Mice are commonly used in diet- and disease-related research because they share a majority of their genes with us and are small and inexpensive. But there are plenty of subtle confounding factors in the mice themselves that, if not accounted and properly controlled for, can really muddy experimental results. Image by ReneS.
A big criticism is that some researchers are ignoring (or not reporting) how even the most subtle environmental factors can influence the mice's biology, and thus the experimental findings. And the thing is, experimental outcomes from one mice study cannot be reproduced and do not even work in other mice. Some reasons why:
- Factors like lighting, air quality, the type and quantity of food, environmental stress, the pH of the water or even where the researchers got their mice from can affect results.
- Mice eat other mice' faeces. When looking at health- or diet-related outcomes, this makes things more complicated when you don't know which mice ate how much of whose poop and what that poop contained.
- Mice may have different metabolic responses to certain food choices, which in turn, could alter their gut and impact diet findings.
If the researchers don't pay extra special attention to these confounding variables, then it makes even less sense to extrapolate any grand conclusion from such food- and health-related studies to humans. As Dr Yoni Freedhoff, assistant professor of family medicine at the University of Ottawa, explains on his blog, "We can't just make conclusions about human diet outcomes based on mice studies."
Mouse Diet Studies Aren't Conclusive For Mice Let Alone People [Weighty Matters]