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Biomedical subjects

R A Goldbohm

Publications and source records attributed to R A Goldbohm.

At least 55 records · Page 3Linked to original sources
PubMed1999

Animal products, calcium and protein and prostate cancer risk in The Netherlands Cohort Study.

Prostate cancer risk in relation to consumption of animal products, and intake of calcium and protein was investigated in the Netherlands Cohort Study. At baseline in 1986, 58,279 men aged 55-69 years completed a self-administered 150-item food frequency questionnaire and a questionnaire on other risk factors for cancer. After 6.3 years of follow-up, 642 prostate cancer cases were available for analysis. In multivariate case-cohort analyses adjusted for age, family history of prostate cancer and socioeconomic status, no associations were found for consumption of fresh meat, fish, cheese and eggs. Positive trends in risk were found for consumption of cured meat and milk products (P-values 0.04 and 0.02 respectively). For calcium and protein intake, no associations were observed. The hypothesis that dietary factors might be more strongly related to advanced prostate tumours could not be confirmed in our study. We conclude that, in this study, animal products are not strongly related to prostate cancer risk.

Aged↗
PubMed1999

Safety evaluation of synthetic beta-carotene.

The safety of beta-carotene was reassessed by evaluating the relevant literature on the beneficial and adverse effects of beta-carotene on cancer and, in particular, by evaluating the results of toxicity studies. Beta-carotene appeared neither genotoxic nor reprotoxic or teratogenic, and no signs of organ toxicity have been found in subacute, subchronic, or chronic oral toxicity studies in experimental animals receiving doses of up to 1000 mg/day beta-carotene per kg body weight via the diet. Synthetic beta-carotene did not exert any carcinogenic effect in Sprague-Dawley rats or in CD1 mice. An enhanced risk of lung cancer was found in two human intervention studies. Although dose and (timing of) exposure, smoking status, and imbalance of antioxidant defense have been recognized as potential factors accounting for the outcome of these studies, a conclusive explanation has not yet been found. It is concluded that exposure to beta-carotene resulting in mean plasma concentrations of no more than 2.2 micromol/l (1.2 microg/ml) is safe to the general population. By contrast, in heavy smokers higher plasma concentrations may be associated with a higher lung cancer risk.

Absorption↗
PubMed1999

A case-cohort study on prostate cancer risk in relation to family history of prostate cancer.

We investigated the risk of prostate cancer in relation to a family history of prostate cancer in 58,279 men ages 55-69 years. We found 704 incident cases after 6.3 years of follow-up. Rate ratios and 95% confidence intervals for having an affected vs nonaffected father and brother were, respectively 1.44 (0.80-2.58) and 5.57 (1.61-19.26). We found no evidence for an increasing risk with an increasing percentage of affected family members. The associations we observed were stronger for cases diagnosed before age 70 compared with cases diagnosed after age 70 and for advanced compared with localized tumors.

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PubMed1998

A prospective cohort study on vegetable and fruit consumption and stomach cancer risk in The Netherlands.

The association between vegetable and fruit consumption and stomach cancer risk was investigated in the Netherlands Cohort Study among 120,852 men and women aged 55-69 years at the start in September 1986. Analyses were based on 282 incident stomach cancer cases after 6.3 years of follow-up. Age- and sex-adjusted rate ratios of stomach cancer in increasing quintiles of combined vegetable and fruit consumption were 1.00, 0.70, 0.65, 0.76, and 0.64 (p trend = 0.04). Multivariate analysis resulted in rate ratios that were somewhat closer to one (p trend = 0.14). Furthermore, inverse associations for total vegetables, pulses, raw leafy vegetables, total fruit, citrus fruit, and apples and pears that were observed in crude analyses became weaker or disappeared in multivariate analyses. Total vegetable, but not fruit, consumption was significantly lower in cases diagnosed in the first follow-up year. In analyses limited to first year cases (resembling a case-control study), rate ratios for increasing tertiles of total vegetable consumption were 1.00, 0.17, and 0.18 (p trend = 0.0001), which may indicate the presence of information bias in case-control studies. This prospective study suggests that vegetable and fruit consumption was not clearly associated with stomach cancer risk in the Dutch population. The findings of this study are comparable with findings of other cohort studies, but they do not support the findings of case-control studies.

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PubMed1998

Alcohol and breast cancer in women: a pooled analysis of cohort studies.

OBJECTIVE: To assess the risk of invasive breast cancer associated with total and beverage-specific alcohol consumption and to evaluate whether dietary and nondietary factors modify the association. DATA SOURCES: We included in these analyses 6 prospective studies that had at least 200 incident breast cancer cases, assessed long-term intake of food and nutrients, and used a validated diet assessment instrument. The studies were conducted in Canada, the Netherlands, Sweden, and the United States. Alcohol intake was estimated by food frequency questionnaires in each study. The studies included a total of 322647 women evaluated for up to 11 years, including 4335 participants with a diagnosis of incident invasive breast cancer. DATA EXTRACTION: Pooled analysis of primary data using analyses consistent with each study's original design and the random-effects model for the overall pooled analyses. DATA SYNTHESIS: For alcohol intakes less than 60 g/d (reported by >99% of participants), risk increased linearly with increasing intake; the pooled multivariate relative risk for an increment of 10 g/d of alcohol (about 0.75-1 drink) was 1.09 (95% confidence interval [CI], 1.04-1.13; P for heterogeneity among studies, .71). The multivariate-adjusted relative risk for total alcohol intakes of 30 to less than 60 g/d (about 2-5 drinks) vs nondrinkers was 1.41 (95% CI, 1.18-1.69). Limited data suggested that alcohol intakes of at least 60 g/d were not associated with further increased risk. The specific type of alcoholic beverage did not strongly influence risk estimates. The association between alcohol intake and breast cancer was not modified by other factors. CONCLUSIONS: Alcohol consumption is associated with a linear increase in breast cancer incidence in women over the range of consumption reported by most women. Among women who consume alcohol regularly, reducing alcohol consumption is a potential means to reduce breast cancer risk.

Alcohol Drinking↗
PubMed1998

Intake of nitrate and nitrite and the risk of gastric cancer: a prospective cohort study.

The association between the intake of nitrate or nitrite and gastric cancer risk was investigated in a prospective cohort study started in 1986 in the Netherlands, of 120,852 men and women aged 55-69 years. At baseline, data on dietary intake, smoking habits and other covariates were collected by means of a self-administered questionnaire. For data analysis, a case-cohort approach was used, in which the person-years at risk were estimated from a randomly selected subcohort (1688 men and 1812 women). After 6.3 years of follow-up, 282 microscopically confirmed incident cases of stomach cancer were detected: 219 men and 63 women. We did not find a higher risk of gastric cancer among people with a higher nitrate intake from food [rate ratio (RR) highest/lowest quintile = 0.80, 95% CI 0.47-1.37, trend-P = 0.18], a higher nitrate intake from drinking water (RR highest/lowest quintile = 0.88, 95% CI 0.59-1.32, trend-P = 0.39) or a higher intake of nitrite (RR highest/lowest quintile = 1.44, 95% CI 0.95-2.18, trend-P = 0.24). Rate ratios for gastric cancer were also computed for each tertile of nitrate intake from foods within tertiles of vitamin C intake and intake of beta-carotene, but no consistent pattern was found. Therefore, our study does not support a positive association between the intake of nitrate or nitrite and gastric cancer risk.

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PubMed1998

Dietary assessment in the elderly: validation of a semiquantitative food frequency questionnaire.

OBJECTIVE: The study was conducted to assess the relative validity of a 170-item semiquantitative food frequency questionnaire (SFFQ) adapted for use in the elderly. DESIGN AND SUBJECTS: The study was carried out in a sample of 80 men and women aged 55-75 y participating in a community based prospective cohort study in Rotterdam, The Netherlands. The two-step dietary assessment comprised a simple self-administered questionnaire (20 min) followed by a structured interview with trained dietitians (20 min) based on the completed questionnaire. Multiple food records (FR) collected over a one year period served as reference method. 24 h urine urea was used as indirect marker for protein intake. RESULTS: Compared with FR, the SFFQ generally overestimated nutrient intake as reflected by difference in means and the ratio of SFFQ to FR. Energy adjustment reduced the observed overestimation. Pearson's correlation coefficients varied from close to 0.5 to about 0.9 for crude data, and after adjustment for age, sex, total energy intake, and for within-person variability in daily intake for 0.4-0.8. Cross-classification into quintiles resulted in correct classification into the same or adjacent quintile of 75.8% for crude and 76.8% for energy-adjusted data. Validation of protein intake estimated by SFFQ with protein excretion from 24h urine urea indicated overestimation of protein intake by SFFQ. Spearman correlation coefficient between protein intake estimated from urea excretion and SFFQ was 0.67. CONCLUSIONS: Adaptation of a SFFQ for use in the elderly resulted in a valid and time-efficient dietary assessment instrument. Its ability to adequately rank study subjects according to their dietary intake support its application in epidemiological studies in the elderly.

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PubMed1998

Socioeconomic status and stomach cancer incidence in men: results from The Netherlands Cohort Study.

STUDY OBJECTIVE: To study the association between socioeconomic status (SES) and stomach cancer incidence (cardia and non-cardia) and the role of lifestyle factors in explaining this association. DESIGN: Prospective cohort study on diet and cancer that started in 1986. Data were collected by means of a self administered questionnaire. SETTING: Population originating from 204 municipalities in the Netherlands. PARTICIPANTS: 58,279 men aged 55-69 years. After 4.3 years of follow up, 162 incident stomach cancer cases were detected (49 cardia and 113 non-cardia cases). MAIN RESULTS AND CONCLUSIONS: After adjustment for age, a lower overall stomach cancer risk was found for men with the highest attained level of education (RR highest/lowest level = 0.54, 95% CI 0.33, 0.89, trend, p = 0.02). This association became less strong after additional adjustment for smoking, intake of vitamin C, beta carotene, alcohol and coffee, family history of stomach cancer, and history of stomach disorders (RR = 0.61, 95% CI 0.34, 1.07, trend, p = 0.11). No clear association was found between occupation based SES indicators and stomach cancer risk. Analyses per subsite of stomach cancer revealed that for people with the highest level of education the age adjusted rate ratio for cardia cancer changed from 0.37 (95% CI = 0.13, 1.00) to 0.60 (95% CI = 0.19, 1.87) after additional adjustment for lifestyle variables, whereas the rate ratio for non-cardia cancer (RR = 0.59, 95% CI 0.33, 1.05) did not change after additional adjustment.

Aged↗
PubMed1998

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.

Age Distribution↗
PubMed1998

The contribution of various foods to intake of vitamin A and carotenoids in The Netherlands.

This study presents data on dietary intake of specific carotenoids in the Netherlands, based on a recently developed food composition database for carotenoids. Regularly eaten vegetables, the main dietary source of carotenoids, were sampled comprehensively and analysed with modern analytic methods. The database was complemented with data from recent literature and information from food manufacturers. In addition, data on intake of vitamin A are presented, which are based on the most recent update of the Dutch Food Composition Table. Intake of vitamin A was calculated for adult participants of the second Dutch National Food Consumption Survey in 1992, whereas intake of carotenoids was calculated for participants of the Dutch Cohort Study on diet and cancer, aged 55 to 69 in 1986. Mean intake of vitamin A amounted to 1.1 and 0.9 mg RE/day for men and women, respectively; the contributions of meat, fats and oils, vegetables and dairy products to total intake were 35%, 24%, 16%, and 16%, respectively. Mean intake of alpha-carotene, beta-carotene and lutein plus zeaxanthin was 0.7, 3.0, and 2.5 mg/day respectively for both men and women, while mean intake of lycopene was 1.0 mg/day for men and 1.3 mg/day for women. The most important foods contributing to intake of beta-carotene and lutein plus zeaxanthin were carrots (beta-carotene only), spinach, endive and kale.

Adolescent↗
PubMed1997

Meat consumption and preparation, and genetic susceptibility in relation to colorectal adenomas.

Epidemiological evidence suggests that a high meat consumption and/or animal fat intake may increase the risk of colorectal cancer. The objective of this study is to examine the role of dietary factors, in particular meat preparation and consumption, in relation to colorectal adenomas, the pattern of DNA-mutations (e.g. K-ras and p53), and genetic susceptibility (NAT2, HNPCC). In a case control study on diet and colorectal adenomas (sporadic and HNPCC), acetylator status (NAT2) of cases and controls as well as K-ras and p53 mutations in adenomas will be assessed. Consumption and preparation of meat, the primary interest of this study, will be assessed by a food frequency questionnaire designed especially for this purpose.

Adenoma↗
PubMed1997

A review of mechanisms underlying anticarcinogenicity by brassica vegetables.

The mechanisms by which brassica vegetables might decrease the risk of cancer are reviewed in this paper. Brassicas, including all types of cabbages, broccoli, cauliflower and Brussels sprouts, may be protective against cancer due to their relatively high glucosinolate content. Glucosinolates are usually broken down through hydrolysis catalyzed by myrosinase, an enzyme that is released from damaged plant cells. Some of the hydrolysis products, viz. indoles and isothiocyanates, are able to influence phase 1 and phase 2 biotransformation enzyme activities, thereby possibly influencing several processes related to chemical carcinogenesis, e.g. the metabolism, DNA-binding and mutagenic activity of promutagens. A reducing effect on tumor formation has been shown in rats and mice. The anticarcinogenic action of isothiocyanates and indoles depends upon many factors, such as the test system, the target tissue, the type of carcinogen challenge and the anticarcinogenic compound, their dosage, as well as the timing of the treatment. Most evidence concerning anticarcinogenic effects of glucosinolate hydrolysis products and brassica vegetables has come from studies in animals. Animal studies are invaluable in identifying and testing potential anticarcinogens. In addition, studies carried out in humans using high but still realistic human consumption levels of indoles and brassica vegetables have shown putative positive effects on health.

Animals↗
PubMed1997

Non-dietary factors as risk factors for breast cancer, and as effect modifiers of the association of fat intake and risk of breast cancer.

To assess more precisely the relative risks associated with established risk factors for breast cancer, and whether the association between dietary fat and breast cancer risk varies according to levels of these risk factors, we pooled primary data from six prospective studies in North America and Western Europe in which individual estimates of dietary fat intake had been obtained by validated food-frequency questionnaires. Based on information from 322,647 women among whom 4,827 cases occurred during follow-up: the multivariate-adjusted risk of late menarche (age 15 years or more compared with under 12) was 0.72 (95 percent confidence interval [CI] = 0.62-0.82); of being postmenopausal was 0.82 (CI = 0.69-0.97); of high parity (three or more births compared with none) was 0.72 (CI = 0.61-0.86); of late age at first birth (over 30 years of age compared with 20 or under) was 1.46 (CI = 1.22-1.75); of benign breast disease was 1.53 (CI = 1.41-1.65); of maternal history of breast cancer was 1.38 (CI = 1.14-1.67); and history of a sister with breast cancer was 1.47 (CI = 1.27-1.70). Greater duration of schooling (more than high-school graduation compared with less than high-school graduation) was associated significantly with higher risk in age-adjusted analyses, but was attenuated after controlling for other risk factors. Total fat intake (adjusted for energy consumption) was not associated significantly with breast cancer risk in any strata of these non-dietary risk factors. We observed a marginally significant interaction between total fat intake and risk of breast cancer according to history of benign breast disease; with fat intake being associated nonsignificantly positively with risk among women with a previous history of benign breast disease; no other significant interactions were observed. Risks for reproductive factors were similar to those observed in case-control studies; relative risks for family history of breast cancer were lower. We found no clear evidence in any subgroups of a major relation between total energy-adjusted fat intake and breast cancer risk.

Breast Neoplasms↗
PubMed1997

Height, weight weight change, and postmenopausal breast cancer risk: The Netherlands Cohort Study.

The association between several anthropometric indices and breast cancer risk was evaluated within the Netherlands Cohort Study on diet and cancer, which began in 1986 and is conducted among 62,573 women aged 55 to 69 years at baseline. After 4.3 years of follow-up, data on 626 women with incident breast cancer were available with complete information on height and weight at baseline. In multivariate case-cohort analyses, a significantly positive association between adult height and breast cancer was found (P trend < 0.001). Compared with women with height < or = 155 cm, the rate ratios of breast cancer for women with heights up to 160, 165, 170, 175, and > or = 175 cm were 1.22, 1.19, 1.44, 1.77, and 2.06, respectively. For weight at baseline, the significant positive association with breast cancer observed in age-adjusted analysis disappeared in multivariate analysis with adjustment for height and other confounders. For body mass index (BMI) (wt[kg]/ht[m]2) at baseline, no association was observed with breast cancer in multivariate analysis; compared with women with a BMI less than 23, the RR for women with a BMI of 30 or more was 0.98 with P trend = 0.46. Weight and BMI at age 20 showed weak inverse associations with breast cancer risk. For gain in weight or BMI between age 20 and cohort baseline age, inconsistent increases in risk were found, with no significant trends. These data support a positive association between height and breast cancer risk among postmenopausal women. Further study is needed to evaluate the role of early diet and breast cancer in this population, and its relationship to height.

Aged↗
PubMed1997

Vitamins C and E, retinol, beta-carotene and dietary fibre in relation to breast cancer risk: a prospective cohort study.

Association between breast cancer risk and the intake of vitamins C and E, retinol, beta (beta)-carotene, dietary fibre, vegetables, fruit and potatoes was examined in The Netherlands Cohort Study, for 62,573 women aged 55-69 years. After 4.3 years of follow-up, 650 incident breast cancer cases were identified. After adjusting for traditional risk factors, breast cancer risk was not influenced by the intake of beta-carotene, vitamin E, dietary fibre, supplements with vitamin C, vegetables or potatoes. Fruit consumption showed a non-significant inverse association with breast cancer risk (RR highest/lowest quintile = 0.76, 95% CI 0.54-1.08). A small reduction in risk was also observed with increasing intake of dietary vitamin C (RR highest/lowest quintile = 0.77, 95% CI 0.55-1.08). For retinol, a weak positive association was observed (RR highest/lowest quintile = 1.24, 95% CI 0.83-1.83). Among subjects with a high intake of polyunsaturated fatty acids (PUFAs), both beta-carotene and vitamin C intake showed a non-significant inverse association with breast cancer risk (P-trend = 0.15 and 0.16 respectively). Our findings do not suggest a strong role, if any, for intake of vitamins C and E, beta-carotene, retinol, dietary fibre, vegetables, fruit and potatoes in the aetiology of breast cancer.

Aged↗
PubMed1997

Socioeconomic status and lung cancer incidence in men in The Netherlands: is there a role for occupational exposure?

STUDY OBJECTIVE: To evaluate the influence of occupational exposure to carcinogens in explaining the association between socioeconomic status and lung cancer. DESIGN: A prospective cohort study. Data on diet, other lifestyle factors, sociodemographic characteristics and job history were collected by means of a self administered questionnaire. Follow up for incident cancer was established by record linkage with a national pathology register and with regional cancer registries. SETTING: Population originating from 204 municipalities in The Netherlands. PARTICIPANTS: These comprised 58 279 men aged 55-69 years in September 1986. After 4.3 years of follow up there were 470 microscopically confirmed incident lung cancer cases with complete data on dietary habits and job history. MEASUREMENTS AND MAIN RESULTS: Estimation of occupational exposure to asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes was carried out by two experts, using information on job history from the baseline questionnaire. Socioeconomic status was measured by means of highest attained level of education and two indicators based on occupation. In the initial multivariate analyses of socioeconomic status and lung cancer, adjustment was made for age, smoking habits, intake of vitamin C, beta-carotene and retinol, and history of chronic obstructive pulmonary disease or asthma. Additional adjustment for occupational exposure to the four carcinogens mentioned above did not change the inverse association between the level of education and lung cancer risk (initial model: RR highest/lowest level of education = 0.53; 95% CI 0.34, 0.82; additional model: RR highest/lowest level of education = 0.53; 95% CI 0.34, 0.84). Nor was the association between the two occupation based indicators of socioeconomic status and lung cancer risk influenced by occupational exposure to carcinogens. The effect of occupational exposure on the association between the level of education and lung cancer risk did not differ between ex-smokers and current smokers. CONCLUSIONS: Occupational exposure to asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes could not explain the inverse association between socioeconomic status and lung cancer risk. More research which explicitly addresses possible explanations for the association between socioeconomic status and lung cancer risk is needed.

Aged↗
PubMed1997

Occupational exposure to carcinogens and risk of lung cancer: results from The Netherlands cohort study.

OBJECTIVES: To investigate risk of lung cancers associated with common established carcinogenic occupational exposures (asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes) in a prospective cohort study among the general population, and to estimate the proportion of lung cancer cases attributable to these occupational exposures. METHODS: A prospective cohort study on diet, other lifestyle factors, job history, and cancer risk that started in 1986 in The Netherlands on 58,279 men, aged 55-69 years. Based on information about job history obtained from a self-administered questionnaire, case by case expert assessment was carried out to assign to each study subject a cumulative probability of occupational exposure for each carcinogenic exposure. For analysis, a case-cohort approach was used, in which the person-years at risk were estimated from a randomly selected subcohort (n = 1688). After 4.3 years of follow up, 524 lung cancer cases with complete job history were available. RESULTS: After adjustment for age, each of the other occupational exposures, and for smoking habits and intake of vitamin C, beta-carotene, and retinol, significant associations were found between risk of lung cancer and cumulative probability of occupational exposure to asbestos (relative risk (RR) highest/no exposure = 3.49, 95% confidence interval (95% CI) 1.69 to 7.18, trend P < 0.01 or paint dust (RR highest/no exposure = 2.48, 95% CI 0.88 to 6.97, trend P < 0.01). The population attributable risks (PARs) for the four exposures based on the multivariately adjusted RRs for ever exposed versus never exposed workers were calculated. The PAR of lifetime occupational exposure to asbestos was calculated to be 11.6%. CONCLUSIONS: This prospective cohort study among the general population showed that occupational exposure to asbestos or paint dust is associated with higher RRs for lung cancer. This study shows that after adjustment for smoking and diet about 11.6% of the cases of lung cancer in men is attributable to lifetime occupational exposure to asbestos.

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