Pumpkin Pie and Mighty Mice: How Your Jack O’ Lantern Might Hold the Key to Increasing Endurance

by Michael Grisafe on October 26, 2012

Pumpkin Mice

Source Photos from Microsoft Clip Art

Just in time for Halloween, researchers have discovered that mice fed pumpkin extract have more endurance, energy, and are generally more bad-ass than other mice.1 On an unrelated side note, Lance Armstrong has purportedly ordered twelve pumpkin pies in the wake of this discovery.

For this study, researchers bought several pumpkins from a local market, cut them open, removed the seeds, and dried them out. Then they ground up the remaining pumpkin, concentrated the extract through liquid distillation, and fed it to mice for two weeks. Based on previous studies which examined the chemical compounds in pumpkin extract, the scientists hypothesized that pumpkins would reduce the fatigue of mice while increasing their physical endurance.

So how do you test the physical endurance of mice? You put them through the mini-mouse Olympics, of course! After feeding several groups of mice different concentrations of pumpkin extract (plus a control group that received no pumpkin extract), the rats either swam or did a “grip test.”

For the swim test, one group of rats had a lead fishing sinker amounting to about 5% of their body mass tied to their tail before being placed in a pool of water. The researchers then timed how long the rats “swam.” In research terms, “swimming” generally just meant floundering about until the mice sank and displayed a “failure to return to the surface within 7 s ” (you really have to wonder about some research protocol…).

Above:  An example of a forced swim test similar to the one used in this experiment (this shows a rat instead of a mouse).

For a strength endurance test, the mice were trained to grip a bar while researchers pulled them away from it. As quoted in the study:

“[…] we grasped the mouse at the base of the tail and lowered it vertically toward the bar. The mouse was pulled slightly backwards by the tail while the two paws (forelimbs) grasped the bar which triggered a ‘counter.’’”

Just think of it as a morbidly fascinating, reverse mouse pull-up.  The counter-pull from this “mouse pull-up” was measured as an indication of the mouse’s strength (…or the researcher’s strength as they tugged on the mouse’s tail).

A third, (slightly less fortunate) group of mice did the swim test described above for 15 minutes and then were immediately euthanized. Researches did this to determine the concentration of several chemicals associated with fatigue in the mice’s bodies.

 Results

Compared to mice fed a non-pumpkin diet, mice swimmers fed pumpkin extract swam significantly longer. Mice husbands loved longer. Mice fathers raised better children. A new mice renaissance was had. Ok, maybe just the swimming part is true, but the pumpkin extract significantly increased the mice’s endurance. In addition, those that received the extract did significantly better on the mouse strength tests (those awkward reverse pull-ups). Progressively larger doses of the pumpkin extract also led to bigger increases in the mice’s performance on the strength and endurance tasks.

Pumpkins

Image courtesy of chokphoto / FreeDigitalPhotos.net   

For the group of mice that were euthanized, those fed pumpkin extract showed a decrease in chemicals associated with muscle and tissue fatigue such as lactate, ammonia, and creatine kinase. Lactate (lactic acid) is a chemical that tends to build up in your muscles during heavy exercise, making them feel sore and tired. Likewise, a build-up of ammonia in your body is linked to fatigue, while creatine kinase is linked to muscle breakdown. The scientists theorized that the lower concentrations of these biochemical in the mice’s body reduced their fatigue and allowed them perform more strenuous tasks longer.

While the chemicals noted above went down as the pumpkin dose increased, two other biochemicals went up: glycogen and glucose. Glycogen serves as a form of energy storage in animals, while glucose is a simple sugar that can be used as a source of immediate fuel. Because each of these are needed for both long-term and short term fuel sources during endurance exercises, the scientists theorized that an increase in these biochemicals kept the mice peppy and anti-fatigued.

 So are pumpkins a super food?

Possibly, but there still hasn’t been an experiment to see if pumpkin extract has the same effect on humans as it did on the mice in this experiment. Although scientists often use mice as a good starting point for looking at metabolism and biochemical effects from food, these effects don’t always carry over to humans.

If the “pumpkin power” effect did work on humans, it would be pretty fabulous though, not only because I love pumpkin ice-cream, but because the lowest dose needed to produce “mighty mice” in the experiment was 50 milligrams per kilogram per day. For humans this translates to roughly less than spoonful of pumpkin extract a day (about 110 milligrams for a 150 lbs. person).

However, until science comes up with a clear answer to this “gourd-ian” knot, feel free to shamelessly enjoy that extra piece of pumpkin pie as your carve your jack o’ lantern this Halloween. And if anyone starts to give you flack, tell them to relax: you’re training for your next decathlon.

Pie Mouse

Source Photos from Microsoft Clip Art

1Wang, S.-Y., Huang, W.-C., Liu, C.-C., Wang, M.-F., Ho, C.-S., Huang, W.-P., Hou, C.-C., et al. (2012). Pumpkin (Cucurbita moschata) Fruit Extract Improves Physical Fatigue and Exercise Performance in Mice. Molecules (Basel, Switzerland), 17(10), 11864–76.

PF Anderson October 26, 2012 at 1:46 pm

Very interesting article. I may comment in more detail later, but for now just a quick comment. The animated GIFs are horribly painfully disorienting and distracting. FYI, they are strongly discouraged for web accessibility reasons.

HTML Techniques for Web Content Accessibility Guidelines 1.0
http://www.w3.org/TR/WCAG10-HTML-TECHS/#animated-images

They actually make content less accessible to:
– persons with seizure disorders
– persons with low vision (as opposed to total vision impairment)
– persons with learning or cognitive disabilities

In general, when writing about health or for an audience that may include persons with disabilities, these are not recommended.

Not to mention, they are plain annoying to some folk.

Animated gifs are a turn off:
http://www.bloorresearch.com/blog/accessibility/2011/11/animated-gifs-turn.html

Here is some more reading on animated images and accessibility:

https://www.google.com/search?q=animated+images+accessibility&oq=animated+images+accessibility&sugexp=chrome,mod=0&sourceid=chrome&ie=UTF-8

Michael Grisafe October 26, 2012 at 2:04 pm

Hmmm… yes…I can see how they would be a problem! I definitely don’t want to cause anyone a seizure (especially just to see a mouse dancing around a pumpkin)! Sigh….all those long hours making friends with Photoshop gone to waste…. Thanks for the heads up though.

number1monkeyfan October 26, 2012 at 2:37 pm

I enjoyed reading this article. However, there seems to be a slight contradiction in the last paragraph of your results section. I may be wrong, but my “inner biochemist” tells me that glycogen and glucose levels aren’t usually observed to increase at the same time. Usually as one goes up, the other one reduces (and vice versa). I may have to read the article you cited to better understand how that happens.

Looking forward to next week!

Michael Grisafe October 30, 2012 at 4:58 pm

Can’t high levels of glucose lead to extra glycogen storage? I’ll have to look into this one…

Bret Mogilefsky October 30, 2012 at 3:15 pm

So what’s the difference between pumpkin extract and (say) canned pumpkin, or the nutritional supplements made from pumpkin seeds? The study doesn’t make their CME’s provenance clear at all. Is it regular pumpkin flesh, or is it filtered or concentrated in some way?

Bret Mogilefsky October 30, 2012 at 3:18 pm

Never mind, I see it’s in “3. Experimental”:

“Fresh pumpkin (C. moschata, CM), fruits were purchased from a local market. Before extraction from the fruits, the seeds were removed and raw fruits with skin were cut with a slicer, and dried by solar drying. The dehydrated fruits were ground into powder. The dried powder (230 g) was extracted three times with 95% ethanol (2 L, 25 C, 1 week). After filtration, the solvent was concentrated by use of a rotary evaporator (Büchi R-215) to obtain the ethanol extract (26.1 g). The ethanolic extract of C. moschata (CME) was used for animal experiments in this study. A voucher specimen of C. moschata was deposited at the Graduate Institute of Sports Science, National Taiwan Sport University (Taoyuan, Taiwan).”

So much for replicating that at home. :(

Michael Grisafe October 30, 2012 at 4:55 pm

Yeah…sorry Brett. To get their exact concentration would take a bit of chemical know-how. I suppose that you could check out the actual pumpkin concentration in canned extract and then create something like a pumpkin pie that contains about the same amount. Just remember that this was a study involving mice, and there still haven’t been any human studies that have duplicated this result.

By the way, is it just me, or did you find it strange that their “methods” section was at the very end of the article? Unusual organization for a paper.

Thanks for reading!

Andrew Maynard October 30, 2012 at 5:57 pm

This is normal for some journals – not all by a long way though

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