A prospective cohort study on toenail selenium levels and risk of gastrointestinal cancer.

BACKGROUND: Various animal studies and ecologic studies suggest an inverse association between low dietary selenium intake and risk of various types of cancer. PURPOSE: The goal of this prospective cohort study was to investigate the association between toenail selenium levels and risks of stomach cancer and colorectal cancer. METHODS: Our cohort study on diet and cancer started in The Netherlands in 1986 with enrollment of 120,852 subjects aged 55-69 years. Of this number, 58,279 were men and 62,573 were women. Following the case-cohort approach for analysis of the data, we randomly selected from the cohort a subcohort of 3500 subjects (1688 men and 1812 women). After 3.3 years of follow-up, 155 incident cases of microscopically confirmed stomach cancer, 313 cases of colon cancer, and 166 cases of rectal cancer had been detected in the cohort. Toenail selenium data were available for 104 patients with stomach cancer, 234 with colon cancer, and 113 with rectal cancer and for 2459 subjects from the subcohort. RESULTS: In a multivariate analysis, the relative rates (RRs) of stomach cancer for subjects in increasing quintiles of toenail selenium level were 1.00, 0.44, 0.59, 0.84, and 0.64 (trend, P = .491). For men, there was some evidence for an inverse association between toenail selenium levels and stomach cancer: The RR for those in the highest compared with the lowest quintile of toenail selenium was 0.40 (95% confidence interval = 0.17-0.96), but the trend was not statistically significant (P = .136). For stomach cancer in women, there was no negative association with toenail selenium levels. Toenail selenium level was not associated with the risk of colon or rectal cancer. After exclusion of cases diagnosed in the 1st year of follow-up, the RRs of colon cancer for increasing quintiles of toenail selenium were 1.00, 1.27, 1.17, 0.75, and 1.07 (trend, P = .544); for rectal cancer, RR estimates were 1.00, 1.73, 0.83, 1.58, and 1.12 (trend, P = .890). CONCLUSIONS: These data support a suggestive but inconsistent inverse association between selenium levels and risk of stomach cancer. Our findings, like those of other studies, do not suggest an inverse association with risk of colorectal cancer.

A prospective cohort study on Allium vegetable consumption, garlic supplement use, and the risk of lung carcinoma in The Netherlands.

The association between the consumption of onions and leeks (vegetables belonging to the Allium genus), garlic supplements, and the risk of lung carcinoma was investigated in a large-scale prospective cohort study on diet and cancer in the Netherlands. The Netherlands Cohort Study was started in 1986 among 120,852 men and women, ages 55-69 years, by collecting information on usual diet and important life-style characteristics. After 3.3 years of follow-up, 550 incident lung carcinoma cases were observed. Information on Allium vegetable consumption was available for 484 lung carcinoma cases and 3123 members of a randomly sampled subcohort. In stratified analysis, a lower lung carcinoma risk was observed in the highest onion intake category [rate ratio (RR) = 0.65; 95% confidence interval, 0.45-0.95] compared to the lowest consumption category. After including other, dietary and nondietary, determinants of lung carcinoma in the multivariable models and using pack years for past and current smoking, instead of using smoking status categorized as never, ex-, and current smoking, the rate ratio in the highest intake category increased to 0.80 and was no longer significantly different from unity (95% confidence interval, 0.52-1.24). Leek consumption was not associated with risk for lung carcinoma (RR = 1.08; 95% confidence interval 0.80-1.45 in the highest intake category, compared to the lowest). No statistically significant trends in the rate ratios associated with increasing consumption of these vegetables were detected for lung carcinoma or the four histological subtypes. A higher lung carcinoma risk was observed for those subjects who used exclusively garlic supplements (RR = 1.78; 95% confidence interval, 1.08-2.92), compared to those not taking dietary supplements. A lower lung carcinoma risk was seen for those using garlic supplements together with any other supplement (RR = 0.93; 95% confidence interval 0.46-1.86) compared to those using any other supplement. In conclusion, we found no evidence of a relation between the consumption of onions or leeks and the risk of lung carcinoma or any of the histological subtypes. Garlic supplement use seems not associated with a lower risk of lung carcinoma.

A prospective cohort study on the relation between meat consumption and the risk of colon cancer.

The high incidence of colon cancer in affluent societies has often been attributed to a high fat diet and, more in particular, the consumption of meat. The association of the consumption of meat and the intake of fat with risk of colon cancer was investigated in a prospective cohort study on diet and cancer, which is being conducted in the Netherlands since 1986 among 120,852 men and women, aged 55-69. The analysis was based on 215 incident cases of colon cancer (105 men and 110 women) accumulated in 3.3 years of follow-up, excluding cases diagnosed in the first year of follow-up. Dietary habits were assessed at baseline with a 150-item semiquantitative food frequency questionnaire. No trends in relative rates of colon cancer were detected for intake of energy or for the energy-adjusted intake of fats, protein, fat from meat, and protein from meat. Consumption of total fresh meat, beef, pork, minced meat, chicken, and fish was not associated with risk of colon cancer either. Processed meats, however, were associated with an increased risk in men and women (relative rate, 1.17 per increment of 15 g/day; 95% confidence interval, 1.03-1.33). The increased risk appeared to be attributable to one of the five questionnaire items on processed meat, which comprised mainly sausages. This study does not support a role of fresh meat and dietary fat in the etiology of colon cancer in this population. As an exception, some processed meats may increase the risk, but the mechanism is not yet clear.

A prospective cohort study on dietary fat and the risk of postmenopausal breast cancer.

In 1986 a prospective cohort study on diet and cancer was started in the Netherlands among 62,573 women ages 55-69 years. Baseline information on diet and other risk factors was collected with a questionnaire. Cancer incidence was measured by record linkage with cancer registries and a pathology register. A case-cohort approach was used, in which the accumulated person time in the cohort was estimated by follow-up of a randomly selected subcohort (n = 1812). After 3.3 years of follow-up, 471 incident breast cancer cases were available for analysis. Questionnaire data for these cases and the 1716 female subcohort members without a history of cancer other than skin cancer were analyzed. In a multivariate analysis, controlling for traditional risk factors, the relative rates for breast cancer in increasing quintiles of energy-adjusted total fat intake were 1.00, 1.00, 1.34, 1.22, 1.08 (P-trend, 0.32). For saturated fat there was some evidence for a weak positive association when quintiles were used (relative rates in quintiles 1-5, 1.00, 1.22, 1.22, 1.38, 1.39; P-trend, 0.049). The 95% confidence interval (CI) for the top quintile was 0.94-2.06, however; and when saturated fat was used as a continuous variable, the effect was no longer significant (P = 0.20). Relative rate estimates for the highest versus lowest quintiles of monounsaturated fat, polyunsaturated fat, and cholesterol intake were 0.75 (95% CI, 0.50-1.12), 0.95 (95% CI, 0.64-1.40) and 1.09 (95% CI, 0.74-1.61), respectively, with no evidence for significant trends. This prospective study does not support a major role of dietary fat in the etiology of postmenopausal breast cancer.

A prospective cohort study on selenium status and the risk of lung cancer.

Selenium has been suggested to be anticarcinogenic and to play a role in the cellular defense against oxidative stress. The association between toenail selenium (a marker of long-term selenium status) and lung cancer was investigated in a cohort study of diet and cancer that started in 1986 among 120,852 Dutch men and women aged 55-69 years. After 3.3 years of follow-up, 550 incident cases of lung carcinoma were detected. Toenail selenium data were available for 370 lung cancer cases and 2459 members of a randomly selected subcohort. The rate ratio of lung cancer for subjects in the highest compared to the lowest quintile of toenail selenium, after controlling for age, gender, smoking, and education, was 0.50 (95% confidence interval, 0.30-0.81), with a significant inverse trend across quintiles (P = 0.006). The protective effect of selenium was concentrated in subjects with a relatively low dietary intake of beta-carotene or vitamin C. The rate ratio in the highest compared to the lowest quintile of selenium was 0.45 in the low beta-carotene group (95% confidence interval, 0.22-0.92; trend P = 0.028) and 0.36 in the low vitamin C group (95% confidence interval, 0.17-0.75; trend P < 0.001). The results of this study support an inverse association between selenium status and lung cancer and suggest a modification of the effect of selenium by the antioxidants beta-carotene and vitamin C.

Folate intake of the Dutch population according to newly established liquid chromatography data for foods.

BACKGROUND: Determining folate intake is difficult because existing folate data in food-composition tables are scarce and unreliable. OBJECTIVE: The purposes of this study were first to analyze 125 of the most important foods that contribute to folate intake in the Netherlands and second to estimate the folate intake of a representative sample of the population. DESIGN: We analyzed the folate content of foods by using a newly developed HPLC trienzyme method combined with an affinity chromatography cleanup step. These results were then used to estimate the folate intake of persons aged 1-92 y who participated in the second Dutch National Food Consumption Survey (DNFCS) in 1992 (n = 6218). RESULTS: For 35 important folate-containing foods, the mean relative folate contents measured by HPLC were 66%, 80%, and 77% of values for comparable foods included in the British food-composition table; the Ministry of Agriculture, Fisheries and Food table; and the US Department of Agriculture database, respectively. P values for comparison of relative values with 100% were 0.001, 0.171, and 0.144, respectively. The mean dietary folate intake of the DNFCS participants was 182 +/- 119 microg/d. Intake of supplement users (n = 86) was 344 microg/d, with 147 microg/d from supplements. On the basis of these findings, 42% of men and 54% of women do not meet current Dutch recommendations of 60 microg/d for children and 200 microg/d for adults. CONCLUSIONS: Total folate quantities in foods, analyzed by HPLC, are approximately 25% lower than amounts listed in recent food-composition tables estimated by use of the microbiological method. On the basis of these new data, approximately 50% of a representative Dutch population sample does not meet the current recommendations for folate intake.

Vegetable and fruit consumption and prostate cancer risk: a cohort study in The Netherlands.

The association between 21 vegetables and eight fruits and prostate cancer risk was assessed in the Netherlands Cohort Study among 58,279 men of ages 55-69 years at baseline in 1986. After 6.3 years of follow-up, 610 cases with complete vegetable data and 642 cases with complete fruit data were available for analysis. In multivariate case-cohort analyses, the following rate ratios (RRs) and 95% confidence intervals (CIs) for vegetable consumption were found (comparing highest versus lowest quintile): total vegetables (RR, 0.80; CI, 0.57-1.12); prepared vegetables (RR, 0.85; CI, 0.61-1.19); and raw vegetables (RR, 0.96; CI, 0.69-1.34). For vegetables categorized in botanical groups, no associations were found except for consumption of pulses (RR, 0.71; CI, 0.51-0.98; P for trend, 0.01). The RRs for total fruit and citrus fruit were 1.31 (CI, 0.96-1.79) and 1.27 (CI, 0.93-1.73), respectively; the corresponding Ps for trend were 0.02 and 0.01, respectively. In a continuous model, no association for total fruit was observed. Individual vegetables and fruits were evaluated as continuous variables (g/day). Nonsignificant inverse associations (RRs per increment of 25 g/day) were found for consumption of kale (RR, 0.74), raw endive (RR, 0.72), mandarins (RR, 0.75), and raisins or other dried fruit (RR, 0.49). Observed positive associations were significant for consumption of leek (RR, 1.38) and oranges (RR, 1.07) and nonsignificant for sweet peppers (RR, 1.60) and mushrooms (RR, 1.49). Results in subgroups of cases were more or less consistent with the overall results. From our study, we cannot conclude that vegetable consumption is important in prostate cancer etiology, but for certain vegetables or fruits, an association cannot be excluded.

Development of a record linkage protocol for use in the Dutch Cancer Registry for Epidemiological Research.

A method has been developed to determine the optimal linkage key for record linkage between the cancer registry and a large-scale prospective cohort study in the Netherlands. The proposed linkage procedure is a two-stage process in which the initial computerized linkage using a particular linkage key is followed by visual inspection with additional information to separate the computer matches into true and false positives. In the determination of the optimal key, both informativeness and susceptibility to error of personal identifiers were taken into account. The performance of the various keys in the linkage was expressed in terms of sensitivity and predictive value of a reported computer match. The key, consisting of date of birth, first four characters of the family name and gender was the optimal choice, with a sensitivity of 98% and an initial predictive value of a computer match of 98%. When additional information on migration, place of birth and first initial was collected in the second stage, it was possible to eliminate the false positives from the reported computer matches without loss of true positives. Thus, the sensitivity remained constant whereas the secondary predictive value of accepted matches was maximized.

Trends in incidence of adenocarcinoma of the oesophagus and gastric cardia in ten European countries.

BACKGROUND: In many western countries an increase in incidence of adenocarcinoma of the oesophagus and/or gastric cardia have been reported. The aim of this study was to describe and compare trends in incidence of adenocarcinoma of the oesophagus and gastric cardia in several areas of Europe, 1968-1995, using Eurocim (a database of cancer incidence and mortality data from 95 European cancer registries). METHODS: Time-trends in age-standardized incidence rates of adenocarcinomas of the oesophagus and gastric cardia are described in 11 population-based cancer registries from 10 countries in North, South, East, West and Central Europe, 1968-1995. The statistical significance of the time-trends in incidence was assessed using Poisson regression analysis. RESULTS: An increase in incidence of adenocarcinomas of the oesophagus and gastric cardia was observed in Northern Europe (Denmark), Southern Europe (Italy, Varese), Eastern Europe (Slovakia) and Western Europe (England and Wales, Scotland). In Central Europe (Switzerland, Basel) and in the cancer registries of Iceland (Northern Europe), France, Bas-Rhin and Calvados, Southern Ireland, and the Netherlands, Eindhoven (Western Europe) no rise in incidence was observed. The increase in incidence of adenocarcinomas of the oesophagus and gastric cardia was accompanied by a decrease in incidence of both adenocarcinomas and non-adenocarcinomas of the non-cardia part of the stomach in almost all of the 11 cancer registries studied. Increased histological verification of tumours of the oesophagus and stomach and improvement in precision of histological diagnosis may partly explain the increase in incidence of adenocarcinomas in some registries. CONCLUSIONS: This study, using Eurocim data, supports the findings from other time-trend studies of population-based cancer registries in western countries.

Agreement between interview data and a self-administered questionnaire on dietary supplement use.

OBJECTIVE: To study the relative validity of an open-ended question on the consumption of dietary supplements in the preceding five-year period, incorporated in a self-administered questionnaire used in the NLCS, The Netherlands Cohort Study on diet and cancer (120,852 men and women aged 55-69 years). DESIGN: Questionnaire data were compared with reference information from three personal interviews carried out within a period of 10 months. SETTING AND SUBJECTS: A randomly selected subgroup (59 men and 50 women) of the cohort living in 12 municipalities in the eastern and western regions of The Netherlands. RESULTS AND CONCLUSIONS: The overall sensitivity of the questionnaire concerning the use of any dietary supplement was 65.9%, the specificity was 98.5%; kappa as measure of agreement was estimated at 0.69. A high percentage recall was observed among women, users of at least three types of dietary supplements, long-term supplement users and those in the oldest age group. Recall of intake of specific supplements ranged from 77.8% for garlic preparations to 11.8% for 'other' supplements. Estimates of consumption of specific supplements (garlic and vitamin preparations) may provide enough precision to correctly classify individuals as users or non-users of those supplements.

The use of vitamins, minerals and other dietary supplements in The Netherlands.

By means of a two-day dietary record, information on the use of dietary supplements has been collected in 1987 and 1988 in a representative sample of the Dutch population aged 1-75 years. More than 17 percent of the population had been using at least one dietary supplement on at least one day of the survey. Age, sex, season, social class, alternative food habits, smoking and diet were related to the use of supplements. In young persons mainly fluoride and vitamin AD preparations were used, while a shift towards other supplements, like garlic and brewer's yeast preparations, was observed as age progresses. The use of single vitamin C supplements was not related to the level of mean daily vitamin C intake by food consumption.

[Incidence and risk factors for eye injuries sustained at fairs: metal particles in the eye after a ride of dodg'em cars]. / Incidentie en determinanten van kermisogen: metaaldeeltjes in het oog na bezoek van een kermis met botsauto's.

OBJECTIVE: To determine the incidence of fair eye and its determinants. DESIGN: Inventory and case referent study. METHOD: All general practices (370) in the middle and south of Limburg, the Netherlands, were asked to report patients with a 'faireye' after having visited a fair in this region (population approximately 866,000) in a 6-week period during the late summer of 1997. Personal data of these patients were obtained by telephone interview. A case referent study was performed to establish the potential protectiveness of wearing glasses, lenses or a cap. RESULTS: 88% of the general practices responded. These reported a total of 40 patients with a fair eye. There were 41 fairs with dodgem cars during the observation period (a relation between dodgem cars and faireyes has been suggested). In the study area the incidence of fair eye was 5 per 100,000 inhabitants per year. Of the 36 responding patients 26 (72%) were male, 97% were 10-19 years old, and 69% had had 11-20 rides in dodgem cars. Glasses (3%), lenses (0%), or a cap (6%) were rarely worn during the rides. The complaints related to the fair eye were: pain in the eye (64%), an irritated eye (42%), a red eye (41%), an inflamed eye (17%), tears (11%) and photophobia (8%). The odds ratio for wearing glasses or lenses in comparison with a sample of the general Dutch population, standardised for age and sex, was 0.1 (95% confidence interval: 0.01-0.69). CONCLUSION: With 5 per 100,000 inhabitants per year fair eye is a regular complaint in general practice in South and Middle Limburg. The metal particles involved probably come from dodgem attractions, which usually move weekly to another town or village between March and November. Wearing glasses or lenses is rare in patients with fair eyes. It is advisable to wear protective goggles when riding dodgem cars.

[Utilization of food supplements in The Netherlands]. / Gebruik van voedingssupplementen in Nederland.

In 1987 and 1988 a dietary survey was carried out in a representative sample of the Dutch population, under the authority of the Ministries of Welfare, Health and Cultural Affairs, and Agriculture and Fisheries. By means of a two day dietary record data were collected on food consumption and the use of dietary supplements. More than seventeen percent of the Dutch population has been using at least one dietary supplement on at least one day of the survey. Age, sex, season, social class, alternative food habits, smoking and diet are related to the use of supplements. In young persons mainly fluoride and vitamin AD preparations are used, while as age progresses a shift towards other supplements, like garlic and brewer's yeast preparations, is observed. The use of single vitamin C supplements is not related to the level of mean daily vitamin C intake from foods.

Factors associated with the intention to use vitamin D supplements: quantitative study among a sample of elderly people in a medium-sized town in the Netherlands.

The objective of this study was to assess which factors are related to the intention of elderly people to use vitamin D supplements.A questionnaire that was based on several theories, feedback of experts, and personal interviews with members of the target group was distributed among a random sample of 497 elderly people in a medium-sized town in the Netherlands (response 46%). Variables measured included perceived susceptibility, severity and control with respect to developing a vitamin D deficiency or getting a bone fracture, and beliefs, perceived social norms, modeling, self-efficacy, and intention with respect to the use of vitamin D supplements. Univariate analyses of variance, chi-square tests, stepwise multiple regression, and stepwise logistic regression analysis were performed. Respondents reporting a high intention had more positive attitudes and normative beliefs, higher self-efficacy expectations with respect to using vitamin D supplements, and more often used other supplements than respondents with a low intention. Subjects who already used vitamin D supplements were more often female and already familiar with the advice and had more positive attitudes and normative beliefs than nonusers. It was concluded that many elderly people have high intentions to start using vitamin D supplements as soon as they hear about the advice. A health promotion campaign to promote the use of vitamin D supplements should aim at making elderly people familiar with the Health Council of the Netherlands' advice. Furthermore, the campaign should place emphasis on changing attitudes, perceived social norms, and self-efficacy expectations toward vitamin D supplement use.

The impact of characteristics of cigarette smoking on urinary tract cancer risk: a meta-analysis of epidemiologic studies.

BACKGROUND: Although narrative reviews have concluded that there is strong support for an association between cigarette smoking and urinary tract cancer, the association has never been quantified systematically in reviews. The purpose of this systematic review was to summarize and quantify the impact of different smoking characteristics (status, amount, duration, cessation, and age at first exposure) both unadjusted and adjusted for age and gender. METHODS: The authors included 43 epidemiologic studies (8 cohort and 35 case-control) and calculated summary odds ratios (SORs) by meta-regression analyses for different smoking characteristics. They also evaluated changes in summary estimates according to differences in study methodology. RESULTS: Smoking status and increased amount and duration of smoking were associated with a strong increased risk of urinary tract cancer. Smoking cessation and age at first exposure were negatively associated with the risk of urinary tract cancer. The age- and gender-adjusted SORs for current and former cigarette smokers compared with those for nonsmokers were 3.33 (95% confidence interval [CI], 2.63-4.21) and 1.98 (CI, 1.72-2.29), respectively. Even though the component studies differed in methodology, the results were rather consistent. CONCLUSIONS: The results suggest a substantial increase in risk of cancer of the urinary tract for cigarette smokers. Based on the results of this study and previous literature, the authors conclude that current cigarette smokers have an approximately threefold higher risk of urinary tract cancer than nonsmokers. In Europe, approximately half of urinary tract cancer cases among males and one-third of cases among females might be attributable to cigarette smoking.

Are coffee, tea, and total fluid consumption associated with bladder cancer risk? Results from the Netherlands Cohort Study.

OBJECTIVES: Coffee, tea, and fluid consumption have been thought to influence bladder cancer incidence. In a large prospective study, these associations were investigated. METHODS: In 1986, cohort members (55-69 years) completed a questionnaire on cancer risk factors. Follow-up was established by linkage to cancer registries until 1992. The multivariable case-cohort analysis was based on 569 bladder cancer cases and 3,123 subcohort members. RESULTS: The incidence rate ratios (RR) for men consuming <2 cups of coffee/day was 0.89 (95% CI 0.51-1.5) using the median consumption category (4-<5 cups/day) as reference. This RR increased to 1.3 (95% CI 0.94-1.9) for men consuming >7 cups/day, although no clear dose response association was found. The RRs decreased from 1.2 (95% CI 0.56-2.7) for women consuming <2 cups of coffee/day to 0.36 (95% CI 0.18-0.72) for women consuming >5 cups/day compared to the median consumption category (3-<4 cups/day). Men and women who abstained from drinking tea had a RR of 1.3 (95% Cl 0.97-1.8) compared to those consuming 2-<3 cups of tea per day (median consumption category). The RR for men and women comparing highest to lowest quintile of total fluid consumption was 0.87 (95% CI 0.63 1.2). CONCLUSION: The data suggest a possible positive association between coffee consumption and bladder cancer risk in men and a probable inverse association in women. Tea consumption was inversely associated with bladder cancer. Total fluid consumption did not appear to be associated with bladder cancer.

Anthropometry in relation to prostate cancer risk in the Netherlands Cohort Study.

In the Netherlands Cohort Study, the authors investigated whether anthropometry is associated with prostate cancer risk. At baseline in 1986, 58,279 men aged 55-69 years completed a self-administered questionnaire on diet, anthropometry, and other risk factors for cancer. After 6.3 years of follow-up, 681 cases were available with complete data on height and weight at baseline, and for 523 cases, there were data for weight at age 20 years. In both age-adjusted and multivariate case-cohort analyses (adjusted for age, family history of prostate cancer, and socioeconomic status), height, body mass index (BMI; kg/m2), and lean body mass (kg) at baseline were not associated with prostate cancer risk. The rate ratios of prostate cancer for men with a BMI at age 20 of less than 19, 19-20.9, 21-22.9, 23-24.9, and 25 or greater were 1.00 (reference), 1.06, 1.09, 1.39, and 1.33, respectively (p for trend = 0.02). For gain in BMI from age 20 years to age of the cohort at baseline, an inverse trend in risk was found (p for trend = 0.01), which did not persist after additional adjustment for BMI at age 20 (p for trend = 0.07). In subgroup analyses, no clear associations between anthropometry and advanced prostate cancer were found. Our findings suggest that body composition in young adulthood may already exert an effect on later risk of prostate cancer.

Allium vegetable consumption, garlic supplement intake, and female breast carcinoma incidence.

The risk of female breast carcinoma in relation to onion and leek consumption and the use of garlic supplements was evaluated in the Netherlands Cohort Study on diet and cancer. Onions, leeks, and garlic contain specific compounds which might act as antimutagens. Animal experiments also suggest a possible role for these compounds in inhibition of mammary carcinogenesis. The Netherlands Cohort Study was started in 1986 among 120,852 Dutch men and women, aged 55-69 years, with collecting information on usual diet and important lifestyle characteristics. After 3.3 years of follow-up, 469 incident female breast carcinoma cases and 1713 female members of a randomly sampled control subcohort were available for analysis. Intake of onions or leeks was not associated with breast carcinoma risk after controlling for dietary and nondietary risk factors: the rate ratios in the highest intake categories were 0.95 (95% confidence interval 0.61-1.47) and 1.08 (95% confidence interval 0.79-1.48), respectively, compared with the lowest intake categories. The tests for trend in the rate ratios were neither significant. Garlic supplement use was also not associated with breast carcinoma incidence (rate ratio = 0.87, 95% confidence interval 0.58-1.31). In conclusion, we found no association between the consumption of onions or leeks, or garlic supplement use, and the incidence of female breast carcinoma.

A prospective cohort study on the relationship between onion and leek consumption, garlic supplement use and the risk of colorectal carcinoma in The Netherlands.

The association between onion and leek consumption, garlic supplement use and colon and rectum carcinoma among men and women was evaluated in the Netherlands Cohort Study, a large-scale prospective cohort study on diet and cancer. Onions, leeks, and garlic belong to the Allium genus and contain large amounts of potentially chemopreventive compounds. The Netherlands Cohort Study was started in 1986 among 120 852 men and women, aged 55-69 years. Dietary intake was measured with a 150-item food frequency questionnaire. After 3.3 years of follow-up, 150 and 143 incident male and female cases of colon carcinoma, and 93 and 57 cases of rectum carcinoma, respectively, with complete dietary data were available for analysis. Dietary data were available for 1525 men and 1598 women of a randomly selected subcohort, that was followed up to estimate person-time in the entire cohort. In men, the adjusted rate ratios (RRs) in multivariable analysis for colon and rectum carcinoma in the highest compared to the lowest onion consumption categories were 0.87 (95% confidence interval [CI] = 0.48-1.65), and 0.66 (95% CI = 0.28-1.52), respectively. The RRs for proximal colon carcinoma were lower than for distal colon carcinoma. Leek consumption was not associated with colon and rectum carcinoma incidence in men. None of the RRs were significantly different from unity and no trends in the RRs were detected. A lower risk was found for rectum carcinoma in women consuming less than 0.25 onions per day (RR=0.36, 95% CI = 0.13-0.99), but the trend in the RRs was not statistically significant (P = 0.25). All other RRs for colon and rectum carcinoma associated with onion consumption were slightly higher than one. Leek consumption was not associated with colon and rectum carcinoma incidence. The use of garlic supplements was not associated with colon and rectum carcinoma in men and women combined. This study does not support an inverse association between the consumption of onions and leeks, or the use of garlic supplements and the incidence of male and female colon and rectum carcinoma.

Consumption of onions and a reduced risk of stomach carcinoma.

BACKGROUND & AIMS: Results from case-control studies and laboratory tests indicate that consumption of allium vegetables may considerably reduce the risk of stomach cancer. The association between onion and leek consumption, garlic supplement use, and the incidence of stomach carcinoma was studied. METHODS: The association was investigated in the Netherlands Cohort Study on diet and cancer, which started in 1986 with 120,852 men and women ranging in age from 55 to 69 years. Dietary data were available for 139 stomach carcinoma cases diagnosed during 3.3 years of follow-up and for 3123 subjects of the randomly selected subcohort. RESULTS: The rate ratio for stomach carcinoma in the highest onion consumption category (> or = 0.5 onions/day) was 0.50 (95% confidence interval, 0.26-0.95) compared with the lowest category (0 onions/day) after adjustment for other risk factors. The reduction in risk was restricted to carcinoma in the noncardia part of the stomach (P = 0.002) and was also found among subjects without a history of stomach disorders (P = 0.01). The consumption of leeks and the use of garlic supplements were not associated with stomach carcinoma risk. CONCLUSIONS: The Netherlands Cohort Study provides evidence for a strong inverse association between onion consumption and stomach carcinoma incidence.