So, if you are a RAT, don't eat fatty food!
At least, that is what a new RAT study found, published August 10 in the FASEB Journal,
"Deterioration of physical performance and cognitive function in rats with short-term high-fat feeding"[1], Andrew J. Murray, lead researcher.
The theory: Since fatty acid metabolism is less efficient than glucose metabolism, would eating a high-fat diet be beneficial or harmful to endurance; the detriment to intelligence was taken as a given over time. The reason? The feeding of a high-fat diet appears to cause
mitochondrial "uncoupling" and energy deprivation.
Or, in plain English:
The researchers sought to show that eating too much fat causes the body to waste energy as heat (the result of mitochondrial uncoupling, especially in the brown fat of...rodents),
leaving the cells "starved" for "useful" energy (glucose), reducing the ability to think and exercise.
The question to answer: How short a period of time does it take for rats who are fed a chow that contains 55% of calories as fat to show deterioration in physical and mental capabilities as versus a control group of rats fed a "low-fat" rat chow (7.5% fat)?
It turns out that the answer is "not long":
[R]ats ran 35% less far on a treadmill and showed cognitive impairment in a maze test with 9 d of high-fat feeding.... Our results suggest that high-fat feeding, even over short periods of time, alters skeletal muscle UCP3 expression, affecting energy production and physical performance.
[1]
It took nine days for the test rats to lose endurance and ability to reason and learn, at least as much as rats ever do.
Does this mean anything for humans? Dr. Gerald Weissman, editor-in-chief of the FASEB Journal, seems to think that what happens in rats is also what happens in humans. He states in a
"Live Science" story:[2]
"It's nothing short of a high-fat hangover," said Dr. Gerald Weissmann, ..."A long weekend spent eating hotdogs, French fries, and pizza in Orlando might be a great treat for our taste buds, but they might send our muscles and brains out to lunch."
[2]
Again, that might be something to worry about...if your name is
Ratatouille.
If you are human? The headlines--and Dr. Weissmann's extrapolation to us hominids--are meaningless:
1.)
Rats are NOT small humans. In fact, rodents are really not the best experimental subjects if one is investigating possible effects of anything on humans. All they are is a.) Prolific; b.) Bred to have any weakness you want; c.)not too likely to get the sympathy of the average person so experimentation is easier to do (unless PeTA or other animal rights activists get a bee in their bonnet); and, d.) Really cheap to house and feed.
2.)
The natural rat diet is NOT at all fatty. This information comes from the
"Pet Rat Information Sheet" (PetRat.info) by A. Robinson and A. Horn, and would apply to our lab rats since they are also the domesticated strain of the
Norway Rat (brown rat):[3]
Like people, rats are omnivores. They fare best on fresh wholesome foods: wholegrain (brown) rice, vegetables, grains (wheat, barley, oats, millet), wholemeal bread, etc. and some animal protein. ... Ideally, an adult rat should be fed some whole-grains, some vegetables, and some protein (lean meat scraps, dog food or mealworms) every day. This can be supplemented with a bowl of 'rodent mix' as a snack food.
...
However "complete foods" in the form of extruded pellets guarantee that rats are getting all of their vital nutrients, and as such can be an important part of a healthy mixed diet ....
...
The following foods can be used as treats/supplements to the regular diet: fruit..., vegetables..., cooked liver, kidney, or other low-fat meat, cooked bones, cooked pulses..., live yoghurt, sunflower seeds..., wholemeal pasta and bread, brown rice, unsweetened breakfast cereals, and the occasional capsule of cod-liver or garlic oil.
[3]
Note the diet: Moderate protein, a moderate amount of fat, mostly vegetarian: Your blogger used to own rats as pets, and their rat food was not at all fatty; 55% fat content pellets would have been noticeable as "grease city". Or, to put it bluntly, the "control group" may well have been fed too little fat, and the test group more fat than most HUMANS eat (who are not living in the Arctic).
3.)
The unsuitable diet in the test group could easily explain why the rats got lethargic and lazy: They were being starved "in the midst of plenty"! .
The human being, on the other hand, is designed to be an omnivore that is able to utilize fat fairly efficiently. However, even humans would still slow down if their body fat was the only source of energy they had...or too much of what they got to eat was fat: Fat is slower to metabolize since it takes longer to digest (or convert to glucose from stored fat).
So, our Masters of the Obvious have come up with their finding, if they would but see it:
Unsuitable diets--no matter how much food energy is in them--leads to starvation, which in turn reduces endurance and alertness IN THE RAT.
Not necessarily in the human being...but try and tell them that; the study abstract concludes:
Our results suggest that high-fat feeding, even over short periods of time, alters skeletal muscle UCP3 expression, affecting energy production and physical performance. Optimization of nutrition to maximize the efficiency of mitochondrial ATP production could improve energetics in athletes and patients with metabolic abnormalities.
[1]
Read: Put the athlete and people with metabolic abnormalities (such as diabetics) on low-fat diets and they will be more energetic and smarter. Who cares if they end up starved in the long run from an unsuitable diet?
After all, being energetic is most desirable, indeed, and worth dry veggies forever. Or, is it?
For the answer? Maybe we should just ask a rat...:)
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1.)Murray AJ, Knight NS, Cochlin LE, McAleese S, Deacon RM, Rawlins JN, Clarke K., "Deterioration of physical performance and cognitive function in rats with short-term high-fat feeding", FASEB J. 2009 Aug 10. [Epub ahead of print],PMID: 19667117. Downloaded August 13, 2009 from http://www.ncbi.nlm.nih.gov/pubmed/19667117?dopt=Abstract
2.) Live Science, "High-Fat Diet May Make You Stupid and Lazy", posted: 12 August 2009 01:06 pm ET. Downloaded August 13, 2009 from http://www.livescience.com/health/090812-fat-lazy-stupid.html
3.) Robinson, A. and Horn, A., "PetRat.Info, Formerly the Pet Rat Information Sheet", "Feeding" section.Document © A. Robinson & A. Horn 1998-2007, all rights reserved. Downloaded August 13, 2009 from http://www.quite.co.uk/rats/
