Review · Nutrients · 2023Conflicts declared

Pumpkin and walnut diet in one boy with autism

What it found

A boy with moderate autism improved over three years on a diet rich in pumpkin and walnuts, alongside a gluten- and casein-restricted diet, GABA supplements and therapy.

This is a single case report, so it cannot show that the diet caused the improvement.

What they found

Studies in people

CARS score change

Child-X's CARS score was 36 before the diet, which falls in the mild-to-moderate autism range. By age 13 it had reached 17, and he is now described as out of autism and in a regular school.

Speech and language

At four and a half, Child-X began to call his mother and say simple words. His mother recorded a remarkable improvement in speech going forward.

Animal and lab studies

Walnut peptides in cells

In lab tests on PC12 cells, walnut peptides reduced calcium entry and harmful oxygen molecules caused by glutamate, and protected the cells' mitochondria.

Pumpkin carotenoids in cells

In lab tests, astaxanthin from pumpkin protected nerve cells from glutamate stress by lowering calcium and harmful oxygen molecules. Lycopene reduced glutamate release from rat brain tissue.

Gut bacteria in animals

In animal studies, eating walnuts increased probiotic-type bacteria such as Lactobacillus and reduced bacteria linked to neuroinflammation. Pumpkin polysaccharide also shifted gut bacteria in ways that enriched species known to be lower in people with autism.

Mitochondria and urolithin A

Walnuts contain ellagitannins, which gut bacteria turn into urolithin A. This compound activates Nrf2 and AMPK pathways that help clear damaged mitochondria, based on lab and animal evidence.

What the authors conclude

“This case study does not support broad food treatments as a treatment for ASD, but it does imply that specialized dietary interventions over time may play a role in the management of certain ASD symptoms, functions, and clinical domains.”
El-Ansary A, Al-Ayadhi L, 2023

Also in their conclusions

  • They say this case study does not support broad food treatments as a treatment for autism.
  • They suggest that specialised dietary interventions over time may play a role in managing some autism symptoms, functions and clinical areas.
  • They propose that the pumpkin and walnut diet improved nutritional status and may have helped brain function by reducing oxidative stress, neuroinflammation, glutamate excitotoxicity, mitochondrial dysfunction and altered gut bacteria.

How it was done

The authors wanted to explore how a pumpkin- and walnut-rich diet might affect specific signalling pathways in autism, after a boy they knew improved considerably on this diet.

They followed one boy, Child-X, from age 2 years and 2 months to age 13. For over three years he ate pumpkin and walnuts daily, along with a gluten- and casein-restricted diet, GABA 500 mg/day for one year, and speech, behavioural and educational therapy twice a week. His autism severity was tracked with the Childhood Autism Rating Scale (CARS).

What it can’t tell you

  • This is a single case report, so it cannot show that the pumpkin and walnut diet caused the improvement.
  • The boy also had a gluten- and casein-restricted diet, GABA supplements and therapy, so the effects cannot be separated.
  • The mechanisms described come mostly from lab and animal studies, which cannot show what happens in people.

The paper

Title
Effects of Walnut and Pumpkin on Selective Neurophenotypes of Autism Spectrum Disorders: A Case Study
Type
ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
Evidence
Studies in people · animals · lab
Summarised from
Full text
Cite
El-Ansary A, Al-Ayadhi L (2023). Effects of Walnut and Pumpkin on Selective Neurophenotypes of Autism Spectrum Disorders: A Case Study. Nutrients. doi:10.3390/nu15214564Free full textPubMed 37960217DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error