Lifestyle & Non-Communicable Diseases (AQA GCSE Biology): Revision Note
Exam code: 8461
Risk factors
Risk factors are linked to an increased rate of a disease
Exposure to a risk factor doesn’t guarantee that an individual will suffer a disease (a person who smokes regularly isn’t guaranteed to develop lung cancer but their risk compared to someone who doesn’t smoke is much, much higher)
Certain risk factors correlate with certain diseases (are related to them) but correlations are not always causations
Risk factors can be:
Aspects of a person’s lifestyle, such as the food they eat or whether or not they drink alcohol
Substances in the person’s body or environment, such as air pollution in a crowded city or asbestos in old buildings
Causal mechanisms & risk factors
A causal mechanism has been proven for some risk factors, but not in others
Risk Factor | Disease Risk Factor is Linked to | Explanation of how Risk Factor may Cause Disease |
|---|---|---|
Smoking | Lung disease, lung cancer and cardiovascular disease | Chemicals in cigarette smoke (such as tar and nicotine) damage the alveoli in the lungs and the endothelial lining of the arteries. |
Obesity caused by a poor diet | Type 2 diabetes | Excess consumption of sugar as a result of a poor diet reduces the body’s sensitivity to insulin. |
Consuming alcohol | Liver disease and impaired brain function | The breakdown of alcohol by cells of the liver produces substances which can be toxic to liver cells in high concentrations. The neurones of the brain are also damaged by alcohol, reducing brain function. |
Exposure to carcinogens | Cancer | Exposure to ionising radiation (e.g. X-rays) or certain chemicals can damage DNA in cells, leading to uncontrolled cell division, causing cancer. |
Smoking and consuming alcohol while pregnant | Poor development of foetus (unborn baby) | Carbon monoxide in cigarette smoke reduces the amount of oxygen transported around the mother’s body, reducing the oxygen delivered to the foetus. Substances in alcohol can impair the development of the brain in a foetus. |
Many diseases are caused by the interaction of a number of factors; the chance of developing cardiovascular disease is higher in individuals who have a poor diet high in cholesterol (fat), don’t exercise regularly and smoke – because all of these behaviours increase the likelihood of damage occurring to the arteries
Unlock more, it's free!
Join the 100,000+ Students that ❤️ Save My Exams
the (exam) results speak for themselves:
Was this revision note helpful?
Build on this topic
