According to The National Cancer Institute, around 1/3 of all cancer deaths may be diet related. Therefore, the selection of food will be very important. Among the common foods, you can find good ones that contain the cancer-fighting ability to stave off cancer, inhibit cancer cell growth or reduce the size.

Here are some samples for foods to help fighting cancer.

Tomatoes contain lycopene, an antioxidant that attacks roaming oxygen molecules, known as free radicals, that are suspected of triggering cancer. It appears that the hotter the weather, the more lycopene tomatoes produce. They also have vitamin C, an antioxidant which can prevent cellular damage that leads to cancer.

Carrots contain a lot of beta carotene, which may help reduce a wide range of cancers including lung, mouth, throat, stomach, intestine, bladder, prostate and breast. It is important not to cook the carrots.

Avocados are rich in glutathione, a powerful antioxidant that attacks free radicals in the body by blocking intestinal absorption of certain fats. Avocados may also be useful in treating viral hepatitis (a cause of liver cancer), as well as other sources of liver damage.

Chili peppers contain a chemical, capsaicin, which may neutralize certain cancer-causing substances (nitrosamines) and may help prevent cancers such as stomach cancer. 

Cruciferous vegetables - broccoli, cauliflower, kale, Brussels sprouts, and cabbage contain two antioxidants, lutein and zeaxanthin that may help decrease prostate and other cancers. 

Figs apparently have a derivative of benzaldehyde. According to the U.S. Department of Agriculture, figs contain vitamins A and C, and calcium, magnesium and potassium, may curtail appetite and improve weight-loss efforts. Fig juice is also a potent bacteria killer in test-tube studies.

Garlic has immune-enhancing allium compounds (dialyl sultides) that appear to increase the activity of immune cells that fight cancer and indirectly help break down cancer causing substances. These substances also help block carcinogens from entering cells and slow tumor development. It is believed garlic may help prevent stomach cancer because it has anti-bacterial effects against a bacterium, Helicobacter pylori, found in the stomach and known to promote cancer there.

Grapefruits, like oranges and other citrus fruits, contain monoterpenes, believed to help prevent cancer by sweeping carcinogens out of the body. Some studies show that grapefruit may inhibit the proliferation of breast-cancer cells in vitro. They also contains vitamin C, beta-carotene, and folic acid.

Red grapes contain bioflavonoids, powerful antioxidants that work as cancer preventives. Grapes are also a rich source of resveratrol, which inhibits the enzymes that can stimulate cancer-cell growth and suppress immune response. They also contain ellagic acid, a compound that blocks enzymes that are necessary for cancer cells - this appears to help slow the growth of tumors.

Kale has indoles, nitrogen compounds which may help stop the conversion of certain lesions to cancerous cells in estrogen-sensitive tissues. In addition, isothiocyanates, phytochemicals found in kale, are thought to suppress tumor growth and block cancer-causing substances from reaching their targets.

Mushrooms - There are a number of mushrooms that appear to help the body fight cancer and build the immune system.  Mushrooms contain polysaccharides, especially  Lentinan, powerful compounds that help in building immunity. They are a source of Beta Glucan. They also have a protein called lectin, which attacks cancerous cells and prevents them from multiplying. They also contain Thioproline. These mushrooms can stimulate the production of interferon in the body. 

Nuts contain the antioxidants quercetin and campferol that may suppress the growth of cancers.

Oranges and lemons contain Iimonene which stimulates cancer-killing immune cells (lymphocytes, e.g.) that may also break down cancer-causing substances.

Seaweed and other sea vegetables contain beta-carotene, protein, vitamin B12, fiber, and chlorophyll, as well as chlorophylones - important fatty acids that may help in the fight against breast cancer. Many sea vegetables also have high concentrations of the minerals potassium, calcium, magnesium, iron, and iodine.

Soy products(tofu) contain several types of phytoestrogens — weak, nonsteroidal estrogens that could help prevent both breast and prostate cancer by blocking and suppressing cancerous changes. There are a number of isoflavones in soy products, but research has shown that genistein is the most potent inhibitor of the growth and spread of cancerous cells.

Teas: Green Tea and Black tea contain certain antioxidants known as polyphenols (catechins) which appear to prevent cancer cells from dividing. Green tea is best.