Effect of daily fruit ingestion on angiotensin converting enzyme activity, blood pressure, and oxidative stress in chronic smokers.
OBJECTIVE
This study examined whether, daily fruit (blueberries) consumption (250 g) for three weeks or acute fruit ingestion (250 g) would attenuate angiotensin converting enzyme (ACE) activity and reduce oxidative stress in chronic cigarette smokers.


METHODS
Twenty subjects were recruited and randomized into fruit or control groups. Blood samples and blood pressure were obtained at baseline and then pre and one hour post when subjects returned to the lab three weeks later. To examine acute effects, the fruit group immediately ingested 250 g of blueberries after returning and at least one hour prior to the post blood draw. Plasma samples were analyzed for ACE activity, F(2)- isoprostanes and lipid hydroperoxides (LH) as measures of oxidative stress, and ferric reducing ability of plasma (FRAP) as a measure of antioxidant potential. A 2 (treatment) x 3 (time) repeated measures ANOVA was used for statistical analysis. If interaction was significant, then Student's t-tests were used to further examine this relationship. For these comparisons, a Bonferroni adjustment was made with statistical significance set at P < 0.025.


RESULTS
The pattern of change between treatments was not significant for any variable except LH (P < 0.001).


CONCLUSIONS
This study indicates that LH are significantly reduced by daily fruit consumption, but not affected by acute ingestion. This finding could be one way in which fruit consumption contributes to prevention of cardiovascular disease.
McAnulty
Steven R
SR
Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA. mcanltysr@appstate.edu
McAnulty
Lisa S
LS
Morrow
Jason D
JD
Khardouni
Daniel
D
Shooter
Lesli
L
Monk
James
J
Gross
Sarah
S
Brown
Victor
V
D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism; D001794:Blood Pressure; D029798:Blueberry Plants; D002318:Cardiovascular Diseases / Q000473:pathology; D004032:Diet; D028441:F2-Isoprostanes / Q000737:chemistry; D005247:Feeding Behavior; D005638:Fruit; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D015233:Models, Statistical; D018384:Oxidative Stress; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D012907:Smoking
D000975:Antioxidants; D028441:F2-Isoprostanes; D008054:Lipid Peroxides; D008055:Lipids; D006861:Hydrogen Peroxide; D007703:Peptidyl-Dipeptidase A