I have recently received a number of emails asking about the role of vitamin A (retinol) in advanced prostate cancer. These questions come from the recently released results of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, which have caused the current stir about PSA screening.
In this study, 803 prostate cancer survivors were compared with 844 cancer-free controls. The study found that men with the highest levels of vitamin A in their blood also had a slightly lower risk of having prostate cancer, but they had over a 40% reduced risk of having advanced prostate cancer! The study did control for other unrelated factors such as smoking etc.
Other studies have shown that diet and supplements alone do not increase vitamin A levels in the blood, so there is no quick fix available. Vitamin A concentrations and their effect on prostate cancer seem to be related to some process in the individual’s body, thus factors such as body mass index, physical activity, and fat in the diet maybe more responsible for how vitamin A gets processed and works against prostate cancer.
Other studies of vitamin A and prostate cancer have had mixed results, again adding to the lack of clarity about prostate cancer and its prevention. In the April issue of Cancer Epidemiology Biomarkers and Prevention there was an article that about a study that indicated that just consuming either supplements of vitamin A or foods that are rich in vitamin A probably will not reduce the chances of developing prostate cancer and probably not effect your chance of developing advanced prostate cancer.
How vitamin A plays a role in prostate cancer remains unknown. Clearly, this is an area that remains in need of further study and evaluation. Could vitamin A level screening at the time of initial diagnosis play a role in the decision process of whether to treat or use active surveillance? Could vitamin A levels play a role in the decision to begin more aggressive treatment for men on active surveillance? Can vitamin A levels be incorporated in the normal monitoring process in men who have been treated to give an early warning that a recurrence is about to happen? All these questions remain unanswered, but possibly important.
Schenk JM, Riboli E, Chatterjee N, Leitzmann MF, Ahn J, Aibanes D, Reding DJ, Wang Y, Friesen MD, Hayes RB, Peters U. Serum retinol and prostate cancer risk: a nested case-control study in the prostate, lung, colorectal, and ovarian cancer screening trial.
Cancer Epidemiol Biomarkers Prev. 2009;18:1227-1231.
Joel T Nowak MA, MSW