Hepatocellular carcinoma, the most common form of liver cancer, is one of least easily treated of all the cancers. There are people who beat liver cancer, but they are still only a small minority of liver cancer patients. And there are hundreds of millions of people worldwide who have been infected with the hepatitis B or hepatitis C viruses, leaving them at elevated risk for developing the disease.

If you have a chronic hep B or hep C infection, if you have a hereditary iron-storage overload disease called hemochromatosis, or if you have been exposed to massive amounts of petrochemicals, there are still some dietary interventions that will won't unduly limit your lifestyle but that may still reduce your risk of developing cancer. Diet is not a guarantee against cancer, but along with reducing or eliminating the use of alcohol and tobacco, it's probably your best bet.

Here are the basic features of a liver cancer prevention diet:

• Eat paleo. The benefit of the paleo diet in preventing liver cancer isn't so much what it includes as what it avoids: Grains. One of the strongest risk factors for liver cancer, especially in Asia and Africa, is exposure to a grain contaminant called aflatoxin. This poison appears on grain that has been contaminated with a fungus that typically grows in extremely dry weather. If you don't eat grain, you aren't exposed to aflatoxin.
• Get rid of visceral fat (belly fat). The hard fat that grows between and around the organs in your abdomen, including your liver, secrete a hormone called vascular endothelial growth factor (VEGF). This hormone does not cause cancer, but it enables cancer to grow its own blood vessels when it reaches the tumor stage.
• Drink coffee (without the cream and sugar). Coffee lowers the production of an enzyme cancer needs to grow, gamma-glutamyltransferase (GGT). Several studies have found that coffee drinkers are less likely to develop cirrhosis of the liver and less likely to develop liver cancer. Coffee seems to be especially cancer-protective for people who have hepatitis C.
• Eat flax seeds and flaxseed oil. Whole flax seeds don't do you any good. They pass right on through the digestive tract. Ground flax seeds and flaxseed oil, however, are associated with lower rates of liver cancer among people who drink and people who have hepatitis B or C infections. Just a tablespoon (about 15 grams) a day is enough.
• Avoid high-iron foods, such as liver and sausage, and foods cooked in cast iron. Don't take iron supplements.
• Avoid vitamin B1 (thiamin) supplements and the breads, cereals, and pastries made with thiamin- and iron-enriched flour.
• Avoid soy products. The genistein in soy products actually reduces the incidence of some kinds of cancer, such as breast and prostate cancer, by encouraging a kind of chemical reaction known as methylation, but this chemical reaction actually increases the risk of liver cancer.

And consider taking a milk thistle (silymarin) supplement. If you have biliary cirrhosis or biliary cancer, milk thistle won't help. It could actually make the underlying problem worse. However, if you have intact bile ducts and gallbladder, the silymarin in milk thistle  encourages the liver to repair itself and to produce the bile that removes “toxins” to the bowel. These toxins have to travel through the bile ducts and the gallbladder, however, to be eliminated from the body.