Dietary fish hydrolysate improves episodic memory in healthy elderly with lower level of memory performance: a double-blind, randomized, placebo-controlled clinical study

Mathilde Chataigner, Adrien Peltier, Elodie Bouvret, Anne-Laure Dinel, Corinne Joffre, Véronique Pallet
The American Journal of Clinical Nutrition. 2026-05-01; : 101360
DOI: 10.1016/j.ajcnut.2026.101360

Chataigner M(1), Peltier A(2), Bouvret E(3), Dinel AL(2), Joffre C(4), Pallet V(5).

Author information:
(1)Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, UMR1286, Bordeaux,
France; Abyss Ingredients, ZA de Kergoussel, Caudan, France.
(2)Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, UMR1286, Bordeaux,
France; Cellule de transfert NutriBrain, Bordeaux, France.
(3)Abyss Ingredients, ZA de Kergoussel, Caudan, France.
(4)Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, UMR1286, Bordeaux,
France. Electronic address: .
(5)Université de Bordeaux, INRAE, Bordeaux INP, NutriNeuro, UMR1286, Bordeaux,
France.

BACKGROUND: Aging is characterized by cognitive decline, including episodic and
working memory impairments, which can lead to loss of autonomy. Among older
adults, one quarter, referred to here as « decliners, » show greater-than-average
cognitive decline for their age group without reporting memory complaints. To
prevent or slow this accelerated decline and maintain a good quality of life in
seniors, nutrition represents a promising approach.
OBJECTIVES: This study evaluates the effect of a 3-mo fish hydrolysate (FH)
supplementation on memory performance in healthy older adults identified as
decliners. The primary outcome of this study was the Paired Associates Learning
Total Error Adjusted (PALTEA) score, assessing episodic memory.
METHODS: In this double-blind, randomized, placebo-controlled trial, 53 healthy
older adults (60-73 y; Mini-Mental State Examination >27; PALTEA ≥41) received
either FH [1 g of low-molecular-weight peptides and 30 mg n-3 (ω-3) long-chain
polyunsaturated fatty acids (PUFAs)] or placebo daily for 3 mo. Cognitive
performance was assessed using the Cambridge Neuropsychological Test Automated
Battery. Statistical analyses were performed using analysis of covariance,
adjusting for baseline values, age, and education level, with significance set
at P < 0.05.
RESULTS: FH supplementation significantly improved PALTEA scores compared with
placebo [P = 0.003; β = -11.75; confidence interval (CI): -19.30, -4.19], with
more patterns completed (P < 0.001; β = 1.34; CI: 0.58, 2.09) and fewer errors
at higher levels (6 and 8 patterns; P = 0.040; β = -3.66; CI: -7.15, -0.17, and
P = 0.004; β = -5.74; CI: -9.60, -1.89). Working memory showed partial
improvement, notably the spatial working memory strategy score (P = 0.018; β =
-1.26; CI: -2.31, -0.22). Verbal recognition did not differ between groups. FH
supplementation increased erythrocyte n-3 PUFA levels (P = 0.036; β = 0.80; CI:
0.05, 1.54), and reduced serum C-reactive protein levels (P = 0.038; β = -0.33;
CI: -0.63, -0.02) and inflammation status score (P = 0.046; β = -0.35; CI:
-0.69, -0.01).
CONCLUSIONS: Three months of FH supplementation improved episodic memory and
working memory in older adults with accelerated cognitive decline, alongside a
better n-3 PUFA profile and reduced inflammation, supporting FH as a promising
strategy to promote healthy cognitive aging. This trial was registered at
clinicaltrials.gov as NCT04910399.

DOI: 10.1016/j.ajcnut.2026.101360
PMID: 42162916

Conflict of interest statement: Conflict of interest EB, implicated in the
BrainBooster project, reports that financial support was provided by Public
Investment Bank France and the Région Bretagne. MC and EB are funded by Abyss
Ingredients. The other authors report no conflicts of interest.