In the early 1980s, Doll and Peto estimated that about 35% of all deaths from cancer in the United States were attributable to dietary factors, with a margin of uncertainty ranging from 10 to 70%. Since then, several dietary factors, e.g. fat and meat, have been suggested to increase the risk for cancer, while other factors, e.g. fibre, fruit and vegetables, have been suggested to decrease the risk. The case-control and cohort studies have, however, given ambiguous results, and the overall evidence is far from conclusive. The major findings on dietary factors that increase risk have been reported from case-control studies, but have not been confirmed in large population-based cohort studies. Although the research in this area indicates that diet is important in cancer prevention, current knowledge does not allow reliable estimates of the numbers and proportions of cancers that could be avoided through well-described modifications of dietary habits. During the last 10 years, low physical activity has been pinpointed as a risk factor for cancers at various sites, especially the colon; however, the causal mechanism is still unknown. Obesity, defined as a body mass index of 30 or more, is consistently associated with endometrial and gall-bladder cancers in women and renal-cell cancer in both men and women. As the prevalence of obesity was between 5 and almost 20% in the Nordic populations in 1995, 625 cancer cases (310 endometrial cancers, 270 renal-cell cancers in men and women and 45 gall-bladder and bile-duct cancers among women) can be predicted in the Nordic countries around the year 2000 to be caused by obesity. This implies that about 1% of all cancers in Nordic women and less than 1% of those in Nordic men could be avoided around the year 2000 if a healthy body weight could be maintained by all inhabitants.
The evidence regarding fatty acids and breast cancer risk is inconclusive. Adipose tissue fatty acids can be used as biomarkers of fatty acid intake and of endogenous fatty acid exposure. Fatty acids in adipose tissue are correlated owing to common dietary sources and shared metabolic pathways, which group fatty acids into naturally occurring patterns. We aimed to prospectively investigate associations between adipose tissue fatty acid patterns and long-term risk of total breast cancer and breast cancer subtypes characterised by oestrogen and progesterone receptor status (ER and PR).
This case-cohort study was based on data from the Danish cohort Diet, Cancer and Health. At baseline, a fat biopsy and information on lifestyle and reproductive factors were collected. From the 31 original fatty acids measured, patterns of fatty acids were identified using the treelet transform. During a median follow-up of 5.3 years, 474 breast cancer cases were identified. Hazard ratios and 95% confidence intervals of risk of total breast cancer and of subtypes according to quintiles of factor score were determined by weighted Cox proportional hazards regression.
After adjustment for potential confounders, factor scores for the seven patterns identified by the treelet transform were not associated with risk of total breast cancer, nor with risk of ER+, ER-, PR+ or PR- tumours.
No clear associations between the patterns of fatty acids at baseline and long-term risk of total breast cancer or ER+, ER-, PR+ or PR- tumours were observed.
The role of diet in the aetiology of renal cell carcinoma was investigated in a population-based case-control study in Denmark. Cases were 20-79 years old, with a histologically verified diagnosis of renal cell carcinoma. Controls were sampled from the general population and were frequency-matched on age and sex. A total of 351 cases (73% of the eligible) and 340 controls (68% of the eligible) were included in the study. Dietary information was obtained in a self-administered food frequency questionnaire and the information was confirmed in a subsequent interview performed by trained interviewers who also elicited information on other suspected risk factors such as smoking, occupation, medical history, education and reproductive history. Logistic regression models were used to calculate the odds ratios, and, both frequency of consumption of various food stuffs and computed nutrients were examined. A positive association was observed between risk of renal cell carcinoma and total energy intake (odds ratio, OR, for highest quartile compared to lowest: 1.7 (95% confidence interval, CI, 1.0-3.0) for men, and 3.5 (95% CI 1.6-6.5) for women), fat intake (OR for highest quartile compared to lowest: 1.9 (95% CI 1.1-3.5) for men, and 3.3 (95% CI 1.6-6.9) for women). For women, an effect was also seen for intake of carbohydrates (OR for highest quartile compared to lowest: 3.2 (95% CI 1.5-6.8), while no protective effect was seen for vegetables or fruit. Dairy products may be associated with risk of renal cell cancer (OR for women using thickly spread butter compared to thinly spread: 11.4 (95% CI 2.8-45), OR for women who drank more than one glass of milk with 3.5% fat content compared to never drink milk: 3.7 (95% CI 1.2-11). As expected, total energy intake, intake of fat, protein and carbohydrates were closely correlated making it difficult to identify one of the energy sources as more closely associated with risk of renal cell cancer than the other. Several energy sources have been identified as possible risk factors for renal cell carcinoma. It is possible that a high energy intake as such rather than the individual sources are responsible for the increased risk. Furthermore, dairy fats may be associated with renal cell carcinoma risk. The observed associations appeared stronger in women, and did not explain the association with obesity and low socio-economic status previously found in Denmark.
In order to test hypotheses on diet and the risk of cancer, a prospective cohort study was established. A total of 57,055 persons living in Copenhagen and Aarhus, between 50 and 65 years of age, visited a study clinic between December 1993 and May 1997. The participants provided questionnaire data on diet and lifestyle. Furthermore, anthropometric measurements, blood pressure and biological material were collected. All participants will be followed by linkage to health registries including the Cancer Registry and by self-administered follow-up questionnaires. The purpose of this publication is to describe the data-base, which will be available for research in the years to come including the results of the first two years of follow-up.
Follow-up studies have suggested that total intake of trans fatty acids (TFA) is a risk factor for gain in body weight and waist circumference (WC). However, in a cross-sectional study individual TFA isomers in adipose tissue had divergent associations with anthropometry. Our objective was to investigate the association between intake of TFA from ruminant dairy and meat products and subsequent changes in weight and WC. Furthermore, potential effect modification by sex, age, body mass index and WC at baseline was investigated.
Data on weight, WC, habitual diet and lifestyle were collected at baseline in a Danish cohort of 30,851 men and women aged 50-64 years. Follow-up information on weight and WC was collected 5 years after enrolment. The associations between intake of ruminant TFA (R-TFA) and changes in weight and WC were analysed using multiple linear regression with cubic spline modelling.
Intake of R-TFA, both absolute and energy-adjusted intake, was significantly associated with weight change. Inverse associations were observed at lower intakes with a levelling-off at intakes >1.2?g/day and 0.4 energy percentage (E %). Absolute, but not energy-adjusted, intake of R-TFA was significantly associated with WC change. An inverse association was observed at lower intakes with a plateau above an intake of 1.2?g/day.
The present study suggests that intake of R-TFA is weakly inversely associated with changes in weight, whereas no substantial association with changes in WC was found.
The aim of this study was to investigate whether air pollution from traffic at a residence is associated with mortality related to type 1 or type 2 diabetes.
We followed up 52,061 participants in the Danish Diet, Cancer and Health cohort for diabetes-related mortality in the nationwide Register of Causes of Death, from baseline in 1993-1997 up to the end of 2009, and traced their residential addresses since 1971 in the Central Population Registry. We used dispersion-modelled concentration of nitrogen dioxide (NO2) since 1971 and amount of traffic at the baseline residence as indicators of traffic-related air pollution and used Cox regression models to estimate mortality-rate ratios (MRRs) with adjustment for potential confounders.
Mean levels of NO2 at the residence since 1971 were significantly associated with mortality from diabetes. Exposure above 19.4 µg/m³ (upper quartile) was associated with a MRR of 2.15 (95% CI 1.21, 3.83) when compared with below 13.6 µg/m³ (lower quartile), corresponding to an MRR of 1.31 (95% CI 0.98, 1.76) per 10 µg/m³ NO2 after adjustment for potential confounders.
This study suggests that traffic-related air pollution is associated with mortality from diabetes. If confirmed, reduction in population exposure to traffic-related air pollution could be an additional strategy against the global public health burden of diabetes.
Obesity may be associated with increased risk of pneumonia, but available data on this relationship are sparse and inconsistent. We followed a prospective cohort of 22,578 males and 25,973 females from the Danish Diet, Cancer and Health Study, aged 50-64 yrs and free from major chronic diseases at baseline (1993-1997), for first-time hospitalisation with pneumonia (median follow-up 12 yrs). Compared with males of normal weight, adjusted hazard ratios (HRs) for pneumonia were 1.4 (95% CI 1.2-1.7) for males with moderate obesity (body mass index (BMI) 30.0-34.9 kg·m?²), and 2.0 (95% CI 1.4-2.8) for males with severe obesity (BMI = 35.0 kg·m?²), controlling for lifestyle and educational variables. Among females the associations were weaker, with adjusted HRs of 0.8 (95% CI 0.6-1.0) for moderate obesity, and 1.2 (95% CI 0.8-1.6) for severe obesity. Adjustment for major chronic diseases diagnosed during follow-up eliminated the associations between obesity and pneumonia risk. Obesity is associated with higher risk of hospitalisation with pneumonia among males but not among females, which is apparently explained by occurrence of other chronic diseases.
Comment In: Eur Respir J. 2011 May;37(5):1298; author reply 1299-130021532024
Comment In: Eur Respir J. 2011 May;37(5):1299; author reply 1299-130021532025
BACKGROUND: Variation in diet associated with drinking patterns may explain why wine seems to reduce ischemic heart disease mortality. OBJECTIVE: Our objective was to study the association between intake of different alcoholic beverages and selected indicators of a healthy diet. DESIGN: This was a cross-sectional study conducted in Copenhagen and Aarhus, Denmark, from 1995 to 1997, and included 23 284 men and 25 479 women aged 50-64 y. The main outcome measures were groups of selected foods that were indicators of a healthy dietary pattern. RESULTS: Wine, as compared with other alcoholic drinks, was associated with a higher intake of fruit, fish, cooked vegetables, salad, and the use of olive oil for cooking in both men and women. Men who preferred beer and spirits had odds ratios of 0.42 (95% CI: 0.39, 0.45) and 0.51 (95% CI: 0.43, 0.60), respectively, for a high intake of salad compared with those who preferred wine. Higher wine intake was associated with a higher intake of healthy food items compared with intake of
Comment In: Am J Clin Nutr. 1999 Jan;69(1):2-39925114