Table 3.
Summary of interventions assessing the effect of fruit supplementation on cognition and mood.
| Reference | Study design | Sample (sample at baseline/N, age (years), male (%), mean BMI (kg/m2), health status) | Intervention type, dose and duration | Cognitive tasks | Effects of intervention | Overall risk of bias |
|---|---|---|---|---|---|---|
| Ahles et al. [49] | Double-blind, placebo-controlled, parallel RCT | N = 35; 53 ± 1 years old; male 32%; BMI 29.5 ± 0.4; healthy | 90 mg Aronia melanocarpa, a berry extract (AME) capsule consisted of 16 mg anthocyanins; 150 mg AME consisted of 27 mg anthocyanins; Maltodextrin containing capsules (150 mg) were used as placebo; 24 weeks | Pegboard dominant hand score; Pegboard non-dominant hand score; Total correct—total incorrect; Total edited—total incorrect and missed; Stroop Interference; Mood (T-Scores); BDNF | AME improved psychomotor speed compared to placebo (90 mg AME: change = −3.37; P = 0.009). Attention, cognitive flexibility, BDNF, and mood were not affected. | Moderate |
| Bowtell et al. [45] | Double-blind, parallel-group RCT | N = 12; 67.5 ± 3.0 years old, male 58.33%; BMI 25.9 ± 3.3; | 30 ml blueberry (BB) concentrate (blueberry active) providing 387 mg anthocyanidins, 12 weeks, isoenergetic synthetic blackcurrant and apple cordial as control | Detection Task, Groton maze timed chase test and learning test, sequential letter 1-back and 2-back tasks, fMRI, serum sample | Improved executive function (Groton maze learning task accuracy). Also improved task-related brain activation (Brodman areas, presumes, anterior cingulate, insula and thalamus regions) | Low |
| Boespflug et al. [46] | Double-blind, parallel-group RCT | N = 8; 75.5 ± 4.8 years; male 37.5%; BMI 26.2 ± 3.6; age-related memory decline. | Blueberry powder: 12.5*2 g equivalent to 148 g whole blueberry, 16 weeks, placebo powder: 12*2 g | Sequential letter n-back tasks, fMRI | Trend for improving working memory at larger sample size (effect size d = 1.02). Also increased BOLD activation in the left pre-central gyrus, left middle frontal gyrus, and left inferior parietal lobe during tasks after BB treatment. | Moderate |
| Calapai et al. [51] | Parallel RCT | N = 57; 56–75 years; male 48.2%;BMI 23.2 ± 1.0; healthy. | 250 mg/d Cognigrape-V. vinifera fruit extracted powder and maltodextrin (30–40%), 12 weeks, placebo was composed of maltodextrin | MMSE score, BDI, HARS, RBANS | Improved attention, language, immediate and delayed memory. Supplementation also produced a significant reduction in BDI ( − 15.8%) and HARS ( − 24.9%) scores with respect to baseline levels (p < 0.0001) and placebo (p < 0.0001 for BDI and p < 0.05 for HARS. | Moderate |
| Chai et al. [41] | Parallel RCT | N = 17; 70.0 ± 3.7 years; male 40%; BMI 28.5 ± 3.7; older adults with normal cognitive function | 480 ml tart cherry juice (68 ml Montmorency tart cherry juice concentrate was diluted with 412 ml water) per day for 12 weeks; placebo consisted of mixing unsweetened black cherry flavoured Kool-Aid (Kraft Foods, United States) with water. Dextrose and fructose were added to match the carbohydrate content found in tart cherry | Memory ability, Memory contentment, Memory strategy, digit span, PAL first trial memory, PAL total errors adjusted, RTI movement time, RTI reaction time, RVIP A, RVIP mean latency, SWM strategy, SWM total error | Increased subjective memory in the domain of contentment with memory by 5% and reduced movement time by 4% in comparison with the control drink. Also reduced errors in episodic visual memory by 23% compared to control drink as assessed by PAL task. | High |
| Crews et al. [44] | Double-blind, parallel-group RCT | N = 24: 69.28 ± 6.45 years; male 42%; BMI N/A; healthy. | 909 ml/d 27% cranberry juice for five weeks, placebo drink | Immediate free recall, long term storage, short-term recall, long-term retrieval, consistent long-term retrieval, random long-term retrieval, cued recall, delayed free recall, delayed recognition, Faces I, Faces II, Digit symbol, Part A, Part B, Word page, colour page, colour-word page | A nonsignificant trend (P = 0.123) observed for twice as many subjects of subjective, self-report improved memory in cranberry group compared to placebo controls. | Moderate |
| Lamport et al. [43] | Double-blind, randomized crossover design | N = 25; 43.2 ± 0.6 years; male 0%; BMI 24.6 ± 0.5; healthy. | 355 ml/d concord grape juice, 6 weeks and 12 weeks, energy-, taste-, and appearance-matched placebo | VVLT and VSLT IR & DR, RVIP, Grooved Pegboard, Tower of Hanoi, SBP, DBP, Subjective Mood, Driving performance | Better immediate spatial memory and aspects of driving performance after GJ intake. No difference in mood between groups | Low |
| Kean et al. [57] | Double-blind, randomized, crossover | N = 37; 66.7 ± 5.3 years; male 35.13%; BMI 26.1 ± 1.1; healthy. | High-flavanone (305 mg) 100% orange juice, 500 ml/d for 8 weeks, equicaloric low-flavanone (37 mg) orange-flavoured cordial (500 mL) as control | SBP, DBP, DSST, DSST dual, Go-NoGo RT, LF, LM, Serial Sevens, CERAD Immediate and Delayed, SWM, Immediate and Delayed VPA, PANAS Positive and Negative Affect Scale | Improved cognition (significant drink x visit interaction for global cognitive function and executive function). No effect on mood and BP. | Low |
| Kent et al. [50] | Parallel RCT | N = 24; 78.9 ± 5.2 years; male 51%; BMI 25.7 ± 3.4; mild to moderate dementia. | 200 ml/d cherry juice, 12 weeks, flavonoid-devoid apple juice as control | RAVLT, SPOT, Boston naming test, TMT, Digit Span Backwards Task, Category and Letter Verbal Fluency, SBP, DBP, serum sample | Improved cognition in memory and executive function and reduced SBP of 7.7 mmHg after juice treatment. No effect on Vitamin C and inflammatory markers. | Low |
| Krikorian et al. [59] | Parallel double-blind RCT | N = 11; 76.9 ± 6.1 years; male 52.38%; BMI N/A; mild cognitive impairment | 100% Concord grape juice 6.3–7.8 mL/ kg/d, 3 portions daily, 16 weeks, placebo beverage. | CVLT, GDS, fMRI, SBP, DBP | Attenuated cognitive error (5.03 vs 7.16 interference errors on recognition memory task) and great activation in right superior parietal cortex and right middle frontal cortex regions after juice treatment. No effect on mood and BP. | Moderate |
| Krikorian et al. [60] | Parallel double-blind RCT | N = 5; 78.2 ± 5.0 years; male 66.67%; BMI N/A; older adults with early memory decline but not dementia. | 100% Concord grape juice, 6 and 9 ml/kg/d, 3 portions daily, 12 weeks, placebo beverage. | CVLT, SPALT, GDS, glucose and insulin | Improved memory and insulin level after juice treatment. No effect on mood. | Moderate |
| Lee et al. [52] | Parallel double-blind placebo controlled RCT | N = 5; 72.2 ± 4.7 years; male 50%; BMI N/A mild cognitive decline. | Grape formulation ---freeze-dried grape powder in 8 oz. water, 72 g/d (3 standard servings daily), 6 months, placebo formulation matched in appearance, flavour, smell, volume and content of fructose and glucose but free of polyphenols | ADAS-Cog, MMSE, Hopkins Verbal Learning Test-Revised, Benton Visual Retention Test, Rey-Osterreith CFT, Boston Naming Test, LF, Category Fluency, Stroop, TMT Parts A and B, Wisconsin Card Sorting Test-64, WAIS-III Tasks, Wechsler Test of Adult Reading, Memory Functioning Questionnaire, Hamilton Mood Scales, Neuroimaging sVOI | Attenuated decline in brain metabolites at regions of right posterior cingulate cortex and left superior posterolateral temporal cortex and improved correlated attention after grape treatment. No effect on mood. | Moderate |
| Miller et al. [48] | Parallel double blind placebo-controlled RCT | N = 18; 67.8 ± 4.6 years; male 28%; BMI 24.1 ± 3.7; age-related motor and cognitive decline. | 24 g/d freeze-dried blueberry powder. 90 days, placebo powder | CVLT, ANT, DS, TMT, TST, wMWM, GDS, POMS | Attenuated cognitive error and improved executive function after blueberry treatment. No effects on mood. | Low |
| Morehen et al. [58] | Cross over single blind RCT | N = 11; 18 ± 1 years; male 100%; BMI 27.83 ± 2.51; professional rugby league players | 60 mL cherry concentrate (30 mL*2) in 100 mL water, placebo drink commercially available fruit cordial, mixed with water and maltodextrin, matched for energy and carbohydrate content daily intake for 1 week. | Self-reported subjective wellness including rating of perceived sleep quality, fatigue, muscle soreness, mood and stress using a 1–5 Likert scale. | No significant changes in sleep, fatigue or mood (P > 0.05) were observed pre to post-match or between groups | Moderate |
| Schrager et al. [47] | Parallel RCT | N = 13; 69.5 ± 9.3 years; male 45%; BMI 26.4 ± 3.9; healthy | 6-cup (48 ounce (1.4 kg))/week frozen blueberries, 6 weeks, placebo/carrot juice with low anthocyanins contents | Grip strength, SRT, adaptive gait tests, TMT-B | Reduced errors (76.9% vs 57.1% of participants in BB vs Control had reduced errors) and improved mobility after BB treatment. | Moderate |
| Whyte et al. [61] | Parallel double blind placebo-controlled RCT | N = 29; 70.8 ± 3.88 years; male 38.50%; BMI 27 ± 4; healthy. | 500 mg, 1000 mg blueberry powder or 111 mg purified blueberry extract for 24 weeks, colour matched placebo | Rey’s Auditory Verbal Learning Task (RAVLT), Picture Recognition Task, Corsi Block Task, Stroop Task, and Modified Attention Network Task (MANT), the Serial 3 s, Serial 7 s, and Sternberg task, the PANAS-NOW | No effect on cognition and mood after the blueberry powder intervention. Improved episodic memory performance in delayed word recognition and marginally significant improved visuo-spatial Corsi Block performance at 3, but not 6, months following blueberry extract intervention. | Low |
ADAS The Alzheimer’s Disease Assessment Scale, ADCS-ADL The Alzheimer’s Disease Cooperative Study-Activities of Daily Living, AG Affect Grid, ANT Attention Network Task, BDI Beck Depression Inventory, CBFV Cerebral Blood Flow Velocity, CERAD Consortium to Establish a Registry for Alzheimer’s Disease, CFT Complex Finger Tapping, CPT Continuous Performance Task, CRT Choice Reaction Time, CS Contrast Sensitivity, CVLT California Verbal Learning Test, DBP Diastolic Blood Pressure, DPR Delayed Picture Recognition, DRS The Dementia Rating Scale, DSST Digit Symbol Substitution Test, DV Digit Vigilance, DVR Delayed Verbal Recall, DWR Delayed Word Recognition, EEG Electroencephalogram, fMRI Functional Magnetic Resonance Imaging, FVT Freiburg Vision Test, GDS Geriatric Depression Scale, HARS Hamilton Anxiety Rating Scale, IWR Immediate Word Recall, IVR Immediate Verbal Recall, LF Letter Fluency, LM Letter Memory, MMSE Mini Mental State Examination, NWM Numeric Working Memory, NIRS Near-IR spectroscopy, NPI Neuropsychiatric Inventory, PANAS Positive and Negative Affect Scale, PP Picture Presentation, POMS Profile of Mood States questionnaire, RAVLT Rey Auditory Verbal Learning Test, RBANS Repeatable Battery for the Assessment of Neuropsychological Status, RT Reaction Time, RVIP Rapid Visual Information Processing, SBP Systolic Blood Pressure, SFT Simple Finger Tapping, SPOT Self-ordered Pointing Task, SPALT Spatial Paired Associate Learning Test, SRT Simple Reaction Time, sVOI Standardised Volume of Interest, SWM Spatial Working Memory, TMT Trail Making Task, TST Task Switching Task, VAS Visual Analogue Scales, vMWM Virtual Morris Water Maze, VPA Verbal Paired Association, VSLT Visual Spatial Learning Test, VVLT Visual Verbal Learning Test, WAIS Wechsler Adult Intelligence Scale, WFC Word Fragment Completion, WMS Wechsler Memory Scale, WP Word Presentation.