Herbs & Supplements:
Phosphatidylserine
Principal Proposed Uses
•
Alzheimer's Disease, Age-Related Memory Loss
Other Proposed Uses
•
General Improvement of Mental Performance, Depression, Performance Enhancement
Phosphatidylserine, or PS for short, is a member of a class of chemical compounds known as phospholipids. PS is an essential component in all our cells; specifically, it is a major component of the cell membrane. The cell membrane is a kind of "skin" that surrounds living cells. Besides keeping cells intact, this membrane performs vital functions such as moving nutrients into cells and pumping waste products out of them. PS plays an important role in many of these functions.
Good evidence suggests that PS can help declining mental function and depression in the elderly, and it is widely used for this purpose in Italy, Scandinavia, and other parts of Europe. PS has also been marketed as a "brain booster" for people of all ages, said to sharpen memory and increase thinking ability, the evidence to support this use is contradictory.
Recently, PS has been marketed as a sports supplement, said to help bodybuilders and power athletes develop larger and stronger muscles.
NOTE: There is one major caveat to keep in mind regarding studies of PS. Virtually all such studies used animal-source PS, a product that is no longer available. Currently available PS products are made from plant products and might not function identically. (See Sources)
Sources
Your body makes all the PS it needs. However, the only way to get a therapeutic dosage of PS is to take a supplement.
PS was originally manufactured from the brains of cows, and all the studies described here used this form. However, because animal brain cells can harbor viruses, that form is no longer available. Most PS today is made from soybeans or other plant sources.
There are reasons to expect that plant-source PS should function very similarly to PS made from cows' brains, and some animal studies suggest that it is indeed effective.1–5,43-45 However, in preliminary human trial, soy-based PS and cabbage-based PS have not been found to be beneficial.7,46 The bottom line: at present, we do not know whether modern plant-source PS is actually effective.
Therapeutic Dosages
For the purpose of improving mental function, PS is usually taken in dosages of 100 mg 2 to 3 times daily. After maximum effect is achieved, the dosage can reportedly be reduced to 100 mg daily without losing benefit. PS can be taken with or without meals.
When taking PS for sports purposes, athletes sometimes take as much as 800 mg daily.
Therapeutic Uses
Meaningful evidence from numerous double-blind studies suggests that animal-source PS is an effective treatment for Alzheimer's disease and other forms of age-related mental decline.8–17
PS is widely marketed as a treatment for ordinary age-related memory loss, technically known as Age-Related Cognitive Decline (ARCD) or Age-Associated Memory Impairment (AAMI), and there is some evidence that it might work. In studies of severe mental decline, PS was equally effective whether the cause was Alzheimer's disease or something entirely unrelated (multiple small strokes). This certainly suggests that PS may have a positive impact on the brain that is not specific to any one condition. From this observation, it is not a great leap to suspect that it might make it useful for much less severe problems with memory and mental function, such as those that seem to occur in nearly all of us who are older than 40. Indeed, one double-blind study did find that animal-source phosphatidylserine could improve mental function in individuals with relatively mild age-related memory loss, although plant-based forms of PS have not been found effective at this time.18,7
PS might be helpful for depression.19,20
Recently, PS has become popular among athletes who hope it can help them build muscle more efficiently. This use is based on modest evidence that PS slows the release of cortisol following heavy exercise.21,22,23 Cortisol is a hormone that causes muscle tissue to break down. For reasons that are unclear, the body produces increased levels of cortisol after heavy exercise. Strength athletes believe that this natural cortisol release works against their efforts to rapidly build muscle mass and hope that PS will help them advance more quickly. However, this idea has not been proven.
What Is the Scientific Evidence for Phosphatidylserine?
Alzheimer's Disease and Other Forms of Dementia
Overall, the evidence for animal-source PS in dementia is fairly strong. Double-blind studies involving a total of over 1,000 people suggest that phosphatidylserine is an effective treatment for Alzheimer's disease and other forms of dementia.
The largest of these studies followed 494 elderly subjects in northeastern Italy over a course of 6 months.24 All suffered from moderate to severe mental decline, as measured by standard tests. Treatment consisted of either 300 mg daily of PS or placebo. The group that took PS did significantly better in both behavior and mental function than the placebo group. Symptoms of depression also improved.
These results agree with those of numerous smaller double-blind studies involving a total of over 500 people with Alzheimer's and other types of age-related dementia.25–32 However, all these studies involved cow-brain PS; studies of plant-source PS for dementia have not been reported.
Ordinary Age-Related Memory Loss
There is some evidence that PS can also help people with ordinary age-related memory loss. In one double-blind study that enrolled 149 individuals with memory loss but not dementia, phosphatidylserine provided significant benefits as compared with placebo.33 Individuals with the most severe memory loss showed the most improvement.
However, another double blind trial of 120 older individuals with memory complaints but not dementia failed to find benefits.47 This discrepancy may have to do with the type of phosphatidylserine used – the second trial used the more modern soy-derived form of the supplement (See Therapeutic Dosages). A cabbage-based source of PS has also failed to prove effective for relatively mild memory loss.7
Athletic Performance
Weak evidence suggests that PS might decrease the release of the hormone cortisol after intense exercise.34 Among its many effects, cortisol acts to break down muscle tissue—exactly the opposite of the effect desired by a strength athlete or bodybuilder. This double-blind placebo-controlled study on 11 intensely trained athletes found that 800 mg of PS taken daily reduced the cortisol rise by 20% as compared with placebo.35 Another small study on 9 nonathletic males found that daily doses of 400 and 800 mg of PS reduced cortisol levels after exercise by 16% and 30%, respectively.36 Another study found that phosphatidylserine could relieve some overtraining symptoms, including muscle soreness, possibly due to effects on cortisol.37,38,39
However, there is as yet no direct evidence to support the claims that PS actually helps athletes build muscles more quickly and with less training effort.
Safety Issues
Phosphatidylserine is generally regarded as safe when used at recommended dosages. Side effects are rare, and when they do occur they usually consist of nothing much worse than mild gastrointestinal distress.40 One study found that use of phosphatidylserine did not alter results on standard medical screening tests.41 However, the maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established.
PS is sometimes taken with ginkgo because they both appear to enhance mental function. However, some caution might be in order: Ginkgo is a "blood thinner," and PS might be one as well. PS is known to enhance the effect of heparin, a very strong prescription blood thinner.42 It is possible that combined use of PS and any drug or supplement that thins the blood could interfere with normal blood clotting enough to cause problems. Some medications and supplements to consider include warfarin (Coumadin), aspirin, pentoxifylline (Trental), clopidogrel (Plavix), ticlopidine (Ticlid), garlic, ginkgo, and vitamin E.
Keep in mind, too, that Alzheimer's disease and other types of severe age-related mental impairment are too serious to treat on your own with PS or any other supplement. In some cases, the symptoms of these diseases may be a sign of other serious conditions. If you suspect that you or a loved one may have a severe age-related mental impairment, see your doctor for diagnosis and treatment.
Interactions You Should Know About
If you are taking
View References
Last reviewed March 2002 by Medical Review Board
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