Blood cell gene expression associated with cellular stress defense is modulated by antioxidant-rich food in a randomised controlled clinical trial of male smokers.
BACKGROUND
Plant-based diets rich in fruit and vegetables can prevent development of several chronic age-related diseases. However, the mechanisms behind this protective effect are not elucidated. We have tested the hypothesis that intake of antioxidant-rich foods can affect groups of genes associated with cellular stress defence in human blood cells.


BACKGROUND
NCT00520819 http://clinicaltrials.gov.


METHODS
In an 8-week dietary intervention study, 102 healthy male smokers were randomised to either a diet rich in various antioxidant-rich foods, a kiwifruit diet (three kiwifruits/d added to the regular diet) or a control group. Blood cell gene expression profiles were obtained from 10 randomly selected individuals of each group. Diet-induced changes on gene expression were compared to controls using a novel application of the gene set enrichment analysis (GSEA) on transcription profiles obtained using Affymetrix HG-U133-Plus 2.0 whole genome arrays.


RESULTS
Changes were observed in the blood cell gene expression profiles in both intervention groups when compared to the control group. Groups of genes involved in regulation of cellular stress defence, such as DNA repair, apoptosis and hypoxia, were significantly upregulated (GSEA, FDR q-values < 5%) by both diets compared to the control group. Genes with common regulatory motifs for aryl hydrocarbon receptor (AhR) and AhR nuclear translocator (AhR/ARNT) were upregulated by both interventions (FDR q-values < 5%). Plasma antioxidant biomarkers (polyphenols/carotenoids) increased in both groups.


CONCLUSIONS
The observed changes in the blood cell gene expression profiles suggest that the beneficial effects of a plant-based diet on human health may be mediated through optimization of defence processes.
Bøhn
Siv K
SK
Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway.
Myhrstad
Mari C
MC
Thoresen
Magne
M
Holden
Marit
M
Karlsen
Anette
A
Tunheim
Siv Haugen
SH
Erlund
Iris
I
Svendsen
Mette
M
Seljeflot
Ingebjørg
I
Moskaug
Jan O
JO
Duttaroy
Asim K
AK
Laake
Petter
P
Arnesen
Harald
H
Tonstad
Serena
S
Collins
Andrew
A
Drevon
Christan A
CA
Blomhoff
Rune
R
D000704:Analysis of Variance; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D001628:Beverages; D001773:Blood Cells / Q000378:metabolism*; D004032:Diet; D005502:Food; D005638:Fruit; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009754:Nuts; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology*; D012639:Seeds; D012907:Smoking / Q000235:genetics; D013662:Tea; D014675:Vegetables
D000975:Antioxidants; D013662:Tea