Colorectal cancer and the consumption of foods: A case‐control study in Belgium

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.     

A case-control study on colorectal cancer in Belgium. Preliminary results

Summary A case-control study on colorectal cancer in Belgium. Preliminary results.Preliminary results of a case-control study in two Belgian provinces, involving 1207 cases of colorectal cancer and 3521 population controls are reported. An excess risk of colon cancer was associated with low intake of calories, proteins and lipids. High intake of vitamin B, vitamin C and fibres had a protective effect on both colon and rectal cancer. When foods were examined, most vegetables were found to have protective virtues, noticeable in all subgroups.

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Resumé Une étude cas-témoins sur le cancer colorectal en Belgique. Resultats préliminaires.Le travail rapporte les résultats préliminaires d'une étude castémoins dans deux provinces belges, portant sur 1207 cas de cancers colo-rectaux et 3521 témoins de population. Un excès de risque de cancer du côlon était associé à un régime pauvre en calories, en protéines et en lipides. Une ration riche en vitamine B, en vitamine C et en fibres avait un effet protecteur sur les cancers du côlon et du rectum. Parmi les aliments examinés, la plupart des légumes avaient des vertus protectrices discernables dans tous les sous-groupes.

     

Folate intake and carcinogenesis of the colon and rectum

Experimental evidence suggests that folate depletion plays a role in carcinogenesis. A case-control study examining folate intake was conducted. Some 428 colon and 372 rectal cancer cases with matched neighbourhood controls were interviewed regarding usual intake of foods, including food preparation. Unadjusted folate was not associated with risk of either cancer. Controlling for kilocalories, odds ratios (ORs) for those with the highest folate intake were 0.5 (95% confidence interval (CI): 0.24-1.03) and 0.31 (95% CI: 0.16-0.59) for females and males for rectal cancer. There was no change in colon cancer risk associated with folate intake. There was an indication of an interaction of folate and alcohol intake; the difference in risk associated with low and high folate intake was highest for males in the highest alcohol category. Associations were of similar magnitude for other dietary factors correlated with folate. It appears that intake of folate or a correlated factor may be negatively related to risk of rectal cancer.     

Calcium, dairy products, and colorectal cancer

The 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.     

Calcium,dairy products,and colorectal cancer

The 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.     

Plant foods, fiber, and rectal cancer

BACKGROUND: Associations between colon and rectal cancer and intakes of vegetables, other plant foods, and fiber have stimulated much debate. OBJECTIVE: We examined the association between rectal cancer and plant food and fiber intakes. DESIGN: Data from 952 incident cases of rectal cancer were compared with data from 1205 population-based controls living in Utah or enrolled in the Kaiser Permanente Medical Care Program in northern California RESULTS: Rectal cancer was inversely associated with intakes of vegetables (odds ratio: 0.72; 95% CI: 0.54, 0.98), fruit (0.73; 0.53, 0.99), and whole-grain products (0.69; 0.51, 0.94), whereas a high intake of refined-grain products was directly associated with an increased risk of rectal cancer (1.42; 1.04, 1.92). Similarly, relative to low fiber intakes, high intakes of dietary fiber reduced the risk of rectal cancer (0.54; 0.37, 0.78). The reduced risk of rectal cancer associated with vegetable (0.48; 0.29, 0.80), fruit (0.63; 0.38, 1.06), and fiber (0.40; 0.22, 0.71) intakes was strongest for persons who received the diagnosis after age 65 y. A threshold effect at approximately 5 servings of vegetables/d was needed to see a reduced risk of rectal cancer. CONCLUSIONS: The results suggest that plant foods may be important in the etiology of rectal cancer in both men and women. Age at diagnosis appears to play an important role in the association.     

Serum insulin-like growth factor I and subsequent risk of colorectal cancer among Japanese-American men

Recent reports suggest that colorectal cancer is positively related to insulin-like growth factor I (IGF-I) and inversely related to insulin-like growth factor binding protein 3 (IGFBP-3). To evaluate these associations further and separately for colon and rectal cancer, the authors conducted a nested case-control study in a cohort of 9,345 Japanese-American men examined in Hawaii in 1971-1977. A total of 177 incident colon cancer cases and 105 incident rectal cancer cases were identified from 1972 to 1996. These patients' stored sera and those of 282 age-matched controls were measured for IGF-I and IGFBP-3. The adjusted mean level of IGF-I was higher in colon cancer cases than in controls (154.7 ng/ml vs. 144.4 ng/ml; p = 0.01). However, the multivariate odds ratio for the highest quartile compared with the lowest was just 1.8 (95% confidence interval: 0.8, 4.3). Adjusted mean IGF-I levels were similar between rectal cancer cases and their controls. For IGFBP-3, adjusted mean levels were lower for both colon and rectal cancer cases than for their matched controls, but the differences were not significant. The IGF-I results weakly support findings from other studies and suggest that there are differences in IGF-I findings between colon and rectal cancer cases. It is possible that IGF-related risk is confounded by other factors that may vary among different cohorts. Further research is needed to clarify these relations.     

Relations between vegetable, fruit and micronutrient intake. Implications for odds ratios in a case-control study

OBJECTIVE: To investigate whether the protection observed for some micronutrients, such as beta-carotene, in several observational studies may simply reflect vegetable and fruit intake. DESIGN: A case-control study conducted in Italy. SUBJECTS: The subjects were 1225 colon cancer patients, 728 rectal cancer patients and 4154 hospital controls. RESULTS: For the 16 micronutrients considered, the more closely a micronutrient was correlated with total vegetable and fruit intake, the more it appeared protective against colorectal cancer. CONCLUSION: When studying the effect of a nutrient on disease risk in an observational setting, its relation to other nutrients and foods must be taken into account.     

Diet and cancer of the colon and rectum: a case-control study in China

A case-control study was carried out in Harbin city to assess the role of diet in the aetiology of colorectal cancer. A total of 336 incident cases of histologically confirmed colorectal cancer (111 colon cancer and 225 rectal cancer) and an equal number of controls with other non-neoplastic diseases were interviewed in hospital wards. Data concerning the average frequency of consumption and amount consumed of single food items were obtained by a dietary history questionnaire. Odds ratios and their confidence limits were computed. Multiple regression for risk status was also used. Vegetables, particularly green vegetables, chives and celery, have a strong protective effect against colorectal cancer. Reduced consumption of meat, eggs, bean products and grain was associated with increasing risk for cancer of the rectum. Alcohol intake was found to be an important risk factor for developing colon cancer and male rectal cancer.     

结、直肠癌与营养因素的流行病学研究

本研究为一项基于人群的病例对照研究，以比较结、直肠癌发病危险因素的差异性。结果表明：①饱和脂肪酸和猪肉类食物的摄入量多可能是结肠癌的重要的危险因素，而与直肠癌关系不密切。②蔬菜类食品（尤其是十字花科类、鲜豆类、根茎类、海带紫菜类）、新鲜水果以及一些主要来源于植物性食品的营养素（如膳食纤维、胡萝卜素，维生素Ｃ等）的摄入量少使结、直肠癌发病危险性增加，这些因素与直肠癌的关系相对较为密切。③高摄入油炸和腌制食品均显著增加结、直肠癌的相对危险度。④结肠癌病例组一级亲属中有大肠癌患者的比例是对照组的２．９倍（Ｐ＜Ｏ．０１），直肠癌病例组仅为１．６倍（Ｐ＞０．０５）。     

Colorectal cancer protective effects and the dietary micronutrients folate, methionine, vitamins B6, B12, C, E, selenium, and lycopene

The data reported here were obtained from the case-control arm of a large, comprehensive, population-based investigation of colorectal cancer incidence, etiology, and survival, the Melbourne Colorectal Cancer Study, conducted in Melbourne, Australia. This part of the case-control study was designed to identify dietary factors associated with colorectal cancer risk in 715 incident cases compared with 727 age/sex frequency-matched randomly chosen community controls, in which a quantitative assessment of all foods eaten was made. New data are presented on the potential of two groups of micronutrients as protective agents, namely, those involved in DNA methylation, synthesis, and repair (folate, methionine, and vitamins B6 and B12) and those with antioxidant properties (selenium, vitamins E and C, and lycopene). The adjusted odds ratios showed that for folate there was significant protection for rectal cancer in second and third quintiles of consumption but not for colon cancer, and this was similar for methionine consumption. Vitamin B6 consumption was significantly protective for both colon and rectal cancer at the higher quintiles, and this was similar for vitamin B12. Dietary selenium was significantly protective at middle quintiles of consumption at both cancer sites. Dietary vitamins E and C were statistically significantly protective for both colon and rectal cancer at all levels of consumption, and for both vitamins there was a dose-response effect of increasing protection, particularly so for colon cancer. Lycopene was not associated with colorectal cancer risk. A combined model included vitamins E, C, and B12 and selenium as micronutrients protective for colorectal cancer and folate, which, however, showed an increased risk at the highest level of consumption. These data support the proposition that a diet containing the dietary micronutrients involved in DNA methylation (folate, methionine, and vitamins B6 and B12) and some of those with antioxidant properties (selenium and vitamins E and C) may have a role to play in lowering colorectal cancer risk and also that such protection can be achieved by dietary means alone.     

Effect of occupational and recreational activity on the risk of colorectal cancer among males: a case-control study.

Epidemiological studies have consistently demonstrated that either occupational or recreational physical activity is protective against colon cancer. However, it is unclear whether recreational activity is similarly protective among those who engage in high or low occupational activity. We therefore compared 440 male cases of colorectal cancer with 1164 male hospital patients. Occupational activity was defined according to job title, while recreational activity was assessed by questionnaire for three different periods of life. Occupational activity was protective with respect to colorectal cancer irrespective of whether one engaged in recreational activity at any different period of life. In contrast, recreational activity, performed at 20-44 years of age appeared to decrease colon cancer risk by 10-25% irrespective of the intensity of job activity. The present results suggest that, although we observed a larger effect with occupational activity than with recreational activity, middle-aged men may reduce their risk of colorectal cancer if they exercise when they are not working. These findings need to be confirmed in other populations.     

Energy balance and rectal cancer: an evaluation of energy intake, energy expenditure, and body mass index

Lack of energy balance, or greater energy intake than expenditure as indicated by a large body mass index (BMI), has been associated with colon cancer, although less is known about its association with rectal cancer. In this study, we examined the association between BMI, energy intake, and energy expenditure and their combined effect on rectal cancer risk. A population-based case-control study was conducted in Utah and Northern California. Incident cases (n = 952) of rectal cancer and population-based controls (n = 1205) were interviewed between 1997 and 2002 to obtain detailed information on body size, dietary intake, and physical activity patterns. BMI (kg/m(2)) was not associated with rectal cancer in either men or women. Participation in vigorous leisure-time physical activity over the past 20 yr was associated with a significant 40% reduction in rectal cancer risk. Energy intake was associated significantly with increased risk of rectal cancer, especially among people whose diagnosis was prior to age 60 yr (odds ratio [OR] = 3.9; 95% confidence interval [CI] = 1.7-9.1 for men; OR = 2.8; 95% CI = 1.1-7.2 for women). There was a significant interaction between energy intake and energy expenditure, although not between BMI and either energy intake or energy expenditure. These data suggest that large BMI, an indicator of lack of energy balance, is not an important component of the etiology of rectal cancer. However, both physical activity and energy intake were significantly associated with rectal cancer risk. These data suggest that energy expenditure and energy intake alter rectal cancer risk through mechanisms other than energy balance.     

Energy Balance and Rectal Cancer: An Evaluation of Energy Intake,Energy Expenditure,and Body Mass Index

Lack of energy balance, or greater energy intake than expenditure as indicated by a large body mass index (BMI), has been associated with colon cancer, although less is known about its association with rectal cancer. In this study, we examined the association between BMI, energy intake, and energy expenditure and their combined effect on rectal cancer risk. A population-based case-control study was conducted in Utah and Northern California. Incident cases (n = 952) of rectal cancer and population-based controls (n = 1205) were interviewed between 1997 and 2002 to obtain detailed information on body size, dietary intake, and physical activity patterns. BMI (kg/m2) was not associated with rectal cancer in either men or women. Participation in vigorous leisure-time physical activity over the past 20 yr was associated with a significant 40% reduction in rectal cancer risk. Energy intake was associated significantly with increased risk of rectal cancer, especially among people whose diagnosis was prior to age 60 yr (odds ratio [OR] = 3.9; 95% confidence interval [CI] = 1.7-9.1 for men; OR = 2.8; 95% CI = 1.1-7.2 for women). There was a significant interaction between energy intake and energy expenditure, although not between BMI and either energy intake or energy expenditure. These data suggest that large BMI, an indicator of lack of energy balance, is not an important component of the etiology of rectal cancer. However, both physical activity and energy intake were significantly associated with rectal cancer risk. These data suggest that energy expenditure and energy intake alter rectal cancer risk through mechanisms other than energy balance.     

Vitamin D receptor gene polymorphisms, dietary promotion of insulin resistance, and colon and rectal cancer

Modifiable risk factors in colorectal cancer etiology and their interactions with genetic susceptibility are of particular interest. Functional vitamin D receptor (VDR) gene polymorphisms may influence carcinogenesis through modification of cell growth, protection from oxidative stress, cell-cell matrix effects, or insulin and insulin-like growth factor pathways. We investigated interactions between foods (dairy products, red and processed meat, and whole and refined grains) and dietary patterns (sucrose-to-fiber ratio and glycemic index) associated with insulin resistance with the FokI polymorphism of the VDR gene and colon and rectal cancer risk. Data (diet, anthropometrics, and lifestyle) and DNA came from case-control studies of colon (1,698 cases and 1,861 controls) and rectal cancer (752 cases and 960 controls) in northern California, Utah, and the Twin Cities metropolitan area, Minnesota (colon cancer study only).Unconditional logistic regression models were adjusted for smoking, race, sex, age, body mass index, physical activity, energy intake, dietary fiber, and calcium. The lowest colon cancer risk was observed with the Ff/ff FokI genotypes and a low sucrose-to-fiber ratio. Rectal cancer risk decreased with greater consumption of dairy products and increased with red or processed meat consumption and the FF genotype. Modifiable dietary risk factors may be differentially important among individuals by VDR genotype and may act through the insulin pathway to affect colon cancer risk and through fat, calcium, or other means to influence rectal cancer risk.     

Carotenoid Intake and Colorectal Cancer Risk: The Multiethnic Cohort Study

Background

A protective effect of fruits and vegetables against colorectal cancer has been supported by many epidemiologic studies. This suggests that the carotenoids frequently found in these foods play a role in the prevention of this common cancer. To examine associations between the intake of individual and total carotenoids and the risk of colorectal cancer, we analyzed prospective data from the Multiethnic Cohort Study.

Methods

This analysis includes 85 898 men and 105 106 women who completed a quantitative food frequency questionnaire in 1993–1996. The participants were African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites aged 45–75 years at cohort entry. After an average follow-up of 8.2 years, 1292 and 1086 incident cases of colorectal cancer were identified in men and women, respectively. Cox proportional hazard models were used to estimate relative risks of colorectal cancer.

Results

No significant associations were found between intake of individual and total carotenoids and colorectal cancer risk either in men or women, except for β-cryptoxanthin, which showed a mild protective effect in men. When the associations were investigated separately for colon and rectal cancer, lycopene intake was related to an increased risk of rectal cancer in men. A decreased risk was seen for total β-carotene in male current smokers, but the test for interaction with smoking status was not significant. No association was observed in each ethnic-sex group.

Conclusion

Overall, our findings do not support a significant association between carotenoid intake and colorectal cancer, although some associations were seen in subgroup analyses.Key words: carotenoids, colorectal neoplasms, smoking, cohort studies, multiethnic population     

Dietary sodium and potassium intake and colorectal cancer risk

In a large, comprehensive, population-based case-control study of colorectal cancer (The Melbourne Colorectal Cancer Study), a high intake of sodium was shown to be a statistically significant risk factor for rectal cancer in males (RR = 1.72, p = 0.01) and was close to statistical significance in females (RR = 1.58, p = 0.06). This was independent of previously described dietary risk factors and also independent of the previously described beer risk. A high intake of potassium was protective for both males and females, but this effect disappeared after adjustment was made for the previously described dietary risk factors. A high ratio of dietary potassium to sodium was a statistically significant protective factor in females for both colon and rectal cancer, and the significance of this effect was reduced after adjustment was made for the previously described dietary risk factor (RR for colon cancer = 0.70, p = 0.08; RR for rectal cancer = 0.67, p = 0.08). So far, no biological explanations are available for these associations, and while they are of obvious etiologic interest, they should be interpreted with caution.     

Salt and gastrointestinal cancer

This study reports on the taste for salt among patients with gastric, colon, or rectal cancers and among population controls, within the scope of an investigation on those cancers in two Belgian provinces. Among people who systematically added salt to their food, the relative risks observed were as follows: 1.78 for gastric cancer, 1.53 for colon cancer, and 1.74 for rectal cancer. Even though all three were statistically significant, these increases are moderate and may be due to interaction with other, as yet unknown casual factors.     

Association of vegetable, fruit, and grain intakes with colorectal cancer: the Multiethnic Cohort Study

BACKGROUND: It is uncertain whether or not vegetables, fruit, or grains protect against colorectal cancer. OBJECTIVE: In a large prospective study, we investigated the association of vegetable, fruit, and grain intakes with colorectal cancer risk. DESIGN: Between 1993 and 1996, 85 903 men and 105 108 women completed a quantitative food-frequency questionnaire that included approximately 180 foods and beverages in the Multiethnic Cohort Study. A diagnosis of colorectal cancer was made in 1138 men and 972 women after an average follow-up of 7.3 y. Cox proportional hazards models were used to calculate multivariate-adjusted relative risks and 95% CIs for colorectal cancer. RESULTS: In men, multivariate adjustment for energy intake, dietary, and nondietary variables resulted in relative risks in the highest quintile group of 0.74 (95% CI: 0.59, 0.93; P for trend = 0.02) for vegetables and fruit combined, 0.80 (95% CI: 0.64, 0.99; P for trend = 0.09) for fruit alone, and 0.85 (95% CI: 0.69, 1.05; P for trend = 0.05) for vegetables alone. When colon and rectal cases were separated among men, the inverse associations were stronger for colon than for rectal cancer. In women, none of the associations with vegetables, fruit, or vegetables and fruit combined were significant. Grain intake was not associated with colorectal cancer for either men or women. CONCLUSION: The intake of vegetables and fruit was inversely related to colorectal cancer risk among men but not among women. The association appears stronger for colon than for rectal cancer.     

Statistical analyses on the pattern of food consumption and digestive‐tract cancers in Japan

The relationships between areal differences in mortality from six digestive‐tract cancers and consumption of selected foods in 46 of the 47 Japanese prefectures (Okinawa being excluded) were analyzed.

Statistical analyses disclosed that the groups of foods positively associated with cancer death were as follows: for esophageal cancer, pork, oil, popular‐grade sake, and green tea; for stomach cancer, fresh fish, salted or dried fish, salt, and special‐grade sake; for colon cancer, bread, milk, butter, margarine, ketchup, beer, and salted or dried fish; for rectal cancer, fresh fish, salted or dried fish, salt, and popular‐grade sake; for cancer of the biliary passages, pork, popular‐grade sake, and green tea; and for pancreatic cancer, oil, mayonnaise, fresh fish, and salted or dried fish.

These results are based on statistical analyses. Further epidemiológica! analyses are required to find a biological causal relationship.

(Nutr Cancer 6, 220–228, 1985)