A supplement that’s garnered a lot of interest among bodybuilders is phosphatidylserine. It consists of phosphates, fatty acids and the amino acid serine and is categorized as a phospholipid. It’s produced in the human body and concentrates in organs that have higher metabolic activity, such as the brain, lungs, heart, liver and skeletal muscle. Located in the inner layer of cellular membranes, it plays a pivotal role in modulating the activity of cell receptors and enzymes and, most important, in controlling cellular fluidity. The original phosphatidylserine supplements were derived from bovine sources, but the fear of contracting deadly diseases, such as Creutzfeldt-Jakob—a.k.a. mad-cow disease—led to the development of a soy-based version. The variants differ primarily in their fatty acid composition.
Several studies have shown that phosphatidylserine is present in the membrane structure of neurons and can therefore favorably influence brain function. A study in which older adults were given phosphatidylserine even concluded that using PS reversed brain aging by an average of 12 years. In younger people it enhances the mood of those who are under great mental stress. For example, researchers recently found that it improved golf-playing performance by reducing the golfers’ stress. In fact, its effect on stress hormones is of most relevance to bodybuilders.
Making maximum gains in muscular size and strength requires an optimum ratio of anabolic to catabolic hormones. The primary anabolic hormones are testosterone, growth hormone and insulin. The main catabolic hormone is cortisol, secreted by the adrenal glands under high-stress conditions. High stress includes overtraining, which can result from too much training volume, not getting enough rest between workouts—even from doing too much aerobic exercise. When that happens, the hormone scale tips toward cortisol and against the muscle-building hormones—thus the loss of muscle size and strength.
Anabolic steroids produce such dramatic effects because they block the impact of cortisol and neutralize the side effects of overtraining. Bodybuilders who don’t juice up have limited choices in curtailing excess cortisol release. Yet contrary to what you might expect, you never want to completely curtail cortisol. Not having cortisol could result in death from shock if you were exposed to trauma. In addition, cortisol is a big-time anti-inflammatory agent. Without it, you experience severe joint pain after intense workouts. The ideal situation, therefore, would be to regulate but not completely curtail cortisol release.
Several studies have demonstrated that phosphatidylserine can hasten muscle recovery, prevent muscle soreness and perhaps even produce ergogenic effects during sports and exercise. Experiments involving cyclists showed that a daily dose of 800 milligrams of PS blunted cortisol response by 30 percent; 400 milligrams had no effect. The 800-milligram dose also lowered the cortisol response to a weight-training session by 20 percent. Although lower doses did limit muscle damage, 800 milligrams a day worked out to be the most effective dose for blunting cortisol release due to exercise.
Exactly how phosphatidylserine affects cortisol isn’t yet clear. Researchers agree that the main sites of its interaction are in the brain. The theory is that PS lowers corticotropin-releasing factor, or CRF, which is produced in the hypothalamus and controls the release of yet another hormone, called ACTH, that’s produced in the pituitary gland. ACTH travels in the blood to the adrenal gland, where it governs the release of cortisol.
Phosphatidylserine is thought to work by manipulating the CRF receptors in the brain. Another theory is that high-intensity-exercise stress leads to the pituitary gland’s release of a substance called arginine vasopressin, which leads to the secretion of both ACTH and cortisol.
Phosphatidylserine prevents oxidation and other activity that would otherwise lead to cell death. In muscle that means it favorably affects ion or mineral balance, which can reduce muscle fatigue.
A study recently confirmed the cortisol-blocking effects of phosphatidylserine and also found that using 600 milligrams a day for 10 days favorably affected the testosterone-to-cortisol ratio. While phosphatidylserine didn’t directly increase testosterone concentration, it did prevent the depletion of testosterone that usually occurs when lots of cortisol is released. Cortisol prevents both the synthesis and release of testosterone in the body, and the authors suggest that phosphatidylserine may help prevent overtraining. The researchers also found that the greater the exercise intensity, the more effective phosphatidylserine is in blunting cortisol’s impact. It did not appear to affect growth hormone, however.
Perhaps the best news about the new study is the finding that a dose of 600 milligrams may work as well as the 800-milligram doses used in previous studies. Meaning: phosphatidylserine may be more affordable than everybody thought. Based on how it’s incorporated in cellular membranes, I’d say that you’d probably get better results with chronic long-term use.
As it happens, I can attest to the safety of phosphatidylserine. For about 10 years—no break—I’ve been taking it to get its beneficial effects on brain function. I figure that means that I’m about 12 years younger than my chronological age. At least my brain is.
Starks, M.S., et al. (2008). The effects of phosphatidylserine on endocrine response to moderate intensity exercise. J Int Soc Sports Nutr. In press. IM