Phosphatidylserine is a phospholipid (fat-soluble substance) that when taken as a supplement, is believed to play a role in improving cognitive abilities and memory.
Phosphatidylserine is required for healthy nerve cell membranes and myelin — the insulating, protective layer that forms around nerves, including those in the brain and spinal cord (1). Myelin allows electrical impulses to transmit efficiently along the nerve cells.
When the myelin is damaged, these impulses slow down. Aging of the human brain is associated with biochemical alterations and structural deterioration that impair neurotransmission, thus leading to age-related memory decline.
Phosphatidylserine supports several human cognitive functions, including the formation of short-term memory, the consolidation of long-term memory, the ability to create new memories, the ability to retrieve memories, the ability to learn and recall information, the ability to focus attention and concentrate, the ability to reason and solve problems and the ability to communicate (2).
It is important to note that modern research is focused on soy-derived or plant-derived phosphatidylserine. Much of the research performed until recently focused on bovine-derived phosphatidylserine. Due to concerns about the possibility of humans contracting infectious diseases (such as “mad cow” disease), bovine phosphatidylserine is not available in the U.S.
Phosphatidylserine may improve age-related cognitive decline. In one study, fifteen healthy elderly volunteers meeting Age Associated Memory Impairment inclusion were treated for 12 weeks with plant-source derived phosphatidylserine (100 mg x 3 times daily). They were evaluated at baseline, after 6 weeks of treatment and at the end of the trial.
Thirteen out of the 15 participants experienced a significant drug effect over time. There was an improvement from base line to week 6 and that effect was maintained at week 12 (3).
In another study performed on college-age males, researchers evaluated the effects of a phosphatidylserine containing formulation on cognitive function, mood and endocrine response before and after intense resistance exercise.
Researchers used the Serial Subtraction Test (5 minutes after, and 60 minutes after exercise) to evaluate cognitive function.
Supplementation for 14 days with soy-derived phosphatidylserine significantly reduced the time needed for a correct calculation on the test by 20 percent; reduced the total amount of errors by 39 percent; and increased the amount of correct calculations by 13 percent prior to or in response to exercise compared to placebo.
Supplementation did not appear to affect mood or endocrine response prior to or following resistance exercise (4).
Phosphatidylserine may improve memory in the elderly with memory complaints (not having dementia). In 2010, researchers evaluating the efficacy of a preparation of phosphatidylserine containing omega-3 long-chain polyunsaturated fatty acids (PS-DHA) were met with encouraging results.
A group of 131 participants were randomized to receive either PS-DHA or placebo for 15 weeks. At the end of the study, verbal immediate recall was significantly improved in the PS-DHA group compared to the placebo group.
Further analysis revealed that a subset of participants with relatively good cognitive performance at baseline had significant treatment-associated improvements in such areas as immediate and delayed verbal recall and learning abilities (5).
Phosphatidylserine may play a future role in the treatment of Alzheimer’s disease. The results of a 2014 study showed that a blend of phosphatidylserine and phosphatidic acid had a positive influence on memory, mood and cognition among elderly test subjects.
Short-term supplementation in patients with Alzheimer’s showed a stabilizing effect on daily functioning, emotional state and self-reported general condition. In addition, no negative side effects were reported (6).
In another study, researchers assessing the effects of phosphatidylserine in Alzheimer’s patients and rats were met with equally promising results.
In Alzheimer’s patients, vocabulary and picture matching scores in the treatment groups increased after supplementation. In addition, the scores in the treated group were significantly greater than the control group.
In the rats, supplementation decreased cholinesterase and improved hippocampal inflammation injury (7).
Phosphatidylserine may improve ADHD symptoms in children. Symptoms of attention-deficit/hyperactivity disorder (ADHD) include not being able to maintain focus, hyperactivity and impulsivity (8).
An estimated 8.4 percent of children and 2.5 percent adults have ADHD.
According to results of a study published in a 2014 issue of the Journal of Human Nutrition and Dietetics, supplementation resulted in significant improvements in inattention and impulsivity and short-term auditory memory.
The children participating in the group were 4-14 years old, and never received drug treatment for ADHD. Groups received either placebo or 200 mg a day of phosphatidylserine for two months (9).
There were no adverse side effects reported throughout the duration of the study.
Phosphatidylserine may enhance physical endurance in young, active men. In a study of active young men, supplementation with phosphatidylserine increased the time the men could exercise until exhaustion by approximately 25 percent.
In another double-blind study of active young men, supplementation with soybean-derived phosphatidylserine per day for 10 days, increased the time the men could exercise until exhaustion by approximately 25 percent (10).
Longer studies are needed to determine the efficacy and safety with continued supplementation (11).
Phosphatidylserine supplementation appears to be safe when taken in moderation and short-term.
According to the authors of a study published in Nutritional Neuroscience, soy-derived phosphatidylserine is a safe nutritional supplement for older persons if taken up to a dosage of 200 mg three times daily (12).
Doses over 300mg have caused stomach upset and insomnia (13).
The doses used in many of the human studies have not exceeded 600mg. The studies, however, were short-term.
More research is needed to fully understand the efficacy and safety of both short-term and long-term supplementation.
Phosphatidylserine is a fat-soluble substance found in high concentrations in the brain. When taken as a supplement, it is believed to play a role in improving cognitive abilities and memory.
Phosphatidylserine is required for healthy nerve cell membranes and supports several human cognitive functions, including memory, the ability to focus attention and reason and solve problems.
The results of studies performed so far show that supplementation may improve age-related cognitive decline, memory, ADHD symptoms and enhance physical endurance.
Short-term supplementation of up to 600mg a day does not appear to cause toxicity or adverse reactions. There have been some reports of insomnia and stomach upset when doses exceed 300mg.
Longer studies are needed to assess if and what side effects occur with long-term supplementation.