摘要:

AbstractThe Melbourne study has shown that dietary factors and alcohol are important in the cause and prevention of colorectal cancer (CRC). A high intake of fat and beef probably causes CRC, and a high intake of beer possibly causes rectal cancer. The beef and beer effects were both independent of other dietary variables, but further research is indicated to explore the mechanisms of their actions. Foods of plant origin protected against CRC, and the“plant food hypothesis”now replaces the dietary fiber hypothesis. Further study is needed on the interrelationships between the various foods of plant origin. Vitamin supplements were protective, and again clarification is needed on the mechanism of action. In high‐risk populations, nutritional risk and causal factors are likely to be difficult to find, whereas protective factors are likely to be found with greater ease. Further analysis of the Melbourne data will reveal the importance of diet in CRC causation, relative to the other hypothesized causal and protective factors.

ISSN:0163-5581    

DOI:10.1080/01635588709513906

出版商:Taylor&Francis Group    

年代:1987

数据来源: Taylor

摘要:

AbstractThe paper is a description of, and a practical guide to, the questions, problems, and pitfalls that can arise in the planning and execution of a large‐scale epidemiological study of diet and disease; this study was an eight‐year project in which diet histories were collected from over 2,000 people. Qualified dietitians obtained a quantitative diet history, which covered all foods eaten in Australia, and assessed as the most representative of the previous 20 years.Because over half of both cases and controls changed their diets in the previous 20 years, the period of recall nominated varied, but this was not a major bias. There was no effect of seasonality on recall. The average duration of the interview was one hour for both cases and controls. The response rate was 84% for cases and 94% for controls, suggesting that the time for interview of the diet history method is not a deterrent for a high response rate.In general, between‐interviewer variation was small, although the intakes of total vegetables, cruciferous vegetables, and leafy green vegetables were the least repeatable. Between‐interviewer differences were not found to affect the relative risks. Reproducibility of placing a dietary factor into a particular quintile of consumption was good for most foods, but it was lowest for cruciferous and leafy green vegetables. Interviewer bias regarding the dietary causes of colorectal cancer was not a major bias. Analysis of within‐interviewer variation over time and analysis of recall bias were not major biases, as far as could be assessed in this study.Indirect validation of the nutritional data in the study (by comparison with other studies, by national per capita consumption, and by a comparison of energy intake with estimated energy requirements based on height, weight, and activity levels) suggested that the data are not an overestimate of intake. Cases and controls were both overestimating and underestimating their dietary intakes to a similar degree.For epidemiological studies of diet and disease, the quantitative diet history method as used here is recommended, particularly if the main objective of the study is to confirm hypotheses.

ISSN:0163-5581    

DOI:10.1080/01635588709513907

出版商:Taylor&Francis Group    

年代:1987

数据来源: Taylor

摘要:

AbstractAs part of a large‐scale investigation of colorectal cancer (CRC) incidence, etiology, and survival, a case‐control study was conducted to identify dietary factors associated with the risk of CRC. The study compared 715 cases with 727 age‐and sex‐matched community controls. A quantitative diet history, assessed to be the most representative of the previous 20 years, was obtained from each subject and analyzed for both food groups and nutrients. The combination of a high‐fiber and high‐vegetable intake was found to be protective against large bowel cancer. Cruciferous vegetable intake was also found, although with less certainty, to be protective. Dietary vitamin C was protective for estimated intakes greater than 230 mg/day. Dietaryβ‐carotene had no separate association with the risk of CRC. Beef intake was a risk factor in males but not in females. Fat intake was a risk factor for both males and females. A low intake of milk drinks was a risk for both males and females. A high intake of pork and fish was protective. The use of vitamin supplements was highly protective. A risk score, which was calculated as the number of risk factors an individual has in his or her diet, showed an increasing mono‐tonic relationship with risk of CRC. The effects of the dietary variables were similar for colon and rectal cancer and, with the exception of beef, were similar for males and females.

ISSN:0163-5581    

DOI:10.1080/01635588709513908

出版商:Taylor&Francis Group    

年代:1987

数据来源: Taylor

摘要:

AbstractAs part of a large‐scale investigation of colorectal cancer incidence, etiology, and survival, a case‐control study was conducted to identify whether diet and alcohol, among other variables, were associated with the risk of colorectal cancer. The study compared 715 cases with 727 age‐and sex‐matched community controls. Findings from the dietary data are presented in the previous paper (Nutr Cancer 9, 21–42, 1987). The total life intake of specific alcoholic beverages was obtained from each subject. Data were classified by consumption of beer, wine, spirits, and alcohol. There was little evidence of an association of any of the alcohol variables with the risk of colon cancer. However, beer was found to be a risk factor for rectal cancer. This effect was more marked in males than in females, but the relative risks for females were consistent with those for males. Relative risk estimates changed only slightly when adjusted for the other alcohol variables and for the variables in the diet model; this suggests that the beer effect is separate from that of other alcohol variables and also from dietary variables. The age differences among beer consumers were found to be associated with cancer risk. Consumption of spirits was associated with a low risk for male rectal cancer. The risk of rectal cancer appeared to depend on beer drinking patterns in the previous 15–20 years.

ISSN:0163-5581    

DOI:10.1080/01635588709513909

出版商:Taylor&Francis Group    

年代:1987

数据来源: Taylor

ISSN:0163-5581    

DOI:10.1080/01635588709513910

出版商:Taylor&Francis Group    

年代:1987

数据来源: Taylor

ISSN:0163-5581    

DOI:10.1080/01635588709513905

出版商:Taylor&Francis Group    

年代:1987

数据来源: Taylor