Question: Do genes or lifestyle affect more on people’s health?

Ellie Dunstone answered on 12 Jun 2020:

Hi Ana,
This one really depends on the particular disease we’re talking about. For some diseases like huntington’s disease, whether you have the disease or not, and how badly you have it, depends pretty much entirely on your genes.
Other diseases are mostly due to lifestyle or the environment, for example the vast majority of some kinds of lung cancers are caused by smoking.
However, lots and lots of diseases are caused by a mixture. For example, some people are genetically more likely to suffer from heart disease, but it is also linked to diets containing high salt and high levels of certain kinds of fats. Similarly, if you catch an infectious disease then it is coming from the environment that you were exposed to, but how badly you suffer from the symptoms can in part be due to your genetics.