RESUMEN
Isothiocyanates (ITCs) are nonnutrient compounds in cruciferous vegetables with anticarcinogenic properties. One proposed mechanism for their protective action is through down-regulation of cytochrome P-450 biotransformation enzyme levels and induction of phase II detoxifying enzymes. Because ITCs also serve as a substrate for GSTs, we evaluated dietary intake of ITCs and GSTM1 and GSTT1 genotype information in a lung cancer case-control study. There were 503 newly diagnosed lung cancer cases (264 men and 239 women) identified from The University of Texas M. D. Anderson Cancer Center and 465 controls (252 men and 213 women) recruited from enrollees in a local managed care organization. Subjects had an in-person interview including a semiquantitative food frequency questionnaire, and blood samples were obtained for genotyping. Cases reported significantly lower ITC intake per day compared with controls (P = 0.009). There was no main effect associated with the GSTM1 null genotype [odds ratio (OR) = 1.09]. However, there was a statistically significant OR of 1.41 associated with the GSTT1 null genotype. On stratified analysis, low ITC intake and the GSTM1 null genotype were associated with increased lung cancer risk in current smokers, with an OR of 2.22 [confidence interval (CI) = 1.20-4.10). For current smokers with the GSTT1 null genotype, the OR with low ITC intake was 3.19 (CI = 1.54-6.62). The comparable OR in the presence of both null genotypes was 5.45 (CI = 1.72-17.22). These effects were not demonstrable for former smokers by GSTM1 genotype, although the risk for low ITC intake and GSTT1 null genotype was 1.79 (CI = 0.95-3.37). Thus, current smokers who are homozygous null for the GST null genotype and who consume less carcinogenic blocking compounds are at higher lung cancer risk. Some of the inconsistencies reported in the role of GST genotypes in lung cancer risk could be due to unexpected confounding from dietary factors.
Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Dieta , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Isotiocianatos/farmacología , Neoplasias Pulmonares/genética , Anciano , Estudios de Casos y Controles , Factores de Confusión Epidemiológicos , Inducción Enzimática , Femenino , Genotipo , Humanos , Neoplasias Pulmonares/etiología , Neoplasias Pulmonares/prevención & control , Masculino , Persona de Mediana Edad , Factores de Riesgo , Fumar/efectos adversosRESUMEN
No risk factor other than cryptorchidism has been consistently associated with testicular cancer, and the influence of diet on testicular cancer risk has not been extensively explored. A few studies have found increased testicular cancer risk in men whose diets are high in fat, red meats, and milk or low in fruits and vegetables. We evaluated the relationship of dietary factors and risk of testicular cancer and also examined whether this risk varied by type of testicular cancer. We conducted a hospital-based case-control study at The University of Texas M. D. Anderson Cancer Center (Houston, TX) of 160 testicular cancer cases diagnosed between 1990 and 1996 and 136 friend-matched controls. The results of multivariable logistic regression analysis showed that after adjustment for age, education, income, ethnicity, cryptorchidism, and total daily calories, increasing total fat, saturated fat, and cholesterol consumption were associated with increasing risk of nonseminoma testicular cancer, with odds ratios (ORs) for the highest vs. the lowest quartiles of 6.3, 5.3, and 4.6, respectively. The risk for seminoma testicular cancer marginally increased with increasing intake of total fat and saturated fat, with ORs for the highest vs. lowest quartiles of 1.9 and 2.1, respectively. Higher total fat consumption was nearly significantly related to increased mixed germ cell tumor risk, with an OR for highest vs. lowest quartile of 4.2. This study supports the hypothesis that diet (particularly high fat consumption) increases testicular cancer risk in young men. However, the small sample size and the possibility that these observations may be due to bias indicate that the relationship of diet and testicular cancer risk needs to be further examined within a prospective or incident case-control study.
Asunto(s)
Dieta , Grasas de la Dieta/administración & dosificación , Neoplasias Testiculares/epidemiología , Adolescente , Adulto , Estudios de Casos y Controles , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo , Encuestas y Cuestionarios , Texas/epidemiologíaRESUMEN
For the past two decades, epidemiologists have observed lower risks of lung, breast, prostate, colon, and other cancers in populations that frequently consume fruits and vegetables. Numerous phytoestrogens have been shown to be anticarcinogenic under experimental conditions and may account for at least part of the cancer-prevention effects of fruit and vegetable consumption. These plant constituents include isoflavonoids, coumestans, lignans, phytosterols, and flavonoids. DietSys, the nutrient analysis program associated with the National Cancer Institute Health Habits and History Questionnaire (HHHQ), and other nationally available nutrient analysis databases do not fully assess these constituents. Therefore, we modified DietSys to include these components in foods on the basis of published values. In addition, as part of an epidemiological study of prostate cancer, we modified the food-frequency component of the HHHQ to include the main foods contributing to phytoestrogen intake. Although there are limitations to the consistency and quality of many of the values because they were gathered from a variety of sources, our approach should provide a useful first tool for assessing the epidemiological association between phytoestrogen consumption and cancer risk. Furthermore, this work has already facilitated the identification of the major dietary contributors with phytoestrogen activity and prioritized future laboratory analyses of specific foods toward the development of a more complete and accurate database.
Asunto(s)
Anticarcinógenos/administración & dosificación , Bases de Datos Factuales , Registros de Dieta , Estrógenos no Esteroides/administración & dosificación , Isoflavonas , Evaluación Nutricional , Diseño de Software , Humanos , Neoplasias/prevención & control , Fitoestrógenos , Preparaciones de Plantas , Encuestas y CuestionariosRESUMEN
In the last several years, attention has been focused on comparing the Western diet, which is rich in fat, protein, and refined carbohydrates, with the Asian diet, which is rich in phytoestrogens, as a possible explanation for the contrasting rates of clinically relevant prostate cancer. Phytoestrogens, plant-derived nutrients, include several isoflavones, flavonoids, lignans, phytosterols, and coumestans, some of which have been postulated as having anticarcinogenic properties. Using a new database, we examined the role of phytoestrogen intake and prostate cancer risk in 83 Caucasian cases and 107 controls. Controls reported consuming higher amounts of foods containing genistein, daidzein, and coumestrol and lower amounts of foods containing campesterol and stigmasterol. Multivariate analysis, after adjustment for age, family history of prostate cancer, alcohol consumption, and total calorie intake, showed an inverse association between coumestrol (p = 0.03) and daidzein (p = 0.07) and prostate cancer risk. Genistein, the most studied phytoestrogen, showed a slight protective effect (p = 0.26). However, a positive association was found between campesterol (p = 0.08) and stigmasterol (p = 0.03) and risk of prostate cancer. These results are suggestive of a possible relationship between phytoestrogen intake and prostate cancer risk. Larger comprehensive studies are needed to further refine the role of phytoestrogen intake in prostate cancer risk.
Asunto(s)
Anticarcinógenos/administración & dosificación , Bases de Datos Factuales , Estrógenos no Esteroides/administración & dosificación , Isoflavonas , Fitosteroles , Neoplasias de la Próstata/etiología , Estudios de Casos y Controles , Colesterol/administración & dosificación , Colesterol/análogos & derivados , Registros de Dieta , Genisteína/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Evaluación Nutricional , Fitoestrógenos , Preparaciones de Plantas , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/prevención & control , Factores de Riesgo , Estigmasterol/administración & dosificación , Encuestas y Cuestionarios , Texas/epidemiologíaRESUMEN
In this case-control study we determined whether dietary differences underlie some of the ethnic and sex differences in US lung cancer rates. We examined the relationship between diet and lung cancer development in 137 lung cancer cases (93 African Americans and 44 Mexican Americans) and 187 controls (78 African Americans and 109 Mexican Americans). Cases reported a higher daily mean total fat intake (p < 0.001), whereas controls had a higher daily mean intake of dietary fiber (p < 0.001) and fruits (p = 0.02). Ethnic differences in diet were also observed: Mexican Americans consumed less total fat (p < 0.02) and more fiber (p < 0.001) and vegetables (p = 0.08) than African Americans. Additionally, men consumed more total fat (p = 0.08) and less fiber (p = 0.001), fruits (p < 0.001), and vegetables (p = 0.002) than women. Multivariable analysis, after adjustment for the effects of pack-years of smoking, age, total energy intake, sex, and ethnicity, demonstrated a positive association between high total fat consumption and lung cancer risk (p < 0.01) and an inverse association between high fruit consumption and lung cancer risk (p = 0.05). In conclusion, our findings support the hypothesis that diet, particularly high fat consumption and low fruit and vegetable consumption, contributes (independent of cigarette smoking) to the excess lung cancer risk in African-American men, who have the highest lung cancer rates in the United States.
Asunto(s)
Negro o Afroamericano/estadística & datos numéricos , Dieta/estadística & datos numéricos , Neoplasias Pulmonares/etiología , Americanos Mexicanos/estadística & datos numéricos , Estudios de Casos y Controles , Grasas de la Dieta/administración & dosificación , Fibras de la Dieta/administración & dosificación , Ingestión de Energía , Femenino , Frutas , Humanos , Incidencia , Modelos Logísticos , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/etnología , Masculino , Factores de Riesgo , Factores Sexuales , Fumar/epidemiología , Clase Social , VerdurasRESUMEN
The cancer rates of immigrant populations in the United States must be taken into account when looking at the importance of diet and culture as it relates to cancer prevention. Unfortunately, some nutrition studies targeted toward nontraditional white populations have not adequately confronted the issue of cultural meaning in efforts to gather dietary data accurate enough to support nutritional analyses, identify marginal diets, or relate risk to dietary patterns. The study presented here resolves many of the culturally specific issues utilizing awareness, attention, and judicious combination of culturally sensitive qualitative and quantitative research techniques. The importance of such a study in an Hispanic population is based on the fact that the age-adjusted rate of breast cancer in countries such as Mexico is among the lowest in the world. In addition, although one of the fastest-growing minority groups in the United States, Hispanic women living in this country have been shown to have the lowest incidence of the mortality rates from this disease across most geographic regions of the United States. Therefore, one might speculate that dietary factors, which have been shown to play a role in breast cancer prevention, may account for this difference. It is well recognized that the traditional Hispanic diet is rich in protective nutrients such as dietary fiber. It is known that through complex mechanisms, dietary fiber works to reduce the amount of estrogens in the body. Research also indicates that it is the level of endogenous estrogen in the body that may influence the onset of breast cancer. In order to better understand how dietary factors may be associated with breast cancer in Hispanic women, it is important that one develop the proper tools to discern any potential differences. Therefore, we developed an approach to obtaining dietary fiber information from a small cohort of 22 Houston-area Hispanic women as a vanguard study for a larger breast cancer prevention trial. Two separate dietary assessment instruments were utilized, a three-day food record and the Southwest Food Frequency Questionnaire. The mean intake of dietary fiber was 16 g/day according to the food record and 21 g/day according to the SWFFQ. Fruits, vegetables, breads, cereals, and beans provided for most of the participants' dietary fiber intake. These results support evidence that the Hispanic population's dietary fiber intake is higher than that for other groups, and this may help explain the lower incidence of breast cancer among some Hispanic populations.
Asunto(s)
Neoplasias de la Mama/mortalidad , Anciano , Grasas de la Dieta/metabolismo , Fibras de la Dieta , Estradiol/metabolismo , Femenino , Hispánicos o Latinos , Humanos , Persona de Mediana Edad , Factores SocioeconómicosRESUMEN
The existence of three different ethnic groups, living within a defined geographic area in Texas and maintaining fairly distinct life-styles, provided an excellent opportunity to compare their dietary behaviors. Information about food consumption was obtained by 24-hour dietary recall from a group of 431 whites, blacks, and Mexican Americans residing in two counties in southeast Texas. Food group and subgroup contributions to 11 nutrients were calculated. The intake patterns of Mexican Americans demonstrated both an adherence to traditional or familiar Mexican food items, such as beans and tortillas, and a preference for foods not previously reported to be commonly consumed by that ethnic group, specifically beef. The current study provides a base of information necessary to implement dietary changes acceptable within the context of a particular culture's world view. Results revealed differences in food intake patterns that would be helpful in designing practical nutrition education programs specifically targeted toward these ethnic groups. For example, inadequate sources of nutrients were identified, as were sources of excess fat.
Asunto(s)
Negro o Afroamericano , Cultura , Alimentos , Hispánicos o Latinos , Fenómenos Fisiológicos de la Nutrición , Población Blanca , Adulto , Dieta , Encuestas sobre Dietas , Femenino , Preferencias Alimentarias , Humanos , Masculino , México/etnología , Persona de Mediana Edad , TexasRESUMEN
Dietary intake was assessed among 431 black, white, and Mexican American men and women in southeast Texas using 24-hour dietary recall interviews. These data were collected to provide information on ethnic-specific food sources of selected nutrients; this information was used to construct a food frequency questionnaire for a study of nutrient intake and cancer. Nutrient content of total fat, total vitamin A, and vitamin C was determined for all foods consumed and was aggregated across unique food codes. These aggregated food codes were then ranked according to the contribution of each food to the total population intake of each nutrient. Ethnic differences existed in food sources of nutrients that would not be identified if data from only the analysis of the combined data set were used. Generally, however, the food sources identified from analyses of the combined data set included those foods that were important nutrient sources for each of the ethnic groups as well.
Asunto(s)
Encuestas sobre Dietas , Etnicidad , Alimentos , Encuestas Nutricionales , Adulto , Negro o Afroamericano , Ácido Ascórbico/administración & dosificación , Grasas de la Dieta/administración & dosificación , Femenino , Análisis de los Alimentos , Hispánicos o Latinos , Humanos , Masculino , Recuerdo Mental , Persona de Mediana Edad , Texas , Vitamina A/administración & dosificación , Población BlancaRESUMEN
Ethnic groups in the United States exhibit different patterns of cardiovascular disease and cancer morbidity and mortality. This has, in part, been attributed to differences in dietary intake. However, there is limited comparative information available regarding the dietary patterns of whites, blacks, and Hispanics residing in the same geographic area. Selected nutrient intakes were obtained by an interviewer-administered 24-hr dietary recall from 231 white, 102 black, and 98 Mexican-American persons residing in the same communities in Southeast Texas. Mean caloric intakes were highest for whites, followed by Mexican Americans and blacks. Mexican Americans had carbohydrate intakes that were significantly higher, but total fat intakes that were significantly lower, than those of whites. Blacks of both sexes had the highest cholesterol intakes and black males had the highest saturated fat intakes. Neither was significantly higher than that of whites or Mexican Americans. Overall, the mean vitamin A and C values were highest for blacks and lowest for whites, although the differences were not statistically significant. Mean calcium and phosphorus intakes were significantly higher for whites compared with those for blacks and Mexican Americans. Blacks had significantly lower mean fiber values than whites or Mexican Americans. International ethnic differences in disease distribution have long been used to provide clues to etiologic factors. National ethnic differences in disease distribution related to dietary intake can further elucidate these causative and/or preventive factors. However, to do so will require additional attention to dietary methodology of the type presented here.