Effects of daily almond consumption for six months on cognitive measures in healthy middle-aged to older adults: a randomized control trial

Figures & data

Table 1. Nutrient profiles of almonds and snack mix.

Nutrient	1.5 oz (42 g) Almonds	3.0 oz (84 g) Almonds	3.5 oz (100 g) Snack mix
Energy (kcal)	253	506	272
Protein (g)	9	18	9
Fat (g)	22	44	20
Carbohydrate (g)	9	18	17
Fiber (g)	5	10	3
Saturated fats (g)	1.7	3.4	13.0
Monounsaturated fat (g)	13.8	27.6	3.8
Polyunsaturated fat (g)	5.5	11.0	4.5
α-Tocopherol (mg)	10.1	20.2	1.5
γ-Tocopherol (mg)	0.3	0.6	1.8
Magnesium (mg)	119	238	21

Table 2. Subject characteristics (n = 60).

Characteristics	1.5 oz Almonds (n = 19)	3 oz Almonds (n = 24)	3.5 oz Snack mix (n = 17)	P value^a
Age (years), mean ± SD	61.6 ± 6.3	60.4 ± 6.8	63.0 ± 5.6	0.44
Sex, n (%)				0.90
Female	9 (47%)	10 (42%)	8 (47%)
Male	10 (53%)	14 (58%)	9 (53%)
Race				0.66
Caucasian	14 (74%)	16 (67%)	10 (59%)
African American	4 (21%)	4 (17%)	3 (18%)
Others	1 (5%)	4 (17%)	4 (24%)
BMI (kg/m^2), mean ± SD	28.9 ± 2.9	28.9 ± 2.8	29.2 ± 2.6	0.93
Highest education level				0.98
High school or less	3 (16%)	4 (17%)	3 (18%)
Some college	3 (16%)	4 (17%)	2 (12%)
Four year college	8 (42%)	8 (33%)	8 (47%)
Graduate school	5 (26%)	8 (33%)	4 (24%)

^a Comparisons among the three groups were performed using ANOVA for age and BMI, and Fisher's exact test for sex, race, and education.

Table 3. Cognitive measures (mean ± SD) at baseline (M0), three months (M3), and six months (M6) in healthy adults consuming almonds (1.5 or 3.0 oz/d) or a snack mix (3.5 oz/d).

Measure ^a	1.5 oz Almonds (n = 19)					3 oz Almonds (n = 24)					3.5 oz Snack mix (n = 17)
	M0	M3	M6	PM3-M0	PM6-M0	M0	M3	M6	PM3-M0	PM6-M0	M0	M3	M6	PM3-M0	PM6-M0
MOT
ML	976 ± 268	857 ± 197	850 ± 203	0.051	0.046*	1108 ± 626	946 ± 268	912 ± 249	0.133	0.071	1022 ± 279	936 ± 174	918 ± 225	0.303	0.261
RTI
FMDMT	318 ± 75	311 ± 91	323 ± 86	0.502	0.615	347 ± 149	324 ± 74	319 ± 65	0.433	0.271	338 ± 73	360 ± 73	346 ± 68	0.338	0.717
FMDRT	400 ± 40	400 ± 31	397 ± 41	0.966	0.770	406 ± 49	415 ± 64	421 ± 55	0.268	0.072	401 ± 51	420 ± 34	419 ± 43	0.052	0.051
DMS
PCS	97 ± 7	95 ± 13	98 ± 6	0.494	0.331	98 ± 6	97 ± 8	97 ± 8	0.162	0.426	94 ± 12	95 ± 9	94 ± 9	0.668	1
PC0	87 ± 14	88 ± 15	86 ± 15	0.834	0.804	83 ± 18	83 ± 17	78 ± 18	1	0.328	89 ± 12	75 ± 23	85 ± 19	0.035*	0.299
PC4	78 ± 23	75 ± 17	79 ± 23	0.615	0.893	83 ± 15	80 ± 17	81 ± 15	0.575	0.732	85 ± 15	89 ± 17	81 ± 19	0.431	0.484
PC12	79 ± 22	78 ± 22	83 ± 20	0.871	0.520	83 ± 16	77 ± 19	84 ± 20	0.258	0.714	75 ± 22	72 ± 20	80 ± 14	0.484	0.482
PCAD	81 ± 11	80 ± 11	83 ± 12	0.737	0.686	83 ± 11	80 ± 10	81 ± 12	0.341	0.626	83 ± 10	79 ± 13	82 ± 12	0.221	0.691
PEGE	0.17 ± 0.19	0.19 ± 0.20	0.08 ± 0.14	0.731	0.091	0.09 ± 0.16	0.11 ± 0.17	0.10 ± 0.16	0.681	0.963	0.09 ± 0.21	0.13 ± 0.17	0.05 ± 0.11	0.299	0.490
SSPF
SL	5.7 ± 0.8	6.1 ± 1.1	5.8 ± 0.8	0.250	0.695	5.8 ± 1.5	6.1 ± 1.5	6.2 ± 1.4	0.207	0.175	5.7 ± 0.7	5.6 ± 1.3	5.8 ± 1.2	0.668	0.608
SSPR
SL	5.6 ± 1.0	5.0 ± 0.7	5.5 ± 0.7	0.023*	0.772	5.6 ± 1.7	6.0 ± 1.9	6.0 ± 2.0	0.106	0.023*	5.5 ± 1.3	5.3 ± 1.4	5.7 ± 1.2	0.387	0.565
PAL
FAMS	10.1 ± 3.9	12.1 ± 4.0	10.9 ± 5.1	0.019*	0.472	11.2 ± 3.9	11.9 ± 5.0	13.1 ± 4.4	0.347	0.017*	9.0 ± 4.2	9.2 ± 4.4	11.4 ± 4.5	0.815	0.059
TEA	23.6 ± 14.6	18.4 ± 12.9	22.8 ± 17.1	0.045*	0.770	21.4 ± 15.0	19.2 ± 17.2	13.8 ± 13.0	0.284	0.004**	29.7 ± 16.8	23.5 ± 14.8	20.2 ± 15.5	0.092	0.030*
RVP
A’	0.92 ± 0.05	0.93 ± 0.04	0.94 ± 0.05	0.387	0.008**	0.91 ± 0.06	0.92 ± 0.07	0.93 ± 0.05	0.245	0.014*	0.89 ± 0.05	0.90 ± 0.05	0.92 ± 0.05	0.351	0.002**
MDL	532 ± 103	543 ± 94	513 ± 89	0.566	0.342	527 ± 95	522 ± 124	511 ± 112	0.786	0.449	529 ± 92	527 ± 98	489 ± 68	0.681	0.151
PFA	0.65 ± 0.96	0.41 ± 0.37	0.51 ± 0.71	0.341	0.380	3.61 ± 11.1	1.56 ± 3.36	2.22 ± 5.61	0.226	0.323	3.53 ± 6.70	1.30 ± 2.36	0.64 ± 0.71	0.162	0.101
OTS
MDLFC	144 ± 65	136 ± 46	148 ± 77	0.546	0.837	159 ± 113	195 ± 159	167 ± 105	0.261	0.632	159 ± 83	160 ± 81	152 ± 82	0.980	0.601
PSFC	8.8 ± 3.7	8.7 ± 3.2	9.9 ± 3.6	0.878	0.109	8.5 ± 3.2	8.6 ± 2.6	10.4 ± 2.9	0.734	<0.001***	7.8 ± 3.9	8.9 ± 3.1	8.4 ± 2.8	0.086	0.440

Abbreviations: MOT: Motor Screening Task, ML: Mean Latency, RTI: Reaction Time, FMDMT: Five-Choice Median Movement Time, FMDRT: Five-Choice Median Reaction Time, DMS: Delayed Matching to Sample, PCS: Percent Correct Simultaneous, PC0: Percent Correct 0 s Delay, PC4: Percent Correct 4 s Delay, PC12: Percent Correct 0 s Delay, PCAD: Percent Correct All Delays, PEGE: Probability of Error Given Error, SSPF: Spatial Span Forward, SL: Span Length, SSPR: Spatial Span Reverse, PAL: Paired Associate Learning, FAMS: First Attempt Memory Score, TEA: Total Errors Adjusted, RVP: Rapid Visual Information Processing, A’: A Prime, MDL: Median Response Latency, PFA: Probability of False Alarm, OTS: One Touch Stockings of Cambridge, MDLFC: Median Latency to First Choice, PSFC: Problems Solved on First Choice.

^a Units are as follows: ML, FMDMT, FMDRT, MDL in milliseconds; PCS, PC0, PC4, PC12, PCAD, PFA in %; SL in boxes; FAMS, TEA in times; MDLFC in seconds; PSFC in trials; PEGE and A’ have no unit.

* p<0.05, ** p < 0.01, *** p < 0.001.

Table 4. Serum, plasma, or red blood cell measures (mean ± SD) of retinol, tocopherols, biomarkers of inflammation and oxidative status, and lipids at baseline (M0), three months (M3), and six months (M6) in healthy adults consuming almonds (1.5 or 3.0 oz/d) or a snack mix (3.5 oz/d).

Measure ^a	1.5 oz Almonds (n = 19)					3 oz Almonds (n = 24)					3.5 oz Snack mix (n = 17)
	M0	M3	M6	PM3-M0	PM6-M0	M0	M3	M6	PM3-M0	PM6-M0	M0	M3	M6	PM3-M0	PM6-M0
α-Tocopherol	1.35 ± 0.52	1.41 ± 0.61	1.35 ± 0.42	0.257	0.505	1.25 ± 0.38	1.36 ± 0.31	1.35 ± 0.33	0.004**	0.019*	1.27 ± 0.4211	1.28 ± 0.28	1.31 ± 0.37	0.568	0.180
γ-Tocopherol	99 ± 49	89 ± 54	97 ± 57	0.196	0.916	148 ± 74	123 ± 84	128 ± 77	0.004**	0.054	4 ± 55	128 ± 59	121 ± 50	0.153	0.310
IL-6	0.57 ± 0.31	0.59 ± 0.30	0.59 ± 0.52	0.511	0.667	0.88 ± 0.87	0.74 ± 0.70	0.84 ± 0.79	0.349	0.777	0.70 ± 0.60	0.75 ± 0.82	1.06 ± 0.90	0.996	0.082
CRP	1.71 ± 1.11	1.50 ± 0.97	2.59 ± 4.00	0.624	0.781	4.13 ± 6.34	3.18 ± 3.88	8.45 ± 23.13	0.946	0.249	3.38 ± 5.74	2.60 ± 3.77	3.57 ± 4.93	0.434	0.792
sICAM-1	320 ± 47	315 ± 54	342 ± 105	0.485	0.404	360 ± 94	339 ± 92	381 ± 91	0.341	0.083	345 ± 81	330 ± 62	333 ± 69	0.328	0.592
Plas-SOD	2.16 ± 0.65	2.04 ± 0.57	2.16 ± 0.57	0.351	0.993	1.90 ± 0.35	1.93 ± 0.49	2.00 ± 0.43	0.659	0.235	1.86 ± 0.63	1.77 ± 0.38	2.02 ± 0.51	0.541	0.297
RBC-SOD	146 ± 21	146 ± 16	136 ± 20	0.939	0.152	140 ± 20	140 ± 19	137 ± 16	0.754	0.557	137 ± 21	137 ± 22	135 ± 20	0.967	0.773
Plas-GR	19.3 ± 9.4	16.4 ± 6.0	15.7 ± 8.9	0.321	0.170	18.5 ± 9.3	19.0 ± 7.6	17.8 ± 7.7	0.756	0.723	15.7 ± 9.4	18.3 ± 9.1	21.1 ± 10.0	0.377	0.114
RBC-GR	178 ± 81	211 ± 109	161 ± 71	0.124	0.662	206 ± 179	175 ± 51	179 ± 59	0.405	0.508	151 ± 72	182 ± 66	162 ± 102	0.287	0.632
RBC-GPX	1.96 ± 0.68	2.03 ± 0.70	2.24 ± 0.64	0.654	0.039*	1.96 ± 0.84	1.91 ± 0.59	1.90 ± 0.66	0.535	0.567	2.05 ± 0.67	2.09 ± 0.94	2.05 ± 0.67	0.724	0.992
RBC-GSH	45.1 ± 43.6	40.4 ± 39.7	51.3 ± 47.6	0.670	0.703	48.3 ± 46.7	64.9 ± 56.4	61.1 ± 64.6	0.099	0.205	79.5 ± 43.3	69.9 ± 63.2	58.2 ± 61.5	0.473	0.153
Total-C	218 ± 47	215 ± 45	210 ± 40	0.435	0.100	222 ± 37	218 ± 46	217 ± 38	0.368	0.351	214 ± 38	224 ± 30	225 ± 29	0.048*	0.043*
VLDL-C	24 ± 13	24 ± 14	24 ± 11	1	0.920	35 ± 27	34 ± 24	31 ± 20	0.565	0.302	27 ± 12	25 ± 9	31 ± 15	0.357	0.083
LDL-C	126 ± 35	122 ± 31	119 ± 32	0.323	0.054	123 ± 34	120 ± 32	123 ± 27	0.607	0.963	126 ± 37	136 ± 25	133 ± 28	0.112	0.145
HDL-C	67 ± 15	69 ± 17	66 ± 13	0.276	0.584	64 ± 22	64 ± 23	63 ± 18	0.712	0.260	60 ± 13	62 ± 16	60 ± 14	0.109	0.845
TG	122 ± 64	121 ± 68	122 ± 56	0.909	0.979	177 ± 138	170 ± 122	158 ± 101	0.570	0.306	137 ± 61	128 ± 46	156 ± 77	0.384	0.079

IL-6: interleukin-6, CRP: c-reactive protein, sICAM-1: soluble intercellular adhesion molecule-1, Plas: Plasma, SOD: superoxide dismutase, RBC: red blood cell, GR: glutathione reductase, GPX: glutathione peroxidase, GSH: reduced glutathione, Total-C: total cholesterol, VLDL-C: very low density lipoprotein cholesterol, LDL-C: low density lipoprotein cholesterol, HDL-C: high density lipoprotein cholesterol, TG: triglyceride.

^a All measures are in serum if not indicated otherwise. Units are as follows: retinol and tocopherols in μg/dL; IL-6 in pg/mL; CRP in mg/L; sICAM-1 in ng/mL; Plas-SOD, RBC-SOD in U/mL; Plas-GR, RBC-GR in nmol⋅min⁻¹⋅mL⁻¹; RBC-GPX in μmol min⁻¹ mL⁻¹; RBC-GSH in μM; cholesterols and TG in mg/dL.

* p < 0.05, ** p < 0.01.