High intake of fruit and vegetables is related to low oxidative stress and inflammation in a group of patients with type 2 diabetes

Figures & data

Table 1. Clinical characteristics of the patient group

	Total	Female	Male	p
Subjects
Number	54	29	25
Smokers/non-smokers	8/46	4/25	4/21
Diet/diet and medication^a	20/34	14/15	6/19
Characteristics
Age (years)	62.6±7.0	62.9±6.7	62.2±7.3	ns
	[63.0]	[63.0]	[63.0]
	(46–75)	(46–75)	(50–72)
Weight (kg)	82.1±13.9	75.5±12.1	89.6±12.0	***
	[83.1]	[73.8]	[89.9]
	(54.9–114.5)	(54.9–103.5)	(72.3–114.5)
Waist circumference (cm)	99.6±11.3	97.2±12.7	102.3±9.0	ns
	[100]	[98.5]	[100.0]
	(70–127)	(70–127)	(87–125)
BMI (kg m^-2)	28.2±3.9	28.3±4.3	28.2±3.4	ns
	[28.1]	[28.2]	[27.8]
	(19.7–37.2)	(19.7–37.2)	(23.6–35.6)
HbA1c (%)	6.1±0.8	6.0±0.8	6.1±0.9	ns
	[6.0]	[5.8]	[6.1]
	(4.7–8.0)	(5.0–7.6)	(4.7–8.0)
Glucose (mmol l^-1)	7.8±2.3	7.6±2.0	8.1±2.6	ns
	[7.4]	[7.4]	[7.4]
	(4.1–14.6)	(4.7–12.1)	(4.1–14.6)
Insulin (mU l^-1)	11.5±6.8	11.1±7.0	11.9±6.7	ns
	[8.8]	[8.3]	[9.3]
	(3.6–28.6)	(3.6–26.2)	(4.9–28.6)

Data are shown as mean±SD, [median] and (range).

^aSubjects were allowed to keep going with their usual treatment of either diet or diet and oral hypoglycaemic medication.

BMI: body mass index; HbA_1c: glycosylated haemoglobin.

Significant difference: ***p<0.001 between genders; ns: not significant (Wilcoxon two-sample test).

Table 2. Dietary intake in the population of patients

Dietary intake (per day)	Total	Female	Male	p
Energy (kJ)	8488±2148	8273±2369	8729±1891	ns
	(5226–13 722)	(5226–13 722)	(5758–12 490)
Proteins (E% )	17.4±2.30	17.6±2.06	17.2±2.57	ns
	(12.5–22.5)	(13.6–21.8)	(12.5–22.5)
Fats (E% )	31.4±5.74	32.1±5.51	30.5±5.99	ns
	(18.8–44.6)	(20.6–44.0)	(18.8–44.6)
Carbohydrates (E% )	48.1±7.00	47.8±5.93	48.5±8.15	ns
	(32.8–67.2)	(35.7–60.5)	(32.8–67.2)
β-Carotene (µg)	3687±2592	4180±3037	3135±1890	ns
	(369–16 276)	(973.0–16 276)	(369.2–6860)
Vitamin E (α-TE)	9.67±7.06	10.4±9.49	8.81±2.29	ns
	(4.28–53.5)	(4.28–53.5)	(5.43–12.2)
α-Tocopherol (mg)	9.17±6.98	9.95±9.38	8.29±2.24	ns
	(4.14–52.8)	(4.14–52.8)	(5.26–11.58)
Vitamin C (mg)	131.1±77.9	138.1±83.9	123.1±71.3	ns
	(43.0–376.4)	(43.0–376.4)	(43.5–307.5)
Vitamin B12 (µg)	7.03±3.62	7.90±4.39	6.05±2.20	*
	(1.95–21.5)	(2.45–21.5)	(1.95–11.9)
Zinc (mg)	12.2±3.11	11.9±3.23	12.5±3.00	ns
	(6.14–18.8)	(6.14–18.1)	(7.43–18.8)
Folate (µg)	296.2±92.0	307.7±112.6	283.3±61.2	ns
	(160.4–601.5)	(160.4–601.5)	(160.9–401.6)
Selenium (µg)	44.1±12.2	42.7±10.6	45.6±14.0	ns
	(22.0–68.2)	(27.2–64.9)	(22.0–68.2)
Fruit and vegetables (g)	501.8±322.9	497.0±257.6	507.2±388.9	ns
	(91.7–2054)	(180.0–1095)	(91.7–2054)

Data are shown as mean±SD (range).

TE: tocopherol equivalents.

Significant difference: *p<0.05 between genders; ns: not significant (Wilcoxon two-sample test).

Table 3. Levels of antioxidants in the patients’ plasma

Antioxidants	Total
α-Carotene (mg l^-1)	0.11±0.15
	(0.01–0.98)
β-Carotene (mg l^-1)	0.28±0.38
	(0.04–2.58)
Lycopene (mg l^-1)	0.16±0.08
	(0.01–0.37)
Lutein (mg l^-1)	0.12±0.05
	(0.04–0.28)
α-Tocopherol (µg ml^-1)	2.03±0.32
	(1.46–3.48)
γ-Tocopherol (µg ml^-1)	0.10±0.04
	(0.03–0.22)
Ascorbate (µM)	34.3±12.2
	(13.2–62.8)

Data are shown as mean±SD (range).

Table 4. Dietary intake, corrected for energy intake, correlated with antioxidants in plasma

Food variable/MJ	Plasma antioxidant	r	p
Fruit and vegetable intake	α-Tocopherol	0.3191	0.0198*
	γ-Tocopherol	-0.4339	0.0012**
	α-Carotene	0.3969	0.0033**
	β-Carotene	0.4382	0.0010***
	Lycopene	0.2867	0.0374*
	Ascorbate	0.2707	0.0500*
β-Carotene	γ-Tocopherol	-0.5119	< 0.0001***
	α-Carotene	0.6419	< 0.0001***
	β-Carotene	0.6578	< 0.0001***
	Lutein	0.3453	0.0113*
	Lycopene	0.3265	0.0170*
α-Tocopherol	α-Tocopherol	0.2826	0.0403*
	α-Carotene	0.3063	0.0257*
	Lycopene	0.3188	0.0200*
Vitamin E	α-Tocopherol	0.3069	0.0254*
	α-Carotene	0.3145	0.0218*
	Lycopene	0.3206	0.0193*
Vitamin C	α-Tocopherol	0.3795	0.0051**
	γ-Tocopherol	-0.3634	0.0075**
	α-Carotene	0.3586	0.0084**
	β-Carotene	0.4052	0.0026**
	Lutein	0.3145	0.0218*
	Ascorbate	0.3428	0.0120*
Selenium	Lutein	0.3033	0.0272*

Significant differences: ***p<0.001, **p<0.01, *p<0.05 (considered not significant) (Spearman rank correlation coefficient).

Table 5. Oxidative stress, chromosomal damage and inflammation variables

Variable	Total
Oxidative stress variables
8-OxodG/10^6 dG	0.97±0.45
	(0.20–2.97)
Comet assay, FPG sites (% tail)	30.2±15.1
	(6.85–65.6)
Malondialdehyde (mmol l^-1)	0.68±0.08
	(0.52–0.85)
8-Iso-PGF2α ?(nmol mmol^-1 creatinine)	0.19±0.09
	(0.06–0.56)
Chromosomal damage variable
Micronucleated Trf reticulocytes (‰)^a	0.92±0.50
	(0.21–2.28)
Inflammation variables
CRP (mg l^-1)	3.15±4.3
	(0.16–27.6)
CRP (mg l^-1), only values < 10 included^b	2.50±2.46
	(0.16–9.53)
IL-6 (ng l^-1)	2.50±2.20
	(0.40–11.20)
15-Keto-dihydro-PGF2α (nmol mmol^-1 creatinine)	0.24±0.10
	(0.08–0.68)

Data are shown as mean±SD (range).

^a36 subjects; ^b 51 subjects.

8-OxodG: 8-oxo-7,8-dihydroguanine; FPG: formamidopyrimidine glycosylase; 8-iso-PGF_2α???8-iso-prostaglandin-F_2α?? Trf reticulocytes: transferrin-positive reticulocytes; CRP: C-reactive protein; IL-6: interleukin-6; PGF_2α: prostaglandin F_2α.

Table 6. Dietary intake, corrected for energy intake, or plasma antioxidant levels correlated with oxidative stress or inflammation (CRP < 10)

	Oxidative stress or inflammation	r	p
Food variable/MJ	Oxidative stress
Fruit and vegetables	8-OxodG/10^6 dG	-0.0940	0.5116
Fruit and vegetables	Comet assay, FPG sites (% tail)	-0.2724	0.0485*
Fruit and vegetables	Malondialdehyde (mmol l^-1)	0.2240	0.1104
Fruit and vegetables	8Table Iso-PGF2α (nmol mmol^-1 creatinine)	-0.2774	0.0443*
Vitamin C	8-Iso-PGF2α (nmol mmol^-1 creatinine)	-0.3318	0.0152*
Plasma antioxidants	Oxidative stress
γ-Tocopherol	Malondialdehyde (mmol l^-1)	-0.2869	0.0373*
Ascorbate	8-oxodG/10^6 dG	-0.2905	0.0367*
Plasma antioxidants	Inflammation (CRP < 10)
α-Carotene	IL-6	-0.4101	0.0025**
β-Carotene	IL-6	-0.3614	0.0085**
Lutein	IL-6	-0.2960	0.0331*
Lycopene	IL-6	-0.2795	0.0448*
α-Tocopherol	IL-6	-0.1344	0.3421
γ-Tocopherol	IL-6	-0.1916	0.1736
γ-Tocopherol	CRP < 10 (mg l^-1)	-0.3145	0.0232*

8-OxodG: 8-oxo-7,8-dihydroguanine; FPG: formamidopyrimidine glycosylase; 8-iso-PGF_2α??8-iso-prostaglandin-F_2α?? CRP: C-reactive protein; IL-6: interleukin-6.

Significant differences: **p<0.01, *p<0.05; ns: not significant (Spearman rank correlation coefficient with Bonferroni–Holm correction).