The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 12 No.
4 • August 2009
n-3 Fatty Acids:
Natural “Doping” for Enhanced Endurance.
Migrating Birds Improve Physical Fitness by Eating!
A most unusual new study reports that feeding sedentary bobwhite quails a diet enriched in n-3 fatty acids DHA and EPA to the levels of that which is eaten naturally in the wild by the semipalmated sandpiper to prepare for a migration from Canada to South America results in similar improvements in oxidative enzymes in muscles. These muscular improvements are obtained in wild semipalmated sandpipers by their stuffing themselves (body mass is doubled) with marine invertebrates containing “record” amounts of EPA and DHA, which results in substitution by n-3 fatty acids in place of n-6 fatty acids in muscle cell membranes. The authors state that “[o]nly extreme regimes of endurance training can lead to increments in oxidative capacity matching those induced here by diet.” Moreover, they suggest, “[c]hoosing n-3 fatty acid doping over endurance training strikes us as a better strategy to boost aerobic capacity when rapid storage of energy is critical.”
The activity of flight muscle CS (citrate synthase, a Krebs Cycle enzyme) was significantly increased by EPA, while CPT (carnitine palmitoyl transferase, a beta-oxidation enzyme that stimulates the use of fats as fuels) was stimulated by DHA. The authors report that six weeks of n-3 fatty acid supplements “were sufficient to increase enzyme activities by 58–90% in quail flight muscles. … A survey of the literature shows that aerobic exercise training can stimulate enzyme activities by up to 42%
in rats [after 8 weeks of training], 38–76% in humans
[7 weeks] and 41–72% in horses [10 weeks]. Therefore, the increases in oxidative enzyme activities observed in birds eating n-3 fatty acids can surpass those reported for mammals after endurance training and they occur more rapidly.” References were included in the original quote, but are deleted here for clarity.
Different experiments were done in which EPA was administered alone, DHA administered alone, or the two administered together to the sedentary quails. Interestingly, EPA and DHA were found to work by different mechanisms. The combined treatment did not provide a metabolic advantage except possibly for an increase in cytochrome oxidase, which was increased only in the EPA + DHA group.
The researchers hypothesize that another substantial benefit of the extreme n-3 diet for the migrating birds may be because the increased ratio of n-3/n-6 fatty acids “causes chronic inhibition of inflammation pathways” that in along-distance flight causes muscle damage.
“In preparation for long migrations, some birds improve their physical fitness by eating!” Importantly, though, over the course of their long flight, the excess fat stored in their bodies is burned as fuel. The paper didn’t discuss what happened to the sedentary quail after their n-3 eating binges (i.e., did they burn off the excess fat over time or remain fat? Of course, they might simply have been euthanized, leaving us in the dark about the fate of their fat).
- Nagahuedi et al. Mimicking the natural doping of migrant sandpipers in sedentary quails: effects of dietary n-3 fatty acids on muscle membranes and PPAR expression. J Exp Biol 212:1106-1114 (2009).