Phosphatidylserine (PS)
This naturally occurring fat may help slow memory loss in older adults?plus improve mood and ease stress

By Victoria Dolby Toews, MPH

What it is
Phosphatidylserine, or PS, is a fat that facilitates communication among brain cells to aid memory and cognitive function. The highest concentration of PS is found in the brain?s cell membranes.

Where it comes from
The body makes its own supply of PS, which naturally declines as we age. Because PS can be found only in small amounts in certain foods, including soy, rice, egg yolks, and green leafy vegetables, dietary supplements of phosphatidylserine can replenish the body?s supply. The supplements are derived from soy.

Why it?s used
Most people take PS because they are concerned about age-related cognitive decline, a normal part of the aging process. Primary signs of this decline include memory problems, less aptitude for learning new information, and difficulty concentrating. PS may also slow the progression of Alzheimer?s disease, improve mood, and reduce stress.

How it works
Phosphatidylserine controls several functions of brain cells, such as the reception of messages from other cells and the release of nerve transmitters. By improving the function of individual brain cells, PS enhances cognitive performance and memory.

Scientific support
The most well-researched health application for PS is for the preservation and boosting of cognitive function in older individuals. Clinical trials conducted at the Memory Assessment Clinics in Bethesda, Maryland, documented phosphatidylserine?s ability to improve cognitive function as measured by tests of learning and memory tasks of daily life (Neurology, 1991, vol. 41, no. 5). And though PS is by no means a cure for Alzheimer?s disease, exciting evidence indicates it may forestall some early symptoms of the disease and perhaps decelerate its progression (Dementia, 1994, vol. 5, no. 2).

PS also has been shown to lift mood in elderly populations. One study of ten elderly, depressed women showed improved emotional functioning and decreased anxiety and irritability after just one month of treatment with the supplement (Acta Psychiatrica Scandinavica, 1990, vol. 81, no. 3). PS may also play a role in stress management. It has been shown to slow the release of the stress hormone cortisol during times of anxiety (European Journal of Clinical Pharmacology, 1992, vol. 42, no. 4; Neuroendocrinology, 1990, vol. 52, no. 3).

Phosphatidylserine supplements are available as capsules, gelcaps, and tablets.

PS should be taken daily in the same amount: 100 mg three times per day.

A month?s supply of phosphatidylserine (taking the standard 300 mg daily dose) is about $65. Most bottles of PS contain 30 pills of 100 mg each.

Side effects
No known safety concerns or medication interactions exist with phosphatidylserine.

Much of the existing PS research cited here was based on phosphatidylserine derived from cow brains, which is no longer used because of the risk of mad cow disease. Instead, soy-derived PS is the only kind now available to consumers. Slight differences between the two forms may exist, although emerging research comparing cow PS and soy PS is showing similar health effects (Journal of Nutrition, 2001, vol. 131, no. 11).

Oregon-based writer Victoria Dolby Toews, MPH, is the author of User?s Guide to Glucosamine and Chondroitin (Basic Health Publications, 2002).