Q Is there a difference in energy between naturally occurring sugars and added sugars?

A There is no difference in energy terms between sucrose in a banana, sucrose in a cake, and sucrose added to a cup of tea.

‘Sugar is a natural carbohydrate’

Sugars is a general term used to describe the types of carbohydrate typically made by plants, although lactose is a sugar made by animals and is generally found in milk. Plants contain varying amounts of different sugars e.g. glucose, fructose and sucrose. Sucrose itself is made up of two components - glucose and fructose. It is the most abundant sugar in plants. Sugar beet (a vegetable) and sugar cane (a grass) naturally contain particularly large amounts of sucrose. Sugar is nature’s way of storing solar energy; plants use sunlight to combine water and carbon dioxide to produce sugars for energy. All these sugars occur naturally and all can be added to many foods during manufacture. Sugar (sucrose) has been around for many centuries and many of the traditional products made today have been developed using sugar’s multi-functional properties.

The sugar that we add to tea and coffee and use in baking is generally pure, natural sucrose. Sucrose is sometimes called 'table sugar' or simply 'sugar'. Table sugar does not contain any artificial ingredients, preservatives, colourings or other additives.

Sugar has been shown to help provide variety in the diet, by making a range of beneficial foods more palatable.

Further Reading
Forshee RA and Storey ML (2001). The role of added sugars in the diet quality of children and adolescents. Journal of the American College of Nutrition 20(1):32-43.
Ruxton et al (1999). Guidelines for sugar consumption in Europe: Is a quantitative approach justified? European Journal of Clinical Nutrition 53; 503-513.

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Q What is the impact of sugars on dental health?

A Tooth decay (dental caries) occurs when the bacteria that live naturally in our mouths produce acids that attack the tooth surface. The bacteria eat when we do. So, as we eat foods that contain carbohydrates such as sugars, the bacteria get a meal too and produce the acids that cause tooth decay.

All sugars and carbohydrates, such as the sugars in fruit and the starches in bread, pasta or potatoes, can be broken down by the bacteria to produce acid.

However, research supports the view that it is the frequency of carbohydrate consumption, rather than the amount of carbohydrate consumed, which is more of an issue in the development of tooth decay.

‘Frequency of exposure to carbohydrates is more important than amount of carbohydrate eaten with regards to oral health’

The best and most practical way to avoid tooth decay is to brush your teeth with fluoride toothpaste regularly in the morning and, especially, last thing at night, as saliva production that can neutralise the acid is much lower when you are sleeping.

Rates of tooth decay have fallen dramatically over the past 20 years. Many people now reach adulthood without any fillings at all. Provided you brush your teeth properly twice a day using a fluoride toothpaste and don't eat carbohydrate-containing foods too often, you can continue to enjoy snacks without harming your teeth.

‘Teeth brushed twice a day
with fluoride toothpaste
can cope with 5 eating occasions a day’

It has never proved possible to limit both sugars and starches in children’s diets to the extent necessary to prevent tooth decay. Children have to eat regularly and their diet will include mostly carbohydrates such as starch and sugar. Don’t forget that fruit and vegetables also contain sugars which can be converted to acid by the bacteria present in the mouth.

Fortunately, fluoride toothpaste has been far more successful than originally anticipated and is now known to be the best method of preventing tooth decay.

Further Reading
Cottrell RC (2005). “Dental Disease” in Encyclopaedia of Human Nutrition, 2nd Edition; p. 527-534. Eds Caballero, Allen & Prentice. Elsevier Academic Press, Oxford
Duggal MS et al., (2001). Enamel demineralisation in situ with various frequencies of carbohydrate consumption with and without fluoride toothpaste. Journal of Dental Research; 80(8):1721-1724.
Konig KG (2000). Diet and oral health. International Dental Journal; 50: 162-74
Gibson et al (1999). Dental caries in pre-school children: associations with social class, tooth brushing habit and consumption of sugars and sugar-containing foods. Caries Research 33:101-113.
Kandelman (1997). Sugar, alternative sweeteners and meal frequency in relation to caries prevention: new perspectives. British Journal of Nutrition S121 - S128
Hussein I, Pollard MA and Curzon MEJ (1996). A comparison of the effects of some extrinsic and intrinsic sugars on dental plaque pH. International Journal of Paediatric Dentistry 6(2); 81 - 87
Konig KG and Navia JM (1995). Nutritional role of sugars in oral health American Journal of Clinical Nutrition 62(suppl):275S - 283S

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Q What is the impact of sugars on obesity?

A It has been observed that those who eat more sugar are likely to be slim and those that eat less sugar tend to over consume fat and are thus fatter. It has also been demonstrated that sugar, along with all carbohydrates has an important role in appetite control which in turn prevents overeating.

Today everyone is concerned about getting fat. Obesity levels are increasing in the UK in both adults and children and the subject has attracted a lot of Government and media attention. Sugar is commonly associated with obesity by the media, consumer pressure groups and the Government. Science, however, does not support the commonly held perception that eating too much sugar is a cause of weight gain.

In fact, many expert reviews have concluded that sugar has no role in encouraging over-eating or obesity.

Additionally, nutritional science suggests that eating plenty of carbohydrates as part of a balanced diet and taking regular exercise is the best way to maintain a healthy body weight.

‘Sugar forms a useful part
of a normal healthy diet’

Eating carbohydrate triggers signals that promote a feeling of fullness (satiety) and decrease hunger. High fat meals do not appear to have the same effect and have been found to result in a greater calorie intake when compared to high sugar or high carbohydrate meals.

The body is able to store large quantities of fat (as body fat) but has only limited carbohydrate reserves. Excess carbohydrate is simply used as fuel rather than stored. This is why athletes need to replace carbohydrate stores regularly but don’t have to worry too much about fat.

Sugar is very rarely eaten alone but is added to a range of nutritious foods eg. cereals and sour fruit - making them more palatable and increasing the likelihood of these foods being incorporated into a healthy balanced diet.

‘Sugar is a source of glucose,
the vital fuel for brain & body’

Carbohydrates, including sugars are now recognised to be important in the diet in order to provide fuel for the brain. Without adequate carbohydrate intake the body has to convert fat and/or protein into glucose for the brain. When it does this, by-products are produced that make you feel sick and light-headed and may affect judgement and skill.

Further Reading
Benton, D. (2005) Can artificial sweeteners help control body weight and prevent obesity? Nutrition Research Reviews 18, 63 - 76
World Health Organization / Food and Agriculture Organization (2003). Diet, Nutrition and the Prevention of Chronic Diseases. WHO Technical Report Series 916. WHO. Geneva
Institute of Medicine, Food and Nutrition Board (2002). Dietary Reference Intakes for Energy, Carbohydrate, Fibre, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. The National Academies Press. Washington DC
Lavin JH, French SJ, Ruxton CHS and Read NW (2002). An investigation of the role of oro-sensory stimulation in sugar satiety, International Journal of Obesity 26; 384 388
Saris et al (2000). Randomised controlled trial of changes in dietary carbohydrate/fat ration and simple vs complex carbohydrates on body weight and blood lipids: The CARMEN study. International Journal of Obesity 24: 1310 - 1318
Gibney M. (1999). Optimal macronutrient balance. Proceeding of Nutrition Society 58: 421 425
Food and Agriculture Organisation of the United Nations & World Health Organisation (1998). Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66. http://www.fao.org/docrep/W8079E/W8079E00.htm
Bolton-Smith and Woodward (1994). Dietary composition and fat to sugar ratios in relation to obesity. International Journal of Obesity 18; 820 – 828

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Q What is the impact of sugars on diet quality?

A As sugar provides carbohydrate and energy and no other nutrients this has caused some people to think of sugar in terms of 'empty calories'. People have also assumed that sugar will dilute the vitamin and mineral content of the diet, but there is good evidence that this is not what happens in practice.

This theory has been challenged in recent years by numerous research studies in both adults and children, which have found that sugar intake is not related to dietary quality and that within a wide range of moderate sugar intakes vitamin and mineral intakes are adequate.

‘Sugar makes food taste better’

People rarely eat sugar on its own. Adding sugar to foods improves their taste and makes a wider range of foods and nutrients palatable. For example, without sugar many breakfast cereals, which provide important vitamins, minerals and fibre, would be unpalatable.

‘Sugar is a medium energy, medium glycaemic index, easily digested carbohydrate’

Sugar also provides a moderate rate of increase in blood glucose – far slower than from bread, rice, potatoes or some pasta. It is therefore rated as medium glycaemic index (GI). Sugar added to many foods eg. breakfast cereals actually reduces the glycaemic index of the final product.

Recent major reviews, including one by the World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO) and one by the National Institutes of Health in the USA, have concluded that sugar-rich foods in moderation can provide a nutritious and palatable diet.

Further Reading
World Health Organization / Food and Agriculture Organization (2003). Diet, Nutrition and the Prevention of Chronic Diseases. WHO Technical Report Series 916. WHO. Geneva
Institute of Medicine, Food and Nutrition Board (2002). Dietary Reference Intakes for Energy, Carbohydrate, Fibre, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. The National Academies Press. Washington DC
Food and Agriculture Organisation of the United Nations & World Health Organisation (1998). Carbohydrates in Human Nutrition. Report of a Joint FAO/WHO Expert Consultation. FAO Food & Nutrition Paper 66. http://www.fao.org/docrep/W8079E/W8079E00.htm
Gibson SA (1997). Do diets high in sugars compromise micronutrient intakes? Micronutrient intakes in the Dietary and Nutritional Survey of British Adults according to dietary concentration of ‘added’, ‘ non-milk extrinsic’ or total sugars. Journal of Human Nutrition and Dietetics 10: 125 -133.
Bolton-Smith C. (1996). Intake of sugars in relation to fatness and micronutrient adequacy. International Journal of Obesity 18: 820-828
Gibney et al (1995). Consumption of Sugars. American Journal of Clinical Nutrition 62 (suppl) 178S - 194S

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Q What is the impact of sugars on other lifestyle diseases?

A Over recent years there have been great advances in understanding the links between diet and lifestyle diseases eg. diabetes and coronary heart disease; it has been demonstrated that sugar is not directly involved in the development of these types of diseases.

Diabetes
There are two types of diabetes - Type I or insulin-dependent and Type II or non-insulin dependent diabetes. The latter usually occurs later in life although in parallel with increasing obesity rates it is becoming more common in younger people.

It has been well established that the most important lifestyle factors which can lead to Type II diabetes are obesity and lack of physical activity and that sugar consumption is not directly involved in its’ development.

Nowadays, people who suffer from diabetes are advised to follow a similar diet to people without diabetes ie. a relatively low fat, high carbohydrate diet and not to avoid sugar either. The major diabetes specialist organisations now recommend that the diets of diabetics are based on carbohydrates, and that sugar is included as a normal carbohydrate food. Indeed its moderate GI makes it preferable to many other carbohydrate sources.

‘People with diabetes can eat sugar
as part of a healthy balanced diet’.

Coronary Heart Disease (CHD)
Eating for a healthy heart simply follows the principles of a healthy balanced diet. There is extremely good evidence that moderately low-fat diets, especially low in saturated fats, but high in carbohydrates, reduce the risk of CHD by inducing favourable blood lipid profiles.

There is no substantive scientific evidence to support the old myth that sugar causes CHD. In fact as long ago as 1989 the UK Government’s COMA committee (Committee on Medical Aspects of Food) dismissed the idea concluding that ‘current consumption of sugars, particularly sucrose, played no direct causal role in the development of cardiovascular disease or of diabetes’. Scientific evidence, both clinical and epidemiological, available since that date has been thoroughly assessed and does not merit any revision of that opinion.

Further Reading
McClenaghan, N. H. (2005). Determining the relationship between dietary carbohydrate intake and insulin resistance. Nutrition Research Reviews 18, 222 - 240
Mann JI et al, on behalf of the EASD (2004). Evidence-Based Nutritional Approaches to the Treatment and Prevention of Diabetes Mellitus. Nutrition Metabolism and Cardiovascular Diseases; 14: 373-394
World Health Organization / Food and Agriculture Organization (2003). Diet, Nutrition and the Prevention of Chronic Diseases. WHO Technical Report Series 916. WHO. Geneva
ADA (2002). Evidence-Based Nutrition Principles and Recommendations for the Treatment and Prevention of Diabetes and Related Complications. Diabetes Care; 25: 202-212
Bell PM (1997). Dietary and lifestyle factors contributing to insulin resistance. Proceedings of the Nutrition Society 56; 263 - 272
Department of Health (1989). Report 37 Dietary Sugars and Human Diease Committee on Medical Aspects of Food Policy

For further information on diabetes, go to the Diabetes UK website at www.diabetes.org.uk

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Q Are there any nutritional benefits in unrefined sugars?

A All crystallised sugar has been refined to some degree. Some sugars are partially refined to retain colour and flavour. However they do not contain any additional micronutrients. All sugars have the same calorific value and provide a natural source of sweetness.

    'Sugar is a natural carbohydrate'

There is no difference between white sugar produced from sugar beet or sugar cane. The sucrose is chemically identical and the functionality of both sugars is the same. 

The route used by the two plants to produce sugar is slightly different and the components present give rise to different colours and flavours for each manufacturing route. Sugar processing produces traditional brown sugars which are commonly used in bakery and confectionery applications.

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Glossary

BMI
Body Mass Index (BMI) is a measure of body weight in relation to height. The formula for calculating BMI is weight (in kilogrammes) divided by the square of the height (in metres) (weight/height2). The healthy weight range for men and women is a BMI of 20 – 24.9; over weight is defined as BMI 25 – 29.9 and obese is defined as a BMI greater than 30.

Epidemiology
Epidemiology is the scientific study of factors affecting the health and illness of individuals and populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine.

Glycaemic Index (GI)
Glycaemic index is a measure of the rate of appearance and removal of glucose in the blood following consumption of a defined weight of ingredient or food. There are standard protocols for the determination of GI and many food products have been assessed using these systems. Glucose is used as the standard and has a GI of 100. On the same scale, sugar has a GI of 65 (medium GI). The GI of food is correlated to insulin release – high GI means high insulin release. High levels of insulin are undesirable because they are thought to increase the risk of heart disease, diabetes and impaired fat metabolism.

Macronutrients
The main food components of our diet – carbohydrates, fats and proteins which provide the main source of energy and the building blocks for growth and repair.

Metabolic rate
The rate at which your body breaks down food to provide energy.

Micronutrients
The minor but essential components of our diet including vitamins and minerals.