Serum beta-glucuronidase activity in response to fruit and vegetable supplementation: a controlled feeding study.
BACKGROUND
Fruit and vegetable (F&V) intake may lower the risk of some cancers. One hypothesized, but understudied, chemopreventive mechanism is that plant food constituents inhibit beta-glucuronidase, an acid hydrolase that deconjugates glucuronides.


METHODS
We conducted a crossover feeding trial in 63 healthy women and men ages 20 to 40 years to examine the effect of diet on serum beta-glucuronidase activity. Participants were randomized to two 2-week experimental diets with an intervening washout period: a diet high in selected citrus fruit, crucifers, and soy (F&V) and a diet devoid of fruits, vegetables, and soy (basal). Serum beta-glucuronidase activity was measured during the preintervention, F&V, and basal periods. Linear mixed models were used to obtain effect estimates and 95% confidence intervals (95% CI).


RESULTS
We observed statistically significantly higher beta-glucuronidase activity during the F&V than the basal diet (ratio, F&V versus basal diet, 1.09; 95% CI, 1.05-1.13; P < 0.01). These results were probably due to decreased beta-glucuronidase activity during the basal diet (ratio, basal period versus preintervention, 0.93; 95% CI, 0.87-0.98; P = 0.01) rather than increased enzyme activity during the F&V diet (ratio, F&V period versus preintervention, 1.01; 95% CI, 0.96-1.06; P = 0.64). Response to the experimental diet did not differ by sex (P(interaction) = 0.30), but there was a suggestion of a short-term diet effect at 8 versus 15 days (P(interaction) = 0.06).


CONCLUSIONS
This intervention of selected F&V did not lower beta-glucuronidase activity. Further investigation is needed regarding what other foods and phytochemicals may influence beta-glucuronidase activity and effect modifiers of this relation.
Maruti
Sonia S
SS
Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
Chang
Jyh-Lurn
JL
Prunty
Jo Ann
JA
Bigler
Jeannette
J
Schwarz
Yvonne
Y
Li
Shuying S
SS
Li
Lin
L
King
Irena B
IB
Potter
John D
JD
Lampe
Johanna W
JW
D000328:Adult; D018592:Cross-Over Studies; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D005638:Fruit; D005966:Glucuronidase / Q000097:blood*; D006801:Humans; D015994:Incidence; D008297:Male; D009369:Neoplasms / Q000201:enzymology / Q000453:epidemiology / Q000517:prevention & control; D012307:Risk Factors; D013053:Spectrophotometry; D014675:Vegetables; D014861:Washington / Q000453:epidemiology; D055815:Young Adult
D005966:Glucuronidase