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Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Objectives To give a definition of nutrition To discuss the history of the study of nutrition To discover food trends in Australia To show the relationship between food and health To outline the Dietary Guidelines for Australians To recognise food fads and fallacies DEFINITION The science of food and its relation to health. It is a new, dynamic field, which changes frequently as our knowledge both of foods and health increases 12. Nutrition is a vital factor in sustaining health. It is not only about calories/kilojoules and carbohydrates, fats and fibre, but is interrelated with a wide range of disciplines, including agriculture, economics, sociology and medicine. Nutrition studies the nature of food, what happens to that food before we eat it, why we choose to eat certain foods and what happens to food in the body. World Health Organisation (WHO) defines health as, “Health is a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity2.” HISTORY OF THE STUDY OF NUTRITION The Bible records the instruction given to the Children of Israel about the type of foods that should be eaten and not eaten. Eight hundred years later Daniel and his three friends asked for vegetarian food and water to replace the king’s meat and wine3. Hippocrates in 400 BC studied the relationship of eating and weight loss 3. Until the nineteenth century, people knew very little about the science of nutrition. They knew that food was necessary for energy, that the lack of foods caused certain diseases – for example, the lack of fresh fruit and vegetables in sailors’ diets caused scurvy12. Dr. Lind, a British physician, carried out the first controlled nutrition experiment in 1747. He attempted to find a cure for scurvy. Dr. Lind treated twelve sailors who had scurvy with six different dietary programs. He found that lemon or lime juice was effective in helping sailors avoid scurvy3. During the nineteenth century it was realised that food was made up of fats, carbohydrates, protein and water. In the early part of the twentieth century, a new era of nutrition discovery dawned as the structure of nutrients came to be understood and vitamins and minerals were found to be vital. Vitamin B12 was discovered in 39 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues 1948 and several of the trace minerals were found to be essential in the 1950’s and 60’s. Discovery has continued12. In the early Australian settlements, nutrition was often poor. The food consisted mainly of grains and meat, in the cities at least there were a few fruits and vegetables available. By 1890, poverty had increased and the diets of the poor deteriorated. Vegetables became prohibitively expensive for many people; wholemeal flour was replaced by white flour; white bread with dripping and golden syrup plus a mug of tea became a common – but inadequate – meal. As sheep production increased, the economy, based on wool improved, and more people could buy better food. The dairy industry prospered and more vegetables were grown12. Earlier in the last century, there was concern for the health of the nation resulting from malnutrition. Nutrient deficiencies were common and food was not always plentiful. Today the concern for health relates to over-nutrition. Food is very plentiful, but diseases of affluence are common3. Research is continuing into the complex composition and principles of our food supply. FOOD TRENDS Over the last 40 to 50 years, the Australian diet has undergone a revolution. Convenience foods now make up a large proportion of the diet, food manufacturers are increasingly assuming the role once held by the housewife, or the provider of food in the home. We continue to consume large quantities of animal foods and sugar; the consumption of wine, poultry and margarine have increased; butter and bread consumption have declined; fruit and vegetable consumption has increased, although more fruit is now consumed in the form of juices. Items such as yoghurt, frozen foods, canned and packaged cooking ingredients, soft drinks, sweetened breakfast cereals; muesli and an extensive range of snack foods have appeared and become very popular12. Why we choose foods We choose foods not only by their availability but also because of price, tradition, taste habits (developed mainly in childhood), culture, social background, religion and various prejudices. Our food choices are also influenced increasingly by advertising12. Selecting an adequate diet The body is made up of thousands of different substances, amazingly, most of them can be made within the body from other substances. But there are some we cannot make: these are the essential building materials called ‘nutrients’, and they must be supplied in food12. The nutrients are proteins, fats, carbohydrates, fibre, vitamins, minerals and water. They all have essential roles in the body’s chemistry and are vital, in the right quantities for health12. 40 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues We may know how much protein, fats and vitamins we need; but, ultimately, these nutrition requirements must be translated into the various kinds of food. No single food contains all the nutrients we need. Instead, a variety of different types of food are needed to produce health and vitality – the characteristic signs of good nutrition12. Variety in choosing, cooking and serving food makes eating a pleasure and is far more likely to result in a balanced intake of nutrients12. FOOD AND HEALTH Nutrition is now taking its rightful place at the top of the health priority list for hundreds and thousands of Australians. Once a neglected subject – the subject of hospitals and health farms – nutrition has blossomed to become a key issue of concern for most Australians. No longer are ‘health nuts’ or dieters the only groups interested in what they eat. Today most people rank nutrition as important as taste, cost and brand name – nutrition terms like ‘kilojoules’ ‘complex carbohydrates’ and even ‘junk foods’ were the buzzwords of the Nineties. Why has nutrition asserted itself? People have discovered when they eat well; they feel good and that a nutritious eating plan is the best insurance for vitality and glowing health. It is interesting that the medical profession, food companies, pharmacies, universities, schools and even governments have accepted the importance of nutrition. Nutrition has the support of major institutions in the country11. Australia had no department of nutrition at any university until the first Professor of Human Nutrition was appointed to Deakin University in Geelong, Victoria in 1977. Soon after, the University of Sydney also established a nutrition department for teaching and research. Today there are graduate courses in training nutritionists and dietitians in most capital cities of Australia12. Medical, pharmacy and dentistry students are being taught the importance of nutrition to health, because nutrition can reduce our susceptibility to infection and even protect against illness in later life. The medical and scientific world is convinced that the Western diet is responsible to a large degree for the high incidence of degenerative diseases – heart disease, cancers of the bowel and stomach, diabetes type two, stroke, high blood pressure, obesity, gall bladder disease and cirrhosis of the liver – which are all linked to nutrition11. A major nutritional concern in Australia is excess weight. The Australian National Nutrition Survey (1995) showed that a growing number of people are becoming overweight or obese. This survey found that 47% of women and 63% of men in Australia are overweight or obese compared to 34% of women and 48% of men in 1989. In contrast, approximately 1.4% of Australian adults are underweight 10. 41 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Fruit and vegetables are protective More than 130 dietary studies have revealed that a regular consumption of fruit and vegetables provides significant protection against many cancers. A recently published study of 2400 Greek women noted that vegetable and fruit consumption was independently associated with significant reductions in the incidence of breast cancer, a cancer claiming the life of 44,000 women in the US every year 3. Protection from whole grains and nuts Many of the cancer-preventative phytochemicals found in fruit and vegetables are very similar to those found in whole grains. These substances reduce the risk of cardiovascular disease and cancer. The active substances are concentrated in the bran and the germ, so that the health benefits of grains are maximised when the whole grain product is consumed. Nuts also contain a variety of nutrients and phytochemicals. A number of studies have shown that a regular consumption of nuts decreases the risk of dying from coronary heart disease6. To help reduce health risks, the Australian Government Health Department has published dietary guidelines covering three age groups: Children and Adolescents in Australia, Australian Adults, Older Australians. 1. DIETARY GUIDELINES FOR CHILDREN & ADOLESCENTS IN AUSTRALIA8,9 Encourage and support breastfeeding Children and adolescents need sufficient nutritious foods to grow and develop normally Growth should be checked regularly for young children Physical activity is important for all children and adolescents Enjoy a wide variety of nutritious foods Children and adolescents should be encouraged to: Eat plenty of vegetables, legumes and fruits Eat plenty of cereals (including breads, rice, pasta and noodles), preferably wholegrain Include lean meat, fish, poultry and/or alternatives Include milks, yoghurts, cheese and/or alternatives – Reduced-fat milks are not suitable for young children under 2 years, because of their high energy needs, but reduced-fat varieties should be encouraged for older children and adolescents Choose water as a drink – Alcohol is not recommended for children and care should be taken to: Limit saturated fat and moderate total fat intake 42 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues – Low-fat diets are not suitable for infants Choose foods low in salt Consume only moderate amounts of sugars and foods containing added sugars Care for your child’s food: prepare and store it safely 2. THE DIETARY GUIDELINES FOR AUSTRALIAN ADULTS8,9 Enjoy a wide variety of nutritious foods Eat plenty of vegetables, legumes and fruits Eat plenty of cereals (including breads, rice, pasta and noodles), preferably wholegrain Include lean meat, fish, poultry and/or alternatives Include milks, yoghurts, cheeses and/or alternatives. Reduced-fat varieties should be chosen, where possible Drink plenty of water. and take care to Limit saturated fat and moderate total fat intake Choose foods low in salt Limit your alcohol intake if you choose to drink Consume only moderate amounts of sugars and foods containing added sugars. Prevent weight gain: be physically active and eat according to your energy needs Care for your food: prepare and store it safely Encourage and support breastfeeding 3. DIETARY GUIDELINES FOR OLDER AUSTRALIANS8,9 1. Enjoy a wide variety of nutritious foods. 2. Keep active to maintain muscle strength and a healthy body weight. 3. Eat at least three meals every day. 4. Care for your food: prepare and store it correctly. 5. Eat plenty of vegetables (including legumes) and fruit. 6. Eat plenty of cereals, breads and pastas. 7. Eat a diet low in saturated fat. 43 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues 8. Drink adequate amounts of water and/or other fluids. 9. If you drink alcohol, limit your intake. 10. Choose foods low in salt and use salt sparingly. 11. Include foods high in calcium. 12. Use added sugars in moderation. Let’s consider some of the main points of these guidelines, focusing particularly on those for the Australian Adult. 1. Enjoy a wide variety of nutritious foods. Variety means that we choose to eat a mixture of foods across the range of food types, (cereals, vegetables, legumes, fruit, protein rich foods, dairy foods etc,) and a variety within each type (e.g. cereals - wheat, corn, oats, rice, etc.) on a regular basis. Variety does not mean rotating through the different brands of cornflakes! The nutritious and healthy diet will have as its central and essential core: Eat plenty of vegetables, legumes and fruits In using vegetables, legumes, and fruits it is preferable to use those without added fats, refined sugars and added salt, and including where possible, the edible skins and seeds Vegetables. All vegetables, fresh and frozen, including potatoes, sweet potatoes, peas, beans, tomatoes, all leafy green vegetables, all root vegetables, pumpkin, squash, cucumber, zucchini, peppers, onion, shallots, garlic, sweetcorn, asparagus, mushrooms etc. Legumes. Includes all canned or dried bean products – baked beans, lentils and lentil flour products (e.g. pappadams), soya beans and soya flour products (e.g. tofu, bean curd) red kidney beans, haricot beans, chick peas, pinto beans, butter beans, mung beans etc. Fruits. All fruits including citrus fruits, apples, pears, bananas, tropical fruits, stone fruits and berries. Eat plenty of cereals, preferably wholegrain Cereals (includes bread, breakfast cereals, pasta, grains, etc). The wholegrain forms of these foods without added fats, refined sugars and salt are preferable. For foods such as breads - where the commonly available forms contain added salt - reduced salt forms should be sought. There are many varieties of breads - Wholemeal, mixed grain, white, rye, Lebanese (unleavened flat) breads, bread rolls, bagels, pumpernickel etc. Some other cereal varieties include oats, rice, corn, polenta, semolina, barley, 44 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues tapioca, burghul, millet, quinoa, etc.) Try to have at least three different varieties of grains in a day. These foods form the major part of the healthy diet in terms of quantity, weight, volume and number of serves of food. In themselves these foods are not high in fat or energy. A variety of different foods eaten each day will be more likely to supply all the nutrients necessary for health than a diet chosen from only a few foods7. There is good evidence from studies in various populations around the world that people who habitually consume diets high in plant foods have lower risks of coronary heart disease, non-insulin dependent diabetes and cancers of the lung, colon, oesophagus and stomach7. Include lean meat, fish, poultry and/or vegetarian alternatives These foods provide protein and other nutrients to ensure adequate growth and maintenance. They should be eaten in moderate amounts. Include milks, yoghurts, cheeses and/or soy alternatives. These foods are high in calcium which is essential for the proper functioning of the body processes and the maintenance of the body skeleton. These foods should be eaten in moderation, taking care to use reduced fat varieties, except in the case of infants. Drink plenty of water. Because the body is largely made up of water and most body processes use water, it is essential that the body be kept well hydrated. To be properly hydrated in a temperate climate, adults require some 2500–3000 millilitres of fluid a day, depending on body size5. Some of this comes from the food we eat. At least 6 – 8 glasses of water for the average adult is necessary to maintain good hydration with more required for larger adults and in times of strenuous exercise and high temperatures. Encourage an early habit of drinking clear fresh water. 2. Take care to Limit saturated fat and moderate total fat intake. Fat is the most energy dense of all the nutrients. There is evidence that humans have less capacity for metabolic adaptation to excess intake of fat (i.e. above energy expenditure) than of carbohydrates. Further, there are some reports that show obese people prefer higher fat diets than lean people. Obesity is a major nutritional disorder among Australians. High fat levels have been shown to increase the risk of heart disease, gall bladder disease, some cancers, and obesity. The average Australian diet contains too much solid fat from animal and vegetable sources. It is better to use liquid vegetable oils in place of solid fat. Remembering the total fat intake needs to be kept at a moderate level7. 45 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Choose foods low in salt. The Working Party on Sodium in the Australian Diet concluded that populations with the highest known sodium intake greater than 300mmol/day, (approximately 6000 mg) have a higher prevalence of hypertension and high morbidity and mortality from cerebrovascular disease, while those with an intake of sodium less than 50 mmol/day, (approximately 1000 mg) have a low prevalence of hypertension and a low mortality from cerebrovascular disease. It is important to be aware that much of the Australian dietary sodium intake comes from staple foods like bread, baked goods, many breakfast cereals, most cheeses, margarine and butter as well as obviously salty, pickled, and snack foods7. Limit your alcohol intake if you choose to drink. Australians especially drink more alcohol than is good for their health. Alcoholic beverages contain ethyl alcohol, a drug which depresses or slows down the activity of the body’s central nervous system. It is classed as a sedative-hypnotic along with barbiturates and minor tranquillisers. Alcohol is a substance produced from fermentation of fruits, vegetables or grains. There are three main groups of alcoholic beverages: beer, wine and spirits 7. Consume only moderate amounts of sugars and foods containing added sugars. Sugars have formed an important part of the Australian diet for as long as recorded history, at least in forms such as honey. Refined sugar (sucrose) has been available since European settlement. The term ‘empty calories’ is often used to imply that the food or ingredient provides relatively insignificant amounts of essential nutrients, or is of low nutrient density. Sugars, particularly sucrose and refined sugars are highly purified substances, providing a readily available source of energy, but virtually no other nutrients and remain a major part of the ‘empty calories’ in the Australian diet. While moderate quantities of sugars are used in a variety of mixed nutritious foods enjoyed in a healthy diet, there are also many foods common in the Australian diet of low nutrient density in which added sugars comprise the major ingredient7. 3. Prevent weight gain: be physically active and eat according to your energy needs. There are health problems associated with carrying too much body fat. Extra weight means more work, especially for the heart. An increase in body weight is accompanied by an increase in the amount of blood vessels through which the blood must be pumped. 46 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Extra weight also means extra work for the lungs and the digestive system. Excessive weight may put an added burden on the back and legs – it’s like carrying around a suitcase weighing five, ten or twenty kilos wherever you go! The latest information shows that it seems just as important to consider where we are carrying the fat on our body, in addition to how much we are carrying. Excess fat around the tummy area, in particular, increases your risk of certain health problems. People gain weight due to an imbalance between the energy gained from the food they eat and the amount of energy their bodies actually use up during the day. The energy that is not used during the day is stored as body fat. If this imbalance continues over time, a person may become overweight. Exercise burns up the energy provided by food and increases the rate at which energy is used for the rest of the day, thereby helping to reduce fat stores 7. 4. Care for your food: prepare and store it safely. Despite having one of the world’s safest food-supply systems, Australia has seen an increase in the number of reported foodborne illnesses in the last 10 years. Correct handling of food during all stages of its preparation and storage is essential in reducing the incidence of foodborne illness8,9. The following are the main causes of foodborne illness in Australia: inadequate cooking improper holding temperatures contaminated equipment unsafe food sources poor personal hygiene4. The following are examples of foods that are normally considered potentially hazardous1: raw and cooked meat or foods containing raw or cooked meat—for example, casseroles, curries and meat pies dairy products and foods containing dairy products—for example, milk, custard and dairy-based deserts seafood and foods containing seafood cooked rice and pasta processed fruits and vegetables such as salads processed foods containing eggs or other protein-rich food foods that contain any of the foods just listed—for example, sandwiches. The foods most commonly implicated in foodborne illness in Australia are meat and seafood4. 5. Encourage and support breast-feeding. Breast-feeding is widely recognised by health authorities as the most appropriate method for feeding infants and to be closely related to infant health. 47 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Breast milk from a healthy well-nourished mother is adequate as the sole source of nutrients for full term infants from birth until 4 – 6 months of life. Aside from the nutritional suitability, colostrum and human milk are hygienic and provide immunoglobulins and other anti-infective agents, which play an important role in protecting the infant against infection and disease. Breast milk is also a convenient and inexpensive food source7. The Dietary Guidelines provide advice to the general population about healthy food choices, so that their usual diet contributes to a healthy life-style and is consistent with minimal risk for the development of diet-related diseases. It is estimated that the current economic cost to the nation of the principal diet-related conditions—coronary heart disease, stroke and cancer—is about $6 billion a year, so the potential economic benefit of an effective nutrition-based preventive strategy is enormous8,9. The latest guidelines focus more on food groups and lifestyle patterns, moving away from specific nutrients. They seek to promote the potential benefits of healthy eating, not only to reduce the risk of diet-related disease but also to improve the community’s health and wellbeing8,9. Nutrition is a complex science and communication of its messages demands more information and explanation than can be given in brief statements. The guidelines summarise current nutrition knowledge and act as triggers to other, more comprehensive education programs for consumers. FOOD FADS AND FALLACIES Magazine articles and advertisements in the media regularly appear making all kinds of false or misleading claims about various food and dietary products. The claims are made in a most appealing and convincing manner. New dietary supplements constantly appear on the shelves of health food shops and supermarkets. Enthusiastic promoters claim that these new dietary products can fight disease, slow aging, promote rapid weight loss, regulate hormones, enhance one’s energy level or perform some other desirable function. Books are published to spread the “good news” about such wonderful products3. What sells the item is often not based on quality or reliability but upon the success of the salesman to convince the consumer that they cannot live without the item being promoted. The consumer should be very cautious and avoid getting ripped off by some over-zealous salesman or health promoter who falsely claims they possess certain knowledge about health or pretends to have certain skills or qualifications. Such a person is called a quack. And their deceptions are not always easy to spot3. 48 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Warning signs of quackery and fraud Watch out for products and practices promoted as a “Major breakthrough”, “Revolutionary”, “Magic”, or “Miraculous”. Be cautious of promotions that try to elicit an emotional reaction than present clear information that helps you make an informed decision about the product. When only anecdotal or testimonial evidence is used to support claims of a product’s effectiveness, beware. Quotes from numerous satisfied customers, even satisfied doctors and nurses adorn Websites, ads on TV and radio and in magazines and newspapers. Even quacks will claim to have scientific evidence supporting their therapies. Watch out for the following: a. Few or no references given to original research studies b. Studies done by only one researcher c. Studies done at obscure, unknown institutions d. Studies reported in obscure or virtually unknown journals e. Studies reported decades ago f. Studies that have not been repeated g. Funding of research by someone with a financial or professional stake in the results There are a few questions that need to be addressed as one evaluates the merits or otherwise, of some new products or program being sold or promoted. Is it physiologically sound? Is there solid scientific data to support its use? Is it consistent with a healthy lifestyle? What do other health professionals say about it? Is it safe and reliable, with no extra freebies thrown in as an enticement to buy? What is the life history and credentials of the person pushing it? If you can give positive responses to all the above questions then it may be worth a try. The old adage is certainly true in this situation: “If in doubt, leave it out” 3. How to pick a food/health quack The food quack is readily recognisable. Such a person: Always has something to sell. It may be pills, diet plans, ‘organically grown foods’, special dietary formulae or supplements, or even special cooking utensils. Makes extravagant claims and guarantees speedy cures or rapid weight loss. Claims to have advanced medical knowledge but alleges persecution by qualified medical people. Uses plenty of names of well-known people – professors, medical researches (whole genuine scientific data may be misquoted or misapplied), or even film stars – who are numbered among patients. Is master of the scare technique and tries to convince you that in your present state, illness or death is just around the corner. 49 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Some of the current fallacies and fraudulent claims made about food include the following3: Our food is vitamin deficient because the crops are grown on soils that are so depleted. Bread and potatoes are fattening. (These foods are high in complex carbohydrates and only become a concern when we regularly add fat to them. They should be part of a nutritious variety of food, prepared in a health promoting manner.) Foods labelled as fat free are the healthiest choice. (We do not recommend a ‘fat-free’ diet.) Honey is more natural and healthier than sugar. (Honey contains traces of some minerals and vitamins. These are in such small quantities that it is not a practical source, considering the number of calories supplied, honey should be treated like sugar and only used in small quantities.) Bee pollen enhances one’s youth and energy. (There is no scientific evidence to prove this, as a matter of fact there are people who experience allergic reactions to bee pollen and related products.) Lecithin lowers cholesterol and cures heart disease. Carbohydrate foods and protein foods should not be mixed together as they cause indigestion and weakness. Raw foods are best as they contain live enzymes. Dietary choices should be made based upon one’s blood type. Organic food provides better nutrition than conventional foods. ‘Natural’ vitamins are promoted as being better than synthesized ones3. In today’s world, many people are out to make a small fortune as quickly as possible. Consumers need to be wary of health quacks that prey on the public with their innocent sounding sales pitches. Anything offered as a cure-all, is simply not that3. ORGANICALLY GROWN FOODS One of the main themes of the health food movement is that foods today lack nutrients because soils are worn out and have lost their vitality from the use of ‘chemical’ fertilisers. The claim is made that only organically grown foods, that is, foods grown without the use of any agricultural chemicals and processed without any food chemicals or additives, are of value to humans15. There is no scientific basis for such claims, and to some extent they arise from a lack of understanding of plant chemistry. Organic matter (compost) does have value for soil by improving soil texture and bacteria, and is a good way of providing nutrients for plants. But providing organic matter for huge Australian wheat farms and even for vegetable farms is impractical at present15. In any case all organic matter has to be broken down to inorganic substances by soil bacteria before being absorbed by plants. Plants really do not ‘care’ where their nitrogen, phosphorus and other minerals come from. The science of agriculture has 50 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues determined what plants need, and the necessary nutrients can then be supplied in optimal amounts by fertilisers15. Claims that soils are depleted and that foods grown in them are deficient ignore the fact that plants grow and in the process, make vitamins for that growth. Plants either absorb the nutrients they need or they do not grow. If needed nutrients are in short supply, there will simply be fewer plants15. Organic Food Statement by Dr Mark Wahlqvist: Professor of Medicine, Professor of Human Nutrition, President of the International Union of Nutrition Sciences. While consumers may wish to choose foods which have used different farming techniques in their production, so-called ‘organic foods’ are not nutritionally superior to the regular counterpart farmed by conventional agricultural methods. A study comparing the nutritional value of potatoes, broccoli, cauliflower and tomatoes grown by conventional or organic farming methods showed that for nutrients analysed, the organically grown vegetables were not superior to the conventionally grown produce. Similarly, the Institute of Technologists (US) concluded that there is no evidence of a nutritional or otherwise health benefit of organic foods over those that are farmed conventionally.20 What are organic foods? An organic food is considered to be a food that has been grown without artificial fertilisers, pesticides or herbicides. Australia Organic farming emphasises the conservation of water, soil and energy, the use of renewable resources and natural farming cycles16. Are organic foods more nutritious compared to conventional foods? To-date, research has not shown that organic foods are consistently more (or less) nutritious than conventional foods. A report from the Food and Agriculture Organisation (FAO), indicated that in several studies, even when some nutritional differences were found between organic and conventional foods, they were of minor importance to overall health. Further work in this area is required for a definitive answer to the question of whether organic foods are indeed nutritionally superior or equivalent to their conventional counterparts17. Is organic agriculture better for the environment? The main objective of organic agriculture is to achieve an ecological balance between the soil and its natural inhabitants, food crops and animal life. For example, the use of physical weed control (instead of pesticide and herbicide use) and animal and green manure (crops grown off-season and ploughed into the soil prior to planting), helps to maintain biodiversity and natural soil fertility18. 51 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Are organic foods free from pesticides and do they taste better than conventional foods? Even if all organic farming practices are followed, organic foods cannot be defined as pesticide free, as the soil may still be polluted from previous farming. However, organic foods are generally lower in levels of chemicals such as pesticides, herbicides and fertilisers compared to conventional foods17. Several studies have been done to investigate the taste and texture properties of organic foods compared to non-organic foods. Some studies have found that there may be slight taste and texture differences with specific foods eg apples, tomatoes and carrots. Overall, research has not shown significant taste differences between organic and conventional foods17. The final verdict on organics The overriding advantage to eating organically grown foods is linked to environmental issues. Organic farming is kinder to the environment and is more likely to be sustainable. Although some studies have shown that particular organic products may taste better, the available scientific evidence suggests that there is no significant difference between the taste and nutritional content of organic foods compared to conventional foods. It is likely that in the near future at least, organic foods will continue to cost more than conventional foods19. PESTICIDES Pesticides are dangerous substances, which can be harmful to humans in certain quantities, but the levels of pesticides found in Australian fruits and vegetables are very low and are continuing to decline. The Australian Government Analytical Laboratories carry out regular testing of pesticide levels for the Department of Primary Industry, because, contrary to popular belief in health-food circles, authorities are concerned that the levels of potentially dangerous substances are kept low12. Without the insecticides and preservation methods now used, we could expect great losses of products experienced in the past (and still experienced in some developing countries). It has been estimated that as much as 30% of the food produced in the world is lost by moulds, insects and other organisms. In Australia such losses are rare because of our advanced agricultural knowledge12. In Australia, the National Food Authority undertakes Australian Market Basket Surveys (which are aimed at assessing the potential health hazard due to pesticide residues and other contaminants) and is part of an international study Global Environmental Monitoring System, to monitor contaminants in the diet 16. The most recent studies found that all estimated dietary intakes of pesticides and other contaminants were within ‘safe’ limits. The National Food Authority concluded that ‘Australians can be confident in the safety of the food they eat from the viewpoint of pesticides and contaminant levels’20. 52 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues SOME FAD, CRASH AND OTHER QUESTIONABLE DIETS13 Fit for Life False Mayo Clinic Diet Calories Don’t Count Diet Drinking Men’s Diet Rotation Diet Israeli Army Diet Grapefruit Diet Blood Type Diet Cellulite Diet Body Type Diet Health Hazards of Fad Diets13 Fatigue Weakness Depression Nausea Dizziness Osteoporosis Hair loss Constipation Elevated Blood Fats Heart Problems Scarsdale Medical Diet Beverly Hills Diet Lecithin, Vinegar Diet Meal Replacement Diet Irritability Headache Dry skin Intestinal Ailments Kidney Problems The Hallelujah Diet by Rev. George H. Malkmus George Malkmus cured his colon cancer, twenty years ago, by following a pure fruit and vegetable diet and drinking lots of carrot juice. He claims that thousands of people have been cured of a variety of diseases including cancer by following God’s way to ultimate health. God created a perfect body……… (This statement ignores the accumulative effect of sin) “You don’t have to be Sick!”14 Is one of the slogans used by George and his wife Rhonda. “Disease and sickness are self-inflicted.”14 “Almost every physical problem, other than accidents, is caused by improper diet and lifestyle! All we have to do to be well is eat and live according to the way God intended.”14 (While in general this is true, there are exceptions. He claims that everyone who goes on his diet regains perfect health. His statement is very discouraging to those unfortunate ones who do not get better.) “Here at Hallelujah Acres we teach a different way….God’s way! We teach that the only nourishment God ever intended to enter our bodies of ours is raw fruit and vegetables. Period! That is it!”14 “The only thing that is cell food is raw food.”14 “You cannot support life with death.”14 “All cooked food is dead food.”14 (These comments are entirely wrong. He omits the necessity to cook grains and legumes; these foods supply important complex carbohydrates, protein and fibre. These foods need to be cooked! Their nutrition content is actually improved by cooking. Various substances in our food are more available to the system when cooked, eg starch, beta-carotene, a precursor of Vitamin A in carrots, plus other phytochemicals in plant foods. Cooking destroys Trypsin inhibitor in soybeans, which makes the protein more available.) 53 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues “ A little cooked food is added for incentive. A reward to keep us on the straight and narrow, not for nourishment.”14 (There is excellent nourishment in cooked food provided it is balanced with raw food. It is in fact an essential part of our health and wellbeing. While it may be feasible for some people to live on all raw permanently, it is not easy. A diet that contains all raw food is not suitable for growing children or people who are physically active or doing a lot of manual work. Some who read or hear the statements made about the Hallelujah Diet may in their enthusiasm discard all cooked food and run into serious trouble.) Summary This is a small sample of the raw food diet that George Malkmus promotes. Raw foods are important in the diet. Carrot juice and other fruit and/or vegetable juice can be included - one glass per day is sufficient when the diet contains enough fruit and vegetables. It is actually better to consume whole foods and add a glass of juice if you feel like it, or you feel you need some extra nutrients. Grains are an important part of our daily food intake and should not be omitted or reduced to less than 6 serves a day for adults. COMMENTS ON SOME POPULAR DIET BOOKS Fit for Life13 A collection of food-fad notions that promote misconceptions about ‘food combining’ and ‘detoxification’ and mystically tying them in with weight loss. The diet plan is nutritionally unbalanced being low in calcium, iron, zinc, and vitamin B12. This could damage health if followed strictly for a long period. Unrealistic changes in eating habits are required. Flatulence and diarrhoea are mentioned as side effects. Numerous unscientific and false statements indicate: It is not what you eat that makes the difference, but when you eat it and in what combinations. 1. Protein foods and carbohydrates eaten at the same meal will ferment and rot, and not be absorbed by the body. 2. Toxic wastes from unabsorbed food make people fat – not excessive calories. 3. No food other than fruit should be eaten before noon. Fruit should never be eaten with or following any other food. 4. Digestion uses more energy than anything else you do. 5. Adults who use milk products do not absorb nutrients as well as other adults who don’t. 6. The degree of flatulence and diarrhoea to be expected by up to 10% of the people on this ‘detoxification program’ depends on the level of toxicity in the body. 54 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues Weight may well be lost on this diet, not because of the reasons given, but because the diet regime avoids certain foods and limits the number of eating opportunities. Beverly Hills Diet13 This is perhaps the worst fad diet book ever written. The author deserves an award in ‘creative physiology’ for her misguided unscientific beliefs on digestion and absorption. The diet is a potential hazard. There are medical reports of people suffering severe diarrhoea, muscle weakness and dizziness in their first week on the diet. Death is possible if blood pressure drops low enough to interfere with blood circulation. The diet is also a nutritional disaster. Poor variety of foods does not provide adequate nutrients to maintain health. Body protein needs are not being met and excessive muscle tissue is likely to be lost instead of fat. Hair loss is also possible. REFERENCES: 1. Australia New Zealand Food Authority; SAFE FOOD AUSTRALIA: A GUIDE TO THE FOOD SAFETY STANDARDS - 2nd edition Canberra: ANZFA, 2001 2. Butler T; HEALTH PROMOTING CHURCHES AdHealth 2000:7 (WHO 1998) 3. Butler T, Butler D, Stanton H; VEGETARIAN COOKING DEMONSTRATOR’S MANUAL – 2nd EDITION Adventist Health Department & Sanitarium Nutrition Education Service. 1995:E1-10 3. Craig W; NUTRITION AND WELLNESS Golden Harvest Books Berrien Springs Michigan. 1999:117, 295 - 300 4. Crerar S, Dalton D, Longbottom H, Kraa E; FOODBORNE DISEASE: CURRENT TRENDS AND FUTURE SURVEILLANCE NEEDS IN AUSTRALIA Med J Aust 1996;165:672-675 5. Food and Nutrition Board; RECOMMENDED DIETARY ALLOWANCES – 10th edition Washington, DC: National Academy Press, 1989. 55 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues 6. Fraser G; THE COMPLEXITY OF NUTS: REDUCING THE RISK OF HEART DISEASE Program and proceedings Sanitarium International Nutrition Symposium. "Nouveau Nutrition: Traditional Foods, Contemporary Science". March 2000:28 7. National Health and Medical Research Council; DIETARY GUIDELINES FOR AUSTRALIANS Australian Government Publishing Service Canberra. 1992 8. National Health and Medical Research Council; DIETARY GUIDELINES FOR CHILDREN & ADOLESCENTS IN AUSTRALIA - 2003 DIETARY GUIDELINES FOR AUSTRALIAN ADULTS - 2003 DIETARY GUIDELINES FOR OLDER AUSTRALIANS - 1999 Australian Government Publishing Service Canberra. 9. National Health and Medical Research Council; http://www.nhmrc.gov.au/publications 10. Sanitarium Nutrition Education Service; HEALTHY WEIGHT, HEALTHY BODY Sanitarium Health Food Company. February 1999 11. Saxelby C; NUTRITION FOR LIFE Hardie Grant Books South Yarra Victoria. 1999:5-8 12. Stanton R; FOOD FOR HEALTH – 2nd EDITION W.B. Saunders Artarmon NSW. 1983:4-5 13. Borushek A; ALLAN BORUSHEK’S DIET MANUAL Family Health Publications West Perth. 1988:7-10 14. Malkmus G; GOD’S WAY TO ULTIMATE HEALTH Hallelujah Acres Publishing, Shelby, NC. 1998 15. Stanton R; FOOD FOR HEALTH – 2nd EDITION W.B. Saunders Artarmon NSW. 1983:131-132 16. Twyford-Jones P, Doolan R; THE INTERNATIONAL MARKET FOR ORGANIC FOOD Information series QI97129 Rural Industry Business Services Department of Primary Industries Queensland. 1998 17. Food and Agriculture Organisation; FOOD SAFETY AND QUALITY AS AFFECTED BY ORGANIC FARMING. 2000 56 Unit 3 AN INTRODUCTION TO NUTRITION Including Food Issues 18. Choice Magazine; ORGANIC FOOD – IS IT REALLY BETTER? September. 2000 19. Sanitarium Nutrition Education Service; GOOD FOOD NEWS – June 2001 Sanitarium Health Food Company 20. Wahlqvist M. L; FOOD AND NUTRITION - Australia and New Zealand 2nd Edition Allen & Unwin Pty Ltd Crows Nest NSW. 2002:112, 130 57