Except for skin cancer, cancer of the prostate is the most common malignancy in American men. In the majority of men with prostate cancer, it is very slow growing, and many, if not most, of these men will not die because of the prostate cancer, but rather will live with it until they eventually die of some other cause. Early prostate cancer is localized (confined) to the gland, and the majority of patients with localized prostate cancer have a long survival after diagnosis.
All men are at risk in industrialized nations. The most common risk factor is age. 90% of men diagnosed with prostate cancer each year are over the age of 65. African American men have a higher risk of prostate cancer than white Americans. Dramatic differences in the incidence of prostate cancer are seen in different countries, and there is some evidence that a diet higher in animal fat may, in part, underlie these differences in risk. Genetic factors also appear to play a role, particularly for families in whom the diagnosis is made in men under 60 years of age. The risk of prostate cancer rises with the number of close relatives who have the disease.
Prostate cancer often does not cause symptoms for many years. By the time symptoms occur, the disease may have spread beyond the prostate.
Two tests are commonly used to detect prostate cancer in the absence of any symptoms. One is the digital rectal exam, in which a doctor feels the prostate through the rectum to find hard or lumpy areas. The other is a blood test used to detect a substance made by the prostate called prostate specific antigen (PSA). Together, these tests can detect many silent prostate cancers, those that have not caused symptoms.
Neither of the screening tests for prostate cancer is perfect. Most men with mildly elevated PSA do not have prostate cancer, and many men with prostate cancer have normal levels of PSA. Testing for the percentage of free PSA can help. The digital rectal exam can miss many prostate cancers.
In a 2003 study from the Memorial Sloan-Kettering Cancer Center in New York City, researchers collected five blood samples each from nearly 1,000 men whose median age was 62 years. More than 20% of the subjects were found to have PSA levels high enough that many doctors would have recommended a biopsy. Half of those men, however, had follow-up tests with normal PSA levels. The Sloan-Kettering team concluded that an isolated PSA screening with an elevated level should be followed with an additional screening several weeks later before proceeding with further testing or a biopsy.
Garzotto and his colleagues studied more than 1,200 men with PSA levels ranging from 4 to 10 (0 to 3 is considered normal) who had biopsies from 1993 to 2000. They found that the most important predictors of cancer were:
- A digital rectal exam to feel for a hardened nodule that may be a tumor.
- A transrectal ultrasound to look for a darkened area that may be cancerous.
- A man’s age: 90% of prostate cancer cases are in men over 65.
- PSA density, which is the ratio between PSA level and prostate size. A smaller gland with elevated PSA is more likely to be cancer than a larger gland with elevated PSA.
When patients were given points on these criteria using a mathematical model called a nomogram, researchers could predict which men had the lowest odds of having cancer, potentially avoiding many unnecessary prostate biopies.
However, the diagnosis of prostate cancer can be confirmed only by a microscopic examination to identify cancerous prostate tissue. This is done by a biopsy performed in the doctor’s office.
Conditions that suggest Increased Risk of Prostate Cancer
Risk factors for Increased Risk of Prostate Cancer
Elevated Testosterone Level, Male
Men older than 50 who have higher levels of testosterone have a higher risk of prostate cancer, U.S. researchers reported. [Presentation at the American Urological Association in San Francisco, May 2004]
A study of more than 750 men showed those with the highest levels of free testosterone in the blood were the most likely to have prostate cancer.
The findings may mean that men should be cautious about testosterone replacement therapy, which is being used in older men who see a decline in general health and vigor.
“Since testosterone replacement therapy increases the amount of free testosterone in the blood, older men considering or receiving testosterone replacement should be counseled as to the association until data from long-term clinical trials becomes available,” J. Kellogg Parsons, a urologist at Johns Hopkins University who led the study, said in a statement.
The association between free testosterone and prostate cancer risk in older men was not affected by height, weight, percent of body fat or muscle mass, Parsons told a meeting of the American Urological Association in San Francisco.
Duke University Medical Center researchers have also found preliminary evidence suggesting a man’s lifetime risk of prostate cancer may be linked to the amount of male hormone testosterone circulating in his body as early as puberty or even in utero, although direct evidence of this link remains to be shown.
The two possible risk factors they found – high “free” testosterone levels in adulthood and a small shoulder span in relation to body size – appear to be unrelated to one another. Demark-Wahnefried’s research set out to measure the link between prostate cancer and factors such as height, weight, musculature and baldness – all of which are related to hormones. The two-year, blinded, case-controlled study compared a group of 159 men with prostate cancer to a control group of 156 men who had come to the urology clinic for prostate screenings and other concerns such as kidney stones. Subjects were aged 50 to 70 years.
In the first phase of the study, Demark-Wahnefried and her colleagues at the Duke Comprehensive Cancer Center found nearly a two-fold increase in the risk of prostate cancer among men with high “free” testosterone levels, the form of testosterone that can readily be used by cells throughout the body. While the link between testosterone and prostate cancer has been made before, previous studies have measured “total” testosterone, a less active form of the hormone that is bound to specific protein and thus cannot enter the cells.
Elevated PSA
Research efforts have been directed at assessing the rate of rise in PSA over time as well evaluation of free PSA. It is currently felt that a rise in PSA of greater than 0.75ng/dl in one year or a rise of greater than 20% over 2 years is suspicious for cancer.
Based on a study’s results, some docotrs recommended that all men with PSA levels of 2.5 to 10 have a free PSA test. Those with a low free PSA level then could decide whether to undergo a biopsy. The researchers found that a lower percentage of free PSA, below 20%, was significantly associated with pathologic features of adverse tumors. They also discovered that a higher percentage of free PSA, above 20%, was associated with potentially insignificant cancers.
Problem Caused By Being Overweight
Obesity was associated with a 2.5-times greater risk of prostate cancer, although men who were merely overweight did not show an increased risk. In this study, a BMI of 25 or more was not related to prostate cancer risk, but having a 30-plus BMI was. The findings are backed up by Swedish, Danish and Irish studies that have suggested an association between obesity and prostate cancer risk, but the link is still controversial. [British Journal of Urology International 2003;91: pp.482-484]
Vitamin D Requirement
Low circulating levels of 25-hydroxyvitamin D were associated with an increased risk of subsequent prostate cancer and more aggressive progression of prostate cancer, especially in men before the age of 52, in the Helsinki Heart Study. Ultraviolet radiation exposure has been shown to be protective against prostate cancer.
Men over the age of 30 should have an annual screening for 25-hydroxyvitamin D levels, especially those at higher risk such as African American men and indoor workers. Vitamin D nutrition should be maintained not only for bone health but also for the possible reduction in risk of prostate cancer and to reduce metastatic activity should prostate cancer develop. [Trends in Endocrinol Metab November 2003;14(9): pp.423-430]
Vitamin A Requirement
Carotene compounds called lycopenes, which are found in high amounts in tomatoes, have been shown to protect against prostate cancer. Several studies have shown that males consuming tomato sauce receive some protection against cancer.
African ethnicity
Prostate cancer screening may be more useful for African-American men than white men. Black men are more likely to suffer and die from prostate cancer than white men, but the disease can be cured at the same rate as that of whites if it is caught and treated early on. In the United States, prostate cancer occurs in African-American men at a rate of 234.2 per 100,000 people, as compared with 144.6 per 100,000 for white men. Black men die from the disease at a rate of 53.1 per 100,000, whites at a rate of 22.4.
Researchers say that in African Americans, this cancer is generally not slow growing, and early diagnosis and treatment would be of benefit for these men. [Radiological Society of North America December 2, 2002]
Selenium supplementation
History of prostrate cancer
Increased Risk of Prostate Cancer suggests the following may be present
EFA (Essential Fatty Acid) Type 6 Requirement
Working with human prostate cancer cells in tissue cultures, researchers found omega-6 fatty acids, added to the mix, spur the production of cPLA2, which then causes the production of the enzyme COX2. The introduction of COX2 stimulates the release of PGE2, a hormone-like molecule that promotes cell growth.
Simply put, if you’re eating a diet that’s high in omega-6 fats, you could be vulnerable not only to prostate cancer, but colorectal and some breast cancers as well.
The incidence of prostate cancer over the past 60 years has risen as dietary ratios of omega-3 and 6 fats have changed. Back at the end of World War II, omega-3 and omega-6 ratios were lopsided (1:2) in favor of omega-3s. Now, that ratio is 25:1 on the omega-6 side.
The scientists who conducted the study were looking at possible new drugs to ward off prostate cancer based on the effect of flurbiprofen, a non-steroidal anti-inflammatory drug commonly prescribed for arthritis. Flurbiprofen blocks the production of cPLA2 and breaks the chain leading to cell growth. [Carcinogenesis May 5, 2005]
Increased Risk of Prostate Cancer can lead to
Recommendations for Increased Risk of Prostate Cancer
Fish Oil / Krill
Several studies have shown an inverse relationship between blood levels of fish oils (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and the risk of prostate cancer. A study by medical researchers at the Karolinska Institute confirms this association. [The Lancet, Vol. 357, June 2, 2001, pp. 1764-66 (research letter), British Journal of Cancer, Vol. 81, No. 7, December 1999, pp. 1238-42]
See also the link between Increased Risk of Prostate Cancer and Essential Fatty Acids. Reference is made here about the value of fish oil in protecting from advanced prostate cancer.
Garlic
A study of Chinese men found that a diet rich in garlic, onions, shallots, leeks and scallions may cut the risk of prostate cancer. Men who ate small amounts of onions, garlic, scallions, shallots and leeks each day decreased their risk of prostate cancer by more than 33%. Those who ate 2 grams of garlic per day decreased their risk of prostate cancer by more than 50%, but even eating only one clove cut the risk. Scallions, which lowered the risk of prostate cancer by 70%, were found to be most beneficial. [J Nat Can Inst, November 6, 2002;94(21): pp.1648-51]
Green / Oolong / BlackTea (Camellia sinensis)
A study has revealed that the once highly praised antioxidants found in red wine, grapes and peanuts were not as effective cancer preventatives as green and black tea, in slowing down the progression of prostate cancer. Participants of the study involved 20 men who had prostate cancer and were pending prostate removal surgery. Each of the men were required to drink five cups of black tea, green tea or soda each day for five days prior to their scheduled surgeries.
The goal of the study was to determine if polyphenols, a substance found in tea, might contribute to slowing down the cell growth of the prostate cancer. One component of the study involved cutting out a piece of each man’s prostate for examination. The study revealed a decrease in the growth rate of the cancer cells in the men who had consumed the black or green tea, however there was no change in the men who drank soda. [Free Radical Biology & Medicine April 2004;36(7): pp.829-37]
Pomegranate
Pomegranate juice has been shown to reduce the doubling time of PSA levels in prostate cancer. If it has this effect with patients who have already been treated for prostate cancer, it should have a similar effect in delaying the onset or initiation of prostate cancer.
Pomegranate extract and pomegranate juice may help to protect against prostate cancer by suppressing the expression of genes linked to the disease, say researchers.
Researchers from the University of California, Los Angeles studied the effect of pomegranate polyphenols, ellagitannin-rich extract, and whole juice extract on the expression of genes for key androgen-synthesizing enzymes and the androgen receptor. Results showed that pomegranate polyphenols led to a statistically significant two-fold suppression in the expression of genes linked to prostate cancer, furthermore the polyphenols were also found to stop the spread of prostate cancer and induce cell death (apoptosis) of cancer cells.
The authors concluded: “This study showed that pomegranate products and their polyphenols reduced tumour cell growth and induced apoptosis in both androgen-dependent and androgen-independent prostate cancer cells. These anti-proliferative effects were also consistent in hormone-treated cells. This implies the potential possibility that pomegranate and its polyphenols are used as novel dietary supplements with maximum potential for androgen-dependent and androgen-independent prostate chemoprevention.”
[Young Hong M, Seeram NP, Heber D. Pomegranate polyphenols down-regulate expression of androgen-synthesizing genes in human prostate cancer cells overexpressing the androgen receptor. Journal of Nutritional Biochemistry. 2008;19:848-855]
Turmeric Extract, Curcumin
Curcumin could be a potentially therapeutic anti-cancer agent, as it significantly inhibits prostate cancer growth, as exemplified by LNCaP in vivo, and has the potential to prevent the progression of this cancer to its hormone refractory state. [Prostate. 2001 Jun 1;47(4): pp.293-303]
Maca (Lepidium meyenii)
Men with a high PSA level or a history of prostate cancer should not be using maca.
Soy Isoflavones (genistein, daidzein)
Soy protein is one of the dietary elements that has been talked about for a long time as having a potentially beneficial effect for preventing prostate cancer. Soybeans are full of chemicals called isoflavones which closely resemble the structure of estrogen-like hormones once widely used to treat prostate cancer.
Laboratory studies are backed up by observations in Asian countries, particularly Japan, where men may develop small prostate tumors but rarely the kind of large, aggressive tumors seen in American men. However, the aggressive form of the cancer becomes more prevalent when Asian immigrants come to the US and are likely to substitute their soy-rich diet with one based mainly on animal protein.
Phytochemicals in soy protect against cancer via several different mechanisms, including interacting with intracellular enzymes, regulating protein synthesis, controlling growth factor actions, inhibiting malignant cell proliferation, inducing differentiation, deterring cancer cell adhesion, and inhibiting angiogenesis.
Since prostate cancer cells usually multiply slowly, the development of prostate cancer can take many years before symptoms appear. During this time period, the benefits of natural therapies like soy consumption are more effective at dealing with the problem while it is still small.
According to a Professor De Sy large quantities of soy products are necessary to be effective against prostate cancer: one must drink 1.5 liters soya milk or 250 grams of soya burger daily. Less than this can be considered when used for prevention purposes.
Juices / Juicing
In men with recurrent prostate cancer, drinking 8 ounces per day of pomegranate juice significantly increases the time it takes for an increase in levels of prostate specific antigen (PSA), an indicator of prostate cancer. Before the men in the study began consuming pomegranate juice, the average PSA doubling time, a measure of tumor activity, was 15 months. The average time after treatment was 37 months. So, there was almost a 2-year increase in the doubling time.
Pomegranate juice contains a number of antioxidants thought to have anti-cancer effects, Pomegranate juice contains estrogen-like plant substances called phytoestrogens that could be useful in combating prostate cancer. Pomegranate juice therapy was well tolerated and no serious adverse effects were reported. In addition to the beneficial increase in PSA doubling time, in vitro testing showed decreased cancer cell division and proliferation and increased cancer cell death. Urine testing confirmed the presence of pomegranate antioxidants in all men. The study was funded by the Stewart and Lynda Resnick Trust, which own the POM Wonderful pomegranate juice company.
Conventional Drugs / Information
Research suggests that an ingredient used in cough medicines for more than half a century may be an effective treatment for prostate cancer.
Dr Israel Barken, Moshe Rogosnitzky, and Dr Jack Geller tested the cough suppressant noscapine, a non-addictive derivative of opium, on mouse models of prostate cancer. Results showed that noscapine reduced tumor growth by 60% and limited the spread of tumors by 65%, all without causing harmful side effects.
This is not the first time that noscapine has been studied as a treatment for cancer. It has previously been studied as a treatment for breast, ovarian, colon, lung, and brain cancers, and for various lymphomas, chronic lymphocytic leukemia, and melanoma. However, because noscapine is a naturally-occurring substance it is non-patentable and thus finding financial backing for clinical trials has proven difficult.
Mosche Rogonsnitzky, of MedInsight Research Institute, a nonprofit organization committed to making doctors aware of commercially unsponsored medications, off-label (secondary) uses for approved medicines, long-lost therapies, and specialized tests that enable treatment to be tailored to the individual, said of the discovery: “Noscapine is effective without the unpleasant side effects associated with other common prostate cancer treatments. Because noscapine has been used as a cough-suppressant for nearly half a century, it already has an extensive safety record. This pre-clinical study shows that the dose used to effectively treat prostate cancer in the animal model was also safe.”
News release: New study shows that a cough medicine ingredient could effectively treat prostate cancer MedInsight Research Institute. December 18th 2008.
Chemical Avoidance
Prostate cancer is entirely absent in parts of Asia and some Third World countries. Prostate disease, in fact, appears to be largely the result of modern technology – the toxins we take into our bodies from processed foods, polluted air and contaminated water.
Atrazine is a widely used herbicide in the United States, with more than 60 million pounds applied annually. Millions of Americans drink atrazine in their tap water, often at peak levels during the spring, when farmers apply it to their fields. Atrazine-poisoned water is not limited to the Midwest, however. The chemical is found in drinking water around the world, in part because it is transported by rain and fog.
Past studies have built a strong case that atrazine is unsafe for humans. Some of these studies have found that the herbicide disrupts the production of normal human hormones, and others have concluded that it is associated with a higher incidence of cancer in both humans and laboratory animals. Several European countries, including France, Germany and Italy, have banned atrazine. Farmers there use safer alternatives, as do many in the United States.
A significant finding was that Syngenta employees (at an atrazine production plant) have markedly elevated incidence rates of prostate cancer – a rate more than 3½ times higher than the Louisiana statewide average. In all, the study identified 17 prostate cancer cases. Among long-time employees, the study revealed 11 prostate cancer victims, nine-fold higher than the expected number based on the statewide prostate cancer rate.
Atrazine causes serious sexual abnormalities in male frogs exposed to the pesticide at levels commonly found in rivers, streams and even rain. Dr. Hayes published his findings in the April 16, 2002, edition of the Proceedings of the National Academy of Sciences, after finding that 16 to 20% of male frogs developed sexual deformities when their tank water contained atrazine at 0.1 parts per billion. The deformities included having both ovaries and testes, and testes containing eggs in addition to sperm. The EPA’s tap water standard for atrazine is 3 parts per billion – 30 times higher than the level at which these dramatic results occurred. The exposed frogs also had much lower testosterone levels as atrazine enhanced the conversion of testosterone to estrogens. [2002 Proc. Natnl.Acad Sci USA 99, pp.5476-80] Atrazine inhibited testosterone production in prepubertal rats also.
Modified Citrus Pectin (MCP)
15gm of MCP per day in three divided doses slowed the progression of prostate cancer as monitered by PSA measurements. MCP is thought to bind to galectin-3, preventing the cancer cell from functioning normally and causing it to self-destruct. [The Prostate, Feb 1, 2003] As prostate cancer is typically slow growing, the use of MCP before the condition becomes detectable seems a good preventive action to take.
Diindolylmethane DIM / Indole 3 Carbinol IC3
Diindolylmethane may reduce prostate cancer incidence as it has been shown to stop human cancer cells from growing by (54-61%) and provoking the cells to self-destruct (apoptosis). DIM (diindolylmethane) also improves prostate function.
In two papers published in the Journal of Biological Chemistry (Mar 27, 2003) researchers report that DIM significantly halted proliferation of androgen-dependent human prostate cancer cells. In one of the studies, androgen-dependent prostate cancer cells treated with DIM (diindolylmethane) grew 70% less than androgen-dependent untreated cells. DIM also inhibited dihydrotestosterone (DHT) stimulation of DNA synthesis in the androgen-dependent cancer cells. These effects were not seen in androgen-independent prostate cancer cells.
To determine whether men are at risk for prostate cancer, they are usually tested for levels of prostate-specific antigen (PSA), a growth factor for prostate cancer. In prostate cancer cells, diindolylmethane reduced intracellular and secreted PSA protein levels caused by DHT. The researchers determined that DIM’s molecular structure is similar to Casodex, a synthetic anti-androgen drug.
Progesterone
Dr. John Lee, M.D., has found that progesterone cream is an effective treatment for prostate cancer. He has had a series of patients with metastatic prostate cancer who went into complete remission with natural progesterone. A typical dose is 5-6mg of cream on the back of the hands twice per day.
Testosterone
One of doctors’ greatest fears about testosterone therapy is that it may cause prostate cancer. But a study shows that it won’t increase a man’s risk of prostate cancer – even if he has precancerous prostate cells. The study sheds light on the risks of testosterone therapy, which is used in men with low testosterone levels to help restore a man’s sexual function, mood, memory, even aspects of his physique – muscle mass, strength, body fat, bone density.
These results indicate that testosterone therapy does not lead to prostate cancer and that men with a history of precancerous prostate cells may be able to safely take testosterone therapy. [Journal of Urology December 2003]
Preliminary research suggests that testosterone replacement therapy for men with low testosterone levels appears to have little effect on the prostate gland, contrary to some reports that this therapy may be harmful, according to a study in the November 15, 2006 issue of JAMA, a theme issue on men’s health.
Tests, General Diagnostic
Elevated Prostate Specific Antigen (PSA) levels can be a sign of prostate cancer spread in men with early cancer. However, the PSA test does not distinguish between slow-growing and aggressive cancers. As a result, there are suggestions that prostate cancer may be overdiagnosed and overtreated.
Robert W. Veltri, from Johns Hopkins University (Maryland, USA), and colleagues have developed a new blood test, known as the Prostate Health Index (PHI). It measures three forms of PSA, including pro-PSA, a shortened molecule that is missing a few of the amino acids that make up the PSA protein, and suggested to be a highly accurate form of PSA.
The team studied 71 men who were diagnosed with small, low-grade, and low-stage prostate cancer based on their PSA results. Approximately four years later, 39 had unfavorable biopsy results that signaled a need for treatment. The PHI test was performed on blood samples, banked at the time of biopsy, from all 71 men.
When the researchers combined the biopsy results with the PHI data, they were able to predict 7 in 10 men that might progress, leading them to conclude that: “Measurement of the serum PHI and tissue DNA content at the time of diagnosis are able to predict which men enrolled in an [active surveillance] cohort will ultimately require treatment for [prostate cancer].” [American Association for Cancer Research 101st Annual Meeting 2010]
Boron
Men who ingested the greatest amount of boron were 64% less likely to develop prostate cancer compared to men who consumed the least amount of boron. The study compared dietary patterns of 76 men with prostate cancer to that of over 7,000 males without cancer. The greater the quantity of boron-rich foods consumed, the greater the reduction in risk of being diagnosed with prostate cancer. Men in the lowest quartile of boron consumption ate roughly one slice of fruit per day, while those in the highest quartile consumed 3.5 servings of fruit per day plus one serving of nuts. [Annual Experimental Biology conference in Florida – FASEB J 15:A1089, 2001]
Selenium
In one study, the risk of prostate cancer for men receiving a daily supplement of 200mcg per day of selenium was found to be one-third that of those receiving a placebo.
Reading List
Prostate Health in 90 Days…without drugs or surgery by Larry Clapp, PhD, JD is a book which is devoted to explaining in detail how to prevent or cure cancer by balancing the body’s pH through clearing toxins from the body, improving diet, exercising, and improving one’s emotional and sexual life. To monitor progress, Clapp introduces the Biological Terrain Assessment (BTA) testing. The BTA measures pH, reduction oxidation, and the resistivity of the blood, saliva and urine.
You can read more about this bookhere. It is available also in downloadable form as an electronic book (E-Book).
Essential Fatty Acids
Prostate cancer patients who added about 3 heaping tablespoons of ground flaxseed daily to their diet had more slowly-dividing tumor cells and a greater rate of tumor cell death than men who did not follow this diet, after about 5 weeks. The investigators found no significant difference in levels of prostate specific antigen (PSA). [Urology July 2001; p.58]
Because prostate cancer is slow growing, generally present for years before detection, the use of flaxseeds would be wise long before the presence of prostate cancer is established.
A new study suggests that it may be better to use fish oil than the ALA found in flax or other oils. This study of about 47,000 men has found the ALA omega-3 fatty acids stimulate the growth of prostate tumors in men. Of the men monitored over 14 years, some 3,000 struggled with prostate cancer and about one in seven were suffering from the advanced stages of the disease. Researchers found men who were suffering from advanced prostate cancer had higher quantities of ALA from non-animal as well as meat and dairy sources.
Scientists also found EPA and DHA could reduce the risk of total and advanced prostate cancer too. [American Journal of Clinical Nutrition July 2004 80(1); pp.204-216]
Omega-3 fatty acids appear protective against advanced prostate cancer, and this effect may be modified by a genetic variant in the COX-2 gene, according to a report in Clinical Cancer Research, March 2009.
“Previous research has shown protection against prostate cancer, but this is one of the first studies to show protection against advanced prostate cancer and interaction with COX-2,” said John S. Witte, Ph.D., professor of epidemiology and biostatistics at the University of California San Francisco.
For the current study, researchers performed a case-control analysis of 466 men diagnosed with aggressive prostate cancer and 478 healthy men. Diet was assessed by a food frequency questionnaire and researchers genotyped nine COX-2 single nucleotide polymorphisms.
Researchers divided omega-3 fatty acid intake into four groups based on quartiles of intake. Men who consumed the highest amount of long chain omega-3 fatty acids had a 63 percent reduced risk of aggressive prostate cancer compared to men with the lowest amount of long chain omega-3 fatty acids.
The researchers then assessed the effect of omega-3 fatty acid among men with the variant rs4647310 in COX-2, a known inflammatory gene. Men with low long chain omega-3 fatty acid intake and this variant had a more than five-fold increased risk of advanced prostate cancer. But men with high intake of omega-3 fatty acids had a substantially reduced risk, even if they carried the COX-2 variant.
“The COX-2 increased risk of disease was essentially reversed by increasing omega-3 fatty acid intake by a half a gram per day,” said Witte. “If you want to think of the overall inverse association in terms of fish, where omega-3 fatty acids are commonly derived, the strongest effect was seen from eating dark fish such as salmon one or more times per week.”
Lycopene
A study conducted by Harvard researchers examined the relationship between carotenoids and the risk of prostate cancer. [J Natl Cancer Inst 1995;87: pp.1767-76] Of the carotenoids studied, only lycopene was clearly linked to protection. The men who had the greatest amounts of lycopene in their diet (6.5mg per day or more) showed a 21% decreased risk of prostate cancer compared with those eating the least. This report suggests that lycopene may be an important tool in the prevention of prostate cancer. This study also reported that those who ate more than ten servings per week of tomato-based foods had a 35% decreased risk of prostate cancer compared with those eating less than 1.5 weekly servings. When the researchers looked at only advanced prostate cancer, the high lycopene eaters had an 86% decreased risk (although this did not reach statistical significance due to the small number of cases).
Contrary to popular opinion, research suggests that there is no preferential concentration of lycopene in prostate tissue. [Am J Epidemiol 2000;151: pp.124-7 (review, discussion 128-30)] Although prostate cancer patients have been reported to have low levels of lycopene in the blood [Nutr Cancer 1999;33: pp.159-64], and lycopene appears to be a potent inhibitor of human cancer cells in test-tubes [Nutr Cancer 1995;24: pp.257-66], evidence is conflicting concerning whether an increased intake of tomato products is protective against prostate cancer. Some studies, like the one discussed above, have reported that high consumption of tomatoes and tomato products reduces risk of prostate cancer. Other studies, however, are inconclusive [Am J Epidemiol 2000;151: pp.119-23], and some have found no protective association.
Vitamin K1/K2
A German study (2008) looked at the relationships between dietary intake of vitamin K1 and K2 on the development of prostate cancer in 11,319 men over a period of 8 years.
Those with the highest level of vitamin K2 intake had a 63% reduced incidence of advanced prostate cancer. The intake of vitamin K1 did not produce this effect. [Am J Clin Nutr. 2008 Apr;87(4):pp. 985-92]
Vitamin E
Among the various forms of vitamin E, researchers discovered that one, gamma-tocopherol, may have value as an anti-cancer agent. Gamma-tocopherol occurs naturally in plant seeds such as walnuts, pecans and sesame seeds.
According to a study, gamma-tocopherol inhibited the production of lab-cultured human prostate cancer cells. And although the presence of gamma-tocopherol caused cell death by interrupting the synthesis of sphingolipids (certain fatty molecules, which are important components of cell membranes), it left healthy human prostate cells unaffected. As researchers increased the amount of gamma-tocopherol, cancer cells slowed in growth and healthy cells grew normally.
“This is the first time gamma-tocopherol has been shown to induce death in lab-grown human cancer cells while leaving healthy cells alone,” said the head researcher of the study.
Since gamma-tocopherol does not appear in most manufactured nutritional supplements, researchers have suggested combining it with another form of vitamin E: Alpha-tocopherol.
Alpha-tocopherol is the major form of vitamin E found in the body and, in contrast to gamma-tocopherol, is found in most manufactured nutritional supplements. It has justifiably earned a good reputation as an antioxidant, which helps fight against damage caused by unwanted free radicals. Thus, it is better to supplement a diet with mixed forms of vitamin E, as together they will enhance the positive effects found in each. [Proceedings of the National Academy of Sciences December 21, 2004;101(51): pp.17825-17830]
High blood levels of alpha- and gamma-tocopherol appeared to reduce the risk of prostate cancer by about 50 percent each.
These results are based on a study involving 100 individuals with prostate cancer and 200 individuals without, participating in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, which included nearly 30,000 men in all. Not only did the study indicate that men with the highest levels of alpha-tocopherol in their blood at baseline were about 50% less likely to develop prostate cancer than those with the lowest level of the vitamin, but it also showed:
*Men with highest levels of gamma-tocopherol were 43 percent less likely to develop the cancer, compared with men with the lowest levels.
*The connection between high tocopherol levels and low cancer risk was stronger among individuals taking alpha-tocopherol supplements compared to those not taking them. [Journal of the National Cancer Institute March 2, 2005;97(5): pp.396-399]
Vitamin D
See the link between Vitamin D Deficiency and Cancer, Prostate, Increased Risk.
Key
| Strong or generally accepted link |
| Proven definite or direct link |
| Strongly counter-indicative |
| Very strongly or absolutely counter-indicative |
| May do some good |
| Likely to help |
| Highly recommended |
| Reasonably likely to cause problems |
Glossary
Cancer
Refers to the various types of malignant neoplasms that contain cells growing out of control and invading adjacent tissues, which may metastasize to distant tissues.
Prostate
The prostate gland in men that surrounds the neck of the bladder and the urethra and produces a secretion that liquefies coagulated semen.
Antigen
A substance, usually protein or protein-sugar complex in nature, which, being foreign to the bloodstream or tissues of an animal, stimulates the formation of specific blood serum antibodies and white blood cell activity. Re-exposure to similar antigen will reactivate the white blood cells and antibody programmed against this specific antigen.
Biopsy
Excision of tissue from a living being for diagnosis.
Testosterone
The principal male sex hormone that induces and maintains the changes that take place in males at puberty. In men, the testicles continue to produce testosterone throughout life, though there is some decline with age. A naturally occurring androgenic hormone.
Hormones
Chemical substances secreted by a variety of body organs that are carried by the bloodstream and usually influence cells some distance from the source of production. Hormones signal certain enzymes to perform their functions and, in this way, regulate such body functions as blood sugar levels, insulin levels, the menstrual cycle, and growth. These can be prescription, over-the-counter, synthetic or natural agents. Examples include adrenal hormones such as corticosteroids and aldosterone; glucagon, growth hormone, insulin, testosterone, estrogens, progestins, progesterone, DHEA, melatonin, and thyroid hormones such as thyroxine and calcitonin.
Kidney Stone
A stone (concretion) in the kidney. If the stone is large enough to block the tube (ureter) and stop the flow of urine from the kidney, it must be removed by surgery or other methods. Also called Renal Calculus. Symptoms usually begin with intense waves of pain as a stone moves in the urinary tract. Typically, a person feels a sharp, cramping pain in the back and side in the area of the kidney or in the lower abdomen. Sometimes nausea and vomiting occur. Later, pain may spread to the groin. The pain may continue if the stone is too large to pass; blood may appear in the urine and there may be the need to urinate more often or a burning sensation during urination. If fever and chills accompany any of these symptoms, an infection may be present and a doctor should be seen immediately.
Protein
Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.
ng
Nanogram: 0.000000001 or a billionth of a gram.
Vitamin D
A fat-soluble vitamin essential to one's health. Regulates the amount of calcium and phosphorus in the blood by improving their absorption and utilization. Necessary for normal growth and formation of bones and teeth. For Vitamin D only, 1mcg translates to 40 IU.
Carotene
Converted into vitamin A in the body from a yellow pigment that has several forms (i.e., alpha-, beta-, and gamma-carotene).
Fatty Acids
Chemical chains of carbon, hydrogen, and oxygen atoms that are part of a fat (lipid) and are the major component of triglycerides. Depending on the number and arrangement of these atoms, fatty acids are classified as either saturated, polyunsaturated, or monounsaturated. They are nutritional substances found in nature which include cholesterol, prostaglandins, and stearic, palmitic, linoleic, linolenic, eicosapentanoic (EPA), and decohexanoic acids. Important nutritional lipids include lecithin, choline, gamma-linoleic acid, and inositol.
Enzymes
Specific protein catalysts produced by the cells that are crucial in chemical reactions and in building up or synthesizing most compounds in the body. Each enzyme performs a specific function without itself being consumed. For example, the digestive enzyme amylase acts on carbohydrates in foods to break them down.
Anti-inflammatory
Reducing inflammation by acting on body mechanisms, without directly acting on the cause of inflammation, e.g., glucocorticoids, aspirin.
Arthritis
Inflammation of a joint, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis. Osteoarthritis, the most common form, is characterized by a gradual loss of cartilage and often an overgrowth of bone at the joints.