Introduction

This complementary and alternative medicine (CAM) information summary provides an overview of the use of various foods and dietary supplements for reducing the risk of developing prostate cancer or for treating prostate cancer. This summary includes the history of research on the following six different foods or dietary supplements, reviews of laboratory and animal studies, and results of clinical trials.

• Green tea.
• Lycopene.
• Modified citrus pectin.
• Pomegranate.
• Soy.
• Zyflamend.

Each type of dietary supplement or food will have a dedicated section in the summary, and new topics will be added over time.

Prostate cancer is the most common noncutaneous cancer affecting men in the United States. From 2004 to 2008, the median age of diagnosis of prostate cancer was 67, and the incidence rate was 156 cases per 100,000 men per year.[1]

Many studies suggest that CAM use is common among prostate cancer patients, and the use of vitamins, supplements, and specific foods is frequently reported by these patients. For example, the Prostate CAncer Therapy Selection (PCATS) study was a prospective study investigating men’s decision-making processes about treatment following a diagnosis of local stage prostate cancer. As part of this study, patients completed surveys regarding CAM use, and more than half of the respondents reported using one or more CAM therapies, with mind-body modalities and biologically based treatments being the most commonly used.[2]

International studies have reported similar findings. A Swedish study published in 2011 found that, overall, participants with prostate cancer were more likely to have used supplements than were healthy population-based control subjects. Supplement use was even more common among the patients with the healthiest dietary patterns (e.g., high consumption of fatty fish and vegetables).[3] In a Canadian study, CAM use was reported among 39% of recently diagnosed prostate cancer patients, and the most commonly used forms of CAM were herbals, vitamins, and minerals. Within those categories, saw palmetto, vitamin E, and selenium were the most popular. The two most popular reasons for choosing CAM were to boost the immune system and to prevent recurrence.[4] According to another Canadian study, approximately 30% of survey respondents with prostate cancer reported using CAM treatments. In that study, vitamin E, saw palmetto, and lycopene were the most commonly used.[5] A British study published in 2008 indicated that 25% of prostate cancer patients used CAM, with the most frequently reported interventions being low-fat diets, vitamins, and lycopene. The majority of CAM users in this study cited improving quality of life and boosting the immune system as the main reasons they used CAM.[6]

Vitamin and supplement use has also been documented in men at risk of developing prostate cancer. One study examined vitamin and supplement use in men with a family history of prostate cancer. At the time of the survey, almost 60% of the men were using vitamins or supplements. One third of the men were using vitamins and supplements that were specifically marketed for prostate health or chemoprevention (e.g., selenium, green tea, and saw palmetto).[7] A 2004 study examined herbal and vitamin supplement use in men attending a prostate cancer screening clinic. Men attending the screening clinic completed questionnaires about supplement use. Of the respondents, analysis revealed that 70% used multivitamins, and 21% reported using herbal supplements.[8]

A meta-analysis published in 2008 reviewed studies reporting vitamin and mineral supplement use among cancer survivors. The results showed that, among prostate cancer survivors, vitamin or mineral use ranged from 26% to 35%.[9]

Although many prostate cancer patients use CAM treatments, they do not all disclose their CAM use to treating physicians. According to results from the PCATS study, 43% of patients discussed their CAM use with a healthcare professional.[2] In two separate studies, 58% of respondents told their doctors about their CAM usage.[4,6]

How do prostate cancer patients decide whether to use CAM or not? A qualitative study published in 2005 described results from interviews with prostate cancer patients who were CAM users or nonusers. The study identified differences in thinking patterns between the two groups and suggested that no specific theme led patients to CAM, rather a combination of ideas directed them. For example, the perception of CAM being harmless was associated with the belief that conventional medicine resulted in many negative side effects.[10] Results of a 2003 qualitative study suggest that decision making by prostate cancer patients about CAM treatments depends on both fixed (e.g., medical history) and flexible (e.g., a need to feel in control) decision factors.[11]

References

1. National Cancer Institute.: SEER Stat Fact Sheets: Prostate. Bethesda, MD: National Cancer Institute, 2011. Available online. Last accessed June 11, 2012. 
   
   
2. McDermott CL, Blough DK, Fedorenko CR, et al.: Complementary and alternative medicine use among newly diagnosed prostate cancer patients. Support Care Cancer 20 (1): 65-73, 2012.  [PUBMED Abstract]
   
   
3. Westerlund A, Steineck G, Bälter K, et al.: Dietary supplement use patterns in men with prostate cancer: the Cancer Prostate Sweden study. Ann Oncol 22 (4): 967-72, 2011.  [PUBMED Abstract]
   
   
4. Eng J, Ramsum D, Verhoef M, et al.: A population-based survey of complementary and alternative medicine use in men recently diagnosed with prostate cancer. Integr Cancer Ther 2 (3): 212-6, 2003.  [PUBMED Abstract]
   
   
5. Boon H, Westlake K, Stewart M, et al.: Use of complementary/alternative medicine by men diagnosed with prostate cancer: prevalence and characteristics. Urology 62 (5): 849-53, 2003.  [PUBMED Abstract]
   
   
6. Wilkinson S, Farrelly S, Low J, et al.: The use of complementary therapy by men with prostate cancer in the UK. Eur J Cancer Care (Engl) 17 (5): 492-9, 2008.  [PUBMED Abstract]
   
   
7. Bauer CM, Ishak MB, Johnson EK, et al.: Prevalence and correlates of vitamin and supplement usage among men with a family history of prostate cancer. Integr Cancer Ther 11 (2): 83-9, 2012.  [PUBMED Abstract]
   
   
8. Barqawi A, Gamito E, O'Donnell C, et al.: Herbal and vitamin supplement use in a prostate cancer screening population. Urology 63 (2): 288-92, 2004.  [PUBMED Abstract]
   
   
9. Velicer CM, Ulrich CM: Vitamin and mineral supplement use among US adults after cancer diagnosis: a systematic review. J Clin Oncol 26 (4): 665-73, 2008.  [PUBMED Abstract]
   
   
10. Singh H, Maskarinec G, Shumay DM: Understanding the motivation for conventional and complementary/alternative medicine use among men with prostate cancer. Integr Cancer Ther 4 (2): 187-94, 2005.  [PUBMED Abstract]
    
    
11. Boon H, Brown JB, Gavin A, et al.: Men with prostate cancer: making decisions about complementary/alternative medicine. Med Decis Making 23 (6): 471-9, 2003 Nov-Dec.  [PUBMED Abstract]