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.