Quails get super fit by
simply eating omega-3 diet
Friday, March 27,
2009
When tiny semipalmated sandpipers
embark on their annual odyssey from the Canadian Arctic to their
winter residences in South America, they set out on one of the
world's longest migrations. On the way, the tiny birds stop off at
the Bay of Fundy on the Canadian east coast, where they spend two
weeks gorging on a superfood, Corophium volutator (mud shrimps),
which have some of the highest levels of n-3 fatty acids (better
known as omega-3 fatty acids) of any marine animal.
According to Jean-Michel Weber from the University of Ottawa,
omega-3 fatty acids have some rather astonishing effects. In humans
they reduce the risk of coronary heart disease and alleviate
depression. But it was not their potential medicinal properties
that intrigued Weber; it was their ability to increase aerobic
capacity, much like endurance training. Could the sandpipers be
building up for their endurance challenge by simply eating? All the
evidence suggest so, but Weber needed to test the miraculous fatty
acids' effects on less athletic birds, bobwhite quails, to be sure.
Could he boost the couch potato quails' endurance by simply feeding
them omega-3 fatty acids? Weber and his team publish their
discovery that quails can get fit simply by eating a diet rich in
omega-3 fatty acids on 27 March 2009 in The Journal of Experimental
Biology.
Teaming up with student Simba Nagahuedi, Weber fed three groups of
the sedentary quails a tightly regulated omega-3 diet of n-3
eicosapentaenoic acid, or n-3 docosahexaenoic acid, or a 50/50
mixture of the two oils for 6 weeks. Then Nagahuedi checked the
quails' pectoral muscles to see if their capacity to consume oxygen
to produce energy had improved. Measuring the activity levels of
four oxidative enzymes the duo found that the enzymes' activity
levels had increased by between 58 and 90% to levels normally only
seen in the migrating sandpipers. Weber admits that he was
astonished by the increase. Even top human endurance athletes only
improve their oxidative enzyme activities by 38 to 76% after 7
weeks of hard endurance training. But the quails had done even
better without getting off their bottoms; they had got fit by
simply eating omega-3 fatty acids.
However when Weber tried to find out how the enigmatic fatty acids
manifested their remarkable influence, the results were less clear.
Teaming up with Vance Trudeau and Jason Popesku to measure the
levels of a key molecule that regulates oxidative enzyme levels,
known as PPAR, Weber could not find any evidence for a change in
PPAR gene expression in response to the 6 week diets. However, he
adds that it does not mean that PPAR levels do not change earlier
to influence the bird's performance during the oil diet.
Nagahuedi and Weber also measured the omega-3 fatty acid levels in
the muscle cell membranes, and found that the fatty acid was evenly
distributed between all of the different membranes in muscle cells.
So the birds were not improving their endurance by selectively
allocating the fatty acids to the energy generating
mitochondria.
Having convinced himself that the sandpiper's mud shrimp diet is
responsible for the migrant's outstanding stamina, Weber is keen to
find out exactly how the birds increase their oxidative enzyme
activity levels to power their long flight south.
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The Company of Biologists
Thanks to The Company of
Biologists for this article.