Unit 10 CARBOHYDRATES INCLUDING FIBRE Objectives To describe the classification of carbohydrates To show that carbohydrates are an important source of food energy To explore the advantages of whole grains To show the digestive process of carbohydrates To discover the major difference between natural and refined sugar To identify the effects of refined sugar in the diet To appreciate the Glycaemic Index (GI) of different carbohydrates To clarify the difference between soluble and insoluble fibre To discover the benefits of fibre and how to increase the intake if needed FORMS OF DIETARY CARBOHYDRATE6 The word carbohydrate was coined from the initial observation that these compounds are comprised of carbon, hydrogen, and oxygen. (CHO) Carbohydrates are sugars and starches, compounds made by plants through the process of photosynthesis. Carbon dioxide from the air, and water from the soil combine in the presence of sunlight with the plant’s chlorophyll to form carbohydrates which are then stored in the fruits, seeds, roots, stems and leaves of the plant12. Carbohydrates should supply 60 – 70% of our energy needs6. Carbohydrates are divided into three groups, which cover: Sugars, starches and dietary fibre. A. Mono-saccharides or simple sugars: (mono = one)6 Mono-saccharides are the simplest units of carbohydrate. Before any carbohydrate food can be absorbed into the blood stream and used for energy, the digestive process must break it down to its simplest form (glucose, fructose and galactose). B. Di-saccharides or double sugars: (di = two)6 Di-saccharides are made up of two mono-saccharides. C. Poly-saccharides or complex sugars (starches): (poly = many)6 Poly-saccharides are chains of many single units. 1. Starch (many glucose units – 1300 or more in a starch grain) found mainly in cereals, grains, vegetables and legumes. Where carbohydrate is the staple diet, it is starches rather than sugars, which predominate. But as countries become richer, consumption of starches decreases while consumption of refined 137 Unit 10 CARBOHYDRATES INCLUDING FIBRE sugar (sucrose) increases. Because foods which contain starches also contain fibre, minerals and vitamins, whereas refined sugar has none of these nutrients, such dietary changes may have great significance. 2. Dextrin (a molecule of lesser complexity than starch) it is formed from starch by the action of heat, acids or enzymes. Commercial dextrin is formed when heating starch. 3. Glycogen (storage form of glucose) found in the liver and muscles of man and animals. 4. Fibre (made up of many glucose units) found in two main types, insoluble and soluble. Insoluble fibre (cellulose) is the structural carbohydrate of plants found in cereals, fruits and vegetables. Not digested by man it increases food bulk and so reduces the transit time of food through the body. Soluble fibre (hemicelluloses, pectins, mucilages, gums, and modified polysaccharides) are found in oats, rice, legumes, fruit and vegetables. In food they provide properties of gelling, thickening (as in jams), emulsifying, stabilizing, and texture. Soluble fibre is related to the slowing down of starch digestion and glucose absorption, in that it puts a gel around the nutrients. This fibre gel also has the ability to attach itself to bile salts helping to reduce high blood cholesterol levels. FUNCTIONS OF CARBOHYDRATES6 Carbohydrates should supply 60 – 70% of our energy needs, or daily calorie intake. Most of this should come from grains, vegetables and fruit. These foods are also high in fibre and contain necessary vitamins and minerals. Carbohydrates serve a number of important functions: They are an economical source of fuel or energy, providing 4 cal./16kJ/g Glucose is the form in which individual cells throughout the body obtain their energy. If there is enough carbohydrate in the diet, protein need not be used for energy, but can serve its proper purpose in making and repairing body cells. Carbohydrate therefore has a protein-sparing action6. 138 Unit 10 CARBOHYDRATES INCLUDING FIBRE THE IMPORTANCE OF WHOLE GRAINS11 Grains have come to mean ‘sustenance’ and ‘life’. Today they are our most important crop, feeding over half the world’s population. For many they truly represent the ‘staff of life’ and nutritionists recognise the valuable contribution grains make to a healthy diet11. Grains are important from a nutritional point of view. They are rich in complex carbohydrates (which helps make them filling and sustaining foods), and they provide a good source of different types of dietary fibre as well as contributing proteins and many vitamins and minerals11. Grains are low in sugars and sodium. Grains are generally low in fat (2-4%), except for oats, which contains double that of other grains (7%). Almost all the fat contained in grains is poly-unsaturated and is located in the germ. Grains are plant products and so contain no cholesterol11. Grains are especially valued for their vitamin B content, especially thiamin, riboflavin and niacin. Vitamin E is found in the germ and is present only in whole grains and wholemeal flour. Grain foods supply iron, plus small amounts of potassium, calcium, zinc, magnesium, manganese and copper11. Refining grains Each grain consists of three parts. The outer ‘bran’ layers protect the seed and are impermeable to water. These layers are rich in fibre, minerals and the important B vitamins – riboflavin, niacin and thiamin. The ‘endosperm’ is the inner storehouse of food material (carbohydrate and protein), and the ‘germ’ is the growing point of the plant from which the new shoot and root emerge. The germ contains most of the grain’s thiamin and vitamin E, and is rich in oils11. White flour is mainly endosperm, plus small quantities of fibre, and less in nutritional value than wholemeal flour11. We have a wonderful variety of cereal grains: barley, wheat, oats, rye, buckwheat, corn, rice and millet11. Cereal grains can be stored for long periods of time with their nutritional value in tact11. 139 Unit 10 CARBOHYDRATES INCLUDING FIBRE DIGESTION OF CARBOHYDRATES6 1. All carbohydrate (except cellulose) is broken down by the digestive process into simple sugar form. 2. The process begins in the mouth where the enzyme amylase begins to breakdown the long starch chains made of glucose units, into smaller chains. Cooked starch is more easily digested than uncooked starch because the cell walls have been broken and the enzymes can reach the starch molecules. 3. The stomach regulates the speed that carbohydrate is released into the small intestine. Amylase from saliva continues to work on starch in the stomach until it is mixed with acid. This can take up to 20 minutes. 4. In the small intestine (main site for carbohydrate digestion) the breakdown of the long glucose chains (starch) is completed. The shorter chains broken down in the mouth or stomach are further broken down into di-saccharides and monosaccharides. Three enzymes, sucrase (breaks down sucrose), maltase (breaks down maltose), and lactase (breaks down lactose). Note: Lactose intolerance is the result of an insufficient supply of the enzyme lactase. The body is therefore unable to break down the di-saccharide lactose into galactose and glucose. Lactose intolerance has two common reactions: a. Osmotic effect – movement of water from blood stream to intestine to dilute sugar concentration, results in diarrhoea. b. The bacteria in the intestine will convert lactose to lactic acid producing gas, pain, and irritable bowel6. USE AND STORAGE OF CARBOHYDRATES6 After carbohydrate has been broken down into simple sugars it can enter the blood stream. In the liver, fructose and galactose are converted to glucose. Glucose serves several functions in the body. The main use of glucose is to provide energy for the body to function. The brain requires 120 grams of glucose daily to function normally. The glycogen store in the liver is used to maintain a stable blood glucose level. 30 grams of glucose is required daily by the blood cells. The skeletal muscles in a sedentary person uses 30 grams of glucose per day. The liver stores a supply of glucose in long chains called glycogen. Glycogen can be broken down very quickly into glucose and is a form of instant energy. Any excess carbohydrate ingested is converted to fat and stored as adipose tissue. It is interesting to note that the body finds it very hard to convert stored fat 140 Unit 10 CARBOHYDRATES INCLUDING FIBRE into energy and will use other available forms of energy first. The body may use protein in muscle tissue to provide energy before it will use adipose deposits. Carbohydrate is an important protein-sparing nutrient6. DEFICIENCY12 A deficiency of carbohydrate is unusual but may occur with some of the popular lowcarbohydrate diets. Low blood-sugar levels can cause symptoms such as fatigue, nausea, loss of appetite, weakness and fainting. These can be relieved by giving carbohydrate. A deficiency of carbohydrate could be accompanied by a lack of fibre, vitamin C, some vitamins of the B group, and trace minerals. EFFECTS OF EXCESS12 If more carbohydrates than required are eaten, the excess is converted into body fat. This is particularly likely to occur with refined carbohydrates such as sugar, which is easily consumed in large quantities. The fibre found in unrefined carbohydrates acts as a natural obstacle to over eating. The amount of chewing which has to be undertaken to over consume vegetables, apples and whole-grained cereals puts a natural brake on the amount eaten. Refining foods and removing fibre, for example in processing sugar or making fruits into ready-to-drink juices, makes them much easier to consume in excessive amounts. If we were to obtain sugar by chewing sugar cane, it would be impossible for anyone to consume the amount of sugar the average Australian eats in refined form12. SUGAR We are all born with a natural inclination towards sweet-tasting foods. Many natural foods are well endowed with sweetness for our enjoyment. Most fruits and some vegetables (such as carrots, peas, corn, pumpkin, sweet potatoes and beets) are noted for their supply of natural sugars – glucose, fructose and sucrose, packaged with many vitamins, minerals and fibre, in a variety of colours, textures and flavours7. Sweet desserts are often the centre of our celebrations. Parties and special occasions such as weddings, birthdays, and anniversaries are usually highlighted by cakes, pies, ice-cream, biscuits and fruit drinks. It is not a sin to occasionally enjoy foods sweetened with sugar, except when these special occasion foods become part of the regular everyday food intake7. On average, Australians consume 46 kilos of sugar a year – which equals 30 teaspoons a day! (Based on 1 teaspoon = 5 grams)6,16 It sounds a lot, but only 25% is used at home, the rest is hidden in processed food products such as soft drinks, cordials, confectionery, biscuits, cakes, jam, sauces, canned fruits, ice-cream, jelly and sweetened breakfast cereals. On average, sugar contributes an extra 480 calories or 2000 kilojoules each day – enough to make a difference between a person being normal weight or overweight5. 141 Unit 10 CARBOHYDRATES INCLUDING FIBRE Different Forms of Sugar6. Be aware that sugar comes in different forms & names: White sugar Raw sugar Brown sugar Cane sugar Sucrose Glucose Fructose Malt, maltose Corn syrup Lactose Sorbitol Mannitol Honey Molasses Golden syrup Treacle Health Problems12 Apart from the obvious effect of excess calories/kilojoules causing excess weight, sugar is harmful to the teeth and displaces more nutritious foods from the diet. It also keeps bad company, as it is usually packaged with fats as in chocolate, biscuits, cakes, sweet pastries etc. Professor John Yudkin, Emeritus Professor of Nutrition at London University, claims that refined sugar also increases the amount of uric acid in the blood (related to gout), increases the likelihood of blood clots, alters the balance of the hormones insulin and cortisol and makes a contribution to the causes of diabetes (refers to foods that contain a combination of sugar and fat) and gastric ulcers. There is still controversy about the exact effects of sugar, but it is a fact that sugar is entirely free of minerals, vitamins, protein, fatty acids and fibre. The greatest problem presented by sugar is its almost addictive nature, which leads to excessive intakes such as we have in Australia, and the way it is packaged in processed foods in the company of fats. As with most substances in the diet, the body might be quite capable of handling small quantities, but is not equipped to cope with large amounts. Cutting our sugar intake by at least half would seem reasonable and worthwhile. Sugar should be limited by everyone, especially by those wanting to lose weight 12. A ‘Natural Part of Life?’5 The promotion of sugar as a ‘natural part of life’ may be misleading to many people. Sugar is natural when it is consumed as part of fruit, milk or other foods. The unnatural form is white sugar, the processed and refined extract of sugar cane or sugar beets. In this form, it is too easy to consume excessive amounts. For example a can of soft drink can contain some 10 teaspoons of sugar! In this context, perhaps the slogan should be ‘Sugar - an unnatural part of life’. 142 Unit 10 CARBOHYDRATES INCLUDING FIBRE Average number of teaspoons of added sugar (hidden) in popular foods 1 can soft drink 1 can flavoured mineral water 1 can low-joule soft drink 1 glass of cordial 1 glass of fruit juice drink 300 ml flavoured milk 1 scoop of ice-cream 1 drumstick cornetto 1 flavoured ice block 1 bowl cereal 1 plain sweet biscuit 1 cream sweet biscuit 1 piece of apple pie 1 iced donut 1 piece of bubble gum 1 piece of licorice twist 1 tbsp jam 1 tbsp marmalade 1 tbsp tomato sauce 50g chocolate bar ½ cup canned fruit in syrup, drained 1 small bowl jelly 1 banana split 1 milk shake 10 tsp 10 0 5 4-5 5 4 6 3 3 1 2 6 6 1 4 3-4 5-6 1 8 3 4 20 155 Value of complex carbohydrates (starches) vs sugar6 If our bodies use glucose as the main fuel source, why not just eat sugar? There are several reasons: 1. Refined sugar eaten alone is too concentrated and is irritating to the mucosa, or lining of the stomach. 2. To transform glucose into energy the body uses many vitamins, minerals, and enzymes. A diet rich in complex or unrefined carbohydrates will adequately provide these essential nutrients. A high intake of refined sugars with no vitamins and minerals present may deplete the body’s store of nutrients. 3. The body needs roughage (fibre), which is not present in refined foods. 4. a. Sugar (whether white, brown, raw or honey) is broken down and absorbed into the bloodstream very quickly within 10-20 minutes. Glucose cannot be utilised by the cells without the insulin, which is produced by the pancreas. b. Insulin pushes glucose into the cells to restore the correct blood glucose level. 143 Unit 10 CARBOHYDRATES INCLUDING FIBRE c. Continually loading the system with foods high in sugar causes the pancreas to work overtime. d. When the blood glucose level rises quickly, too much insulin may be secreted in an effort to restore normal glucose levels. As a result, the glucose level ends up too low and the person feels hungry again. By continually overloading the system with foods high in sugar, the pancreas can become diseased increasing the risk of diabetes, hypoglycaemia and obesity. 5. If complex carbohydrates are the major source of energy, it takes 2 – 4 hours to break down these substances into glucose. There is a slower, more gradual release of energy into the bloodstream. This also helps satiety. Consumption of large amounts of sugar will increase the occurrence of tooth decay and obesity. If refined sugar contributes most of the energy in the diet there will probably be a poor supply of vitamins and minerals and an over abundance of fat. It is suggested that a consumption of LESS than 10 teaspoons of sugar per day is a safe level. Hints to reduce sugar intake: Eat fewer desserts. Drink mainly water, limit soft drinks, cordials and other flavoured beverages. Limit sugar to 2 teaspoons per serve in desserts and slices. Use more fruits – they are nature’s desserts. Use fruits preserved in their own juices. Don’t be fooled by other names that are used for sugar - it is the same thing6. At the supermarket5 Read the ingredient labels. Identify the various forms of sugar in a product. Select items lower in total sugar if possible. Buy fresh fruits or fruits packed in water or juice. Avoid those in heavy syrup. Buy fewer foods that are high in sugar such as prepared baked goods, confectionery, sweet desserts, soft drinks, cordials, and fruit juice drinks. In the kitchen6 Reduce the sugar in foods prepared at home. Try new recipes or adjust your own. Start by reducing the sugar gradually until you have decreased it by 1/3 or more. Taste and quality need not suffer. Often sugar in a cake can be halved before taste and quality suffers. 144 Unit 10 CARBOHYDRATES INCLUDING FIBRE At the table6 Use less of all sugars. This includes white and brown sugar, honey, molasses and syrups. Choose fewer foods high in sugar such as cakes, biscuits, confectionery and desserts. Reach for fresh fruit instead of a sweet dessert or when you want a snack. Add less sugar to hot drinks, cereal or fruit. Get used to using half as much, then see if you can cut back even more. Cut back on soft drinks and cordials. Better still quench your thirst with plain water6. GLYCAEMIC INDEX (GI) OF DIFFERENT CARBOHYDRATE FOODS14 The GI of foods refers to the rate at which carbohydrates in foods are converted into glucose within the blood stream. Foods with a high GI release their glucose quickly into the bloodstream, while those with a low GI give a slower sustained release of glucose. There is no doubt that having more foods with a lower GI is valuable for non-insulin dependent diabetics, as these foods release glucose slowly and put less strain on insulin supply. The GI may also have benefits for appetite control and sports performance. It should be pointed out however that the GI should not be the only measure used to judge different foods. The GI of foods is affected by many factors including amount of protein and fat present, as well as the amounts and types of fibre and starch present. For example, the GI may be low because a food is high in fat and therefore takes a long time to be digested. A Snickers bar has a lower GI than many fruits, but it is not a better food because of that. In a similar way, Weet-Bix, which has a GI of 69 (intermediate/moderate GI food) – is therefore not classed as a low GI food, despite its high nutritional value eg. low fat, low sugar, low salt, good source of fibre. It is useful for people to include some low GI foods as part of an overall varied diet – but not every food eaten has to be low GI. For people with diabetes, it is recommended that they try to include one low GI food at each meal. Overall, the GI concept, while useful in many instances, should not replace the importance of looking at the total nutritional content of any food 14. 145 Unit 10 CARBOHYDRATES INCLUDING FIBRE FIBRE, ARE YOU GETTING ENOUGH10? Dietary fibre is essential for good health. The term ‘dietary fibre’ actually refers to the parts of plant foods, which escape the usual process of digestion in the small intestine. Instead, dietary fibre moves into the colon (also known as the large intestine), where it is broken down by bacteriaError! Reference source not found.. Fibre is found in plant foods such as fruits, vegetables, cereals, grains, legumes and nuts. Meat and other animal foods (such as dairy products and eggs) do not naturally contain dietary fibre. Different types of fibre There are three major types of dietary fibre, soluble fibre, insoluble fibre and resistant starch. (although not actually a fibre, resistant starch is now being recognised as a member of the ‘fibre family’ due to its similar beneficial effects on the body4.) Soluble fibre is beneficial to help lower blood cholesterol levels and, in people with diabetes, helps to control blood sugar levelsError! Reference source not found.. Soluble fibre is found in fruits, vegetables, legumes, oats, rice and barley. Insoluble fibre is so called because of its ‘bulking properties’. It helps keep us ‘regular’2. Foods containing insoluble fibre include wholegrain and wholemeal wheatbased breads, cereals and pasta. Resistant starch is a type of starch found in plant foods that escapes digestion in the small intestine. Resistant starch may provide similar benefits to other types of fibre, such as helping to prevent constipation4. Foods containing resistant starch include firm bananas, chickpeas, boiled long grain rice, baked beans, cooked potato as well as cornflakes13. Why fibre is important Research has established that a diet high in dietary fibre can provide a number of health benefits. It has been shown to help in the management or prevention of bowel disorders and bowel disease, heart disease, diabetes and weight control 4. A fibre rich diet is also a vehicle for providing many other protective plant compounds, such as phytochemicals (natural plant chemicals) that may provide protection against certain diseases, such as cancers and heart disease 14. Bowel health and disease Apart from its role in the prevention of constipation, dietary fibre can help maintain bowel health in other ways. During the fermentation of fibre by bacteria in the colon, substances called ‘short chain fatty acids’ are produced which help keep the cells of the lower colon healthy4. In addition, dietary fibre, particularly the insoluble type, can help reduce the risk of diverticular disease (a condition where pouches form in the wall of the intestine)1. 146 Unit 10 CARBOHYDRATES INCLUDING FIBRE The role of dietary fibre in the prevention of colon cancer has long been debated by researchers. The World Cancer Research Fund Report (1997), which examined the findings of over 4,000, published scientific papers, found that dietary fibre may possibly decrease the risk of colon cancer15. The report suggested that other dietary factors (eg. antioxidants) found in high fibre foods (such as fruits, vegetables, cereals and legumes) may contribute to this reduced risk of colon cancer that has been linked with fibre15. It is also possible that the short chain fatty acids produced as a result of eating fibre may help prevent against colon cancer4. Heart disease Diets rich in soluble fibre (particularly from oats) have been shown to reduce heart disease risk by lowering blood cholesterol levels9. Research suggests that including legumes (eg. soybeans and chickpeas) oat bran or psyllium can significantly reduce the total and LDL cholesterol (the ‘bad’ type of cholesterol) levels9. Diabetes Dietary fibre (in particular, soluble fibre such as that from beans, lentil and oats) can slow the absorption of nutrients from the small intestine4. Slower absorption of sugar/glucose from the small intestine will mean slower rise in blood sugar levels. This is important for people with diabetes who need to avoid sharp peaks and falls in blood sugar levels14. Weight control Dietary fibre may play a role in promoting and maintaining weight loss by increasing the feeling of ‘fullness’ after a meal is eaten4. Also, many foods that are naturally high in fibre, such as cereals, fruits and vegetables, are generally low in fat (which is important for weight loss) and can take longer to chew, which could lead to eating less4. How much fibre do you need? Dietary surveys show that the average Australian does not eat enough dietary fibre3,4. Health professionals advise that adults should eat at least 30 grams of fibre each day, for health benefits4. How much food would provide 30 grams of fibre? It is not difficult to add more fibre to our diets. As an example, the following foods eaten over the day will provide over 30g of dietary fibre8. 1 serving of high-fibre breakfast cereal (like Weet-Bix Hibran) 2 slices of wholemeal bread 2 serves of fresh fruit (eg. apple and banana) 3 serves (1/2 cup) of vegetables (eg. green beans, carrots and broccoli) ½ cup cooked kidney beans 30 g almonds 147 Unit 10 CARBOHYDRATES INCLUDING FIBRE What about fibre supplements10? Fibre supplements can contribute fibre to the diet. However, there are several reasons why it may be preferable to eat foods as a source of fibre, rather than taking supplements: There are a number of different types of fibre found in foods, not all of which may be present in a supplement. Consuming fibre supplements, rather than high-fibre foods, may mean missing out on the other nutrients (such as vitamins, minerals and phytochemicals) that are supplied by foods. Some fibre supplements have become popular as a supposed aid for weight control. However, studies on the use of various fibre supplements for weight reduction, show that weight loss is rarely sustained 4. Hints for getting more fibre10 1. The best way to get enough dietary fibre is to regularly eat wholegrain or wholemeal breads and cereals, legumes, fruits, vegetables, nuts and seeds. 2. Choose brown rice, wholemeal pasta, whole grain crispbreads and wheatmeal biscuits. 3. Add legumes to soups, casseroles, salads and sauces. 4. Sprinkle chopped fresh or dried fruits, wheat germ or seeds on breakfast cereal. 5. Eat unpeeled fruits and vegetables wherever possible as the skins are a valuable source of fibre. 6. In general, look on the nutrition panel of food products and choose those which provide at least 1.5 grams of dietary fibre per serve. It is also important to note that fibre absorbs water, so to further assist the effects of fibre on bowel regularity, be sure to drink plenty of water throughout the day2. Good Sources of Fibre Poor Sources of Fibre (No Fibre) Cereals and grain products Legumes Vegetables Fruit Meat Fish Poultry Dairy products Eggs Fats and oils 148 Unit 10 CARBOHYDRATES INCLUDING FIBRE Summing it all up10 Eating enough dietary fibre is essential for good health. Different types of fibre provide different health benefits so it’s important to include a wide range of fibre containing plant foods each day. REFERENCES: 1. Aldoori W, Giovannucci E, Rockett H, Sampson L, Rimm E, Willett W; A PROSPECTIVE STUDY OF DIETARY FIBER TYPES AND SYMPTOMATIC DIVERTICULAR DISEASE IN MEN Journal of Nutrition 1998;128:714-9 2. American Dietetic Association; POSITION OF THE AMERICAN DIETETIC ASSOICATION: HEALTH IMPLICATIONS OF DIETARY FIBRE 1996 3. Australian Bureau of Statistics NATIONAL NUTRITION SURVERY - SELECTED HIGHLIGHTS Australia 1997 4. Baghurst P, Baghurst K, Record S; DIETARY FIBRE, NON-STARCH POLYSACCHARIDES AND RESISTANT STARCH: A REVIEW Food Aust 1996;48(3:suppl)S3-35 5. Borushek A; ALLAN BORUSHEK’S DIET MANUAL Family Health Publications West Perth 1988:39-41 6. Butler T, Butler D, Stanton H; VEGETARIAN COOKING DEMONSTRATOR’S MANUAL – 2nd EDITION Adventist Health Department & Sanitarium Nutrition Education Service, 1995:E13-E21 7. Craig W; NUTRITION AND WELLNESS Golden Harvest Books Berrien Springs Michigan. 1999:51-56 149 Unit 10 CARBOHYDRATES INCLUDING FIBRE 8. Department of Community Services and Health; NUTRITONAL VALUES OF AUSTRALIAN FOODS AGPS Australia 1992 9. Glore S, Van Treeck D, Knehans A, Guild M; SOLUBLE FIBER AND SERUM LIPIDS: A LITERATURE REVIEW Journal of American Dietetic Association1994;94:425-36 10. Sanitarium Nutrition Education Service; ARE YOU GETTING ENOUGH FIBRE? Sanitarium Health Food Company 1999 11. Sanitarium Nutrition Education Service; GRAINS FOR GOODNESS Sanitarium Health Food Company June 1990 12. Stanton R; FOOD FOR HEALTH – second edition W.B. Saunders Artarmon NSW 1983:19-21 13. Topping D; RESISTANT STARCH, FOOD AND LARGE BOWEL HEALTH Heinz Sight 1998;49(11) 14. Wahlqvist M; FOOD AND NUTRITION - Australia and New Zealand 2nd Edition Allen & Unwin Pty Ltd Crows Nest NSW 2002:397,431,432 15. World Cancer Research and American Institute for Cancer Research; FOOD NUTRITION AND THE PREVENTION OF CANCER: A GLOBAL PERSPECTIVE 1997 16. FOOD TECHNOLOGY February 1988: Chemistry and Analysis of Soluble Dietary Fibre vs. Insoluble Fibre – Different Physiological Responses: 81 150