Prostate cancer is a complex and varied disease.  That’s why researching how nutrition and diet affect it is so difficult, and often produces no definitive answers. In spite of these facts, experts in the field are becoming increasingly convinced that diet plays an important role. Some foods and nutrients seem to protect against prostate cancer or slow its growth, while others act as a spur.

So is there a “prostate cancer diet”? Are there dietary changes that men diagnosed with prostate cancer might want to consider making? The answer is yes, but a qualified yes.

Two national diets are associated with a reduced prostate cancer risk: the traditional Japanese diet and the typical diet followed in southern Europe, which is often referred to as the Mediterranean diet. Both diets do not include much red meat. The Japanese diet is low in calories and fat and high in soy, fish, green tea, and vegetables. The Mediterranean diet is high in fresh fruits and vegetables (especially tomatoes and garlic), red wine, and olive oil, and it also includes a lot of fish. The elements of these two diets have been researched to develop general advice about what to eat if you have prostate cancer.

Men should remember, however, that dietary guidelines are general and subject to change---new research is uncovering more about the connection between lifestyle factors and prostate cancer each month. Also, the most important rule is to make sure that any diet you follow is healthy for you, specifically, and does you no harm---moderation, common sense, and the advice of your doctors are key when it comes to deciding how to adapt any diet to your own unique circumstances.

Here are the main dietary strategies that have the potential to reduce your risk of prostate cancer recurrence or to delay the progression of the disease if you are still fighting it.

• Reduce the amount of fat in your diet, especially the amount of animal fat. Do this by limiting red meat and high-fat dairy products. (Current guidelines suggest limiting the fat in your diet to 20 per cent of your daily calorie intake.)
• Substitute a variety of plant proteins, such as lentils, beans, grains, and nuts and seeds, for the high-fat animal proteins you are avoiding. Remember to maintain a sufficient level of protein consumption from diverse plant sources to ensure your body has the proper building blocks for tissue growth and repair.
• Add soy to your diet as one of the substitutes for high-fat dairy and animal protein. (Research suggests a daily intake of 40 grams of soy protein might be optimal, but remember to consult your doctors and, with their go-ahead, build up to this level gradually if you are not used to consuming soy products. You will also need to adjust your diet by limiting your intake of other caloric proteins, e.g., meat and milk, as you add soy.)
• Significantly increase your intake of fruits, herbs, and vegetables, particularly of dark-green leafy vegetables, red and purple vegetables and fruit (e.g., tomato juices or sauces, watermelon, red grapes, and pomegranates), and cruciferous vegetables such as cabbage, broccoli, and cauliflower. Specifically, choose by colour to ensure that you consume foods that contain different anti-cancer properties:
  • Red group (containing lycopene): tomato juice or sauce, watermelon, pink grapefruit.
  • Red/purple group (containing various anthocyanins): pomegranates or pomegranate juice; red grapes, red grape juice, or red wine; plums; assorted berries.
  • Orange group (containing alpha and beta carotene): carrots, pumpkin, sweet potatoes, mangoes, cantaloupes, apricots.
  • Orange/yellow group (containing beta-cryptoxanthin): oranges, peaches, papaya.
  • Yellow/green (containing lutein and zeaxanthin): spinach, yellow corn, green peas, honeydew melon.
  • Green (containing isothiocyanates, indoles, and sulforaphanes): broccoli, bok choy, cabbage, Brussels sprouts, kale.
  • White/green (containing allyl sulfides): garlic, leeks, shallots, chives, onions.
• Drink green tea at least several times a week. (Current research suggests that at least 3 cups a day may be better.) The polyphenols found in green tea are thought to slow the progression and spread of prostate cancer.
• Avoid excessively preserved, pickled, or salted foods.
• Use olive oil, which is rich in vitamin E and antioxidants.
• Avoid refined sugars, and limit your calorie intact (if necessary) so as to achieve and maintain a healthy body weight.

For more detailed information, download these excellent books:

Challenging Prostate Cancer: Nutrition, Exercise, and You (from the Prostate Centre, Toronto).

Nutrition, Exercise, and Prostate Cancer (from the Prostate Cancer Foundation)