The relative importance of the major individual carotenoids was investigated in studies of lung and upper aerodigestive tract cancers. In a cohort of Japanese Hawaiian men, low prediagnostic serum levels of alpha-carotene and beta-carotene were each predictive of increased risk of oral-pharyngeal, esophageal, and laryngeal cancer. Similarly, in a case-control study in New Jersey white men, intake of both alpha-carotene and beta-carotene were each inversely associated with lung cancer risk. In two placebo-controlled clinical trials conducted in an area of rural China with documented micronutrient deficiency, hypertension and cerebrovascular disease risk were reduced among men and women taking vitamin/mineral supplements. Heterocyclic aromatic amines (HAAs), animal carcinogens found in meats cooked at high temperatures, were determined to be relatively low in fast-food meat products but unexpectedly higher in chicken (cooked by certain methods) than in red meat. Meat preparation methods that generate HAAs were positively associated with increased risk of stomach but not esophageal cancer in a case-control study in Nebraska and with colorectal adenomas in a sigmoidoscopy-based case-control study in southern California. In a case-control study in Nebraska, animal protein intake was not significantly related to risk of non-Hodgkin's lymphoma, although vegetables and fruits were protective. In a case-control study of cancers that occur excessively in U.S. blacks, heavy drinking was not causally related to multiple myeloma, but seemed to be related to pancreatic cancer. Alcohol use in all forms was a strong risk factor for esophageal cancer but did not explain racial differences in incidence. However, risk of esophageal cancer increased with obesity and decreased with intake of raw vegetables and fruits; obesity may partially explain recent epidemic increases reported in the incidence of this tumor. In a case-control study of pancreatic cancer conducted in Shanghai, diets high in vegetables and fruits were protective, obesity increased risk, but meat, fat, and alcohol, at the levels of intake characteristic of China, were unrelated to risk. Extensive reviews of the role of diet in the etiology of lung and cervical cancer were published.
