12 Diet Tips for Fighting Prostate Cancer

It has been suggested that some dietary factors can play a significant role in overall prostate health and in the fight against prostate cancer. This section of healwithfood.org's Guide to Prostate Cancer Prevention provides some of the best diet tips for preventing prostate cancer.

Important note: Prostate cancer is a serious disease and requires immediate medical attention. The information below and elsewhere on this website is not intended or implied to be a substitute for professional medical or health advice. Always seek the advice of a professional health care provider.

#1: Choose Low Glycemic Foods

Tip #1: Favor foods that rank low on the Glycemic Index. Glycemic Index (GI) is a ranking of carbohydrate-rich foods based on their effect on blood sugar (glucose) levels. Foods that break down slowly digested help maintain stable blood glucose levels and are considered low glycemic. Most non-starchy vegetables, legumes and fruit have a low GI rating. Foods that are digested at a rapid pace, including most refined carbohydrate-rich foods and potatoes, cause sharp fluctuations in blood glucose levels and have a high GI rating. Diets rich in high-GI foods have been associated with an increased risk of prostate cancer. Scientists believe that this association is linked to the ability of high GI foods to promote the secretion of insulin and insulin-like growth factor one (IGF-1). These hormones are known to increase cell growth and decrease cell death, thus increasing the risk of developing prostate cancer.

#2: Avoid Excess Protein

More than hundred years ago John Beard, a Scottish doctor, discovered that the body's primary defense against proliferating cancer cells is pancreatin, a mix of enzymes that are also involved in the digestion of proteins. High protein diets force pancreatic enzymes to focus on the digestion of protein rather than on the eradication of cancer. A certain amount of protein is necessary for the proper functioning of the body, but excessive amounts of protein should be avoided if you want to reduce your odds of developing prostate cancer. It may be a good idea to skip protein at one or two meals a day. Indeed, some experts believe that the body needs a protein-free period of approximately 12 hours a day in order to combat cancer.

I3C in cruciferous vegetables inhibits proliferation of prostate cancer cells.

#3: Consume Foods That Deliver I3C

Crucifrous vegetables such as broccoli, cabbage, cauliflower, kale and Brussels sprouts have long been touted for their anti-cancer properties. These properties are mainly attributed to indole-3-carbinol (I3C), a compound found in cruciferous vegetables when their cell walls are broken through chopping, crushing, or chewing. When I3C is digested, it is converted into diindolylmethane (DIM). DIM appears to be a strong anti-androgen that has been shown to inhibit the proliferation of prostate cancer cells in culture tests.

#4: Count on Curcumin

Curcumin, a plant pigment responsible for turmeric's bright yellow color, has been used in Ayurvedic and Chinese medicine for centuries due to its beneficial effects on a wide range of diseases and conditions. In recent years, also western medicine has started to pay greater attention to this extraordinary compound. Recent studies suggest that curcumin could be effective not only at preventing prostate cancer but also at inhibiting the spread of existing prostate cancers. Curcumin has been shown to be able to trigger apoptosis (programmed cell death) in human cancer cells and to scavenge free radicals. It may also help prevent nitrosamine formation and aflatoxin production which have been associated with an increased risk of cancer.

#5: Consume Foods That Provide Ellagic Acid

Raspberries provide a concentrated source of ellagic acid.

In the battle against prostate cancer, ellagic acid is definitely among the best dietary weapons you can have. Scientific evidence indicates that ellagic acid can effectively clear potentially prostate cancer causing substances by activating certain detoxifying enzymes in the liver. In can also prevent carcinogens from attaching to cellular DNA. Furthermore, ellagic acid has been shown to stimulate the immune system to more effectively fight cancerous cells as well as to induce normal self-destruction of cancer cells. Additionally, ellagic acid has antioxidant properties which allow it to attack free radicals. Ellagitannin — which is converted into ellagic acid by the body — is abundant in red fruits and berries, especially raspberries, as well as in some nuts such as pecans and walnuts.

#6: Avoid Meat Products That Contain Nitrates

Nitrates are substances that naturally occur in our environment. They can be found in the air, soil, surface water, ground water, and plants. They are also used in processed and cured meat products to give meat a nice red color. The body can convert nitrates present in food into nitrites, which in turn can form nitrosamines. Evidence has directly linked nitrosamine exposure to cancer in humans. Luckily, nitrosamine formation is inhibited by certain antioxidants, including vitamin C and vitamin E, and therefore nitrosamine formation is usually not a concern if you eat plenty of vegetables (which are typically rich in antioxidants). This is supported by population studies which have found no association between a high consumption of nitrate-containing vegetables (such as carrots) and cancer, but which show that diets rich in nitrate-containing processed meats are a risk factor.

Allicin in garlic has been shown to prevent prostate cancer.

#7: Eat Foods That Deliver Allicin

Since 1950s, several scientific studies have associated allicin with a lowered risk of several types of cancer, including prostate cancer. Allicin is a compound that naturally occurs in garlic and other members of the Allium family, such as onions and scallions, when the plant is crushed or chopped. Allicin, which is responsible for garlic's distinctive odor, has been shown to slow and prevent prostate cancer when consumed regularly. According to a study conducted by the National Cancer Institute, the high consumption of garlic in China may be the reason why the incidence of prostate cancer is so low among Chinese men. To fully benefit from garlic's prostate cancer fighting properties, let crushed garlic sit for 10 minutes before eating or cooking — this should leave enough time for allicin to form after crushing.

#8: Avoid Foods That May Be Contaminated with Aflatoxin

Avoid Foods That May Be Contaminated with Aflatoxins. Carcinogenic substances can occur in foods when certain types of fungus grow on food producing toxins during processing, storage, or transport. These toxins include aflatoxins — poisonous substances that can damage DNA and that may be able to cause prostate cancer. Peanuts appear to be particularly susceptible to contamination with aflatoxins, but also many other types of foods, including whole grains, legumes, nuts, and spices are vulnerable to the fungus producing aflatoxins. These poisons are resistant to cooking and freezing, but care in selecting your foods can greatly reduce your risk of exposure to these toxins:

• Select fresh seeds, nuts, legumes, and grains (or at least avoid nuts and grains from last year's harvest)
• Look for signs of proper storage and avoid foods from countries that have substandard storage requirements
• Discard nuts that taste stale or look suspicious
• Eat green vegetables that are rich in chlorophyll to further reduce the risk of harmful impacts of aflatoxins; chlorophyll has been shown to reduce aflatoxins levels

#9: Limit Fat Intake, Especially from Animal Fat

Reduce fat intake especially from animal fat. A vast body of scientific literature suggests that diets rich in animal fat can significantly increase the risk of prostate cancer in men. Arachidonic acid — a type of omega-6 fatty acids abundant in red meat, egg yolks, and organ meat — appears to play a key role in this context. Arachidonic acid has been shown to enhance prostate cancer growth, but it may also destroy cells of the immune system that are involved in the protection against prostate cancer. In contrast, omega-3 fatty acids, found in fatty fish such as salmon and mackerel and in a few other foods including flaxseed and walnuts, have been shown to guard against prostate cancer. However, even then it is advisable to limit the total intake of fat to not more than 20% (of total caloric intake) because all dietary fat stimulates the production of bile. Bile can convert into apocholic acid, a carcinogenic substance, if a lot of fat stays in the gut for an extended period of time.

#10: Ensure a Sufficient Intake of Vitamin C and Vitamin E from Foods

Vitamin C, abundant in kiwis, may inhibit nitrosamine formation.

Vitamin C and vitamin E are known to have strong antioxidant activity and to boost the immune system. In addition, the presence of vitamin C and vitamin E in the stomach has been shown to prevent the formation of nitrosamine, a potentially carcinogenic substance. However, this effect may not be relevant if fat is present in the stomach: A group of researchers replicated the chemical conditions of the upper stomach and measured the impact of vitamin C on the production of nitrosamines, both when fat was present in the stomach and when it was absent. Without fat, vitamin C decreased the levels of nitrosamines, but when 10% fat was added, vitamin C actually boosted the formation of nitrosamines.

#11: Be Sure to Get Enough Selenium from Foods (but Be Wary of Supplements)

Large-scale population studies suggest that the risk of death from prostate cancer is lower among people who eat plenty of foods that contain selenium. Death rates from prostate cancer are much lower in areas of the world where the soil is rich in selenium than in areas where selenium levels are low. Experts believe that selenium can reduce cancer risk in two ways: First, selenium is a key constituent of glutathione peroxidase, an enzyme with strong antioxidant powers. Second, selenium is believed to inhibit tumor growth by boosting the immune system and by inhibiting the development of blood vessels to the tumor. Nutritionists generally recommend that you get your selenium through diet rather than via supplements as high-dose selenium supplements can be risky due to the narrow margin between safe and toxic doses of selenium. In fact, one large placebo-controlled trial suggests that selenium supplements might even increase cancer risk.

#12: Eat Plenty of Foods Rich in Vitamin A and Carotenoids

A large and compelling body of evidence indicates that a diet rich in foods that contain vitamin A and its precursors, carotenoids, can help reduce the risk of many types of cancer. Carotenoids are pigments that give many fruits and vegetables such as cantaloupe, sweet potato, carrots, kale, spinach, and collard greens their vibrant colors. The most common carotenoids in the Western diet are beta-carotene, lycopene, lutein and zeaxanthin. Foods rich in vitamin A and carotenoids have been shown to be particularly effective at preventing lung cancer, but also the risk of prostate cancer may be significantly reduced by eating plenty of these foods.