Ginkgo nuts: the memory claim belongs to the leaf

The memory claims attached to ginkgo come from leaf extract, and in healthy people even the extract showed no significant effect. Across randomized trials in 1132 participants, the effect on memory was d = -0.04 (95% CI -0.17 to 0.07), with attention and executive function also close to zero. None of that research fed anyone the nuts. What is documented about the nuts themselves comes from case reports, and the reports describe poisoning. A 2-year-old girl had repeated convulsions after eating 20 to 30 seeds. That number is a poisoning report, not a portion, and it does not mark any smaller amount as safe for a child. A 2026 review of 703 published adverse events from 8 medicinal and edible seeds found 70.8% in children and 68.9% linked to excessive intake. Ginkgo seeds caused 29 of the 96 serious cases, though the abstract does not say how many of the 703 involved ginkgo. We found no trusted source that sets a safe number of nuts for anyone, so parents should not read any count on this page as safe for a small child: most of the reported harm is in children, and the reports describe poisoning.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• USDA's single composition record for raw ginkgo nuts lists 6 mg niacin, 0.274 mg copper and 0.328 mg vitamin B6 per 3.5 oz (100 g). It describes nutrients, not whether raw nuts are safe to eat. — US reference food record (n = 1 record) Evidence E source
  Per 100 g: niacin 6 mg; copper 0.274 mg; vitamin B6 0.328 mg

What your body absorbs

• Adults are not immune: a 51-year-old woman had a seizure and confusion after eating large amounts of ginkgo nuts, and her blood vitamin B6 was low. — One 51-year-old woman (n = 1) Evidence D source
  Generalized seizure and postictal confusion; low blood B6

What cooking and storage change

• For boiled nuts, the USDA retention table keeps 95% of niacin and vitamin B6 and all of the copper, so boiling costs ginkgo nuts little of these nutrients. — USDA retention factors for the group Nut and Seed Products, the group ginkgo nuts belong to Evidence E source
  Retn_Code 2204 NUTS,BOILED: niacin 95%, vitamin B6 95%, copper 100%
• In laboratory tests, drying ginkgo seeds cut their ginkgotoxin about fourfold compared with fresh seeds. — Ginkgo biloba seeds dried by 4 methods, laboratory Evidence D source
  Ginkgotoxin reduced about fourfold by drying

What people believe that the data does not support

• The memory claims attached to ginkgo come from leaf extract, and even that showed no significant effect in healthy people: memory effect size d = -0.04 across 1132 participants. — Healthy individuals in RCTs of Ginkgo biloba extract (n = 1132) Evidence A source
  Memory d = -0.04 (95% CI -0.17 to 0.07); executive function and attention near zero
• Anti-inflammatory findings for ginkgo concern leaf extract pills: across 17 trials and 1104 people, CRP fell by 1.5 mg/L, which says nothing about eating the nuts. — 1104 participants in 17 trials of Ginkgo biloba leaf extract, 1-24 weeks (n = 1104) Evidence A source
  CRP WMD -1.5 mg/L (95% CI -2.16 to -0.85)

Who this works differently for

• A 2-year-old boy vomited and had a convulsion 4 hours after eating a large number of roasted ginkgo nuts. — One 2-year-old boy, Japan (n = 1) Evidence D source
  Vomiting and afebrile convulsion 4 h after ingestion
• A 2026 review of 703 adverse events from edible seeds found 70.8% were in children, and ginkgo seeds caused 29 of the 96 serious cases. — 703 published adverse event reports for 8 medicinal and edible seeds (n = 703) Evidence D source
  70.8% in children; 68.9% excessive intake; ginkgo 29 serious cases
• In one reported poisoning case, a 2-year-old girl had repeated convulsions after eating 20 to 30 ginkgo seeds. The report does not show that fewer seeds are safe. — One 2-year-old girl (n = 1) Evidence D source
  Repetitive tonic-clonic convulsions after 20-30 seeds

The bottom line

Adults are not exempt. A 51-year-old woman had a generalized seizure and confusion after eating large amounts of ginkgo nuts, and her blood vitamin B6 was low. A 2-year-old boy in Japan vomited and had a convulsion 4 hours after eating a large number of roasted nuts. In both reports the amount was not measured, and single cases cannot tell you how often this happens. Some people should be careful. Children account for most of the reported harm. The one toddler case with a count, 20 to 30 seeds, describes a poisoning, and nothing in the reports shows that fewer seeds are safe for a child. We have no evidence card on pregnancy, breastfeeding or interactions with medicines, so this page cannot tell you anything about them. In a laboratory study, drying the seeds cut their ginkgotoxin about fourfold compared with fresh seeds, a result that still does not set a safe number to eat. As food, USDA has a single record for raw ginkgo nuts: per 3.5 oz (100 g), 6 mg niacin, 0.328 mg vitamin B6 and 0.274 mg copper. That record describes nutrients only and says nothing about whether raw nuts are safe to eat. The laboratory study above found more ginkgotoxin in fresh seeds than in dried ones, and we have no evidence card on how to prepare the nuts safely. Its retention factors for boiled nuts, set for nuts as a group and not for ginkgo by name, keep 95% of the niacin and B6 and all of the copper. Anti-inflammatory claims also come from leaf extract pills. Across 17 trials of 1 to 24 weeks in 1104 people, C-reactive protein fell by 1.5 mg/L (95% CI -2.16 to -0.85), in trials that differed widely and that gave nobody a nut.

Sources

1. gink-daily-r8-01 · dataset
   Nuts, ginkgo nuts, raw | FDC 170584 | per 100 g: niacin 6 mg, copper 0.274 mg, vitamin B6 0.328 mg
   USDA FoodData Central, SR Legacy 2018, Nuts, ginkgo nuts, raw (FDC 170584) · checked 2026-10-01
2. gink-daily-r8-04 · case report
   We experienced a case of a 51-year-old female patient with generalized tonic clonic seizure and postictal confusion after eating large amounts of ginkgo nuts. Blood vitamin B6 level was decreased.
   J Epilepsy Res, 2015 · checked 2026-10-01
3. gink-daily-r8-02 · dataset
   USDA-RETN-R6:2204 | Nut and Seed Products | NUTS,BOILED,W/DRIPPINGS | niacin 95%, vitamin B6 95%, copper 100%
   USDA Table of Nutrient Retention Factors, Release 6, 2007, Retn_Code 2204 · checked 2026-10-01
4. gink-daily-r8-09 · laboratory analysis
   Ginkgotoxin was reduced fourfold, and the contents of acrylamide, ginkgolic acid and cyanide in dried G. biloba seeds were reduced to the scope of safety.
   Journal of the Science of Food and Agriculture, 2021 · checked 2026-10-01
5. gink-daily-r8-05 · meta-analysis
   Effect sizes were non-significant and close to zero for memory (d = -0.04: 95%CI -0.17 to 0.07), executive function (d = -0.05: 95%CI -0.17 to 0.05) and attention (d = -0.08: 95%CI -0.21 to 0.02).
   Hum Psychopharmacol, 2012 · checked 2026-10-01
6. gink-daily-r8-06 · meta-analysis
   Trials were of 1-24 weeks of duration and included 1,104 participants. In the meta-analysis, the weighted mean differences (WMD) in change for serum CRP were -1.5 mg/L (95% CI: -2.16, -0.85, p < 0.001).
   Phytother Res, 2022 · checked 2026-10-01
7. gink-daily-r8-03 · case report
   The patient presented with vomiting and afebrile convulsion 4 hours after eating a large number of roasted gingko nuts.
   Pediatr Neurol, 2006 · checked 2026-10-01
8. gink-daily-r8-07 · systematic review of case reports
   Among the AEs, 70.8% occurred in children, and 68.9% were associated with excessive intake...Ninety-six were classified as serious; these were caused by Ginkgo semen (29 cases), Armeniacae semen amarum (60 cases), Persicae semen (4 cases), Canavaliae semen (2 cases), and Myristicae semen (1 case).
   Integrative Medicine Research, 2026 (systematic review of seed adverse events) · checked 2026-10-01
9. gink-daily-r8-08 · case report
   A 2-year-old girl required medical attention for a sudden onset of repetitive tonic-clonic convulsions after ingesting 20-30 ginkgo seeds.
   Brain & Development, 2019 · checked 2026-10-01