Dietary fat intake and prostate cancer risk: a case control study in Spain.

January 1, 2000 Human Health and Nutrition Data 0 Comments

Dietary fat intake and prostate cancer risk: a case control study in Spain.

Year: 2000
Authors: Ramon, J.M. Bou, R. Romea, S. Alkiza, M.E. Jacas, M.
Publication Name: Cancer Causes & Control
Publication Details: Vol. II; Pages 679-685.

Abstract:

Epidemiological evidence suggests that dietary factors can play a role in the etiology of prostate cancer.  Results from several case control and cohort studies on nutrient intake and prostate cancer have been unclear. The authors examined the effect of lipid intake on the risk of prostate cancer. In order to assess associations between lipid intake and prostate cancer risk, a case control study was conducted between May 1994 and March 1998 in the Barcelona metropolitan area, Spain. Two hundred seventeen incident cases with histologically confirmed diagnosis of prostate cancer were matched to 434 hospital and community controls by age and residence. Information about food intake was gathered by a semi-quantitative food-frequency questionnaire. Unconditional logistic regression was used for the analysis. Animal fat intake was associated with prostate cancer with an estimated OR for highest quartile of 2.0 (95% CI 1.2�3.2). Vitamin C intake was inversely associated with prostate cancer (OR = 0.6; 95% CI 0.3�0.9). The prostate cancer risk increased in proportion to alpha-linolenic acid intake. In the analysis adjusting for energy and major co-variables the estimated OR for upper quartile of
alpha-linolenic acid was 3.1 (95% CI 1.1�3.8). In conclusion, the association between fat intake and prostate cancer may be correlated with alpha-linolenic acid, although the specific mechanism has to be determined. (Author's abstract)
The association between polyunsaturated fatty acids and prostate cancer is unclear. Previous
findings from case controls studies for dietary intake of polyunsaturated fats as a group showed no significant association with prostate cancer risk. The association of alpha-linolenic acid intake with prostate cancer has been found to non-significant.  In order to assess associations between lipid intake and prostate cancer risk, this case control study was designed in a university hospital in the Barcelona metropolitan area, Spain, and its surrounding area. Bias inherent to retrospective collection of dietary data with a possibility of recall bias and over-reporting of dietary intake is a confounding factor in this investigation. The data suggest a positive association between fat from animal sources and prostate cancer. Unlike in other studies, total fat intake was not associated with prostate cancer risk after adjustment for total energy intake, protein and carbohydrates. A high intake of alpha-linolenic acid was positively associated with prostate cancer. However, another cohort study by Gann et al. observed that low plasma levels of alpha-linolenic acid were associated with a decreased risk for prostate cancer. Results from three retrospective studies showed a non-significant association between prostate cancer and alpha-linolenic acid. Questions can be raised as to the association of alpha-linolenic acid with red meat and dairy products, the food groups commonly associated with the risk of prostate cancer. Unlike what the investigators claim, these food groups are not a source
of alpha-linolenic acid. The inconsistencies in the dietary assessment and food composition in this (and other non-nutritional studies) stress the need to conduct analysis of any relationships of alpha-linolenic acid and prostate cancer under conditions whereby an understanding of food sources of alpha-linolenic acid exist. (Editor's abstract)



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