Studies have shown that eating a specific diet can reduce a persons chances of developing certain cancers. All other factors aside, people who eat more alkaline foods have lower cancer risks, when compared to people who eat mostly foods that result in making the body more acidic after eating such a food. As such, it is recommended to consume only about 20 - 25% of your diet as acidifying foods. This has nothing to do with the pH of the food itself, only how it causes your body to react.
Small Portion
The following foods should be avoided or at least reduced in your diet to represent the smaller portion of your daily intake. These are the acidic foods, or foods that result in making your body acidic.
Some Fruits such as Cranberries, Plums (and Prunes), Olives, and green bananas.
Preserves like jellies, jams and pickles. Fresh Coconut can also be acidic.
Certain vegetables, like dried beans, Lentils, Chick Peas, Peanuts, Onions, Rhubarb and Tomatoes.
Dairy products, either from goats or cows, tend to result in acidifying your body, most cheeses, milk, and butter. (see also below)
Cooking oils, potatoes and grains should also be limited.
All Meats are acidifying, beef, fish, rabbit, lamb, and others.
Alcohols is also something that needs to be limited.
Large Portion
The following are the foods which need to be the largest portion of your diet, 75- 80%. These are the beneficial foods that will help prevent cancer.
Vegetables such as Carrots, Cucumbers, Beets, Peas, Broccoli, and Pumpkin.
Fruits like Apples, ripe Bananas, Grapes, Melons, and all Berries.
Protein sources like eggs (particularly fresh, free range eggs), cottage cheese and yogurt. Sunflower seeds, pumpkin seeds, fermented tofu, and millet.
Drinks such as Green Tea, Vegetable juices, and fruit juices are alkaline, and thus are beneficial.
All herbs are alkaline, as are most spices, such as cinnamon, ginger, and sea salt.
Other Contributing Factors
Now, you must also note that some things will make products worse or better. Specific to making foods worse, we must also consider the chemicals used in, or on them, herbicides, pesticides, growth hormones (for the meat) and so on, all make foods more acidifying. You can reduce this somewhat in your fruit and vegetables by washing them, or even better still, grow your own! Purchase "Organic" products when ever possible.
With eggs, the freshness really does make a difference, if you can have your own chickens for egg production you will be well ahead of people buying battery hen eggs from the store. I am certain the living conditions of the chickens, their mental happiness, and what they eat, also impacts the quality of the eggs.
Your Pets?
If you have pets you will also want to be aware that second to accidents, cancer is the leading cause of pet death. Many ingredients in lower quality pet foods have been linked to causing cancer in pets. Particularly BHT and BHA. By-Products are cheap filler, beaks, feet, feathers, but the main problem here is that they are preserved with a chemical pesticide, Ethoxyquin, this chemical is linked to causing cancer. You need to read the ingredient list for your self. Also note, many pet foods do not use "human grade" ingredients.
As such I believe we can improve our pets chances of survival by selecting to feed them healthier foods as well. When we pump our pets with indigestible filler this stresses out their body, thus also contributing to their risks of developing cancer.
Other Factors
Of course there is no guarantee that following a proper diet will prevent cancer, there are other contributing factors, such as genetics, environment, and even stress. However this is something that should help to whatever extent it can.
