Dietary patterns in relation to prostate cancer in Iranian men: a case-control study

Dietary patterns in relation to prostate cancer in Iranian men: a case-control study


Authors:

Askari F1*Rashidkhani B2 1 MS of nutrition, Students' Research Committee, National Nutrition and Food Technology Research Institute, Faculty of Nutrition and Food Technology, Shaheed Beheshti University of Medical Sciences, Tehran, Iran. 2 Community Nutrition Department, Nutrition and Food Technology Research Institute, Faculty of Nutrition and Food Technology, Shaheed Beheshti University of Medical Sciences, Tehran, Iran.

Correspondence:

faezeh askari - askaryfaezeh@yahoo.com

Back ground: Prostate cancer is the most frequent cancer among males in economically developed countries. Among the several risk factors that have been suggested for prostate cancer, only age, ethnicity, and family history of prostate cancer are well-established and primary prevention of this disease is limited. Prior studies had shown that dietary intake could be modified to reduce cancer risk. Most of the data in this area have been drawn from Western world studies and there isn’t enough published data in developing countries. This study aimed to examine the association between dietary patterns and risk of prostate cancer in Iran.

Methods: We conducted a hospital-based, case–control study. Cases were patients aged 40–78 years who were admitted to ‘Labbafi-Nejad Hospital’ with incident, histologically confirmed cancers of the prostate. Cases were diagnosed not before 6 months of the interview, with no history of cancers of other sites. Controls were patients (43-71years) who were admitted to the emergency service of the same hospital without neoplastic conditions and long-term modification of diet. Cases and controls were frequency matched according to the age (10-year groups). A total of fifty patients with prostate cancer and a hundred controls underwent face-to-face interviews. We assessed participants’ dietary intakes during the past year, using a valid and reliable semi-quantitative food frequency questionnaire (FFQ). This FFQ consists of 168 food items with standard serving sizes.Factor analysis was used to detect dietary patterns. Multivariate logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI).The SPSS version 16 was used for analyzing the data.

Results: We defined two major dietary patterns in this population: ‘western diet’(high insweets and desserts, organ meat, snacks, tea and coffee, French fries, salt, carbonated drinks, red or processed meat) and ‘healthy diet’ (high in legumes, fish, dairy products, fruits and fruit juice, vegetables, boiled potatoes ,whole cereal and egg). Both healthy andwestern pattern scores were divided into two categories (based on medians).Higher healthy pattern scores were significantly related to decreased risk ofProstate cancer (high 2nd median vs. low 1st median, OR =0.05, 95% CI=0.01- 0.27). An increased risk of prostate cancer was observed with the western pattern (high 2nd median vs. low 1st median, OR = 12.68, 95% CI= 2.72- 59.01).

Conclusions: The results of this study suggested that diet might be associated with prostate cancer.

Key words: prostate cancer; diet; case control study