This one-to-one, age- and race-matched case-control study involved 181 histologically confirmed black prostate cancer patients and 181 controls seen at three major hospitals in Washington, DC, during the period 1979-1982. Personal interviews were conducted to obtain the number of times food items of specified serving size were consumed per week by cases and controls during the age periods 30-49 and 50 years and older. Then the average daily consumption of each of 18 nutrients per 1,000 calories was calculated. There was risk enhancement associated with increased intake of proteins, total fat, saturated fat, oleic acid, and vitamin A during the age period 30-49 years. The association was highly significant for vitamin A and approached statistical significance for the other four nutrients. A hypothesis based on disturbance of the zinc-retinol binding protein-vitamin A axis was put forward to explain the relative risk enhancement effect of vitamin A on prostate cancer.

No abstract

This is a one-to-one, age- and race-matched case-control study involving 55 histologically confirmed black prostate cancer patients and 55 controls who were seen at three major hospitals in Washington, DC from 1982 to 1984. Personal interviews were conducted to obtain the number of times food items of specified serving size were consumed per week by cases and controls; the subjects were grouped according to the age periods 30-49 and 50 years and older. We then calculated the average daily consumption of each of 18 nutrients per 1,000 calories. There was a significant negative association between linoleic acid (p less than 0.04) for the 50 years and older group, thiamin (p less than 0.05) for those 30-49 years old, riboflavin (p less than 0.03) for the 50 and older group, and iron (p less than 0.05) for those 30-49 years old. The results of this study suggest that the intake of thiamin and iron (in subjects 30-49 years old), linoleic acid and riboflavin (in subjects 50 years and over) could be protective because control subjects consumed more of these nutrients than did the cases.

The proposed study was designed to investigate the effect of growth hormone (GH) on liver vitamin A release and uptake at the tissue level. Labeled vitamin A (retinol) was injected in hypophysectomized (hypox) rats, and plasma radioactivity was monitored at intervals for up to 6 hours and at 24 hours following injection. Controls (intact sham-operated) received similar treatment. The results showed that the radioactivity reached its maximum levels in both groups between the third and fourth hours following injection and declined thereafter at different rates in each group. At 24 hours following injection, plasma radioactivity in the intact rats was less than 10% of its maximum levels while in the hypox rats for the same time period it remained at 80--90% of its maximum levels. A single injection of GH at the third hour after injection in the hypox rats decreased significantly (P less than 0.01) plasma radioactivity while radioactivity in the testes and kidneys and in urine collected for the 24 hours increased significantly (P less than 0.01). Hypophysectomy had no effect of vitamin A absorption and liver vitamin A release to the blood. Also, hypophysectomy had no significant effect on plasma and tissue retinol-binding protein levels and its binding capacity to retinol. It is concluded that a facilitory effect of GH at the tissue level may be an important factor in vitamin A metabolism.