The effect of kiwifruit consumption on blood pressure in subjects with moderately elevated blood pressure: A randomized, controlled study

Figures & data

Table I. Content of energy and some nutrients in study fruits.

Nutrients	Kiwi	Apple
Energy, kcal/100 g	57	59
Fibre, g/100 g	2.7	2.0
Potassium, mg/100 g	290	147
Vitamin C, mg/100 g	59	3
Lutein, μg/100 g	160	84
FRAP, mmol/100 g	91	13

Composition data except lutein are from the Norwegian nutrition composition table. Composition data for lutein are from ref. (9). Ferric-reducing antioxidant power (FRAP) measurements in kiwi and apple were done according to ref. (8).

Figure 1. Flowchart of subjects.

Table II. Blood pressure measured ambulatory and standardized at office before and after intervention in the kiwifruit and apple group.

	n	Kiwi fruit group	n	Apple group	Between group difference in change^a	p
24-h SBPrand	51	132 ± 13^b	55	133 ± 13
24-h SBPweek 8	51	131 ± 12	55	135 ± 14
Change in 24-h SBP^c	51	− 1.1 (− 3.2 to 1.1)^d	55	2.5 (0.5–4.6)	− 3.6 (− 6.6 to − 0.6)	0.017
24-h DBPrand	51	82 ± 8	55	82 ± 7
24-h DBPweek 8	51	82 ± 9	55	83 ± 7
Change in 24-h DBP^c	51	− 0.2 (− 1.5 to 1.1)	55	1.7 (0.5–3.0)	− 1.9 (− 3.7 to − 0.1)	0.040
SBPrand	56	127 ± 14	59	129 ± 14
SBPweek 8	56	126 ± 14	59	127 ± 16
Change in SBP	56	− 1.1 (− 4.1,1.8)	59	− 1.8 (− 4.6 to 1.1)	0.6 (− 3.5 to 4.7)	0.762
DBPrand	56	84 ± 9	59	85 ± 7
DBPweek 8	56	81 ± 9	59	83 ± 8
Change in DBP^d	56	− 3.0 (− 4.8 to − 1.2)	59	− 1.3 (− 3.1 to 0.5)	− 1.7 (− 4.2 to 0.8)	0.177

SBT, systolic blood pressure in mmHg; DBT, diastolic blood pressure in mmHg; rand, randomization; 24-h, ambulatory blood pressure measured for 24 h.

^aLeast square means, between group difference adjusted for blood pressure at randomization.

^bMean± SD and all such values.

^cLeast square means, within group difference adjusted for blood pressure at randomization.

^dWithin and between group difference with 95% CI and all such values.

Table III. Functional and biochemical markers of endothelial function and plasma antioxidants before and after intervention in the kiwifruit and apple group.

	Kiwifruit group				Apple group				Between group difference in change^a	p ^b
	n	Randomization	n	Week 8	n	Randomization	n	Week 8
Endothelial function
SI	48	10.9 ± 2.8^c	48	11.5 ± 2.7	54	11.4 ± 2.9	54	11.6 ± 2.3	− 0.48 (− 1.4 to 0.5)	0.333
RI	48	80.3 ± 6.3	48	80.1 ± 7.9	54	81.7 ± 7.1	54	80.4 ± 6.5	− 1.1 (− 3.9 to 1.7)	0.443
PPT	48	171.3 ± 51.0	48	160.1 ± 45.0	54	162.5 ± 44.1	54	159.0 ± 40.1	7.8 (− 6.7 to 22.3)	0.289
Endothelial biomarkers
l-arg, mmol/l	54	89.9 ± 14.4	52	88.0 ± 15.8	57	88.9 ± 12.6	56	87.4 ± 12.3	1.1 (− 2.3 to 4.5)	0.520
ADMA, mmol/l	54	0.58 ± 0.09	52	0.59 ± 0.09	57	0.59 ± 0.10	55	0.58 ± 0.10	− 0. 01 (− 0.03 to 0.02)	0.541
SDMA, mmol/l	54	0.43 ± 0.07	51	0.42 ± 0.08	57	0.41 ± 0.09	56	0.41 ± 0.07	0.01 (− 0.02 to 0.03)	0.576
l -arg/ADMA	54	157.4 ± 25.4	52	150.3 ± 27.4	57	154.5 ± 28.7	56	151.5 ± 21.0	2.5 (− 5.1 to 10.0)	0.519
Plasma carotenoids
Lutein, μM	55	0.31 ± 0.12	55	0.41 ± 0.16	59	0.29 ± 0.12	59	0.25 ± 0.11	0.13 (0.11–0.16)	0.000
Zeaxanthin, μM	55	0.07 ± 0.03	55	0.07 ± 0.02	59	0.06 ± 0.03	59	0.06 ± 0.02	0.01 (− 0.001 to 0.13)	0.129
β-cryptoxan, μM	55	0.19 ± 0.14	55	0.21 ± 0.16	59	0.18 ± 0.11	59	0.21 ± 0.16	− 0.02 (− 0.08 to 0.03)	0.464
α-carotene, μM	55	0.21 ± 0.15	55	0.18 ± 0.13	59	0.17 ± 0.12	59	0.17 ± 0.16	− 0.03 (− 0.07 to 0.13)	0.167
β-carotene, μM	55	0.75 ± 0.50	55	0.69 ± 0.40	59	0.68 ± 0.37	59	0.63 ± 0.36	− 0.01 (− 0.08 to 0.06)	0.790
Lycopene, μM	55	0.61 ± 0.25	55	0.63 ± 0.25	59	0.62 ± 0.26	59	0.59 ± 0.26	0.04 (− 0.04 to 0.11)	0.328

SI, stiffness index; RI, reflection index; PPT, pulse propagation time; l-arg, l-arginine; ADMA, asymmetric dimetyl l-arginine; SDMA, symmetric dimetyl l-arginine; l-Arg/ADMA, ratio of l-arginine and asymmetric dimetyl l-arginine.

^aMean group difference with 95% CI and all such values.

^bThe between group difference was tested by independent sample Student t-test.

^cMean± SD and all such values.

Table IV. Body weight, physical activity energy expenditure and daily dietary intake before and after intervention in the kiwifruit and apple group.

	Kiwifruit group (n = 56)		Apple group (n = 59)		Between group difference in change^a	p ^b
	Randomization	Week 8	Randomization	Week 8
Body weight^c, kg	74.8 ± 11.5^d	75.1 ± 12.0^e	78.8 ± 12.7	78.8 ± 13.5	0.29 (− 1.37 to 1.95)	0.143
PAEE^f, kcal	551 ± 655	459 ± 837	450 ± 395	430 ± 430	− 95 (− 396 to 206)	0.534
Energy intake, kcal	2421 ± 1077	2265 ± 904*	2270 ± 543	2135 ± 618*	− 20 (− 185 to 145)	0.811
E% protein	17.1 ± 2.2	16.4 ± 2.4*	16.9 ± 2.5	16.9 ± 3.0	− 0.6 (− 1.5 to 0.3)	0.177
E% fat	35.1 ± 5.9	33.6 ± 5.2	34.7 ± 5.3	34.7 ± 6.2	− 1.5 (− 3.6 to 0.6)	0.163
E% carbohydrate	41.3 ± 7.9	43.4 ± 4.6*	41.7 ± 6.3	41.5 ± 6.4	2.3 (− 0.1 to 4.6)	0.051
E% alcohol	3.1 ± 2.5	3.3 ± 2.6	3.8 ± 3.6	4.0 ± 3.9	0 (− 0.9 to 0.9)	0.939
Calcium, mg	994 ± 571	923 ± 561	862 ± 282	787 ± 306*	8 (− 97 to 114)	0.876
Sodium, mg	2936 ± 1373	2663 ± 1117*	2740 ± 824	2693 ± 978	− 226 (− 562 to 108)	0.182
Potassium, mg	4960 ± 2103	5074 ± 2213	4538 ± 977	4291 ± 1066	361 (24–697)	0.036
Magnesium, mg	488 ± 231	460 ± 184	449 ± 100	429 ± 129	− 9 (− 50 to 32)	0.670
Vitamin C, mg	177 ± 77	307 ± 132***	169 ± 68	151 ± 67*	149 (118–180)	0.000

^aMean group difference with 95% CI and all such values.

^bThe between-group difference was tested by independent samples Student t-test.

^cWeights were missing for 21 subjects at randomization and three subjects at week 8, missing values were replaced by multiple imputation (series means).

^dMean± SD and all such values.

^eThe within-group difference was tested by paired samples t-test.

^fPhysical activity data were missing for 7 subjects in the kiwi group and 2 subjects in the apple group. PAEE, physical activity energy expenditure; E%, energy percentage.

*p < 0.05; **p < 0.01; ***p < 0.001.

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