摘要:

AbstractClinical and ecological evidence supporting an association between human papillomavirus (HPV)‐related tumors and dietary factors are presented. Abstinence from high intake of fried pork (600–1,000 g/day) was associated with regression of an urethral condyloma in a healthy 19‐year‐old man treated with interferon gamma. International correlations suggest that pork intake is positively associated with incidence of cervical cancer, a disease also related to HPV. Pork meat or dietary factors associated with pork meat consumption may be involved in the development of HPV‐related diseases.

ISSN:0163-5581    

DOI:10.1080/01635589009514062

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractThere is currently a great interest in the protective potential ofβ‐carotene and other micronutrients against carcinogenesis. We investigated the role ofβ‐carotene in modifying 7,12‐dimethylbenz[a]anthracene (DMBA)‐initiated, 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐promoted, two‐stage skin carcinogenesis. We were interested in comparing the protective effects of two types of dietaryβ‐carotene, a beadlet formulation and crystallineβ‐carotene, in two strains of mice (Skh:HR‐1 and CR:ORL Sencar). Mice were maintained throughout the study on one of these 3%β‐carotene‐fortified diets or on control diets. In Week 11 after the start of the diets, the DMBA/TPA treatment regimen was begun. The resulting skin tumors were counted weekly. In addition, serum and skin levels were monitored forβ‐carotene at the time of chemical initiation and at the termination of the study. A decrease in the number of cumulative tumors in theβ‐carotene‐fed animals compared with the appropriate control groups was observed in both strains of mice. However, statistical evaluation of the data revealed that the decrease was significant only in Skh mice. This phenomenon might be explained by the inherent sensitivity of Sencar mice to the two‐stage carcinogenesis treatment regimen. The mechanism of the protective effect found in this study is still not clear. Recent data suggest that a vitamin A pathway is not probable but that a direct1O2 and/or radical‐quenching property of the parentβ‐carotene molecule may be involved. This study also demonstrates that tvo‐stage‐induced skin tumorigenesis can be modified by both types ofβ‐carotene‐fortified diets.

ISSN:0163-5581    

DOI:10.1080/01635589009514063

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractCases (n= 263) and controls (n =200) returned self‐administered food frequency questionnaires in 1980–1982 and again in 1986 as part of a case‐control study of breast cancer. The questionnaires asked about consumption of specific food items as recalled for four different age periods. K‐statistics comparing responses in the first and second questionnaires were generally similar for cases and controls and were consistent across the different age periods. The influence of recent dietary change on dietary recall diminished for the more distant past. The food frequency questionnaire was found to be more reliable for specific food items for the distant past than for the more recent past. Differential misclassification bias between cases and controls was less apparent for the more distant past. The frequency and interpretation of missing values is discussed.

ISSN:0163-5581    

DOI:10.1080/01635589009514064

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractRats fed diets high (24%) or low (5%) in fat were given dietary levels of vitamin A (retinyl acetate) ranging from 0.3 to 30μg/food. The lowest tumor incidence was in the group fed diets high in vitamin A and low in fat. When the diet was high in fat and low in vitamin A, tumor incidence and frequency were significantly increased over that in rats fed the high‐fat diet with normal levels of vitamin A (10μg/g feed). However, even with a high level of fat in the diet, raising the level of vitamin A above 10μg/g feed had no further beneficial effect. Thus, although there was a significant interaction between vitamin A and fat, it is the latter that appears to require the most attention, once the vitamin A intake is adequate. These data support the view that we should set as a goal an adequate, diversified diet that is low in fat but that an excessive intake of vitamins such as vitamin A that are toxic should be avoided.

ISSN:0163-5581    

DOI:10.1080/01635589009514065

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractThe effects ofβ‐carotene, canthaxanthin, and extracts of tomato paste (containing lycopene) and orange juice (containing cryptoxanthin) on aflatoxin B1 (AFB1)‐induced mutagenesis inS. typhimuriumTA 100 and TA 98 were investigated. Inhibition of mutagenesis was studied during and following completion of AFB, metabolism (i.e., after the addition of menadione), thereby permitting separate examination of the metabolic activation and phenotypic expression phases. Each experimental carotenoid, except lycopene, inhibited AFB1‐induced mutagenesis in both tester strains. Cryptoxanthin was the most potent inhibitor, being at least an order of magnitude more potent than the other carotenoids. Inhibition byβ‐carotene and canthaxanthin was more prominent during the activation phase, whereas cryptoxanthin was more effective during the subsequent phenotypic expression phase. These inhibitory effects were not dependent on conversion to retinol.

ISSN:0163-5581    

DOI:10.1080/01635589009514066

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractThe relation between calcium intake, estimated from frequency of use of 29 food items, and colorectal cancer risk was analyzed using data from a case‐control study conducted in Northern Italy. The study was conducted on 558 cases of colon cancer, 352 cases of rectal cancer, and 1,032 controls admitted to the hospital for acute, nonneoplastic, nondigestive tract disorders (39% with traumas, 17% nontraumatic orthopedic diseases, 25% acute surgical conditions, 19% other miscellaneous disorders). There was no appreciable trend in risk of colon or rectal cancer in relation to measures of calcium intake. The multivariate relative risk (adjusted for age, sex, education, area of residence, and consumption of selected indicator foods) for highest versus’lowest quintile was 1.1 for colon and 1.0 for rectum. Likewise, there was no appreciable difference between cases and controls with reference to frequency of consumption of the two major calcium‐containing foods (milk and cheese), with relative risk for the highest level of intake between 0.9 and 1.2. This study indicates that little or no protection on large bowel cancer risk is provided by dairy products or calcium intake in a range of 0.5–1.5 g per day.

ISSN:0163-5581    

DOI:10.1080/01635589009514067

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractPlasma vitamin K concentrations and prothrombin coagulation activity were determined in 26 normal adults who had received daily (S‐carotene supplementation (0,15,30, or 60 mg) for six months. Neither plasma vitamin K nor coagulation activity were significantly decreased at any supplementation level. Thus, chronicβ‐carotene supplementation, even at high daily doses, is not expected to result in clinical vitamin K deficiency. The data suggest separate mechanisms for intestinal absorption ofβ‐carotene and vitamin K.

ISSN:0163-5581    

DOI:10.1080/01635589009514068

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractDietary fiber has been suggested to alter the colonic environment and protect against colorectal diseases, but several recent epidemiological studies indicate that cereal and vegetable fibers may not confer the same benefit. To address this issue, five common cereal brans (barley, corn, oat, rice, and wheat) and five vegetable fiber isolates (broccoli, cabbage, carrot, cauliflower, and lettuce) were fermentedin vitrowith human fecal microbiota for 4, 8, 12, and 24 hours. Short‐chain fatty acid (SCFA), hydrogen (H2), and methane (CH4) productions and neutral‐detergent fiber (NDF) digestibility differed significantly with fiber source. The vegetable fibers were significantly more fermentable than were the cereal brans, as evidenced by greater NDF digestibility and increased productions of SCFA, H2, and CH4,despite the presence of fermentable starch and protein in the latter. We concluded that vegetable fibers may more effectively stimulate colonic fermentation than cereal brans do. These findings suggest an attribute (i. e., fermentability) that may partially explain previously observed differences between vegetable and cereal fiber consumption patterns and colorectal carcinogenesis.

ISSN:0163-5581    

DOI:10.1080/01635589009514069

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

摘要:

AbstractA self‐administered dietary assessment questionnaire was developed for the microcomputer to identify individuals whose dietary patterns may put them at risk for cancer. It was tested among 50 adult volunteers in a New York school district. The quantitative food frequency portion of the questionnaire (FFQ), administered twice one month apart, was reproducible for calories, fat, percentage of calories from fat, cholesterol, vitamin A, vitamin C, calcium, and dietary fiber (Spearman r = 0.56–0.87). To test for relative validity, individual nutrient intake calculated from each administration of the FFQ was compared with the nutrient intake calculated from seven‐day food records collected one month after the second FFQ administration. Nutrient intake from the first and second FFQ compared with food record nutrient intake yielded a Spearman's correlation coefficient of 0.58 and 0.62, respectively, for percentage of kilocalories from fat. No significant difference in mean intake of percentage of calories from fat was found between the FFQ 1 and FFQ 2 or between the FFQs and the food record. However, there were significant differences between mean food record and FFQ estimates of kilocalories, fat, vitamin A, vitamin C, calcium, and dietary fiber. We concluded that computerized nutrient assessment, which utilizes the subject in data entry, may be suitable for some clinical and educational uses and research studies of intake of fat as a percentage of calories among healthy adults.

ISSN:0163-5581    

DOI:10.1080/01635589009514070

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor

ISSN:0163-5581    

DOI:10.1080/01635589009514061

出版商:Taylor&Francis Group    

年代:1990

数据来源: Taylor