A recent article (22nd March 2012) in the Daily Mirror, entitled Just how unhealthy is our daily bread? contained a number of inaccuracies, particularly about the nutritional content of bread and the role that it plays in the UK diet. This article promulgated many common misconceptions about bread and the scientific facts behind these myths are discussed below.
Myth – Bread causes bloating and other digestive problems
There have been media reports that bread and in particular bread made with the Chorleywood Bread Process (CBP), a process commonly used in modern bread making, can make us feel bloated. However, a recent review of this topic by the British Nutrition Foundation (Weichselbaum 2012) concluded that there is no scientific evidence that regular consumption of bread, whether produced by the ‘modern’ CBP or by traditional methods, causes bloating or gastrointestinal discomfort, unless there is a sudden increase in fibre intake. Some people experience discomfort and wind after increasing the amount of fibre from habitual levels, but the large intestine and gut bacteria adapt to increased fibre intake and the symptoms usually decrease. Being physically active and drinking plenty of fluids can also help to prevent these symptoms.
Myth – Bread does not contain any nutrients
Nutrients are lost during the milling process of flour that is used in a whole host of products including bread and the amount lost will depend on the amount of bran and germ removed. However, the key nutrients lost through milling – i.e. calcium, iron, and the B vitamins thiamine and niacin, must be restored to white and brown bread flour by law in the UK. This ensures that white and brown breads contain similar levels of these key nutrients to wholegrain bread.
According to the Government’s National Diet and Nutrition Survey (NDNS), bread provides more than 10% of our daily intake of protein, folate and iron, and around 20% or more of fibre, calcium and magnesium. Wholemeal bread contains more of some vitamins and minerals than white bread, because some of the parts of the grain removed to make white flour are nutrient-rich. As many of the nutrients are restored in white and brown bread flour (detailed above) although there are small differences in the content of some minerals (i.e. magnesium and zinc) the main difference between white, brown and wholemeal bread is the fibre content. Nevertheless, because of its popularity, white bread still provides some 10% of our daily fibre, iron, magnesium and calcium and smaller proportions of other vitamins and minerals.
Myth – Modern bread is less nutritious than bread produced by traditional processes
The kind of flour used and the addition of nutrients to restore those lost during milling, rather than the bread making process itself, have the most significant impact on total nutrient content of bread. Studies have not found significant differences in the nutrient content of bread made using the ‘modern’ CBP or more traditional methods (see Weichselbaum 2012).
Myth – Wheat allergy and intolerance is on the increase
Many population-based studies have not included standardised diagnostic tests and there is therefore uncertainty regarding the actual prevalence of wheat allergy. Prevalence of wheat allergy and intolerance (excluding Coeliac Disease) is estimated to be low, although it is difficult to estimate the proportion of the population affected. As with other forms of allergy, it seems that the proportion of people who perceive they are allergic to wheat is clearly higher than the actual prevalence of wheat allergy. If wheat allergy or intolerance is suspected this needs to be diagnosed using standardised tests delivered by a qualified health professional before deciding to avoid wheat and unnecessarily restricting the diet without actually being allergic.
Myth – Bread is high in salt
Salt is added to bread for flavour and because it helps to control yeast in fermentation. It also makes the gluten more stable and less extensible. However, UK bakers have gradually reduced the salt content of bread by about a third since the 1980s. It is now at the lower end of the range for European countries. Some loaves contain more salt than others, and so if you are worried about your salt intake, it is a good idea to compare the different breads by checking the labels – this helps you pick the bread that is lowest in salt.
Myth – We eat too much bread
Bread is a starchy food along with foods such as potatoes, pasta, rice and breakfast cereals. The UK Government’s Eatwell Plate model that depicts a healthy diet, illustrates that about a third of our diet should comprise food from the starchy foods group. This is similar to dietary guidelines from other countries around the world. Although all types of bread belong to this food group and provide us with fibre and other nutrients, for many of us it is best to choose wholegrain/wholemeal or granary varieties, as these have a higher fibre content than white bread. Many of us in the UK don’t eat enough fibre, and consuming wholemeal or multigrain bread is an easy way to increase our fibre intake. For those who may need to eat a lower fibre diet, such as toddlers or older people with poor appetites who may not be able to get all the nutrients they need if they eat a bulky, high fibre diet, white bread is a good alternative to wholegrain. Seeded bread also provides some extra nutrients from the added seeds, including vitamin E and essential fatty acids (e.g. omega-3 fatty acids).
Dietary fibre is important for gut health as it is the fuel for our ‘friendly’ gut bacteria and it helps keep bowel movements regular. Fibre can also help you feel fuller and therefore help with weight control. High dietary fibre intakes have also been found to positively influence blood lipids (e.g. blood cholesterol levels) and so lower the risk of heart disease, and have also been associated with a lower risk of bowel cancer. Furthermore, according to government statistics (from the NDNS), bread consumption per person has been steadily falling over the last thirty years.
Myth - Because of bloating you should limit bread intake to one portion a day (have it for breakfast or lunch, but not both)
For most healthy people, there is no evidence that regular consumption of bread causes bloating or gastrointestinal discomfort. There are no official recommendations about the quantity of bread, specifically, we should eat each day. But the Government’s Eatwell Plate model illustrates that about a third of our diet should comprise starchy foods. In practice this means including a source of starchy carbohydrate at each meal. The starchy food group includes foods such as bread, potatoes, cereals, pasta, rice and breakfast cereals. Bread is an important staple food in the UK diet and therefore plays an important role in most people’s diets.
Myth - White bread is bad for you because it has a high GI
The glycaemic index (GI) of a food is a measure of how quickly glucose is released into the bloodstream after eating. Low GI foods, such as brown pasta, porridge, beans and lentils, breakdown slowly during digestion and therefore release glucose slowly into the blood stream. Although some studies have suggested that a low GI, high fibre diet may help to reduce the risk of type 2 diabetes, there is not sufficient consistent evidence to recommend a low GI diet for prevention. However, many low GI foods that are rich in fibre are an important component of a healthy, varied diet.
Both white and wholemeal bread have a relatively high GI. However, the addition of fat and protein slows down the absorption of carbohydrate. Therefore, if bread is eaten with a meal or in combination with other foods (e.g. a sandwich), the carbohydrate is broken down more slowly and glucose enters the bloodstream at a slower rate.
Whether and how GI impacts on appetite control and therefore helps with weight management is disputed among experts. Fibre, present in bread and in particular wholemeal varieties, has been found to help us feel fuller. A high fibre diet is generally promoted for those trying to lose weight in order to help appetite control.
Myth – Bread is bleached and blanched
European Union (EU) regulations prohibit the use of flour bleaching agents. In terms of food-technology blanching is a process where a food is parboiled for a short period of time. Blanching is not used in the production of white, brown or wholemeal bread
Last reviewed 23/03/2012. Next due for review by 23/03/2015