Relevance of nutritional epidemiology

So what is Epidemiology? Epidemiology is derived from the Greek words 'epi' (on or upon), 'demos' (people), and 'logos' (word or statement) (1).

Literally, it translates as 'a statement of what is upon the people' (2). A more practical translation is the scientific method used to investigate, analyse and prevent or control a health problem within a population. That population could be the entire world, as may be the case with an influenza epidemic. Or it can be a relatively small group of people - a single high school, for example, with an unusually high number of children with asthma. 

It may be useful to think about how epidemiology is different from the practice of medicine. If you have a case of food poisoning, your doctor would examine you and recommend treatment. An epidemiologist would want to know more:

• What food made you ill?
• Where did you get the food?
• Who else might have eaten it?
• What groups of people, such as children or the elderly, are most threatened by the disease?
• How could people be notified and treated?
• How did the food become tainted in the first place?

As you can see, epidemiologists are interested in all kinds of health issues - not just the well-known diseases such as cancers or HIV. An 'epidemic' is simply a health problem that exists in a community to a greater degree than you would expect. Other examples of trends epidemiologists might look at are:

• chronic illnesses, such as heart diseases or obesity
• factors that put people at risk for health problems, such as smoking
• factors that keep people healthy, such as a balanced diet or regular physical activity
• the effectiveness of various treatments, such as weight loss for hypertension

Answers can be found by comparing disease impacts (outcome) among people with and without the condition (exposure).



References:
1. Oxford Dictionary Online. [Internet] Oxford University Press, 2013. [cited 2013 June 5]. Available from: http://oxforddictionaries.com/definition/english/epidemiology?q=epidemiology

2. Definition of Epidemiology [Internet] 2003[cited 2013 June 5] Available from: http://gwxy.sysu.edu.cn/lxbx/english/epidemiologic%20knowledge/Scope%20and%20Significance%20of%20Epidemiology/definit.html#]