Nutritional Strategies to Preserve Memory and CognitionFebruary 2007
By Laurie Barclay, MD
Phosphatidylserine: A Versatile Memory Enhancer
Phosphatidylserine plays an extraordinarily varied role in supporting brain health. It enhances the availability of acetylcholine,33 lowers levels of the stress hormone cortisol, and promotes the release of dopamine, an important neurotransmitter known to improve mood and movement control.
Phosphatidylserine also supports the function of many vital enzymes, acts as an antioxidant to combat free-radical damage, and quells inflammation that can exert deleterious effects in the brain.34 In Europe and Japan, phosphatidylserine is sold as a prescription drug to treat memory and learning dysfunction, but it is available as a nutritional supplement in the United States.
Humans manufacture phosphatidylserine to maintain the structure and function of cell membranes, but its production in the body declines with advancing age. Aged rats with cognitive deficits have demonstrated decreased phosphatidylserine in the hippocampus,35 and subjects with a genetically determined type of cognitive deficit exhibit low phosphatidylserine levels in nerve cell membranes.36
When aged rats were given phosphatidylserine for two months, their performance on an age-related memory impairment test improved significantly, indicating better memory function. Phosphatidylserine supplementation restored the rats’ acetylcholine release and energy metabolism in nerve endings to levels typically seen in young rats.37
Further animal studies suggest that phosphatidylserine acts as an antidepressant agent.38 This finding could have far-ranging implications for elderly humans, in whom depression is often confused clinically with cognitive impairment.
By stimulating acetylcholine production,39 phosphatidylserine has proven useful in clinical trials of patients with cognitive impairment.5 These include an open study in patients with age-related cognitive decline,40 well-controlled, randomized trials in patients with senile dementia,41 and a study in Alzheimer’s patients who exhibited the stiffness and rigidity associated with Parkinson’s disease.42
A review of the available research indicates that while phosphatidylserine may help improve memory in elderly patients,43 its effects may be most pronounced in early cognitive impairment44—an observation that underscores the vital importance of beginning supplementation with brain-nourishing nutrients like phosphatidylserine early in life.
A leading scientist at the Alzheimer’s Prevention Foundation has suggested that phosphatidylserine may be a useful component in a lifestyle and nutrition program aimed at preventing Alzheimer’s disease.45 He concludes that memory loss is not an inevitable consequence of aging, and that Alzheimer’s can be prevented or reversed using an integrated approach that includes phosphatidylserine and other brain-supportive nutrients.
Although phosphatidylserine is generally safe and well tolerated,46,47 it may increase the blood-thinning effect of heparin, and therefore should not be used with medications that thin the blood without consulting a physician.48
Phosphatidylserine and DHA: Synergistic Support for Brain Cells
Phosphatidylserine may be even more beneficial for brain and nervous system health when coupled with the omega-3 fatty acid DHA.
DHA is a major structural and functional component of the central nervous system, accounting for 30-50% of the total fatty acid content of the human brain. In infants and children, DHA is essential for the brain’s growth and functional development. It also helps support normal brain function in adults, including learning and memory. Low levels of DHA, by contrast, are associated with an increased risk for Alzheimer’s.49
In the brain, DHA combines enzymatically with phosphatidylserine to form nerve cell membrane components that support healthy nerve function. Substantial laboratory research suggests that phosphatidylserine’s ability to improve cognitive skills is greatly increased in the presence of DHA.50
Furthermore, the combination of DHA and phosphatidylserine powerfully supports energy production in brain cells. Scientists from the National Institutes of Health believe that phosphatidylserine with attached DHA is among the most critically important molecules for healthy brain function, and that phosphatidylserine works optimally in the presence of abundant levels of DHA.51
Researchers have developed an innovative phosphatidylserine-DHA (PS-DHA) compound designed to optimally support brain cell structure and function. To evaluate its effects on memory, they examined middle-aged rats with accelerated brain aging. While DHA alone showed minimal effects, PS-DHA substantially protected against the memory-robbing effects of brain aging.52
This unique combination of PS-DHA was also examined in a randomized, double-blind, placebo-controlled study of people with attention deficit hyperactivity disorder (ADHD). At the end of three months, those receiving the PS-DHA compound had a total response to treatment of 47%, compared to just 19% in the placebo group. These findings suggest that the phosphatidylserine-DHA combination may improve behavioral and learning disabilities in ADHD patients.52
Vinpocetine: Enhancing Cerebral Blood Flow
The brain health benefits of vinpocetine, derived from the periwinkle flower, are widely recognized in Europe, where it is available only by prescription to treat symptoms of age-related memory impairment.
By improving sluggish cerebral blood flow, vinpocetine enhances the brain’s use of oxygen and glucose.53 Vinpocetine also increases electrical conductivity between nerve cells and supports the activity of nerve pathways related to mental alertness.54 When combined with the popular herb ginkgo biloba, vinpocetine speeds the processing of short-term working memory in normal adults.55
By enhancing vasodilation (relaxation of blood vessels), vinpocetine offers targeted benefits for cognitive dysfunction related to vascular disease involving vessels that supply the brain with blood.5 In three studies of older adults with memory impairment related to poor brain circulation or dementia, vinpocetine produced significantly more improvement than placebo in tests of attention, concentration, and memory.43
In a well-controlled trial of 203 patients with mild-to-moderate dementia, 30 or 60 mg of vinpocetine taken daily for four months was deemed safe and was associated with substantial improvements relative to placebo in ratings of overall status, cognitive performance, and severity of illness.56
By interfering with blood clotting at several points during the chain reaction that ultimately causes ischemic stroke, vinpocetine may even protect high-risk individuals from this devastating disease.57 Vinpocetine appears to work by blocking the activation of voltage-sensitive channels for calcium and sodium,58 and by preventing release of potentially toxic glutamate and free radicals.59,60
Because vinpocetine may inhibit blood clotting, it should not be used with Coumadin® or other blood thinners, except under a doctor’s recommendation.