Growing prostate cancer cells need an essential nutrient, the amino acid called leucine, which is pumped into the cell by specialised proteins. And this could be prostate cancer’s weak link.

The team at the Centenary Institute found, in a study to be published this month in Cancer Research, that prostate cancer cells have more pumps than normal. This allows the cancer cells to take in more leucine and outgrow normal cells.

Dr Holst says one of the other spin-offs of the discovery is a better understanding of the links between prostate cancer and eating foods high in leucine which include meat and poultry, seafood and dairy. Read more

In this latest study, 63 percent of African-American men were deficient in vitamin D compared with 18 percent of Caucasian men. To make matters worse, the blood serum levels of vitamin D in the African-American men were even lower than those in Caucasian men who were deficient: vitamin D levels were only 17.2 ng/ml among black men compared with 24.2 ng/ml among the white men.

When vitamin D levels fall below 20 ng/ml, “the bone starts to become brittle in adults and in kids it causes rickets,” noted Murphy. Vitamin D deficiency is also associated with prostate cancer, diabetes, multiple sclerosis, and rheumatoid arthritis. The commonly used and healthier cutoff point is 30 ng/ml of vitamin D, although the Vitamin D Council recommends 50 ng/ml as the optimal, minimal level for health.

All the men in this study were from Chicago, an area of low sunlight compared with more southern regions. When you combine insufficient exposure to sunlight with the fact that the pigment called melanin in darker skin blocks the ultraviolet rays needed by the body to produce vitamin D, the result is that African-American men need up to six times more exposure to sunlight than Caucasian men, Murphy noted.

Murphy, a Chicago-based African-American physician, pointed out that he needs 90 minutes of sunlight three times a week to get enough vitamin D compared with just 15 minutes three times a week for a Caucasian male in Chicago.

Murphy explained that all men who live in the northern third of the United States need to increase their vitamin D supplementation.  To achieve a healthy level of vitamin D in their bloodstream, Murphy said African-American men who live in Chicago need to take nearly 2,500 International Units of a vitamin D supplement. Yet the standard, one-size-fits-all recommendation from the Institute of Medicine is merely 600 IUs daily for adults.

All men, and especially African-American men, should evaluate their vitamin D intake and talk to their doctor about supplementation. Foods that contain vitamin D include cold-water fish such as salmon, herring, trout, sardines, and halibut; fortified orange juice, tuna, and fortified cereals are moderate sources.

Sources:

Northwestern University

Vitamin D Council: http://www.vitamindcouncil.org/about-vitamin-d/vitamin-d-deficiency/am-i-vitamin-d-deficient/

Results of this research were released on the heels of another study, from Harvard, in which investigators named cruciferous vegetables capable of reducing prostate cancer progression. Together, these studies support the hypothesis that men who consume a diet high in vegetables can benefit in the fight against prostate cancer.

In the UCSF study, the authors compared the highest to lowest intake of different vegetables, including leafy greens and those with a high content of carotenoids, which are the pigments that color fruits and vegetables. Among the most commonly recognized carotenoids are alpha-carotene and beta-carotene which, along with the estimated 600 other carotenoids, also act as antioxidants.

A total of 982 men (470 aggressive prostate cancer cases, 512 controls) were enrolled in the study. Eating the most leafy greens was associated with a 34 percent reduced risk of aggressive prostate cancer, while enjoying lots of vegetables rich in carotenoids was associated with a 29 percent reduced risk. The authors also looked at foods high on the glycemic index (e.g., white rice, white bread, baked goods) and reported that they were associated with a 36 percent increased risk of aggressive prostate cancer.

For men, the take home message from this study and the Harvard research is to eat your vegetables, and lots of them, to help in the battle against aggressive prostate cancer and prostate cancer progression.

Sources:

Hardin J et al. Impact of consumption of vegetable, fruit, grain, and high glycemic index foods on aggressive prostate cancer risk. Nutr Cancer 2011 Aug-Sept; 63(6): 860-72

Richman EL et al. Vegetable and fruit intake after diagnosis and risk of prostate cancer progression. Int J Cancer 2011 Aug 5; doi: 10.1002/ijc.26348

It’s been established that abdominal fat and type 2 diabetes are associated with sexual dysfunction, urinary issues, and chronic inflammation. All in all, not a healthy package, and one that is also a recipe for cardiovascular problems.

But according to endocrinologist Dr. Gary Wittert, of the University of Adelaide in Australia, and his team, there is “a lifestyle change that’s quick, cheap, easy, and can improve health substantially beyond anything that medication can do.”

See Weight Loss, Exercise, and Prostate Health

That lifestyle change involves losing about 10 percent of body weight. To show the potential impact of weight loss on erectile function and urinary symptoms, Wittert and his colleagues enrolled 31 obese men who had type 2 diabetes into their study.

All the men were screened for urological and sexual problems and then were assigned to one of two diets: a liquid meal replacement plan that provided about 1,000 calories per day, or a high-protein diet that included fresh fruits and vegetables, lean meat, and fish, and that reduced caloric intake by about 600 calories per day.

The men followed their assigned diet plan for eight weeks: those on the liquid diet lost 8 to 10 percent of their body weight, and those on the high-protein diet lost 5 percent. In addition, men in both groups said their sexual health and urinary symptoms had improved, too.

For the next 44 weeks, all the men were switched to the high-protein diet, and they responded well, losing about 10 percent of their body weight while continuing to enjoy better erectile function and an improvement in urinary function.

See The Prostate Diet

Another benefit seen in the study: the high-protein, low-fat diet reduced inflammation throughout the body, which helped sustain the improvements in sexual, urinary, and endothelial function. What’s endothelial function? Glad you asked.

The inside of blood vessels, including those in the penis, have a lining called the endothelium. When a man becomes aroused, the endothelium in the blood vessels in the penis release nitric oxide, a substance that allows the surrounding muscles to relax, and then from there, things start to look up.

See How Do Erections Work?

The endothelium can be damaged by various factors, including high blood pressure, diabetes, oxidative stress, and excess weight. When the endothelium is damaged, blood flow can be impaired and a man may find it difficult or impossible to get or maintain an erection.

So although the sample size in this study was small, its results suggest—and other evidence supports them—that overweight diabetic men could do themselves and their partners a big favor by losing weight.

Study: Khoo J et al. Comparing effects of a low-energy diet and a high-protein low-fat diet on sexual and endothelial function, urinary tract symptoms, and inflammation in obese diabetic men. J Sexual Med 2011 Aug; doi: 10.1111/j.1743-6109.2011.02417x

While a healthy diet is certainly important in the fight against many diseases, adding dietary supplements is not a sure-fire way to prevent problems from occurring.  Most recently, researchers from the University Health Network in Toronto, Canada found that three hopeful contenders in the fight against prostate cancer – vitamin E (as alpha-tocopherol), selenium, and soy – were not found to be effective, even after three years of taking them daily.

For the study, Dr. Neil Fleshner MD, FRCSC, MPH, the head of the urology department at UHN, and colleagues randomly assigned 303 men to take either a combination of the three nutrients or a placebo every day.  The experimental group received 40 grams of soy (equivalent to about 1/3 of a cup), 800 IU of vitamin E (as alpha-tocopherol) (35 times the recommended dietary levels), and 0.2 grams of selenium (4 times the RDA).

All of the men had a precancerous condition called high-grade prostatic intraepithelial neoplasia (HGPIN) that placed them at a higher risk for developing prostate cancer.  After three years, twenty-six men out of every 100 developed prostate cancer regardless of whether they took the dietary supplement or the placebo control.

Selenium and vitamin E (principally, as alpha-tocopherol) are two nutrients that were also studied in the large SELECT prevention clinical trial funded by the National Cancer Institute.  Both are antioxidants which are thought to help control cell damage that can lead to cancer.  Over 35,000 men participated in the study however, the researchers found that selenium, either alone or combined with vitamin E (as alpha-tocopherol), did not prevent the development of prostate cancer. The researchers did observe a statistically nonsignificant increased risk of prostate cancer with vitamin E alone and newly diagnosed type 2 diabetes with selenium alone. (Lippman 2009) A post-SELECT Trial analysis, however, has suggested that further research is needed to determine whether selenium should still be considered in the fight against prostate cancer. (Ledesma 2010)

“I think in the absence of more compelling scientific data for vitamin E and selenium that we should move on” said Dr. Eric Klein.  Dr. Klein was not involved with the Canadian study, but is the chair of the Glickman Urological and Kidney Institute at the Cleveland Clinic and headed previous research into the nutrients’ potential affects against prostate cancer.

It should be noted that the studies that have evaluated the potential benefit of vitamin E supplements and health conditions use the form alpha-tocopherol, which is the most common form of the vitamin in both body tissues and dietary supplements.  Emerging research is taking into consideration another form of vitamin E, known as gamma-tocopherol which is the major form of vitamin E found in plant seeds and the diet.  According to a study published in 2001 in the American Journal of Clinical Nutrition, gamma-tocopherol may well be more effective of an antioxidant than alpha-tocopherol and it has been shown that alpha alone, without gamma is not as effective as when higher concentrations of gamma exist in the right ratio.  Researchers are looking into the gamma form for benefits in preventing both prostate cancer and heart disease and the results to date are encouraging.

On the other hand, previous research has shown a beneficial association between soy and prostate cancer.  Genistein is an antioxidant and isoflavone found primarily in soybeans and has been shown in test tube and animal studies to interfere with the growth of prostate cancer cells and help prevent metastasis.  Observational studies note that men in countries such as China in Japan who regularly eat soy products such as tofu and miso have lower rates of prostate cancer incidence, although the type and quantity of soy consumed in those countries is much different than consumed in the West.

Dr. Fleshner notes that the study may not have shown positive benefits because taking the dietary supplements for just three years may not have been enough to prevent HGPIN from progressing to prostate cancer.

Resources:

1.  Original Reports – Urologic Oncology:Progression From High-Grade Prostatic Intraepithelial Neoplasia to Cancer: A Randomized Trial of Combination Vitamin-E, Soy, and Selenium

Neil E. Fleshner, Linda Kapusta, Bryan Donnelly, et al. JCO May 2, 2011:JCO.2010.32.0994; published online on May 2, 2011;

http://jco.ascopubs.org/content/early/2011/04/26/JCO.2010.32.0994

2.  Medical News Today, Prostate Cancer: More Soy In Diet May Protect Against Deadly Disease, accessed May 5, 2011 at http://www.medicalnewstoday.com/articles/224373.php

3.  NCHS Data Brief, Number 61, April 2011

Dietary Supplement Use Among U.S. Adults Has Increased Since NHANES III (1988–1994), accessed May 5, 2011 athttp://www.cdc.gov/nchs/data/databriefs/db61.htm

4.  gamma-tocopherol, the major form of vitamin E in the US diet, deserves more attention.  Jiang Q, Christen S, Shigenaga MK, Ames BN.  Source:  University of California, the Department of Molecular and Cell Biology, Berkeley, USA.  Am J Clin Nutr. 2001 Dec;74(6):714-22.  accessed May 7 at http://www.ncbi.nlm.nih.gov/pubmed/11722951

5.  Dr. Neil Fleshner’s profile can be found at:

http://www.uhnresearch.ca/researchers/profile.php?lookup=1843

In a new review of the literature, J. Kellogg Parsons, MD, MHS, associate professor of surgery at the University of California, San Diego, Moores Cancer Center, outlined the modifiable lifestyle factors that contribute to the development of BPH and LUTS.  These two conditions are often studied together because BPH is the main cause of LUTS.

In the review, Parsons named three factors associated with an increased risk of both BPH and LUTS: obesity, diabetes, and consumption of meat and fat. He noted that most studies have found a relationship between obesity and an increased risk of both BPH and LUTS, including a Norwegian study of 21,700 men (Seim 2005) and the seven-year prospective analysis of 5,700 men who participated in the Prostate Cancer Prevention Trial. (Kristal 2007)

Parsons stated that “disruptions in glucose homeostasis have been strongly and robustly associated with a higher likelihood of prostate enlargement, BPH, and LUTS” in a variety of studies involving tens of thousands of men. Results from the Prostate Cancer Prevention Trial also show that meat and fat consumption are associated with an increased risk of BPH and LUTS. (Kristal 2008)

On the positive side, lifestyle factors found to help reduce the risk of BPH and LUTS include exercise, vegetable intake, and alcohol consumption. Regarding exercise, Parsons noted a 2008 study in which a meta-analysis of 11 studies involving 43,083 men found that moderate to vigorous exercise was associated with up to a 25 percent reduced risk of both BPH and LUTS. (Parsons 2008)

Vegetable consumption can reduce a man’s risk of BPH and LUTS, (Kristal 2008) and benefits are especially good for higher blood levels of carotene and lycopene, which are found in high concentrations in vegetables such as tomatoes, carrots, and greens. (Tavani 2005; Rohrmann 2004)

The research findings on alcohol consumption are mixed. While a meta-analysis of 19 studies involving 120,091 men found a 35 percent reduced likelihood of BPH among men who drank moderately daily, the study also found an increased risk of LUTS. (Parsons 2009)

Parsons also reported that research thus far has not reached any definite conclusions about the associations between cholesterol/triglycerides and BPH and LUTS, nor between smoking and both of these conditions.

This review suggests that modifiable lifestyle factors, including exercise, obesity, diabetes, diet, and alcohol consumption have a substantial impact on the development of BPH and LUTS. Parsons thus noted “there is little, if any, downside to promotion of healthy lifestyle interventions—weight loss, exercise, decreasing meat and fat intakes, and increasing vegetable intake—among BPH and LUTS patients.”

Sources

Kristal AR et al. Race/ethnicity, obesity, health related behaviors and the risk of symptomatic benign prostatic hyperplasia: results from the prostate cancer prevention trial. J Urol 2007; 177:1395–1400.

Kristal AR et al. Dietary Patterns, Supplement Use, and the Risk of Symptomatic Benign Prostatic Hyperplasia: Results from the Prostate Cancer Prevention Trial. Am J Epidemiol 2008; 167:925–34.

Parsons JK. Lifestyle factors, benign prostatic hyperplasia, and lower urinary tract symptoms. Curr Opin Urol 2011; 21:1-4

Parsons JK, Im R. Alcohol consumption is associated with a decreased risk of benign prostatic hyperplasia. J Urol 2009; 182:1463–68.

Parsons JK, Kashefi C. Physical activity, benign prostatic hyperplasia, and lower urinary tract symptoms. Eur Urol 2008; 53:1228–35.

Rohrmann S et al. Association between serum concentrations of micronutrients and lower urinary tract symptoms in older men in the Third National Health and Nutrition Examination Survey. Urology 2004; 64:504–9.

Seim A et al.  The prevalence and correlates of urinary tract symptoms in Norwegian men: the HUNT study. BJU Int 2005; 96:88– 92.

Tavani A et al. Intake of selected micronutrients and the risk of surgically treated benign prostatic hyperplasia: A Case–Control Study from Italy. Eur Urol 2005. http://www.sciencedirect.com/ and http://www.europeanurology.com/.

“It’s a really sad thing about selenium,” concedes Dr Helen Rippon, head of research management at the UK Prostate Cancer Charity (www.prostate-cancer.org.uk). “All the initial laboratory data seemed to suggest it could be particularly useful in combating prostate cancer, but when it came down to the really big human-based trials it just didn’t cut it.” READ MORE

Results of a new study show that among men with prostate cancer who were treated with hormone therapy, those who were overweight or obese had a higher risk of worsening prostate cancer than did normal weight men.  The research, conducted by researchers at Duke University Medical Center, was presented at the 2011 American Urological Association Annual Meeting.

One reason for the interest in obesity and prostate cancer is the prominence of both conditions: one-third of men in the United States are obese, and prostate cancer affects about 16 percent of US men. The relationship between the two factors was examined by Christopher J. Keto, MD, a urologic fellow at Duke, and his colleagues, who evaluated 287 men who had undergone prostatectomy. All the men had then undergone hormone therapy to inhibit production of testosterone.

Keto and his team found that men who were overweight or obese had a threefold increased risk of cancer progression than did men of normal weight. Overweight men also had a greater than threefold increased risk of cancer metastasis to the bone compared with normal-weight men, while obese men had a fivefold increased risk. Keto noted that obese men may need a higher dose of hormone therapy, because currently “the dose is the same regardless of weight.”

Stephen J. Freedland, MD, associate professor of urology in the Duke Prostate Cancer Center and senior author of the study, noted that “the study supports a growing body of literature showing that obese men with prostate cancer do worse,” and that “if obesity is bad for prostate cancer, we may have to be more aggressive in our treatment.”

Source: Duke University Medical Center: http://www.dukehealth.org/health_library/news/obesity-linked-to-higher-risk-of-prostate-cancer-progression