Chapter 23 - Tomatoes, Tomato Products, and Lycopene in Prevention and Therapy of Prostate Diseases – Is There Evidence from Intervention Studies for Preventive and for Therapeutic Effects?

Abstract

Based on epidemiological data, regular consumption of tomatoes, tomato products (TTP), and isolated lycopene is postulated to contribute to the prevention of prostate cancer (PCA), whereas epidemiological data for the prevention of benign prostate hyperplasia (BPH) are scarce. There is a body of in vitro evidence that lycopene protects from DNA damage by increasing antioxidant protection. Moreover, lycopene induces apoptosis and phase II enzymes and inhibits the IGF-1 pathway, which might prevent the development and progression of PCA. Furthermore, lycopene reduces the synthesis of 5-α-dihydrotestosterone stimulating the growth of the prostate gland. The protective effect of TTP and/or lycopene on the development of PCA can only be verified by intervention studies. Since an intervention study with the endpoint PCA would last several years, the benefit from diet or nutrients can only be assessed by suitable surrogate markers that are associated with PCA, such as DNA damage and changes in the insulin-like growth factor I (IGF-1) signaling pathway. The therapeutic value of TPP and/or lycopene for treatment of PCA was evaluated by consideration of intervention studies in which clinically or prognostically relevant parameters were measured. The same procedure was applied for the therapy of BPH.