摘要:

AbstractApproximately 200 studies that examined the relationship between fruit and vegetable intake and cancers of the lung, colon, breast, cervix, esophagus, oral cavity, stomach, bladder, pancreas, and ovary are reviewed. A statistically significant protective effect of fruit and vegetable consumption was found in 128 of 156 dietary studies in which results were expressed in terms of relative risk. For most cancer sites, persons with low fruit and vegetable intake (at least the lower one‐fourth of the population) experience about twice the risk of cancer compared with those with high intake, even after control for potentially confounding factors. For lung cancer, significant protection was found in 24 of 25 studies after control for smoking in most instances. Fruits, in particular, were significantly protective in cancers of the esophagus, oral cavity, and larynx, for which 28 of 29 studies were significant. Strong evidence of a protective effect of fruit and vegetable consumption was seen in cancers of the pancreas and stomach (26 of 30 studies), as well as in colorectal and bladder cancers (23 of 38 studies). For cancers of the cervix, ovary, and endometrium, a significant protective effect was shown in 11 of 13 studies, and for breast cancer a protective effect was found to be strong and consistent in a meta analysis. It would appear that major public health benefits could be achieved by substantially increasing consumption of these foods.

ISSN:0163-5581    

DOI:10.1080/01635589209514201

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractIn a hospital‐based case‐control study, 290 oral cancer cases and 133 esophageal cancer cases were queried as to smoking status, alcohol consumption, and dietary exposures, including vitamin supplement history. Among oral cancer cases, vitamin E use appeared to exert a protective effect. Vitamins C and E had protective effects among esophageal cancer cases. When stratified by smoking status, the protective effect of vitamin C use in esophageal cancer was significant only among current smokers, as was vitamin B use. A reduced risk of oral cancer was correlated with multivitamin use and increasing vegetable consumption, as was vegetable/fruit consumption and vitamin C supplementation. Among esophageal cancer cases, increasing meat consumption and vitamin C use were associated with a significantly reduced cancer risk.

ISSN:0163-5581    

DOI:10.1080/01635589209514202

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractEpidemiologkai and experimental studies have shown that increased intake of plant foods and decreased meat consumption are correlated with a decreased risk for colon cancer. Many components of plant foods are suggested to mitigate colon carcinogenesis, including vitamins, minerals, and dietary fiber. Phytosterols are a common component of plant foods consumed in relatively large quantities by vegetarians, who are at lower risk for colon cancer development than individuals on a Western diet low in phytosterols. In addition, phytosterols have been shown experimentally to inhibit colon cancer development. Dietary cholesterol, although structurally similar to the phytosterols, is correlated etiologically to the incidence of colon cancer, with changes in serum cholesterol levels and fecal bile acid profiles suggested to increase susceptibility to colon tumorigenesis. The objective of this paper is to discuss the effect of dietary phytosterols on cholesterol and bile acid metabolism and how these effects may lead to a decreased risk for colon cancer development.

ISSN:0163-5581    

DOI:10.1080/01635589209514203

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractFusarin C (FC) is a naturally occurring mutagen found onFusarium moniliforme‐contaminated corn. In Linxian, China, an area of exceptionally high incidence of esophageal cancer, the milled corn is made into small cakes called wotou, which are steamed. It has been suggested that FC may play a role in the etiology of esophageal cancer, but this has been questioned, in part, because of the thermal instability of FC. We therefore measured the effects of temperature on FC stability, mimicking the cooking process. FC was extracted from the wotou and quantitated by both reverse‐phase high‐performance liquid chromatography and the Ames assay. Afterwotou were steamed for 30 minutes, 11% and3% of the initial FC remained, as detected by the two assays, respectively. The milled corn, when moistened with water, had a pH of 6.1, which was lowered to 5.3 when it was inoculated withF. moniliformeand cultured for three weeks. Pickled vegetables are sometimes added to the wotou, which further reduces the pH. To determine the effects of pH on FC, it was heated in solution, with the pH varied between 4 and 8. Its stability was very pH dependent, decomposing more rapidly as the pH increased. Because ingested FC would also be subjected to the low pH of thestomach, it was treated for 30 minutes at 37°C and pH values ranging from 1.0 to 7.0. FC was stable (<15% decomposition) under these conditions. If FC is a significant health threat, it could most easily be destroyed by cooking at slightly basic pH values.

ISSN:0163-5581    

DOI:10.1080/01635589209514204

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractThe anticarcinogenic effect of the dietary antioxidant butylated hydroxytoluene (BHT) correlates with a preservation of nuclear envelope (NE) cytochromeP‐450 in rats undergoing chemically induced hepatocarcinogenesis. This effect of BHT on NE cytochromeP‐450 was observed during both the initiation and the promotion stages of hepatocarcinogenesis. Complex interactions between the two different mechanisms of action of BHT (i.e., enzyme induction and antioxidant activity) may account for some of the differences between the patterns of response to BHT observed during initiation and promotion.

ISSN:0163-5581    

DOI:10.1080/01635589209514205

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractNormal healthy volunteers (n= 8) received low‐and high‐fat (14% and 53% energy/day, respectively) and dietary fiber‐supplemented high‐fat diets (fiber 25 g/day, fat 52% energy/day) for 10 days each. Colon cancer risk factors in feces were measured by colonic nuclear aberration assay, the AmesSalmonellatest using strain TA100, and measurement of bile acids and calcium soaps. Nuclear aberrations in colonic epithelium increased during the high‐fat diet period and then decreased during the fiber‐supplemented high‐fat diet period. There were no significant differences in the mutagenicity onSalmonellaTA100 or in the concentration of bile acids during the high‐fat diet period. Bile acids decreased during the fiber supplementation period. The marked increase in calcium soaps during the high‐fat diet period indicates an increase in long‐chain fatty acids in the fecal lipid component and conversion of these fatty acids to insoluble calcium soaps when enough calcium is present.

ISSN:0163-5581    

DOI:10.1080/01635589209514206

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractRecently, we and others showed that the components of green tea may be useful cancer chemopreventive agents. It has been suggested that (‐)‐epigallocatechin‐3‐gallate (EGCG), the major constituent in green tea, may possess antitumor‐promoting and/or anticarcinogenic effects in rodent tumor bioassay systems. During the chemical analysis of various green tea products, we found a traditionally preserved preparation of green tea used by tribes in the Himalayan region of Sikkim, India that was rich in EGCG. EGCG was isolated from this tea product, and its inhibitory effects were evaluated against the binding of topically applied3H‐labeled polycyclic aromatic hydrocarbons (PAHs) to epidermal DNA and 12‐O‐tetra‐decanoylphorbol‐13‐acetate (TPA) caused induction of epidermal ornithine decarboxylase (ODC) activity in Sencar mice, the short‐term markers of tumor initiation and tumor promotion, respectively. Preapplication of EGCG resulted in significant inhibition (p<0.05) in the binding of [3H] PAH to epidermal DNA. Similarly, the topical application of EGCG resulted in significant inhibition (p<0.005) in TPA‐caused induction of epidermal ODC activity. In further studies, we assessed the anti‐skin tumor‐initiating effect of EGCG in Sencar mice in an initiation‐promotion protocol. The application of EGCG before challenge with 7,12‐dimethylbenz[a]anthracene as tumor initiator resulted in significant reduction both in percentage of mice with tumors and number of tumors per mouse compared with a non‐EGCG‐pretreated group of animals. The results of the present study suggest that the green tea preparation from Sikkim may be a good source for the isolation of EGCG and that this compound may have significant potential as a cancer chemopreventive agent.

ISSN:0163-5581    

DOI:10.1080/01635589209514207

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

摘要:

AbstractIthas been estimated that approximately 40% of human cancers may be associated with dietary factors. The relationship is more significant in esophageal cancers. Case‐control studies involving 35 subjects of early‐diagnosed esophageal cancers showed low mean blood levels of retinol, zinc (p<0.001), folk acid (p<0.01), and albumin (p<0.05). Relative risk was significantly higher for low levels of retinol and zinc. Diet, in general, in both groups reflected poor intake of several nutrients.

ISSN:0163-5581    

DOI:10.1080/01635589209514208

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor

ISSN:0163-5581    

DOI:10.1080/01635589209514200

出版商:Taylor&Francis Group    

年代:1992

数据来源: Taylor