Lung Cancer: Nutritional Considerations

Although environmental exposures (particularly tobacco smoke and, to a lesser extent, air pollution, asbestos, and radon) are the chief causes of lung cancer, diet also plays a surprisingly important role. Research on the relationships between diet, smoking, and lung cancer risk is complicated by the fact that smokers tend to have lower intakes and/or lower blood levels of many protective nutrients, compared with nonsmokers. Nonetheless, certain patterns have emerged.

Overall, evidence suggests that individuals (eg, Seventh–Day Adventists) eating plant–based diets, rich in vegetables and fruits, may be at lower risk for lung cancer, independent of tobacco use. The aspects of the diet associated with reduced risk are avoiding meat and saturated fat, consuming antioxidant–rich fruits and vegetables, and limiting alcohol, as described below:

Avoiding meat and saturated fat. Some studies suggest that vegetarian diets are associated with lower risk for lung cancer.⁴ Increased risk is also associated with red meat,⁵ particularly ham, sausage, and liver,⁶ saturated fat,⁷ and dairy products.^{8, 9}

Consumption of fruits and vegetables. Several studies show that individuals with diets rich in vegetables and fruits have reduced risk for lung cancer, independent of smoking. Nutrients that appear responsible for these protective benefits include carotenoids (as opposed to vitamin A found in animal products); vitamin C;^{10, 11} sulfur compounds incruciferous vegetables (broccoli, cauliflower, cabbage);¹² flavonoids;¹³ and folic acid.^{14, 15} A comprehensive antioxidant index that summarized the collective intake of carotenoids, flavonoids, vitamins E and C, and selenium among male smokers found that those with the highest antioxidant consumption had a significantly lower risk for lung cancer than those with the lowest antioxidant intakes.¹⁶ There appears to be no decrease in lung cancer incidence in persons taking antioxidant supplements, with the exception of individuals with poor selenium status who take selenium supplements.¹⁷ Beta–carotene supplements may actually raise lung cancer risk, at least in certain subgroups.^{18, 19}

Limiting alcohol intake. Intake of higher amounts of beer and spirits in particular appears to increase lung cancer risk up to 3 times that of nondrinkers.^{20, 21} One reason may be that acetaldehyde, an alcohol metabolite, is a known carcinogen. In contrast, several studies suggest that moderate consumption of wine lowers the risk for lung cancer.^{21, 22} However, part (though not all) of the increased risk for alcohol may be due to its association with smoking.

Orders

Smoking cessation.

Lung cancer prevention: See Basic Diet Orders chapter.

Treatment of lung cancer: There are as yet no specific guidelines for dietary interventions associated with improved survival. However, see Diet during Cancer Treatment chapter for general guidelines.

What to Tell the Family

In the case of lung cancer, prevention is clearly the most effective strategy. Family members and the patient should be encouraged to quit smoking. Smoking is the primary risk factor for lung cancer, and those who quit smoking experience a gradual risk reduction over time. This lower risk may be enhanced in persons who avoid alcohol and eat a diet low in saturated fat and high in fruits and vegetables.