bean, sugar, skim milk, VMC

357

ND

ND

Niger

Bitamin

Millet, cowpea, peanut, sugar

406

8.9

19.7

Rwanda

Sosoma

Sorghum, wheat, soya bean

400

7.7

17.3

Senegal

AGETIP

Millet, cowpea, peanut

440

7.9

14.2


Ruy Xalele

Millet, skim milk, peanut oil, palm oil, monkey bread, cowpea, egg, sugar

421

5.2

11.1

Chad

Vitafort

Millet, maize, rice (or sorghum), cowpea, peanut, sugar

417-430

5.5-8.5

14.8

Togo

Nutrimix 1

Maize, sorghum, rice, sugar

426

2.8

5.9


Nutrimix 2

Maize, rice, soya bean, sugar

444

9.0

16.2


Viten 1

Maize, rice, sorghum, sugar

385

3.4

8.0


Viten 2

Maize, rice, soya bean, sugar

400

7.6

17.1

Vietnam

FIRI

Rice, soya bean, mung bean, dried meat, beer yeast

439

10.2

20.9

Zaire

Cerevap

Maize, wheat, vegetable oil, soya bean, sugar, milk, VMC

430

9.2

19.3

Source: ref. 43.
Abbreviations: ND, not determined; VMC, vitamin and mineral complement.

Besides the fat needed for energy, breastmilk plus complementary food must supply adequate essential fatty acids. If total fat intakes are too low, essential fatty acids could be utilized for energy. The estimates for essential fatty acids in breastmilk and complementary foods in developing countries are given in table 8. Milk provides adequate linoleic acid for infants 0 to 8 months of age. Complementary food could provide additional linoleic acid (213 mg/day) for infants 9 to 11 months of age. It is more difficult to satisfy the requirements for n-3 linolenic acid, which appears not to be sufficient in partially or wholly breastfed infants. Staple foods, such as cereals, roots, tubers, and starchy fruits, are extremely low in linolenic acid, and only foods such as green leafy vegetables, some oilseeds, or soya bean oil could significantly increase the content of linolenic acid in complementary foods. Long-chain polyunsaturated fatty acids, which are lacking in current complementary foods, may be provided by fish, meat, and eggs or novel foods. Traditional complementary foods to supplement breastmilk should provide more energy from fat and contain sources of essential fatty acids.

Saturated and trans fatty acids

The intake of dietary fat is generally high in developed countries and low in developing countries. Although both the quantity and the quality of fat can influence the risk of cardiovascular disease, saturated fatty acids are in general hypercholesterolaemic [53,54]. The various saturated fatty acids, however, behave differently. Evidence in 1991 showed that myristic acid had a greater effect in raising cholesterol levels than did palmitic acid [55]. On the basis of experiments in which the triacylglycerols were structurally modified, regression equations predicting the response of plasma cholesterol to dietary fatty acids indicated that total saturated fatty acids were twice as effective in raising cholesterol as polyunsaturated fatty acids were in decreasing cholesterol, and that monounsaturated fatty acids were neutral. Confounding effects came from the different species of triacylglycerol and the minor components in the fat or oil.

Several human clinical trials suggest that palm oil and palm olein do not raise total cholesterol and LDL cholesterol to the extent predicted from the fatty acid composition. In a normocholesterolaemic Malaysian population obtaining approximately 30% of their energy from fat, palm olein and soya bean oil had similar effects on plasma levels of total cholesterol and LDL cholesterol [56]. A switch from coconut oil (containing predominantly lauric and myristic acids) to palm olein (containing predominantly palmitic and oleic acids) lowered total cholesterol and LDL cholesterol; the switch to corn oil (containing predominantly linoleic acid) lowered it further [57]. Current evidence indicates that the cholesterolaemic effects of the various saturated fatty acids are not equal and that myristic acid is the most potent in raising plasma cholesterol [58]. This is of public health relevance, especially in populations in which coconut oil is the principal fat consumed.

In an Indian population obtaining 27% of its energy from fat, partial replacement of groundnut (peanut) oil by palm olein did not affect total cholesterol or lipo-protein cholesterol levels [30]. Australian men and women obtaining 30% of their energy from fat and ingesting less than 200 mg of cholesterol per day showed no difference in their plasma and lipoprotein levels resulting from a 5% exchange of energy between palm oil and olive oil [59]. These investigators also reported similar results from a human study comparing palm olein and canola oil [60]. Also, diets containing palm olein and canola oil, and the step 1 diet of the American Heart Association, all of which provide about 31% of their energy as fat and less than 200 mg cholesterol per day, had similar effects on levels of total cholesterol, very low-density lipoprotein (VLDL) cholesterol, and LDL cholesterol; only the step 1 diet increased HDL cholesterol and altered the LDL/HDL ratio beneficially [61]. The studies conducted in humans obtaining about 30% of their energy from fat in a mixed diet showed that vegetable oils, such as palm oil, palm olein, olive oil, canola oil, and soya bean oil, behave similarly with respect to blood cholesterol and lipoproteins.

TABLE 7. Energy needed from fat in complementary food to provide 40% or 55% of total daily energy from fat

Age group (mo)

Breastfed

Required energy (kcal/d)a

Fat calories

Energy from milkfatb

Energy (kcal) needed from fat in complementary food




40%

55%

kcal

%

40%

55%

0-2

Exclusively

404

162

222

180

41

0

42


Partially

404

162

222

155

41

6

667

3-5

Exclusively

550

220

303

198

41

22

105


Partially

550

220

303

167

41

53

135

6-8

Partially

682

273

375

166

41

106

209

9-11

Partially

830

332

457

155

41

177

301

a. According to Butte [44].
b. Assuming a breastmilk fat content of 28 g/L and energy density of 0.59 kcal/g.

TABLE 8. Essential fatty acids needed from complementary foods to meet minimum or optimal infants' requirements

Age (mo)

Breastfed

Average body weight

Required energy

Average milk intake

EFA supply by milk intake

Minimum EFA requirement

EFA needed from CF to meet minimum requirement

Optimal EFA requirement

EFA needed from CF to meet optimal requirement



(kg)a

(kcal/d)b

(g/d)c

(mg/d)d

(mg/d)e

(mg/d)f

(mg/d)g

(mg/d)f

18:2 n-6

0-2

E

4.2

404

714

2,630

1,212

0

2,520

0


P

4.2

404

617

2,280

1,212

0

2,520

240

3-5

E

6.4

550

784

2,890

1,650

0

3,840

950


P

6.4

550

663

2,450

1,650

0

3,840

1,390

6-8


8.0

682

660

2,439

2,046

0

4,800

2,361

9-11


9.2

830

616

2,277

2,490

213

5,520

3,243

18:3 n-3

0-2

E

4.2

404

714

99

202

103

210

111


P

4.2

404

617

86

202

116

210

124

3-5

E

6.4

550

784

109

275

166

320

211


P

6.4

550

663

93

275

182

320

227

6-8


8.0

682

660

92

341

249

400

308

9-11


9.2

830

616

86

415

329

460

374

20:4 n-6 and associated n-6 fatty acids

0-2

E

4.2

404

714

159

U

-

168

9


P

4.2

404

617

138

U

-

168

30

3-5

E

6.4

550

784

175

U

-

256

81


P

6.4

550

663

149

U

-

256

107

6-8


8.0

682

660

148

U

-

320

172

9-11


9.2

830

616

138

U

-

368

230

22:6 n-3

0-2

E

4.2

404

714

79

U


84

5


P

4.2

404

617

69

U

-

84

15

3-5

E

6.4

550

784

87

U

-

128

41


P

6.4

550

663

74

U

-

128

54

6-8


8.0

682

660

74

U

-

160

86

9-11


9.2

830

616

69

U

-

184

115

Abbreviations: E, exclusively; EFA, essential fatty acid; CF, complementary food; P, partially; U, unknown.

a. According to WHO [51].
b. According to Butte et al. [44].
c. According to WHO/UNICEF [46].
d. Assuming an average content of 13.2% of 18:2 n-6, 0.5% of 18:3 n-3, 0.8% of 20.4 n-6 and associated n-6 fatty acids, and 0.4% of 22:6 n-3 [52], and a milkfat content of 28 g/L.
e. 300 mg 18:2 n-6 and 50 mg 18:3 n-3 per 100 kcal.
f. Optimal (or minimum) EFA requirement = EFA supplied by milk.
g. 600 mg 18:2 n-6, 50 mg 18:3 n-3,40 mg 20:4 n-6 and associated fatty acids, and 20 mg 22:6 n-3 per kilogram of body weight according to WHO [1].

Partial hydrogenation of vegetable oils results in the formation of isomers of monounsaturated fatty acids and sometimes polyunsaturated fatty acids. Trans monounsaturated fatty acids are the most common of these isomers, and their physico-chemical properties are similar to those of saturated fatty acids. Their effects on blood cholesterol and lipoproteins, however, are different when compared to the most common cis monounsaturated fatty acids. Relative to oleic acid, trans fatty acids raise the atherogenic LDL and probably lipoprotein (a) and lower the beneficial HDL [16, 62-65]. In a comparison between two diets providing 32% to 34% of their energy as fat, one with 8.7% of total energy from trans monounsaturated fatty acids and the other with 9.3% of total energy from stearic acid, the diet containing trans monounsaturated fatty acids had a more adverse effect on lipoproteins [66]. As compared with the other diet, the diet containing stearic acid lowered LDL levels, and the diet containing trans monounsaturated fatty acids lowered HDL levels and also significantly increased lipoprotein (a) levels. These studies were conducted in industrialized countries where the fat intake was high (providing 36%-40% of total energy), but a study conducted in Malaysia (with 32% of total energy from fat) showed that trans fatty acids had a greater adverse effect than saturated fatty acids [67]. Generally, trans fatty acids tend to worsen the LDL/HDL ratio.

Food products requiring a solid or semi-solid consistency have traditionally been formulated with saturated and/or trans fatty acids. In view of the growing knowledge of trans fatty acids and their health implications, formulations should aim to reduce or eliminate the use of partially hydrogenated fats. Saturated fatty acids on their own could fulfil the same functional requirements. This may be an important consideration in some developing countries where the consumption of solid fats containing trans fatty acids is high. Although stearic acid has been reported to be neutral with respect to its effects on blood cholesterol and lipoproteins, questions remain about its possible thrombogenicity. In any case, it is best to avoid high levels of trans fatty acids in the diet.

Fats and oils as sources of vitamin A and carotenoids

Palm oil is by far the most important source of carotenoids. Total carotenoid levels have been reported between 300 and 3,000 ppm. On average palm oil contains 500 to 700 ppm of carotenoids [68]. The major carotenoids in palm oil are a- and b-carotenes, but more than 10 others have been detected. Ratios of Otto (b-carotene have been reported between 1/2 and 1/10 [68], but commercial crude palm oil normally has a ratio of 7/10. Corn oil (90 ppm), rapeseed oil (<100 ppm), and olive oil (5 ppm) have been reported as having lower carotenoid levels.

The purpose of refining palm oil is to remove undesirable odour and colour compounds, but at the same time refining removes all carotenoids. It has been observed that heating can transform carotenoids completely into hydrocarbon-type derivatives [69]. These compounds will not have the physiological effects of carotenoids. Refining of the world production of palm oil (13.5 million tons in 1996) destroys approximately 6.8 tons of carotenoids. Improved technologies are being developed to preserve the carotenoids in palm oil.

Vitamin A values (retinol equivalents or RE) for palm oil between 3,600 and 21,700 RE/100 g have been reported, using the NAS-NRC conversion factor of 1 RE to 6 mg trans b-carotene [64]. This makes palm oil a very significant contributor to vitamin A needs, especially in developing countries.

Fat-based products may contain b-carotene (e.g., for colour in spreads) or be fortified with vitamin A. The latter is a legal obligation in a considerable number of countries. Most developing countries do not have such legislation, but when fat is fortified in developing countries, the range is 5 to 10 mg/kg (table 9). Both vitamin A and carotenes are well absorbed from fat-based products.

Summary and recommendations

» Data on the composition and intake of dietary fat are scarce in developing countries. Collection of reliable data should be encouraged.

» Updated knowledge on dietary fat should be available. Analysts and local analytical capacity are needed to examine these constituents of the diet.

» In determining the intake of dietary fat, the sometimes large differences between population groups have to be taken into account.

» Energy deficiency is normally associated with a low-fat diet. To reach FAO/WHO recommendations, an increased fat intake may be necessary. In most cases, for the general population the fatty acid composition is less critical than the amount of total fat.

» In general, dietary guidelines should not be automatically adopted from industrial countries but should take into account local health issues and positive features of the local dietary situation.

» For groups in developing countries who have a high-fat intake, dietary guidelines similar to those of industrialized countries are applicable.

» Where n-3 fatty acids are in short supply, consideration should be given to the n-6/n-3 balance of fatty acids. Special attention should be given to women of reproductive age, infants, and children.

» High concentrations of trans fatty acids in food products should be avoided.

» Infants should be breastfed. Complementary foods, produced locally whenever possible, should contain more energy from fat and provide essential fatty acids with a balanced n-6/n-3 ratio.

» Fortification with vitamin A through concerted efforts of governments, international organizations, and industry is recommended to overcome critical vitamin A deficiency. Where unrefined palm oil is used, its continued use should be encouraged. Alternatively, red palm oil rich in carotenoids should be included in the total dietary fat to enhance vitamin A activity.

TABLE 9. Vitamin A in margarines in developing and emerging markets

Country

Brand

Vitamin A type

Quantity (g/kg)

Quantity (IU/kg)

Central and East Europe

Czech Republic

Flora

Aa

7,650

26,250


Rama

A

6,120

20,200

Hungary

Liga light

A

6,010

16,630

Poland

Bono

Palmitate + D3

9,000

29,700


Kasla

Palmitate + D3

9,000

29,700

Turkey

Almost all

Palmitate (1 mIU/g)

63,000

207,900

Latin America

Brazil

Becel CV

Palmitate 1.7 mIU/g

4,950

16,330


Clayborn Sabor & Saude

Palmitate 1.7 mIU/g

9,690

31,980


Doriana Light

Palmitate 1.7 mIU/g

4,950

16,330

Chile

Doriana (Sabor) (kitchen)

Palmitate + D3

9,000

29,700


Doriana (Sabor) soft

Palmitate + D3

9,000

29,700

Venezuela

Blue Band6

A

9,640

31,800

Netherlands Antilles

Blue Band Packets

A

9,090

30,000


Blue Band Tins

A

9,090

30,000

Peru

Astra

Palmitate 1.7 mIU/g

102,000

36,660



Vitamin A + D3

11,700

38,610


Dorina Potae 454 g

Vitamin A + D3

7,500

24,760

Chile

All

Vitamin A + D3

900

2,970

Panama

All

Vitamin A + D mix

6,430-6,930


Africa

Cote d'lvoire

Blue Band

A

6,300

30,790

South-East Asia

Malaysia

Dorinab

A

7,570

25,000


Plartab

A

7,570

25,000

Sri Lanka

Astrab

A

1,000

33,000

Indonesia

Astrab

A

1,000

33,000

a. The type of vitamin A used was not specified in the database.
b. Information from Golden Yellow Fats database. Food Applications Unit, URL, and from margarine labels.

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