The Biology of Food 6: A cooked breakfast with coffee
In this series of ten blogs, various parts of the IGCSE Science and IGCSE Biology specifications will be explored through the context of food. As well as assisting students revising for their GCSE and IGCSE exams, the blogs also provide an every-day context for science which all readers should find accessible, interesting and useful.
A cooked breakfast with coffee – cholesterol, statins and caffeine
Cholesterol, statins and caffeine appear in the following subject specifications: AQA GCSE Biology, AQA GCSE Science, 11.1, 11.2, 11.3, and Edexcel Biology IGCSE 2.3.
Sausages, bacon, fried eggs and a cup of coffee could be your idea of breakfast heaven … but it could just inspire a discussion of health issues and drugs.
Cholesterol
The foods listed above can all affect the amount of cholesterol in the blood. Cholesterol, a steroid, is produced by the liver and is essential for the body to make hormones, cell membranes and vitamin D. It is carried around the body by two different types of molecules – low and high density lipoproteins (LDLs and HDLs). Balancing these lipoproteins is important for a healthy heart. The foods present in a cooked breakfast contain lots of saturated fats which increase blood cholesterol levels which can lead to heart disease. Recently, analysis of eggs has shown a reduction in cholesterol: it is thought that this is caused by hens having a more healthy diet!
Statins
Statins are drugs that are very successful in lowering cholesterol. Concerns have been raised that prescribing these drugs will mean people do not improve their own health by making lifestyle changes, but rely on statins to prevent heart disease. What do you think?
Caffeine
Coffee contains the drug caffeine which, like all drugs, affects the way the body works. Coffee originated in Ethiopia; it has certainly been drunk for hundreds of years. Caffeine from other sources has been consumed since the stone-age. Caffeine stimulates the central nervous system causing alertness and warding off tiredness. It is the most widely used recreational drug: in North America 90% of people are users.
