If causality is assumed, we estimate that risk of colorectal cancer in the U.S. population could be reduced about 31% (50,000 cases annually) by an average increase in fiber intake from food sources of about 13 g/d, corresponding to an average increase of about 70%.
The role of nutrients and food factors in relation to esophageal cancer was observed in a large case-control study in a region having a high incidence of the disease. Several factors that increased or decreased the risk were identified. After adjusting for other covariates, we found that animal proteins and polyunsaturated fats had a significant protective effect. Separating the effects of specific nutrients was difficult because of the intercorrelation between individual intakes of most nutrients. Foods were not so highly intercorrelated. Fresh meat, citrus fruits, and oil were found to be protective. A dietary index combining these foods was used; between the lowest and the highest levels of intake, a nine-fold difference in risk was observed. This effect is added to that of alcohol, which remains the major risk factor. The adequacy of the concepts of nutrients and foods in epidemiological studies is discussed in addition to the theoretical and practical implications of the findings.
A case-control study on 453 cases with colon cancer, 365 with rectal cancer, and 2,851 population controls was carried out in two Belgian provinces known to differ in certain dietary habits, particularly with regard to the use of butter. All raw vegetables had a clear protective effect for both colon and rectal cancer; bread was also protective for colon cancer. Starchy foods and foods rich in oligosaccharides (sugar) caused an increased risk for both colon and rectal cancer. No other foods were found to have a systematic effect in both sexes and in both provinces, either in one direction or in the other, except for maize, soybean, and sunflower oils, which were clearly protective in all cases. Among the foods contributing to the intake of fats, there was no effect either for butter, margarine, or fatty meats; the only clear-cut protective effect was that of the oils having a high polyunsaturated-to-saturated ratio. These findings are consistent with our previous findings on the role nutrients play in the relationship with colon and rectal cancers.
Alcohol and tobacco are the two major risk factors for cancer of the oesophagus; they usually combine their action. The action of each factor is studied here in non-users of the other. Among non-drinking male smokers the relative risk is higher than 5; among non-smoking drinkers, risks are much higher and increase with average daily intake; this effect is also observed in females, with risk values of the same order of magnitude as for males. Thus the high sex ratio of oesophageal cancer in France can be entirely ascribed to different drinking levels in females and in males.
The risk of ascitic cirrhosis increases with average daily consumption of alcoholic beverages, both in males and in females. For the latter, however, the curve is much steeper, indicating a greater risk for the female liver, with the disease occurring earlier in life. Health implications are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.