Evaluation of the effect of dietary vegetable consumption on reducing risk of transitional cell carcinoma of the urinary bladder in Scottish Terriers.

OBJECTIVE

To evaluate the effects of vegetable consumption and vitamin supplementation on the risk of developing transitional cell carcinoma (TCC) of the urinary bladder in Scottish Terriers.

DESIGN

Case-control study.

ANIMALS

92 adult Scottish Terriers with TCC (cases) and 83 Scottish Terriers with other conditions (controls).

PROCEDURE

Owners of dogs with TCC completed a questionnaire regarding their dogs' diet and intake of vitamin supplements in the year prior to diagnosis of TCC; owners of control dogs completed the questionnaire for a comparable time period. The risk (odds ratio [OR]) of developing TCC associated with diet and vitamin supplementation was determined by use of logistic regression.

RESULTS

After adjustment for age, weight, neuter status, and coat color, there was an inverse association between consumption of vegetables at least 3 times/wk (OR, 0.30; 95% confidence interval [CI], 0.15 to 0.62) and risk of developing TCC. For individual vegetable types, the risk of developing TCC was inversely associated with consumption of green leafy vegetables (OR, 0.12; 95% CI, 0.01 to 0.97) and yellow-orange vegetables (OR, 0.31; 95% CI, 0.14 to 0.70). Consumption of cruciferous vegetables was not significantly associated with a similar reduction in risk of developing TCC (OR, 0.22; CI, 0.04 to 1.11). The power of the study to detect a 50% reduction in TCC risk associated with daily vitamin supplementation was considered low (25%).

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that consumption of certain vegetables may prevent or slow the development of TCC in Scottish Terriers.