For many years, lung cancer has been blamed almost entirely on tobacco smoke along with asbestos and radon gas. The role of diet has been largely ignored, yet epidemiological studies have shown that lung cancer is more common in smokers who eat a typical American diet than in those who eat a low-fat, more vegetarian diet with plenty of fruits and vegetables. Japanese smokers are considerably less likely to develop lung cancer than American smokers.

Several epidemiological studies have shown a positive association with serum cholesterol and the risk of developing lung cancer after correcting for smoking, age and other risk factors. A study in Hawaii that compared the amount of cholesterol in the diet and its association with lung cancer found a strong positive association after adjusting the data for other risk factors for lung cancer such as age, pack-years of smoking, and occupational exposure to lung carcinogens. Cholesterol oxides, which are produced when meat is cooked at high temperatures, have been shown to be mutagenic and carcinogenic in animals. Burning fat produces benzyapyrene and other known and suspected carcinogens. Cooking meats at high temperatures produces heterocylic amines, which promote cancer in animals. Which, if any of these compounds may contribute to the risk of developing lung cancer is not known but it seems wise to limit ones exposure to such compounds if one is at high risk for lung or other cancers.Another study in Hawaii found a reduced risk of lung cancer in those people who consumed the most vegetables, and particularly those who ate more cruciferous vegetables, dark green vegetables and tomatoes. A recent study in China found that an increased intake of cruciferous vegetables (e.g., cabbage, broccoli, bok choy, cauliflower, brussel sprouts, watercress), was associated with a 40% decreased risk of developing lung cancer overall but a remarkable 64% reduction in those who were at highest risk due to a genetic prediposition. The protective chemicals in cruciferous vegetables are isothiocynates. These phytochemicals are found only in cruciferous vegetables.Bottom Line: People who wish to avoid lung cancer should obviously be advised to limit their exposure to cigarette smoke, asbestos and radon gas. They should be encouraged to limit their intake of meat, eggs and full fat dairy products and consume more fruits, vegetables and whole grains. They should be advised against taking beta-carotene supplements, especially if they continue to smoke.