Three studies have examined phosphatidylserine’s ability to reduce cortisol levels. In the first, a double-blind, randomized study conducted at the University of Naples, Italy, eight healthy males exercised on a bicycle ergometer (designed to increase their cortisol levels) on three separate days one week apart.10 Before each exercise session, the test subjects were given either a placebo or a 50-or 75-mg intravenous dose of phosphatidylserine. As expected, ACTH and cortisol levels rose after this intensive exercise protocol, but the increases in the subjects who received the 50- or 75-mg dose of phosphatidylserine were approximately 33% and 45% less, respectively, than in those who received the placebo.
In a second study, the Italian scientists tried the same experiment using 400 mg and 800 mg of phosphatidylserine taken orally.11 They found that the plasma cortisol responses were 16% and 25% lower, respectively. These reduced percentages suggest that part of the orally administered phosphatidylserine was degraded before it reached the bloodstream.
In the third study, a double-blind, crossover study conducted at California State University at Chino, 10 men were given 800 mg of phosphatidylserine a day and then put through a vigorous whole-body workout (designed to elicit a cortisol response) four times a week.12 Each participant received phosphatidylserine for two weeks and then repeated the workout program for another two weeks with a placebo after a washout period of three and one-half weeks. Blood samples were taken 15 minutes after each workout. This study found that phosphatidylserine reduced cortisol levels after exercise by 20%.
The researchers also found that testosterone levels, which normally decline after intensive exercise, were not reduced. In exit interviews, the subjects said they “felt better” while taking phosphatidylserine, and their perceived exertion also dropped.
These experiments show that phosphatidylserine is able to reduce cortisol levels when the body experiences stress. While the studies used exercise to produce the stress, the same principle holds for other types of stress, such as that elicited by mental exertion or physically demanding tasks. This makes phosphatidylserine a valuable tool for controlling cortisol levels. Bear in mind, however, that not all exercise results in increased cortisol production. Scientists have discovered that short-term, moderate exercise does not increase cortisol concentration in plasma at all, and only minor changes in cortisol concentration occur during more intensive exercise lasting less than an hour.13 Thus there is no need to avoid exercise for fear of boosting one’s cortisol level. A game of tennis, bike ride, or walk around the block will not increase cortisol production. In fact, the stress-reducing benefits of moderate exercise help to keep cortisol in check. Physical activity also promotes cardiovascular health and mental acuity, helping to maintain a higher quality of life as we age.
Unfortunately, phosphatidyl-serine is found in only trace amounts in common foods. Al-though the body is able to produce phosphatidylserine on its own, it must go through a series of reactions that require a substantial investment of energy. This makes supplementation an attractive option. When phosphatidylserine is taken orally, the non-degraded portion is rapidly assimilated and easily crosses the blood-brain barrier. Because phosphatidylserine can produce nausea if taken on an empty stomach, it should be taken with meals. Phosphatidylserine should not be taken just before going to bed, as the neurotransmitters it helps to release could make it harder to fall asleep. Phosphatidylserine does not appear to have any other side effects when taken at the recommended dosages.
Yet Another Benefit of DHEA
Life Extension members are well aware of the multiple benefits of DHEA, which range from increased energy and reduced heart disease risk to greater fat loss and better immune function. Now scientists have discovered yet another benefit: cortisol reduction. In a single-blind, placebo-controlled study at the University of Pittsburgh, seven men and seven women with an average age of 70 took 200 mg of DHEA for 15 days.14 Each dose was taken in the morning 30 minutes after a light breakfast. The researchers found a significant reduction in cortisol concentrations in both sexes, ranging from a 26% drop in the women to a still-impressive 18% decline in the men. The normal diurnal pattern in plasma cortisol levels, which includes an early-morning peak and an evening nadir, was preserved, though the extent of cortisol release during these periods was reduced after DHEA administration.
The scientists did not address possible reasons for these dramatic reductions, but they suggested that either DHEA or its sulfated form, DHEA-S, may have an inhibitory effect on the activity of the hypothalamic-pituitary-adrenal axis. While the researchers do not believe that DHEA or DHEA-S directly inhibits ACTH or cortisol release, they suggest that some alteration in the availability of corticotropin-releasing factor may be responsible for the observed changes.
It should be noted that Life Extension does not recommend a 200-mg dose of DHEA unless prior blood testing reveals a low level of this hormone. Just as low levels of this or any hormone can be damaging to long-term health, so can hormone levels that exceed the normal physiological range. Life Extension strongly recommends a DHEA blood test before one considers such a high level of supplementation. Fortunately, a study at the University of Pisa, Italy, has shown a progressive drop in cortisol levels even when a more moderate 50-mg dose of DHEA was administered daily for a six-month period.15# These results were obtained in both early postmenopausal women (50-55 years old) and late postmenopausal women (60-65 years old). While men were not tested in this study, there is no reason to believe they would not achieve equivalent benefits.
Ginkgo Biloba Also Lowers Cortisol
The leaf extract from the ginkgo biloba tree has a multitude of beneficial effects on the human body, from improved cognitive function to regained sexual potency. Ginkgo biloba promotes blood flow to the brain, enhancing mood while also helping to reduce memory loss, confusion, and fatigue. Ginkgo biloba also has antioxidant properties, making it a very desirable supplement for older individuals.
As if this were not enough, a recent study conducted in Slovakia found that a standardized extract of ginkgo biloba is able to reduce cortisol levels.16 Seventy volunteers from the University of Bratislava participated in this double-blind, placebo-controlled study, which measured the effect of a 120-mg dose of ginkgo on the cortisol produced by a stress model that included a mental challenge and a static exercise test. Measurements were performed in the morning and evening to capture the normal high points in daily cortisol production. The researchers found that ginkgo inhibited the rise in salivary cortisol levels after the stress test, with the greatest benefit in the afternoon.