Sunday, December 14, 2014

Phosphatidylserine: Where's the Research?

Seeking the truth?
Do not strive to prove, but to disprove.

From my perspective, the increasing popularity of phosphatidylserine (PS) as an ergogenic aid is entertaining. When a new supplement hits the market with claims of improved performance, increased this, decreased that... The "gurus" want a piece of the action - they jump on the bandwagon; like they've known all along. Now they're giving dosing protocols, touting the supposed benefits of "the next big thing."

PS is not a new supplement - you can find research on PS and exercise dating back to the 80's. It used to be obtained from bovine cortex (cow brains), but after the mad cow disease scare, it has more recently has been extracted from soy (Jager et al., 2007).

If you rely on the gurus' supplement reviews or forums for your nutrition information, you may be on your way to the nearest supplement shop. But before we get carried away, I have a few thoughts and questions about PS:

If PS decreases salivary/plasma cortisol following exercise, what effect does this have on subsequent protein synthesis? Cortisol has been demonized as a catabolic hormone, but it is a normal response to exercise. Perhaps cortisol is not the demon.

No, cortisol's a necessary hormone - it mobilizes glucose, fatty acids and amino acids during times of stress (like exercise). Isn't maintaining plasma glucose important during exercise? And couldn't having free amino acids available for protein synthesis following exercise improve recovery?

Further, if phosphatidylserine decreases the cortisol response to exercise, does this reduce the stimulus for adaptation?

Training induces stress, this stress results in perturbation from the normal homeostatic environment and triggers a response. Whether it's from a hormonal standpoint or substrate availability, perhaps it's physical damage from a mechanical stimulus; it's these deviations from homeostasis that provoke adaptation. If you limit the stress response, do you limit the stimulus of the training?

Take antioxidants for example: Ten years ago, antioxidants were miracle molecules. And because athletes (especially endurance athletes) are exposed to high levels of free radicals, they were advised to take antioxidants like herbal supplements and vitamins A,C,E. 

Well, guess what - reactive oxygen species may stimulate mitochondrial biogenesis (Baar, 2014). And taking in excessive antioxidants may limit the stress response, limiting the stimulus for adaptation (Paulsen et al., 2014).  Is phosphatidylserine supplementation any different?

Similar arguments can be made for or against the use of NSAID's following training (Trappe & Liu, 2013).

Sure, antioxidant supplementation could be, and has been shown to be beneficial in specific circumstances. PS may be the same. But in this arena of uncertainty, one thing is for sure - we need more research. Specifically, we need more training studies - not just looking at the supplement's effects on acute performance or hormonal measures.

Further Reading
Antioxidant supplementation:
http://www.ncbi.nlm.nih.gov/pubmed/22928084
http://www.ncbi.nlm.nih.gov/pubmed/22060178
http://www.ncbi.nlm.nih.gov/pubmed/20350594
http://www.gssiweb.org/en/Article/sse-137-endurance-exercise-and-antioxidant-supplementation-sense-or-nonsense---part-1

Phosphatidylserine:
http://www.jissn.com/content/4/1/5
http://www.ncbi.nlm.nih.gov/pubmed/16869708
http://www.ncbi.nlm.nih.gov/pm...MC2503954/
http://www.ncbi.nlm.nih.gov/pubmed/24959196


References
Baar, K. (2014). Nutrition and the adaptation to endurance training. Sports Med, 44 Suppl 1, S5-12.

Jager, R., Purpura, M., & Kingsley, M. (2007). Phospholipids and sports performance. J Int Soc Sports Nutr, 4(1), 5.

Paulsen, G., Cumming, K. T., Hamarsland, H., Borsheim, E., Berntsen, S., & Raastad, T. (2014). Can supplementation with vitamin C and E alter physiological adaptations to strength training? BMC Sports Sci Med Rehabil, 6, 28.

Trappe, T. A., & Liu, S. Z. (2013). Effects of prostaglandins and COX-inhibiting drugs on skeletal muscle adaptations to exercise. J Appl Physiol (1985), 115(6), 909-919.

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