Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

SOY, CURCUMIN & PROSTATE CANCER RISK

Because chronic inflammation within the prostate gland is through to be an important risk factor for prostate cancer, anti-inflammatory dietary supplements and medications may be able to reduce the risk of prostate cancer by reducing inflammation.

Isoflavones from soy-based foods are known to act as a weak form of estrogen (the dominant female sex hormone).  Based upon this estrogen-like behavior, as well as potential anti-inflammatory properties, soy isoflavones are being studied as possible prevention and treatment agents for prostate cancer, and other types of cancer. 

Curcumin, which is present in the Indian curry spice turmeric, is also known to have potent anti-inflammatory properties, and has also been the subject of considerable cancer prevention and cancer treatment research.

A newly published prospective, randomized, blinded, placebo-controlled research study, published in the current issue of the journal Prostate, suggests that the combination of soy isoflavones and curcumin may have important potential prostate cancer prevention properties.

In the first part of this study, human prostate cancer cells were treated with a combination of soy isoflavones and curcumin.  Treatment of these human cancer cells with soy isoflavones and curcumin resulted in a significant reduction of prostate-specific antigen (PSA) production by these malignant cells (PSA is a marker of both prostate gland inflammation and prostate gland cancer).

As regular readers of this column are already aware, treatments performed in the laboratory that have beneficial effects on cancer cells, or on mice or rats, do not always have the same positive effects on living, breathing human beings.  Therefore, the findings of the second part of this study are of particular interest.  A total of 85 men with elevated PSA levels, but without prostate cancer (as confirmed by prostate biopsy), were enrolled in the second phase of this intriguing small study.  These 85 men were divided into two groups, and one group received daily supplements containing both soy isoflavones and curcumin, while the second (control) group of men received placebo (sugar) pills that were identical in appearance to the supplement pills (neither the 85 men, nor the nurses who dispensed the supplement pills and placebo pills, were aware of which pills each study volunteer was receiving until after the research study had been completed).

PSA blood levels were tested at the beginning of the clinical portion of this study, and once again 6 months later.  As was observed in the prostate cancer cells during the first part of this study, men with a PSA level of 10, or higher, experienced a significant reduction in their blood PSA levels 6 months after starting daily supplementation with soy isoflavones and curcumin.

Although this brief study cannot definitively confirm that soy isoflavone and curcumin supplements reduce the risk of prostate cancer, their ability to reduce elevated PSA levels in men with chronic prostate inflammation, but without evidence of prostate cancer, at least suggests a potential role in the prevention of prostate cancer (presumably through a reduction in prostate gland inflammation).

While there are multiple human research studies underway that are evaluating the effectiveness of soy isoflavones as cancer prevention agents, currently, there are no major human studies looking at the effects of curcumin on prostate cancer risk.  Based upon the findings of this small, interesting study of soy isoflavones and curcumin, which suggest a potential additive effect on PSA reduction when both of these dietary supplements are taken together, human research trials should be developed to look at the long-term impact, if any, of combined soy isoflavone and curcumin supplementation on prostate cancer risk.

For additional research information on soy isoflavones and curcumin in cancer prevention and cancer treatment, please review the following previous columns:

Soy Foods & Stomach Cancer Risk

Cruciferous Vegetables, Soy & Breast Cancer Risk

Soy Isoflavones & Recurrent Prostate Cancer

Soy Isoflavones Decrease Breast Cancer Recurrence Risk

Genistein (Soy Isoflavone) & Prostate Cancer

Diet, Soy & Breast Cancer Risk

Viagra & Sexual Function in Women; Patient-Reported Adverse Hospital Events; Curcumin & Pancreatic Cancer

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author  

http://www.youtube.com/watch?v=7-Tdv7XW0qg

I and the staff of Weekly Health Update would like to take this opportunity to thank the more than 100,000 new and returning readers who visit our premier global health information website every month.  As always, we enjoy receiving your stimulating feedback and questions, and I will continue to try and personally answer as many of your inquiries as I possibly can.

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers” 

SOY & CURCUMIN REDUCE PROSTATE-SPECIFIC ANTIGEN (PSA)

Regular readers of this column are already aware that the regular consumption of foods containing soy isoflavones may be associated with a reduced risk of developing prostate cancer, and other types of cancer as well.  Curcumin, as curry lovers know, is contained within the spice known as turmeric.  Curcumin has been extensively studied, and it too may possess anti-cancer properties as well.  Both of these dietary compounds are thought to have potent anti-inflammatory effects on the prostate gland, and on other organs of the body.  Additionally, soy isoflavones also act weak estrogens (“phytoestrogens”), and may suppress prostate gland activity on this basis too.

Prostate cancers, as well as the normal prostate gland cells that give rise to prostate cancer, produce PSA (prostate-specific antigen), which allows doctors to detect new or recurrent prostate cancers by measuring the level of PSA in the blood.  A newly published research study, which appears in the current issue of the journal The Prostate, adds further evidence that soy isoflavones and curcumin may have an important role to play in prostate cancer prevention and, possibly, prostate cancer treatment.

This study consisted of both a laboratory experiment and a small clinical research trial with human volunteers.  In the laboratory portion of this study, human prostate cancer cells were treated with soy isoflavones and curcumin.  When these prostate cancer cells were treated with soy isoflavones and curcumin, the production of PSA by these cells was dramatically decreased.  Moreover, a receptor for male sex hormones, which prostate cancers use to fuel their growth, was significantly suppressed following treatment of these cells with soy isoflavones and curcumin.

In the clinical portion of this research study, men who had undergone prostate gland biopsies due to an elevated PSA blood level, but who were subsequently found not to have prostate cancer, were also evaluated.  In this prospective, randomized, placebo-controlled trial, 85 men without prostate cancer, but with elevated blood PSA levels, were divided into two groups.  The “experimental group” of men received curcumin and soy isoflavones once per day.  The “control group” of men received a placebo (“sugar pill”) once per day.  Neither group of male volunteers, nor the research assistants who dispensed these pills, knew which men received the placebo pills and which received the soy isoflavone and curcumin pills.

PSA levels were tested in all of these male volunteers at the beginning of the study, and 6 months later.  Among the men randomized to receive daily supplements of soy isoflavones and curcumin, the level of PSA in their blood dramatically declined following 6 months of supplementation with soy isoflavones and curcumin. 

While the results of this small and elegant research study do not prove that soy isoflavones and curcumin can actually prevent prostate cancer in humans, these results do suggest, at least, a biological mechanism whereby these dietary compounds might reduce the risk of developing prostate cancer, and might also have anti-cancer effects in patients with prostate cancer.  However, only large-sale prospective, randomized, blinded, placebo-controlled human clinical trials will be able to prove that these dietary compounds can actually prevent or effectively treat prostate cancer.

At this time, there are multiple ongoing and recently completed prostate cancer prevention and treatment clinical research trials using soy isoflavone supplements.  The results of several of these studies will, hopefully, become available within the next 3 to 5 years. 

While there are multiple cancer prevention and cancer treatment research trials underway that are evaluating curcumin, none of these ongoing curcumin clinical trials are focused on prostate cancer, unfortunately. 

Based upon the findings of this small and innovative research study of soy isoflavones and curcumin, the next logical step would be a large prospective, randomized, placebo-controlled, blinded study that randomizes patient volunteers to placebo, versus soy isoflavones only, versus curcumin only, versus a combination of soy isoflavones and curcumin.  A cancer prevention study could look at prostate cancer incidence in men who are already at high risk of developing this common form of cancer.  A prostate cancer treatment study, using the same methods, could assess the clinical impact of soy isoflavones and curcumin on the progression or recurrence of prostate cancer in men who have already been diagnosed with this form of cancer.

To learn more about the role of soy isoflavones and curcumin as potential cancer prevention nutrients, look for the publication of my new landmark evidence-based book, “A Cancer Prevention Guide for the Human Race,” in the summer of this year.

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author

http://www.youtube.com/watch?v=7-Tdv7XW0qg