Prostate cancer, and all cancer for that matter, can be prevented. While there’s certainly a genetic component to disease progression, the majority of our health outcomes are firmly within our control. Epigenetic (literally meaning “above the genes”) research is beginning to elucidate what we’ve known in Naturopathic Medicine for years: health promoting choices lead to longer, healthier, and happier lives. Since we are in so many ways “what we eat”, any rational approach to cancer prevention must start with health promoting nutritional choices.
HOW THE WEST WAS LOST
The incidence of prostate cancer in the United States and other industrialized nations has been gradually increasing despite advances in screening and treatment. In fact, those very same advances partly explain why we are seeing more prostate cancer (specifically, early screening programs based on a blood marker called Prostate Specific Antigen – PSA). However, this difference in incidence was already apparent in the 1980s before PSA screening was readily available (please note, the choice to undergo prostate cancer screening is an important and individual one, so men should discuss this with their urologist and health care team), meaning other factors must be at play. Studies suggest that the approximately 6-fold difference in rates of prostate cancer between Western and non-Western countries is related to how we choose to live our lives: particularly poor dietary choices and sedentary lifestyles which both lead to elevated rates of obesity. Below, we’ll review the role of diet in the development of prostate cancer based on findings from a recent review of the available literature.
OVERALL IMPACT OF VARIOUS DIETS
While the typical Western diet has been implicated in elevated rates of prostate cancer, the Mediterranean diet and other whole foods predominantly plant-based diets have been shown to be protective.The typical diets found in Asian countries are higher in omega 3 fatty acids, soy, and green tea than most Western diets, and men in these countries tend to have less prostate cancer.Though no diet is truly “typical”, the cancer promoting diet so common in the US consists of high intake of red meat, processed meats, dairy, fried foods, added sugar, and chemical preservatives/additives.
Rather than focusing on the amount of fat we consume (the sweeping long-term vilification of fat has been detrimental to the health of millions of people), the type of fat we choose is far more important. In a study of 14,514 men, intake of saturated fat (which is especially high in meat sources) was related to increased risk of prostate cancer, while intake of plant-based fat was associated with reduced risk. The ratio of omega 3 (most readily found in cold water fish) to omega 6 (most readily found in animal meats) polyunsaturated fatty acids we consume also plays a role, potentially through anti-inflammatory mechanisms. Increased Omega 3 fatty acid intake is related to reduced risk of high-grade fatal prostate cancer.In one study of men who had already received a prostate cancer diagnosis, reducing animal fat intake by 10% and replacing it with vegetable fat intake lead to a 44% reduction in death from prostate cancer.
Not all protein is created equal. Protein from animal, plant, and dairy sources can have a unique impact on cancer progression. In addition, how we cook our protein plays a role: generally speaking, meats cooked at high temperatures promote prostate cancer progression (likely due to heterocyclic amine content). Baked poultry has been associated with reduced risk, while cooked red meat is associated with increased risk.Protein from dairy sources (milk, cheese, yogurt) was found to be associated with increased risk in a study of 21,660 men, with low fat dairy increasing overall risk and high fat dairy increasing risk for fatal forms of prostate cancer. In men already diagnosed with prostate cancer, higher intake of dairy is associated with a worse prognosis.Though soy protein and certain isoflavones in soy have been proposed as having cancer protective effects, the jury is still out on their effect in humans. Based on the work of researchers such as T. Colin Campbell, we know that animal sources of protein tend to increase overall cancer risk, and plant sources tend to decrease risk.
The amount and type of carbohydrates consumed plays a role in cancer development, partially through their impact on insulin metabolism. High intake of refined carbohydrates has been associated with an increased risk of prostate cancer. Animal studies show that both no carbohydrate (ketogenic) and low carbohydrate (20% of calories) diets slow prostate tumor growth.
Fruits and Vegetables
While research in humans on the benefit of individual nutrients such as Vitamin E, Vitamin C, and Selenium on prostate cancer progression are currently lacking, a whole foods diet high in fruits and vegetables is key. There is an inverse relationship between their intake and prostate cancer risk, and sulfur containing vegetables such as garlic and onion are particularly impressive in their impact.Cruciferous vegetables are also a great source of anti-cancer compounds, and broccoli is especially beneficial. Higher lycopene consumption (found in tomatoes) has been shown to reduce prostate cancer risk.
Coffee, Green Tea, and Water
Through various mechanisms, moderate intake of coffee likely reduces risk of prostate cancer. Green tea has been well studied in its effects, and in a trial of 60 men, daily intake of a green tea extract reduced prostate cancer occurrence by 90%.High intake of sugary drinks such as soda or juice impairs immune function and thus should be avoided. It is important to consume enough water every day to maintain appropriate hydration, especially when consuming daily caffeine through coffee and tea sources.
NO ONE DIET RIGHT FOR EVERYONE
Despite the breadth of population based research available, one must be careful not to extrapolate these findings to everyone. While studying health outcomes in thousands of people provides better evidence of efficacy in terms of public health decisions, everyone has individual needs. These unique needs must be systematically assessed and addressed to find an optimal nutrition plan. Make sure to find a Naturopathic Physician near you to begin to set a foundation for long-term health through proper diet.
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