A Case‐Control Study of Prostatic Cancer With Reference to Dietary Habits

A case‐control study of prostatic cancer which consisted of 100 patients with prostatic cancer, matched for hospital, age (±3 yr) and hospital admission date (±3 months) to patients with benign prostatic hyperplasia (BPH) and hospital controls, was conducted from 1981 to 1984. Low daily intake of beta‐carotene (RR = 2.13: 95% confidence interval, 1.20–3.77) and of vitamin A (RR = 1.94: 1.10–3.43), as compared to the intake of those substances by BPH controls, were factors significantly correlated with the development of prostatic cancer. Low daily intake of beta‐carotene (RR = 2.13: 1.20–3.77), as compared with hospital controls, were significantly correlated with prostatic cancer development. Infrequent intake of bread (RR = 2.40: 1.31–4.38), intended to represent a westernized diet, and of spinach (RR = 1.96: 1.01–7.73), a typical green and yellow vegetable, as compared to BPH controls and infrequent intake of spinach (RR = 4.55: 1.82–11.11) as compared to by hospital controls, were significant risk factors for prostatic cancer. Intake of carbohydrates, protein, fat, total calories, fibers, vitamin B and vitamin C were not correlated with the development of prostatic cancer.