Fruit and vegetable consumption and its relation to markers of inflammation and oxidative stress in adolescents.
BACKGROUND
Fruits and vegetables, foods rich in flavonoids and antioxidants, have been associated with lower risk of stroke, coronary heart disease, and markers of inflammation and oxidative stress in adults. Markers of inflammation and oxidative stress are predictors of coronary heart disease risk; however, it is unknown whether these markers are related to dietary flavonoid and antioxidant intake in youth.


OBJECTIVE
To determine whether greater intakes of fruit and vegetables, antioxidants, folate, and total flavonoids were inversely associated with markers of inflammation and oxidative stress in 285 adolescent boys and girls aged 13 to 17 years.


METHODS
In this cross-sectional study conducted between February 1996 and January 2000, diet was assessed by a 127-item food frequency questionnaire. Height and weight measurements were obtained and a fasting blood sample drawn. Spearman partial correlation analyses evaluated the relation of intakes of fruit and vegetables, antioxidants, folate, and flavonoids with markers of inflammation (C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and 15-keto-dihydro-PGF(2alpha) metabolite and oxidative stress (urinary 8-iso prostaglandin F(2alpha), an F(2)-isoprostane), adjusting for age, sex, race, Tanner stage, energy intake, and body mass index.


RESULTS
Urinary F(2)-isoprostane was inversely correlated with intakes of total fruit and vegetables, vitamin C, beta carotene, and flavonoids. Serum C-reactive protein was significantly inversely associated with intakes of fruit (r=-0.19; P=0.004), vitamin C (r=-0.13, P=0.03), and folate (r=-0.18; P=0.004). Serum interleukin-6 was inversely associated with intakes of legumes, vegetables, beta carotene, and vitamin C. Serum tumor necrosis factor-alpha was inversely associated with beta carotene (r=-0.14, P=0.02) and luteolin (r=-0.15, P=0.02).


CONCLUSIONS
Study results show that the beneficial effects of fruit and vegetable intake on markers of inflammation and oxidative stress are already present by early adolescence and provide support for the Dietary Guidelines for Americans "to consume five or more servings per day" of fruits and vegetables to promote beneficial cardiovascular health.
Holt
Erica M
EM
Division of Epidemiology, University of Minnesota School of Public Health, Minneapolis, USA.
Steffen
Lyn M
LM
Moran
Antoinette
A
Basu
Samar
S
Steinberger
Julia
J
Ross
Julie A
JA
Hong
Ching-Ping
CP
Sinaiko
Alan R
AR
D000293:Adolescent; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood / Q000652:urine; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000517:prevention & control; D003430:Cross-Sectional Studies; D004032:Diet; D004034:Diet Surveys; D015237:Dinoprost / Q000031:analogs & derivatives / Q000652:urine; D028441:F2-Isoprostanes / Q000652:urine; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage* / Q000378:metabolism; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007249:Inflammation / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014675:Vegetables / Q000737:chemistry
D000975:Antioxidants; D015415:Biomarkers; D028441:F2-Isoprostanes; D005419:Flavonoids; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; C075750:8-epi-prostaglandin F2alpha; D002097:C-Reactive Protein; D005492:Folic Acid; D015237:Dinoprost