Validation of a dietary questionnaire used in a large-scale prospective cohort study on diet and cancer.

Objective: The study was conducted to assess the validity of a self-administered 150-item food frequency questionnaire (FFQ), used in a cohort study on diet and cancer (120,852 men and women, aged 55-69).

Design & Subjects: The study was carried out in a subgroup of the cohort (59 men and 50 women) 2 years after the baseline FFQ was completed. A dietary record, kept over three 3-day periods, 4-5 months apart, served as reference method.

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.

Prospective study on alcohol consumption and the risk of cancer of the colon and rectum in the Netherlands.

The association between alcohol consumption and cancer of the colon and rectum was investigated in a prospective cohort study, conducted in the Netherlands from 1986 onwards among 120,852 men and women, aged 55 to 69 years. During 3.3 years of follow-up, 312 and 166 cases of colon and rectal cancer had accumulated, respectively.

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.

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.

Cholecystectomy and colorectal cancer: evidence from a cohort study on diet and cancer.

The association between cholecystectomy and subsequent risk for colorectal carcinoma was investigated in a prospective cohort study on diet and cancer (n = 120,852), which is being conducted in the Netherlands from 1986 onwards among 120,852 men and women, aged 55 to 69. After a follow-up period of 3.3 years, 478 incident cases of colorectal cancer (258 men and 220 women) were identified in the cohort, 64 of whom reported at baseline to have undergone previous gall-bladder surgery (21 men and 43 women).

Predictors of toenail selenium levels in men and women.

Potential predictors of toenail selenium levels were studied in 1211 men and 1248 women aged 55-69 years. These subjects were randomly selected cohort members without prevalent cancer (other than skin) participating in a prospective study on diet and cancer in the Netherlands. Information on the considered potential predictors (gender, age, smoking, intake of dietary selenium and alcohol, Quetelet index) was collected together with toenail specimens in 1986.

Garlic and its significance for the prevention of cancer in humans: a critical view.

Recently published results of epidemiologic case-control studies in China and Italy on gastric carcinoma in relation to diet suggest that consuming garlic may reduce the risk of gastric cancer. Chemical constituents of garlic have been tested for their inhibiting effect on carcinogenesis, using in vitro and in vivo models. In most experiments inhibition of tumour growth was established using fresh garlic extract, garlic compounds or synthetically prepared analogs.

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.

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.

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.

Comparison of questionnaire information and pharmacy data on drug use.

Information on chronic drug use at any time in the past was collected with a self-administered questionnaire as part of a prospective cohort study on diet, other life-style factors and cancer among subjects aged 55-69 years. The validity of the questionnaire information on drug use was evaluated among 207 subjects by comparing it to pharmacy records of dispensed drugs. The comparison could be made for the 2.

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.

Cross-sectional versus longitudinal investigations of the diet-cancer relation.

Within a prospective cohort study on diet and cancer, information was collected on cancer prevalence and baseline meat consumption. A nested case-control study on meat and cancer was conducted with 656 prevalent colorectal cases, 1,894 breast cancer cases, and 4,701 controls. When analyzed cross-sectionally, prevalence odds ratios for eating meat rarely versus regularly were 2.

A large-scale prospective cohort study on diet and cancer in The Netherlands.

In 1986, a prospective cohort study on diet and cancer was started in The Netherlands. The cohort (n = 120, 852) of 55-69 year old men (48.2%) and women (51.