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Phosphatidylserine and memory: grade C

Limited evidence. Direction: No effect.

C LimitedIndustry-funded

Educational guidance, not medical advice

Why this grade

Rubric condition met: C: results only in clinical/older populations being extrapolated to healthy adults (A and B not met: no meta-analysis; soy-PS RCTs inconsistent)

The positive placebo-controlled trials (149 adults with age-associated memory impairment; 494 older patients with cognitive decline) used bovine-cortex PS, which FDA says may not be the same substance as soy PS. The 120-person soy-PS RCT found no differences on any outcome; a 78-person soy-PS RCT found no group difference overall, only within-group gains in a low-baseline subgroup; a PS-DHA RCT found one measure improved. All trials are in older or clinical populations, and most soy and PS-DHA trials were run or funded by ingredient makers. The evidence is dated (the positive bovine-cortex trials are from 1991 and 1993) and comes only from older or clinical populations, which caps the grade at C.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)199019952000200520102015RCTControlled trialOpen-label studyCenacchi 1993, 1993: RCT, n = 494, result not recordedVakhapova 2010, 2010: RCT, n = 157, result not recordedCrook 1991, 1991: controlled trial, n = 149, result not recordedJorissen 2001, 2001: RCT, n = 120, result not recordedKato-Kataoka 2010, 2010: RCT, n = 78, result not recordedRichter 2013, 2013: open-label study, n = 30, result not recorded
each study this grade rests on, by publication year and design. Solid: effect versus the comparator; half-filled: mixed; hollow: no effect; dashed: result not recorded yet. Larger marks had more participants.
Show the numbers
StudyYearDesignParticipantsResult
Crook 19911991controlled trial149result not recorded
Cenacchi 19931993RCT494result not recorded
Jorissen 20012001RCT120result not recorded
Vakhapova 20102010RCT157result not recorded
Kato-Kataoka 20102010RCT78result not recorded
Richter 20132013open-label study30result not recorded

Phosphatidylserine containing omega-3 fatty acids may improve memory abilities in non-demented elderly with memory complaints: a double-blind placebo-controlled trial.

Vakhapova V, Cohen T, Richter Y. Phosphatidylserine containing omega-3 fatty acids may improve memory abilities in non-demented elderly with memory complaints: a double-blind placebo-controlled trial Dement Geriatr Cogn Disord, 2010. PMID 20523044

Result not recorded
Design
Double-blind, placebo-controlled RCT, 15 weeks (PS-DHA)
Sample
n = 157
Population
Non-demented older adults with memory complaints
Funding
not stated in abstract; the companion safety report of the same trial (S22) states it was funded by Enzymotec

The effect of soybean-derived phosphatidylserine on cognitive performance in elderly with subjective memory complaints: a pilot study.

Richter Y, Herzog Y, Lifshitz Y. The effect of soybean-derived phosphatidylserine on cognitive performance in elderly with subjective memory complaints: a pilot study Clin Interv Aging, 2013. PMID 23723695

Result not recorded
Design
Open-label pilot study without placebo group, 12 weeks
Sample
n = 30
Population
Older adults aged 50-90 with memory complaints
Funding
not stated; all authors Enzymotec employees

Soybean-derived phosphatidylserine improves memory function of the elderly Japanese subjects with memory complaints.

Kato-Kataoka A, Sakai M, Ebina R. Soybean-derived phosphatidylserine improves memory function of the elderly Japanese subjects with memory complaints J Clin Biochem Nutr, 2010. PMID 21103034

Result not recorded
Design
Double-blind RCT, 6 months (soy PS, 100 or 300 mg/day)
Sample
n = 78
Population
Japanese adults aged 50-69 with memory complaints (described as mild cognitive impairment)
Funding
not stated; authors employed by Yakult, which made the test product

The influence of soy-derived phosphatidylserine on cognition in age-associated memory impairment.

Jorissen BL, Brouns F, Van Boxtel MP. The influence of soy-derived phosphatidylserine on cognition in age-associated memory impairment Nutr Neurosci, 2001. PMID 11842880

Result not recorded
Design
Randomized, placebo-controlled trial, 12 weeks (soy PS, 300 or 600 mg/day)
Sample
n = 120
Population
Adults over 57 with age-associated memory impairment
Funding
not stated

Cognitive decline in the elderly: a double-blind, placebo-controlled multicenter study on efficacy of phosphatidylserine administration.

Cenacchi T, Bertoldin T, Farina C. Cognitive decline in the elderly: a double-blind, placebo-controlled multicenter study on efficacy of phosphatidylserine administration Aging (Milano), 1993. PMID 8323999

Result not recorded
Design
Double-blind, placebo-controlled multicentre RCT, 6 months (bovine-cortex PS)
Sample
n = 494
Population
Elderly patients aged 65-93 with moderate to severe cognitive decline (clinical population)
Funding
not stated

Effects of phosphatidylserine in age-associated memory impairment.

Crook TH, Tinklenberg J, Yesavage J. Effects of phosphatidylserine in age-associated memory impairment Neurology, 1991. PMID 2027477

Result not recorded
Design
Placebo-controlled trial, 12 weeks (bovine-cortex PS)
Sample
n = 149
Population
Adults meeting criteria for age-associated memory impairment
Funding
not stated

Search and history

Search (): phosphatidylserine[ti] AND (memory[tiab] OR cognitive[tiab] OR cognition[tiab]) AND randomized controlled trial[pt] AND humans[mh]

  • Graded C (proposed): Proposed in the monograph draft
  • C to C (proposed): Updated in the monograph draft
  • C to C (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page