The Small Print Sarah MarriotBread is called the "staff of life" because it contains so many of the vital nutrients we need for good health: fibre, protein, vitamins, minerals and carbohydrates. When you make your own bread at home, the only ingredients are flour, yeast and water - but labels on much of the packaged white bread show a long list of items which you would never find in a kitchen cupboard.
The reason for this, argues Felicity Lawrence in her new book Not on the Label, is that bread made the old-fashioned way "needs time and space and in mass manufacturing, time and space mean money. Only a tiny fraction of our bread is made this way now."
Searching supermarket shelves for a loaf made only from natural ingredients can take a while. One ingredient almost impossible to avoid is hydrogenated vegetable oil, an industrially produced fat with a high melting point which is added to bread to give it structure. Hydrogenated and partially hydrogenated vegetable oil contain trans fatty acids, which may be 10 times worse for your heart health than saturated fats and can be found in thousands of processed foods - from bread, cakes and biscuits to microwave popcorn, margarine, chocolate and ready-meals.
Harvard scientists discovered trans fatty acids lower HDL ("good" cholesterol) and raise LDL ("bad" cholesterol) and can lead to thousands of premature deaths as a result of heart disease. Although these "bad" fats occur naturally in meat and dairy products, they account for under 5 per cent while in some processed food, they can account for up to 50 per cent.
In 1994, the Harvard team published research showing that replacing 2 per cent of your energy intake from trans fats with unhydrogenated or unsaturated fats could reduce your chances of getting heart disease by 50 per cent. The US Institute of Medicine says the only safe level of intake is zero.
A Danish Nutrition Council study reports that trans fatty acids cross the placenta and concludes that there are "justified suspicions that a high trans fatty acid intake may have adverse effects on foetal growth" and also increase the risk of preeclampsia. However, a recent study by the European Food Safety Authority concluded that although trans fatty acids can significantly increase cardio-vascular risk, saturated fat is of greater concern since many Europeans consume over the recommended limits.
If you avoid a daily diet of bread, ready-meals, deep-fried fast-food and processed snacks, it is possible to reduce your intake of trans fatty acids. Also a point worth noting is that organic producers are not permitted to use oil which has been hydrogenated.
But what percentage of trans fatty acids is in bread? Although ingredients lists of most white-sliced pans on supermarket shelves include hydrogenated vegetable oil, labels are less than informative. "It would be beneficial if the amount of trans fatty acids was listed on labels," says Janis Morrissey, dietician with the Irish Heart Foundation.
Bread labels can be mystifying in other ways. What exactly is "mono- and di-acetyltartaric esters of mono- and di-glycerides of fatty acids" and why is it in bread? This mouthful is the emulsifier E472 (e), a complex compound made from petro-chemicals which enables dough to retain more air and slows down staling. Since consumers became distrustful of E numbers, the full name of chemical ingredients is often listed, which makes life harder for those who wish to avoid certain ones.
One preservative often found in bread, other bakery products and processed cheese is calcium propionate (aka E282). Not only has this mould inhibitor been linked to migraines, the Bakers' Union in the UK has banned its use in the pure form because it provokes skin rashes in bakery workers, according to E for Additives.
Bread is high in salt; many loaves contain 1.25 grammes of salt per 100 grammes. This means four slices of bread can contain half a six-year-old child's daily recommended salt intake and 25 per cent of an adult's.
In addition, there is a good chance that bread using soya flour, micronutrients (vitamins) and certain "processing aids" contains genetically modified ingredients, according to Dr Pat O'Mahony of the Food Safety Authority of Ireland. But if the amount of GMO is under 0.9 per cent, or is not present in the final product, you won't see "GM" on the label.
An increasing number of people cannot eat bread because of gluten-intolerance or yeast allergies. "It's the fermentation time which makes wheat digestible," says the miller John Lister in Not on the Label. "When we made bread that had been given 36 to 48 hours to ferment, it did not cause a reaction in people who suffer from gluten allergies.
"It didn't take 2,000 years to develop the process of making bread for us just to bin it without consequences. The question is, have we made our staple indigestible?"
Not on the Label; What Really goes into the Food on your Plate by Felicity Lawrence is published by Penguin (2004).
smarriott@irish-times.ie