Impact of Diet on Prostate Cancer Risk and Mortality
If the information you are about to read could be turned into a patented drug, it would be worth billions of dollars of annual sales to whoever owned it.
What’s regrettable is very few doctors provide this lifesaving data to their prostate cancer patients. A staggering number of lives could be spared if the dietary changes discussed in this protocol are widely implemented.
In the February 2007 issue of Life Extension magazine, we published an article titled “Eating Your Way to Prostate Cancer.”
In the April 2003 issue, we published an article titled “Eating Food Cooked at High Temperature Accelerates Aging.”
Since these articles were published, large numbers of confirmative studies have been conducted that substantiate what we warned about.
This section will describe recently published science showing how eating the wrong foods markedly increase one’s risk of developing prostate cancer.
It also reveals data showing that men already diagnosed with prostate cancer who consume the wrong foods progress to advanced disease and death faster.
Cancer cells are present in the prostate glands of many aging men, yet only one in six men are ever diagnosed with prostate cancer (ACS 2013e; Roehrborn 2006). If one looks at what is required for a single cancer cell to develop into a detectable tumor, it becomes obvious that natural barriers exist to protect men against full-blown cancer.
Unfortunately, dietary choices in the Western world circumvent the body’s protective barriers (Erdelyi 2009). The end result is that most men unwittingly provide, through their food choices, biological fuel for existing prostate cancer cells to propagate and metastasize.
An understanding of the biological roles of diet and specific nutrients can enable aging men to achieve a considerable amount of control over whether isolated cancer cells in their prostate gland will ever show up as a clinically diagnosed disease.
The impact of the food we ingest on cell growth and death is so pronounced that it can be similar to the effects displayed by anticancer drugs—without the toxicities.
Don’t Eat Overcooked Meat
Any meat (including fish) cooked at high temperatures creates dangerous carcinogens (NCI 2010). Scientists looked at men whose diets included high intake of red meat cooked at high temperatures, pan-fried, or well-done. Their findings published in 2012 showed specific gene expression changes that predisposed these men to advanced prostate cancer (Joshi 2012). These kinds of studies show that one can exert a degree of control over their cell regulatory genes by avoiding overcooked meats.
Aggressive malignancies are those that rapidly propagate, infiltrate and metastasize (NCI 2013b). A 2011 study evaluated almost 1,000 men and found that higher consumption of any ground beef or processed meats was associated with an increased risk of aggressive prostate cancer (Punnen 2011). Men who ate ground beef showed the strongest association with a 130% increased incidence. The association primarily reflected intake of grilled or barbequed meat, with more well-done meat conferring a higher risk of aggressive prostate cancer. In contrast, consumption of rare/medium cooked ground beef was not associated with aggressive prostate cancer (Punnen 2011).
A 2011 study looked at dietary patterns of 726 newly diagnosed prostate cancer cases and compared them to 527 controls (John 2011). For advanced prostate cancer (but not localized disease), there was an associated 79% increased risk in men who ate hamburgers, a 57% increased risk with processed meats, a 63% increased risk with grilled red meat, and a 52% increased risk with well-done red meat (John 2011). This study corroborated others associating consumption of processed meat and red meat, especially when cooked at high temperatures, with increased cases of advanced prostate cancer (Joshi 2012; NCI 2013b).
Concern About Eggs and Milk
Large-scale studies associate egg consumption with sharply increased cancer risks (Richman 2011; Aune 2009).
A 2011 study looked at 27,607 men who developed or died from prostate cancer over a 14-year period (Richman 2011). Men who consumed 2.5 or more eggs per week had an 81% increased risk of lethal prostate cancer compared to those who consumed less than half an egg per week (Richman 2011). This study showed that consumption of eggs increased the risk of healthy men developing metastatic prostate cancer.
A 2013 evaluation was done using data from the famous Physician’s Health Study to identify the impact of consumption of skim or whole milk on incidence and survival after diagnosis of prostate cancer (Song 2013). This analysis involved 21,660 physicians who were followed for 28 years. Skim/low fat milk was associated with increased risk of low grade prostate cancer, whereas whole milk was associated with increased risk of fatal prostate cancers. In these men diagnosed with prostate cancer, consumption of whole milk was associated with a 117% increased risk of progression to fatal disease (Song 2013). This finding further substantiates the important role of diet even after prostate cancer is diagnosed.
The take-home lesson so far is if one has an elevated or rising PSA, it is especially prudent to avoid over cooked red meats, processed meat, eggs, and whole cow’s milk.
Confusion About Omega-6 Fats
Omega-6 fats are essential to life. We are unable to make them in our body and must get them from foods (UMMC 2013b).
The problem is that Western diets have become so overloaded with omega-6s that our bodies have become poisoned with them. The typical American tends to consume up to 25 times more omega-6 fats than the healthier omega-3 fats (UMMC 2013b).
One reason we have become so overloaded with omega-6s is that in the rush to switch from red meat and other saturated fats such as lard, we have been gobbling down too many omega-6-rich foods. These include vegetable oils used in all kinds of processed and fried foods, margarine, salad dressing, mayonnaise, certain nuts, peanut butter, and even poultry, a meat with high omega-6 content (SELF 2012). `
Commercial food companies deceivingly promote polyunsaturated vegetable oils like corn and safflower as healthy because of early studies showing reduced cardiovascular risk factors in those who consumed vegetable oils compared to animal-based fats such as butter (Mekki 2002).
Remember that you require omega-6s to live, but not in the large quantity consumed in the typical American diet. This means you want to lower the percentage of calories in your diet that comprise of omega-6 fats.
Table 1 lists foods high in omega-6 fats. Eating any of these foods in moderation is not a problem, but when they comprise a high percentage of your overall diet, your body becomes overloaded with omega-6s, which sets the stage for a wide variety of disorders. We next describe how a high intake of omega-6 fats contributes to prostate cancer.
Role of Omega-6 Fats in Prostate Cancer
Diets high in omega-6 fats and saturated fats are associated with greater prostate cancer risk, whereas increased intake of the type of omega-3 fats found in fish has been shown to confer protection (Newcomer 2001; Leitzmann 2004; Pelser 2013).
Based on consistent epidemiological findings across a wide range of human populations, scientists have sought to understand why eating the wrong kinds of fat (saturated and omega-6 fats) provokes a stimulatory effect on prostate cancer (Newcomer 2001; Pelser 2013).
To ascertain what happens after we eat bad fats, all one has to do is look at the metabolic breakdown pathways that these fats follow in the body, as shown in Figure 1. For example, let us assume that for dinner, you eat a steak (a source of saturated fat), potato (a high-glycemic starch) and a salad with a typical dressing of soybean and/or safflower oils (omega-6 fats).
As can be seen in the flow chart, omega-6 fats can convert to arachidonic acid in the body. Meat itself contains arachidonic acid (Sears 2011). One way that the body rids itself of excess arachidonic acid is by provoking a dangerous metabolizing pathway through 5-lipoxygenase (5-LOX).
It is well established that 5-LOX products stimulate prostate cancer cell proliferation via several well-defined mechanisms (Hassan 2006; Moreti 2004; Ghosh 1998). High glycemic foods also promote formation of 5-LOX in the body, via activation of enzymes involved in the formation of arachidonic acid (Sears 2011).
Arachidonic acid, found abundantly in eggs and chicken, is metabolized by the 5-LOX enzyme to 5-hydroxyeicosatetraeonic acid (5-HETE), a potent survival factor that prostate cancer cells use to escape destruction (Sears 2011; Ghosh 1998; Sundaram 2006). The flow chart (Figure 1) clearly demonstrates how consuming a diet rich in arachidonic acid provokes the production of dangerous 5-LOX products, which can promote prostate cancer progression (Sears 2011; Hassan 2006; Moretti 2004; Ghosh 1997; Ghosh 1998; Sundaram 2006). In addition to 5-HETE, 5-LOX also metabolizes arachidonic acid to leukotriene B4 and other pro-inflammatory agents that promote cancer (Larré 2008).
The chart (Table 1) provides a long list of foods that are high in arachidonic acid. Just because a food is listed on this chart does not mean you have to avoid it. It is wise, however, to pick which high-arachidonic acid foods are that important compared to ones you may not even realize you’re consuming.
Flow chart showing how the body metabolizes common foods via a 5-lipoxygenase (5-LOX) pathway.
5-LOX Is Over-Expressed in Prostate Cancer
Based on studies showing that consumption of foods rich in omega 6 fatty acids is associated with higher incidences of prostate cancer, scientists sought to determine how much of the 5-LOX enzyme is present in malignant versus benign prostate tissues (Ritch 2007).
Using biopsy samples taken from living human patients, the researchers found that 5-LOX mRNA levels were an astounding six-fold greater in malignant prostate tissues compared with benign tissues. This study also found that levels of 5-HETE were 2.2-fold greater in malignant versus benign prostate tissues (Gupta I 2001). The scientists concluded this study by stating that selective inhibitors of 5-LOX may be useful in the prevention or treatment of patients with prostate cancer (Gupta I 2001).
5-LOX Promotes Tumor Growth Factors
As the evidence mounts that ingesting “bad fats” increases prostate cancer risk, scientists are evaluating the effects of 5-LOX on various growth factors involved in the progression, angiogenesis, and metastasis of cancer cells.
One study found that 5-LOX activity is required to stimulate prostate cancer cell growth by epidermal growth factor (EGF) and other tumor cell proliferating factors produced in the body (Hassan 2006). When 5-LOX levels were reduced, the cancer cell stimulatory effect of EGF and other growth factors was diminished (Hassan 2006).
In a mouse study, an increase in 5-LOX resulted in a corresponding increase in vascular endothelial growth factor (VEGF), a key growth factor that tumor cells use to stimulate new blood vessel formation (angiogenesis) into the tumor. 5-LOX inhibitors have been shown to reduce tumor angiogenesis along with a host of other growth factors (Ye 2004).
In both androgen-dependent and androgen-independent human prostate cancer cell lines, the inhibition of 5-LOX has consistently been shown to halt the growth stimulatory action of 5-LOX and prompt rapid and massive apoptosis (cancer cell destruction) (Moretti 2004; Ghosh 1998; Ghosh 2003; Anderson 1998).
Omega-3 Fatty Acids: A First Line of Defense
One reason that fish oil supplements have become so popular is that their beneficial EPA/DHA fatty acids can help reduce the production of arachidonic acid-derived tumor promoting byproducts in the body (Norris 2012; Barham 2000; Adan 1999; Schwartz 2000). As shown in Figure 2, if arachidonic acid levels are reduced, there would be a corresponding suppression of 5-LOX and its metabolic byproducts 5-HETE and leukotriene B4.
Once one understands the lethal 5-LOX cascades, it is easy to see why people who excessively consume foods rich in arachidonic acid, and those who fail to reduce the production of arachidonic acid metabolites (such as 5-HETE) by ensuring adequate intake of omega-3 fatty acids, are setting themselves up for prostate cancer and a host of inflammatory disorders (including atherosclerosis).
Nutrients That Suppress 5-LOX
Health-conscious people already take nutrients like curcumin and fish oil that help to lower 5-LOX activity in the body (Taccone-Gallucci 2006; Gupta SC 2013). Studies show that lycopene and saw palmetto extract also help to suppress 5-LOX (Hazai 2006; Bonvissuto 2011). The suppression of 5-LOX by these nutrients may partially account for their favorable effects on the prostate gland.
As humans age, however, chronic inflammatory processes can cause the over-expression of 5-LOX in the body (Qu 2000). For maturing males, the result of excess 5-LOX may be the epidemic of prostate cancer observed as men age (Roehrborn 2006).
Based on the cumulative knowledge that 5-LOX itself and its metabolic products can promote the progression and metastasis of prostate cancer cells, it would appear advantageous to take aggressive steps to suppress this lethal enzyme (Hazai 2006).
This can be done by avoiding foods that promote 5-LOX formation in the body and taking supplements that inhibit 5-LOX via differing pathways.
Research Substantiating Boswellia
Specific extracts from the boswellia plant selectively inhibit 5-lipoxygenase (5-LOX), a potent inducer of inflammation and carcinogenic byproducts (Safayhi 1997; Safayhi 1995).
Boswellia extracts have been used for centuries, particularly in India as anti-inflammatory agents (Siddiqui MZ 2011). In several well-controlled human studies, boswellia has been shown to be effective in alleviating various chronic inflammatory disorders (Kimmatkar 2003; Ammon 2002; Gupta I 2001; Gerhardt 2001; Gupta 1998).
Scientists have discovered that the specific constituent in boswellia responsible for suppressing 5-LOX is AKBA (3-O-acetyl-11-keto-B-boswellic acid) (Siddiqui MZ 2011). Boswellia-derived AKBA binds directly to 5-LOX and inhibits its activity (Siddiqui MZ 2011). Other boswellic acids only partially and incompletely inhibit 5-LOX (Siddiqui MZ 2011; Sailer 1996).
Formulas containing high concentrations of AKBA from boswellia have been developed based on its ability to treat inflammatory disorders. Standardized boswellia extracts have long been included in prostate support nutrient formulas for the purpose of suppressing excess 5-LOX.
Prostate-Protecting Properties of Boswellia
Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that often increases in aging people (Gupta 2003).
From the standpoint of keeping prostate cancer cells in check, boswellia has been shown to prevent the TNF-alpha-induced expression of a proteindegrading enzyme called matrix metalloproteinase (MMP) (Roy 2005). Cancer cells use the MMP enzyme to tear apart natural barriers in the body that would normally encase them (Katiyar 2006). Prostate cancer cells are notorious for inducing the production of this enzyme (TNF-alpha) that causes containment structures within the prostate gland to vanish, thus enabling the cancerous prostate cells to break through healthy prostate tissue and eventually metastasize (Ridriguez-Berriguete 2013; Mizokami 2000).
Prostate cancer cells use adhesion molecules (known as VCAM-1 and ICAM-1) to facilitate their spread throughout the body. Boswellia has been shown to prevent the up-regulation of these adhesion molecules, which are directly involved in inflammatory processes (Roy 2005). Chronic inflammation is tightly linked to the induction of aberrant angiogenesis used by cancer cells to facilitate the growth of new blood vessels (angiogenesis) into tumors (Rajashekhar 2006).
The potent 5-LOX-inhibiting properties of boswellia, and its ability to suppress other inflammatory factors such as TNF-alpha, make it an important nutrient for those concerned with prostate cancer (Siddiqui MZ 2011; Roy 2005).
Urgent Need to Alter Dietary Patterns
Those consuming Western diets predispose themselves to cancer (Erdelyi 2009). It is encouraging that we know what food groups increase prostate cancer risk and what foods/nutrients reduce it.
All aging men should shift their diet towards foods that protect against prostate cancer. Those with rising or elevated PSA should be especially diligent in avoiding dietary factors that can fuel the growth of prostate tumors (WHF 2013).
The lethal impact of cancer-promoting foods may be mitigated by taking supplements such as green tea, curcumin, fish oil, pomegranate, and boswellia, along with regular inclusion of cruciferous vegetables and other healthy foods in one’s diet.