While hereditary cancer is unpreventable, there does indeed exist foods that can help prevent avoidable cancer.
When it comes to cancer, cutting out any habits that are detrimental to the health is key. Smoking and drinking are such habits, with smoking being the most preventable cause of cancer in the world. If you smoke or drink, quitting them is the first step to take to a healthier lifestyle.
The second step to take is in ensuring that your body is in its best health. This involves taking steps in your diet that will help strengthen your immune system and bodily functions.
Berries in particular, have ranked most likely to help prevent cancer. Pterostilbene, an antioxidant found in abundance in berries, have been shown to contain large amounts of natural cancer-fighting chemicals.
Food rich in Vitamin C, an antioxidant that helps prevent the formation of cancer-causing nitrogen compounds, should be consumed. Vitamin C is found in many fruits such as oranges, grapefruits and other citrus fruits. A Vitamin C rich diet has been shown to reduce the risk of colon, stomach, esophagus, breast and bladder cancer.
Red fruits and vegetables are also shown to prevent cancer. Lycopene, thepigment that gives red fruits and vegetables their colour, is a free radical-fighting antioxidant that has shown to help prevent prostate, lung and stomach cancer. Free radicals are molecules that disrupt cells and promote diseases. Consumption of lycopene through red fruits and vegetables like tomatoes also helps reduce cholesterols, aiding not only in preventing cancer but also in preventing heart diseases.
In general, diets that help prevent cancer should be rich in antioxidants that prevents cell damage.
For cancer patients undergoing treatment, problems that they face may include anorexia, nausea and diarrhea, which may affect their diet and appetite.
Foods that they consume should thus prevent or treat such nutritional problems and to decrease the side effects of their cancer treatments.
This include eating before treatment, eating foods that are easy to digest, and staying from greasy or spicy foods.
Herbal drinks such as fresh ginger and honey-fried licorice root can also be consumed to help with the nausea post-treatment.
References
http://www.joybauer.com/photo-gallery/10-best-foods-for-cancer-prevention.aspx
http://www.pcrm.org/health/cancer-resources/diet-cancer/nutrition/how-lycopene-helps-protect-against-cancer