A recently published small study (1) has found that men with prostate cancer who consumed an active green tea supplement had significant reductions in biological-markers predictive of prostate cancer progression.

Green tea has become an incredibly popular drink and supplement and an increasing number of studies are being published with regards its health benefits.  The number of current human studies investigating the relationship between green tea and prostate cancer is small.  This study (1) was preliminary but informative.  It involved just 26 men aged 41-72 years old who were diagnosed with prostate cancer and due to undergo radical prostatectomy.  The trial looked to determine the effects of short-term supplementation with the active compounds found in green tea on biological-markers in patients diagnosed with prostate cancer.  These biomarkers [technically looking at hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and prostate specific antigen (PSA)] are good prognostic indicators of prostate cancer progression.

The men involved in the study were given 4 green tea capsules for an average of 34 days prior to surgery.  The 4 capsules provided the equivalent of around 12 cups of normally brewed green tea.  Results showed that there was a significant reduction in blood serum levels of the biological-markers of prostate cancer after treatment with the green tea capsules.  Some of the patients had reductions in the biomarker levels of more than 30%.  The supplements had no effect on liver function, which was used as a measure of toxicity.

The supplement used contained 1.3g tea polyphenols, bioactive plant nutrients, that are found naturally in green tea: 800 mg of epigallocatechin-3-gallate (EGCG) and lesser amounts of epicatechin, epigallocatechin, and epicatechin-3-gallate.  Green tea supplements often have these polyphenols listed as active 'ingredients'.

In a press release(2) one of the authors commented: "These studies are just the beginning and a lot of work remains to be done, however, we think that the use of tea polyphenols alone or in combination with other compounds currently used for cancer therapy should be explored as an approach to prevent cancer progression and recurrence". 

In the same press release(2) William G. Nelson, V., M.D., Ph.D., professor of oncology, urology and pharmacology at the Johns Hopkins Kimmel Cancer Center, said that he believed the reduced blood serum biomarkers of prostate cancer may be attributable to some sort of benefit relating to green tea components "Unfortunately, this trial was not a randomized trial, which would have been needed to be more sure that the observed changes were truly attributable to the green tea components and not to some other lifestyle change (better diet, taking vitamins, etc.) men undertook in preparation for surgery,". However, "this trial is provocative enough to consider a more substantial randomized trial."

The researchers of this study are currently conducting a comparable trial among patients with breast cancer.

For general information about nutrition and prostate health please read my previous blog posts on the subject (Prostate health Part I and II).  For more information on prostate cancer please visit the Prostate Cancer Care website.

The World Cancer Research Fund (WCRF) estimate that lifestyle factors such as being overweight, eating an unhealthy diet and being inactive are responsible for about a third of all cancers in developed countries (3).  Please visit the WCRF website for information related to diet and cancer prevention.

1. McLarty J et al.  2009.  Tea Polyphenols Decrease Serum Levels of Prostate-Specific Antigen, Hepatocyte Growth Factor, and Vascular Endothelial Growth Factor in Prostate Cancer Patients and Inhibit Production of Hepatocyte Growth Factor and Vascular Endothelial Growth Factor In vitro.  Cancer Prevention Research, 10.1158/1940-6207.CAPR-08-0167.  Published online June 19
2.Sciencedaily.com press release.  American Association for Cancer Research (2009, June 22). Green Tea May Slow Prostate Cancer Progression. ScienceDaily. Retrieved June 23, 2009, from http://www.sciencedaily.com¬ /releases/2009/06/090619112329.htm
(3) WCRF/AICR.  2009.  Policy and action for cancer prevention.  Food, nutrition and physical activity: a global perspective.  Washington DC: AICR, 2009.

Written by Ani Kowal

Following on from Monday, here are some more important dietary and lifestyle factors that may help to prevent prostate problems:

Lycopene is an antioxidant carotenoid that I have mentioned a few times in my blog posts.  It can be found within red/orange coloured fruits and vegetables such as tomatoes, watermelon, pink and red grapefruits, guava and papaya .  A review of multiple studies was published this year(1), it discusses the role of lycopene in the prevention of prostate cancer.  The paper states “Based on the evidence from epidemiologic [association/observational studies], animal, in vitro [test tube] and human clinical trials, it is evident that lycopene, a non-provitamin A carotenoid, is a promising agent for prostate cancer prevention”, the authors go on to suggest that larger trials should be implemented in order to assess whether this nutrient could be used as a medical agent for prostate cancer prevention.  If you do not regularly consume lycopene containing foods you may wish to consider a lycopene supplement.  Absorption of lycopene from foods, or indeed supplements, is affected greatly by fat.  Without a fat source lycopene will not be efficiently absorbed into the body so you would do well to find supplements that contain an oil base (there are many available) and dress any salads or vegetables with a little olive oil.  Studies (2,3) also suggest that lycopene may be useful in reducing the risk and progression of BPH.

Again I am going to mention oily fish and the essential omega 3 fatty acids which they contain!  It seems that I mention these essential fats consistently through my blog posts – they are certainly not labelled ‘essential’ for no reason!  Back in 1999 a study(4) in men found that patients with prostate cancer and BPH had significantly lower levels of omega 3 fatty acids in their blood serum compared to healthy men with no signs of either disease.  A study published in 2004(5) involved a cohort of 47,866 men aged 40-75 with no history of cancer at the start of the study (in 1986).  They were followed for 14 years during which time 2965 new cases of prostate cancer were diagnosed, 448 cases being advanced.  A higher intake of the omega 3 fatty acids EPA and DHA (found in oily fish such as salmon, mackerel, sardines and trout) was related to a lower risk of prostate cancer and advanced prostate cancer.  Frequent oily fish consumption has also been strongly associated with a decreased risk of prostate cancer in other studies(6,7). 

Trying to eat at least two portions of oily fish per week would probably benefit multiple health factors, it is yet unknown whether there is a benefit from taking supplemental omega 3 fatty acids for reducing the risk of prostate cancer.  However, if you are not a regular eater of oily fish I would suggest a daily supplement providing around 250g of EPA and 250g of DHA daily.  Since these fatty acids are known to reduce inflammatory markers in the body they may well be helpful in preventing BPH.

Eating well is important for every cell in our body!  A healthy diet could certainly help protect your prostate! 

It is also important for me to mention exercise.  Studies show that men who regularly take some form of physical activity have reduced incidence of BPH and other urinary tract symptoms(8,9).  I am not suggesting a daily pounding of the treadmill in the gym or excessive iron-man measures.  Walking could be enough to help!  One study(9) found that walking for 2-3 hours per week was associated with a 25% reduced risk of having BPH compared to those not walking.  Choose an activity you enjoy, something that gets you moving a few times per week.

(1)Dahan M et al.  2008.  Lycopene in the prevention of prostate cancer.  J Soc Integr Oncol.  6:29-36
(2)Kristal AR et al.  2008.  Dietary patterns, supplement use, and the risk of symptomatic benign prostatic hyperplasia: results from the prostate cancer prevention trial.  Am J Epidemiol.  167:925-934
(3)Schwarz S et al.  2008.  Lycopene inhibits disease progression in patients with benign prostate hyperplasia.  J Nutr.  138:49-53
(4)Yang YJ et al.  1999.  Comparison of fatty acid profiles in the serum of patents with prostate cancer and benign prostatic hyperplasia.  Clin Biochem.  32:405-409.
(5)Leitzmann MF et al.  2004.  Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer.  Am J Clin Nutr.  80:204-216
(6)Hedelin M et al.  2007.  Association of frequent consumption of fatty fish with prostate cancer risk if modified by COX-2 polymorphism.  Int J Cancer.  120:398-405
(7)Augustsson K et al.  A prospective study of intake of fish and marine fatty acids and prostate cancer.  Cancer Epidemiol Biomarkers Prev.  12:64-67
(8)Orsini N et al.  2006.  Long-term physical activity and lower urinary tract symptoms in men. J Urol.  176:2546-50
(9) Platz EA et al.  1998.  Physical activity and benign prostatic hyperplasia.  Arch Intern Med.  158:2349-56.

Written by Ani Kowal

Broccoli, of all things, drew me into writing about prostate problems!  It is being consistently branded as a ‘superfood’ and recently a study found that eating just a few portions of broccoli each week could really go far to protect men from prostate cancer(1).

The most common prostate problem in men over 50 years of age is benign (non harmful/cancerous) enlargement of the prostate gland, known as Benign Prostatic Hypertrophy (BPH).  This noncancerous condition tends to cause an impediment in the flow of urine and often an increased frequency of urination, especially at night.  Sometimes men also experience a difficulty in urinating or a weak flow stream. 

BPH is the most common cause of prostate enlargement, however, prostate cancer can cause similar symptoms and so it is ALWAYS important to visit a GP in the first instance before deciding to follow any natural guidance for BPH.  The good news is that BPH responds very well to nutritional approaches (any programme may take 6-8 weeks to produce results).

Today I am going to talk about BPH and prostate cancer prevention as both are linked to similar nutrients and dietary advice.  It is important to talk about prostate cancer as it is the most frequently diagnosed non-skin cancer within the male population of western countries.

Back to the broccoli!  Multiple studies have linked the eating of diets rich in fruit and vegetables to a reduced risk of prostate cancer, however the broccoli study(1) is the first human trial which investigated the mechanisms behind the positive results.  Amazingly the broccoli seemed to be switching on genes in the body which prevent cancer developing and switching off genes which usually help cancer to spread.  Broccoli is a cruciferous vegetable, as are brussel sprouts, cauliflower, cabbage, rocket, watercress and horseradish.  Cruciferous vegetables contain compounds called isothiocyanates, responsible for the bitter taste, these are likely to be providing the cancer-prevention benefit.  

Other studies have also suggested that consuming one or more portions of broccoli per week can reduce the risk of prostate cancer(2).  Different fruits and vegetables probably work through different mechanisms (for example through their anti-oxidant potential) and so providing a wide variety in the daily diet will confer the best protection to health!

One nutrient that is gaining attention for its cancer preventative prospects is Selenium.  Here in the UK many of us will not obtain much selenium from our diets because our soils are fairly deficient and so agricultural crops contain less selenium than from elsewhere in the world.  Since reducing our wheat imports from the USA our selenium intakes have dropped.  One sure fire way to provide ourselves with enough of this essential mineral is to eat Brazil nuts!  These nuggets are packed with selenium and just 5-6 a day would be beneficial!  A review paper has just been released(3) which assessed several observational and supplement studies that support a preventative effect of selenium against prostate cancer. 

Evidence suggests that selenium acts via multiple mechanisms and pathways, most-notably through its anti-oxidative and anti-inflammatory effects.  Selenium is an integral constituent of many hundreds of enzymes which work in most cells throughout the body and so it is not surprising that it shows anti-cancer potential.  Although larger-scale trials are needed it is, in my opinion, necessary that we make sure that our diets contain adequate amounts of this nutrient.  It is an essential mineral that the body cannot do without and so it seems prudent to at least provide the minimum amounts needed for health.  If you are not a regular consumer of Brazil nuts then you may wish to consider a supplement.  However, single nutrient supplements are not something that I recommend.  If you already take a multi-vitamin and mineral supplement check to see if it contains Selenium.  There is no current recommendation but many health professionals recommend at least a minimum of 35µg (micrograms) a day and no more than 200 µg a day (selenium in high doses can be toxic).  Many multivitamin-mineral supplements provide 75µg. 

Check back later in the week for part II

(1)Traka M, Gasper AV, Melchini A, Bacon JR, Needs PW, et al. Broccoli Consumption Interacts with GSTM1 to Perturb Oncogenic Signalling Pathways in the Prostate. PLoS One, 3(7): e2568 DOI: 10.1371/journal.pone.0002568
(2)Joseph MA et al.  2004.  Cruciferous vegetables, genetic polymorphisms in glutathione S-transferases M1 and T1, and prostate cancer risk.  Nutr Cancer 50:206-213
(3)Peters U & Takata Y.  2008.  Selenium and the prevention of prostate and colorectal cancer.  Mol Nutr Food Res.  Sep 2 [EPub ahead of print]

Written by Ani Kowal