Table 2.
Randomized controlled trials of nuts with outcomes on cognitive performance in adults.
| Author, Year | Study Design (Source) |
N | Age (Years) | Participant Characteristics |
Neuro-Psychological Tests |
Nut Dose/Day (Range) |
FU | Outcome |
|---|---|---|---|---|---|---|---|---|
| Martinez- Lapiscina, 2013 [55] |
Parallel (Sub-sample of PREDIMED study) |
522 | 55–80 | Men & women at high cardiovascular risk | MMSE and Clock Drawing Test (Administered once at the end of the study) |
Mixed nuts, 30 g with MedDiet |
6.5 years |
MedDiet + nuts: better global cognition compared to control diet. |
| Valls-Pedret, 2015 [56] | Parallel (Sub-sample of PREDIMED study) |
334 | 55–80 | Men & women at high cardiovascular risk | Tests of memory, executive function, global cognition (Administered at baseline and end of study) | Mixed nuts, 30 g with MedDiet |
4.1 years |
MedDiet + nuts: better memory and a tendency to improved executive function and global cognition compared to control diet. |
| Barbour, 2017 [57] | Crossover | 61 | Mean 65 | Men and women with overweight/obesity | Tests of memory, executive function, and processing speed | High-oleic acid peanuts, 56–84 g | 12 weeks |
Short-term memory and verbal fluency improved with the peanut diet compared to control diet. |
| Dhillon, 2017 [58] | Parallel | 86 | Mean 31 | Men and women with overweight/obesity | Tests of memory and attention | Almonds, dry-roasted at 15% energy | 12 weeks |
Cognition similarly improved with the almond and control diets. |
| Sala-Vila, 2020 [59] |
Parallel (WAHA study) |
708 | 63–79 | Cognitively healthy | Complete test battery | Walnuts at 15% energy | 2 years |
No effect on cognitive scores in the whole cohort. |
| Mustra Rakic, 2022 [60] |
Parallel | 60 | 50–75 | Healthy adults | CANTAB | Almonds/day: 1.5 oz, 3 oz or 3.5 oz snacks |
6 months |
No among-group changes in cognitive measures. |
Abbreviations: CANTAB, Cambridge neuropsychological test automated battery: taps several cognitive domains, including memory, processing speed, and attention; FU, follow-up; MedDiet, Mediterranean diet; MMSE, Mini-Mental State Examination; N, number of study participants; PREDIMED, PREvención con DIeta MEDiterránea. WAHA, Walnuts And Healthy Aging trial.