Unlike other foods, sugar supplies energy only, which is why it is often accused of providing 'empty kilojoules'. The underlying fear is that if you eat a lot of sugar, you may leave out more nutritious foods, to the extent that your diet may be deficient in nutrients such as minerals and vitamins. However, studies of nutrient intakes have shown that this is not necessarily the case. There is in fact no evidence that people who eat a lot of sugar are more likely to suffer from nutrient deficiencies than those who eat very little.
The explanation for this apparent contradiction lies in the composition of the diet as a whole. Generally speaking, sugar consumption rises with income (up to a point), therefore people whose diets contain relatively large amounts of sugar also tend to eat large amounts of a wide variety of other foods, so it is unlikely that they will suffer from nutrient deficiencies. Incidentally, it is important to realise that when referring to sugar consumption we are talking not so much about `sugar bowl' sugar as about that contained in processed foods, desserts, and so on - in other words, in the diet as a whole.
Another interesting point here is the apparent inverse relationship between sugar and fat in the diet - described by some authors as the 'Sugar:Fat See-Saw'. Recent studies have shown that in certain populations, people who eat less sugar tend to eat more fat and vice versa. What these studies also revealed was that those who ate more sugar but less fat were taking in more of other essential nutrients and fibre as well.
The conclusion that can be reached from all this is that there is no direct relationship between the amount of sugar you eat and the overall quality of your diet. Far more important is the composition of the diet as a whole. Obviously, excessive sugar intake should be avoided, but if you are aiming to improve the nutritional value of your diet it would
be better to examine what you eat in total and make all-round improvements, than to focus on the elimination of a single foodstuff such as sugar.
The 'pure, white and deadly' tag
In the past few decades there has been an alarming increase in the incidence of so-called Western diseases such as heart disease, cancer, diabetes, hypertension and certain gastro-intestinal disorders. In the search to find out why this was happening, attention naturally focused on diet, since this was one of the areas that had undergone remarkable changes. Amongst other things, one aspect of the average diet that had changed was sugar intake.
In the early days sugar was a rare commodity out of the price range of most people, but as it became increasingly available, it was eaten in greater quantities by more and more people. Recognition of this fact led to a series of investigations in which sugar intake was compared with the incidence of various diseases and in many cases, the relationship seemed obvious - hence the claim made in the 1970's that sugar was 'pure, white and deadly'. However, in drawing simple comparisons such as these it is both easy and tempting to ignore the many other factors that could influence the outcome. In the years that have elapsed since these claims were first made, a great deal of research has been done on the causes of these diseases and we are now better able to identify those to which sugar may genuinely be linked.
Sugar and diabetes
Diabetes (or more correctly, diabetes mellitus) is a very complex disorder and neither its causes nor its treatment are as yet fully understood. For many years it was believed that eating too much sugar caused diabetes, but this theory has now been discounted. The cause is not yet known, although it is accepted that obesity is a contributory factor. Recent years have seen a considerable shake-up of traditional views on the treatment of diabetes. Nowadays, the diet recommended for diabetics is high in complex carbohydrates and low in fat. Some experts believe that a small quantity of simple carbohydrate can also be included, provided the condition is well-controlled and the intake of fibre sufficiently high. This is however controversial and no diabetic should eat sugar without the go-ahead from his or her doctor and/or dietitian.
Sugar and heart disease
The subject of diet and heart disease continues to be controversial and although there seems to be little doubt that the amount and type of fat you eat is important in determining your risk of having a heart attack, no such link has been confirmed for sugar. However, a small proportion of people are particularly sensitive to carbohydrate - for them, eating large quantities of sugar can result in a higher level of fat in the blood so sufferers of this condition should reduce their sugar intake to a minimum. This is generally referred to as 'carbohydrate sensitivity', a term used to describe a condition where serum triglyceride levels are elevated and the insulin response to a sucrose load is accentuated. The condition can only be diagnosed by a doctor with the aid of certain blood tests.
Sugar and dental decay
There are several factors involved in the development of dental caries (tooth decay), including heredity, oral hygiene and of course, diet. The role played by diet is more complex than you might think - it is not only what you eat that's important, but also how you eat it. The adhesiveness (stickiness) or abrasiveness of specific foods is yet another factor.
It is common knowledge that sugar contributes to dental decay, but perhaps less well-known is the fact that this applies to all fermentable carbohydrates, including those that don't even taste sweet (such as sausage rolls or potato chips). Research has shown that perhaps the most important thing to consider in terms of diet and dental caries is how often you eat cariogenic (caries-producing) foods such as those containing sugar. To help prevent caries, these foods should be eaten with meals rather than in between. This is because tooth decay is caused by acid-producing bacteria present in the mouth. Each time cariogenic foods are eaten, acid is produced, so it follows that the more often you eat these foods, the greater the likelihood of caries developing. In addition, try to choose foods that are easily chewed and swallowed - the longer the food stays in your mouth, the more likely it is to cause trouble. Boiled sweets that are sucked slowly, or foods that leave bits stuck to the teeth (such as biscuits or dried fruit) are particularly cariogenic.
Interestingly, some foods act as 'buffers' and counteract the harmful effects of other foods on the teeth. These include nuts and certain cheeses (for example, mature Cheddar, Gouda, blue Brie and Mozzarella). Such foods cause less acid to be produced than does cariogenic food. So the long-standing tradition of following a sugary dessert with cheese is highly recommended, at least as regards dental health!
