Question: if we tested on rats would it have a different affect on people

Richard Unwin answered on 20 Nov 2015:

Hey Science_is_awesome,

This is a brilliant question, and is a major concerns for people doing out kind of research, because the answer is yes. While rats (and mice) can provide what we call a ‘model’ of disease, clearly rats and mice are not humans. In the fields of diabetes and dementia, for example, rodents tend not to get these diseases, so we give them to the animals artificially, using a drug or massively high fat diet or adding or taking away a gene – but these are NOT how these diseases are caused in humans (although there is a relationship it’s NOT the same), and as scientists you have to be aware of the differences all the time, to make sure that you constantly compare back to human disease where possible. I’ve heard that some labs are now abandoning animal models of dementia altogether because they just don’t tell us anything about some critical aspects of human disease.
The only real exception to this is in testing whether new medicines are likely to be harmful – if a new medicine is going to be poisonous to a person it’s likely to be also poisonous to a rodent, although again things like how much of the new medicine you give and how the body breaks it down can cause differences.