By Debbie Edson RPh
Prostate cancer is the second most common cancer found in American men, and the second leading cause of cancer death among men. Food choices, according to the American Cancer Society, may impact the risk of developing prostate cancer. Simple, tasty shifts in meal preparation may, over time, reduce your chances of developing prostate cancer.
Strategies for a prostate healthy diet focus on dampening inflammation and managing blood insulin levels and maintaining a healthy weight.
Dampening Inflammation
Many men develop cancer cells in their prostate glands as they age. Not all men, however, go on to develop overt prostate cancer. We don’t understand why some cancer cells develop into detectable tumors and why some don’t progress. Diet appears to play a role. Food choices influence the level of inflammation in the body. Inflammation acts like a fire that promotes and spreads cancer. Some foods fuel inflammation; other foods dampen biochemical pathways that govern inflammation.
Arachidonic Acid
Arachidonic Acid (AA), an omega-6 fatty acid found in animal cell membranes and in the brain, is an important mediator of inflammation. Levels of AA are profoundly influenced by food choices. Arachidonic acid (AA) is a necessary substance, however, like most things in life, it needs to be kept in balance. Excessive levels of AA drive inflammation and are associated with a host of chronic illnesses. AA rich foods include fatty red meats, high fat dairy products, and egg yolks. AA is also made by the body from plant derived omega-6 oils, such as soy, safflower, peanut and corn. Completely eliminating these foods is not practical and not advised. We need some AA and omega-6 oils. The goal of prostate healthy food preparation is to re-balance. AA containing foods, omega-6 oils and refined carbohydrates are decreased, while foods that fight inflammation and re-balance biochemical pathways away from inflammation are increased to comprise a greater proportion of the diet.
Fish Oil Dampens AA Derived Inflammation
AA contributes to inflammation because it is a reservoir that feeds into a cascade of powerful pro-inflammatory local hormones called series 2 prostaglandins and leukotrienes. Fish oil, an omega-3 oil, dampens the levels of these mediators. Fish oil plugs into biochemical pathways that produce series 3 prostaglandins, which inhibit the production of pro-inflammatory AA series 2 prostaglandins and leukotrienes. In short, fish oil quiets down the inflammatory cascade of hormones that flow off arachidonic acid.
Flax oil is a plant-derived omega–3 oil. There is a controversy over flax oil’s role as a prostate healthy food. Contrary to what we know about its biochemistry, which should be anti-inflammatory, one lab study suggests that flax oil may fuel prostate cancer. Udo Erasmus, PhD (www.udoerasmus.com), an expert in the biochemistry of oils, questions the validity of this lab study. He believes that either low grade or rancid oils were used and there is no need for concern if fresh, high quality flax oil is used.
Herbs and Drugs Dampen AA Activity
Certain enzymes transform AA into inflammatory mediators. They are called COX-1, COX-2 and lipoxygenases. Excessive activity of these enzymes is associated with cancer, arthritis, Alzheimer’s disease, and arteriosclerosis. With regard to prostate cancer, a lipoxygenase called 5-LOX is particularly important. Biopsy studies show that 5-LOX levels are very high in prostate cancer cells. 5-LOX activity stimulates prostate tumor growth factors. Substances that inhibit 5-LOX induce prostate cancer cell death, a process called apoptosis.
5-LOX and COX Inhibitors
Certain, herbs, supplements and drugs inhibit COX-1, COX-2 and 5-LOX enzymes. Aspirin and ibuprofen inhibit COX-1. Common kitchen herbs also block inflammatory enzymes. Culinary herbs that block COX-2 and 5-LOX can be incorporated into your prostate healthy meal planning. Turmeric, basil, rosemary and green tea are foods that inhibit COX-2. Turmeric extract, also known as Curcumin, pumpkin seed oil, extra virgin olive oil, ginger, rosemary inhibit 5-LOX.
Saw Palmetto and Nettle, are herbs that inhibit 5-LOX. One of the most potent inhibitors of 5-LOX is an herb called boswellia. Boswellia is the Biblical incense Frankincense. A boswellia extract that concentrates a fraction of the herb with particularly strong 5-LOX inhibitory activity is marketed as a supplement called 5-Loxin®. A combination herbal supplement called Zyflamend® has been studied at Columbia University as a COX-2 and 5-LOX inhibitor. Zyflamend® (New Chapter) contains a variety of herbs, including Holy Basil, turmeric, ginger, green tea, rosemary, oregano. Prostate 5LX, a supplement also made by New Chapter, combines herbs that modulate 5-lipoxygenase.
Insulin Levels and Weight
Elevated insulin levels and obesity are associated with increased prostate mortality. This makes sense from the point of view of the inflammatory model because we know that high blood insulin levels stimulate the “bad” inflammatory pathways that flow off AA. Replace high sugar, high-glycemic carbohydrates (white flour, high fructose corn syrup) foods with beans and whole grains. Learning to use the anti-inflammatory spices with whole grain and bean dishes is a great way to wean off sugar-laden meals.
Other Prostate Protecting Foods
In addition to fatty fish, nuts and sesame seeds are prostate healthy foods. Nuts contain vitamin E and selenium, which support a healthy prostate. Brazil nuts have are a great source of selenium. Turkey and shrimp are low fat and contain high amounts of selenium. Sesame lignans and flax seed lignans and soy may also be protective. Walnuts contain omega-3 oils and are great for snacks. Garlic, fennel, red chili, onions, shallots, scallions and chives are healthful foods that contain compounds that are thought to be cancer protective. Tomatoes and tomato sauces, red grapefruit, and watermelon contain a vitamin A like substance, called lycopene, may support healthy prostate function. Cruciferous vegetables, such as broccoli, kale, and cabbage should be part of your prostate healthy meals. Pomegranate juice (8 ounces a day) slowed rising PSA levels in men with prostate cancer. Pomegranate is rich in ellagic acid and other natural compounds called polyphenols and flavoinoids, which are anti-inflammatory and possibly anti-cancer.
In addition to fish and flax oils, extra virgin olive, pumpkin, and grape seed, and coconut oils are healthful choices to replace omega-6oils.
Vitamin D
Adequate vitamin D blood levels are associated with lower prostate cancer risk. Most people living in northern latitudes don’t get enough vitamin D from the diet. Ask your doctor for a blood level and supplement accordingly. For more information on vitamin D go to www.vitamindcouncil.org
The Bottom Line
Prostate healthy diets avoid fatty meats and high fat dairy products and sugar. They include anti-inflammatory culinary herbs and prostate protective fruits and vegetables. Avoid bottled dressing made with heavily processed omega-6 oils. Cold water fatty fish should be included at least weekly. By the way – the prostate healthy diet described also promotes cardiovascular and brain health.
A great resource that addresses the topics of inflammation, herbs and diet and men’s health is a book called Dr. Katz’s Guide to Prostate Health by Aaron E Katz, MD.
These statements have not been evaluated by the Food and Drug Administration. They are not intended to diagnose, treat, cure, or prevent any disease. They are for information purposes only. Consult your doctor before taking supplements, especially if you are taking prescription medication, are pregnant or nursing.
Resources:
Ma J et.al “Prediagnostic body-mass index, plasma C-peptide concentration, and prostate cancer-specific mortality in men with prostate cancer: a long-term survival analysis” Lancet Oncol 2008
Bharat B Aggarwal and Shishir Shisodia. Suppression of the Nuclear Factor-kB Activation Pathway by Spice-Derived Phytochemicals – Reasoning for Seasoning. NY Acad. Of Sciences 1030:434-441 (2004)
“Eating Your Way to Prostate Cancer” by W. Faloon, Life Extension Magazine, Feb, 2007.
Pantuck, AJ et al. “Phase II Study of Pomegranate Juice for Men with Rising Prostate-Specific Antigen following Surgery or Radiation for Prostate Cancer.” Clin Cancer Res 2006;12(13): 4018-4026.