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- Saadatian-Elahi, Mitra, et al.
(author)
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Plasma phospholipid fatty acid profiles and their association with food intakes: results from a cross-sectional study within the European Prospective Investigation into Cancer and Nutrition
- 2009
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In: American Journal of Clinical Nutrition. - : Elsevier BV. - 1938-3207 .- 0002-9165. ; 89:1, s. 331-346
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Journal article (peer-reviewed)abstract
- Background: Plasma phospholipid fatty acids have been correlated with food intakes in populations with homogeneous dietary patterns. However, few data are available on populations with heterogeneous dietary patterns. Objective: The objective was to investigate whether plasma phospholipid fatty acids are suitable biomarkers of dietary intakes across populations involved in a large European multicenter study. Design: A cross-sectional study design nested to the European Prospective Investigation into Cancer and Nutrition (EPIC) was conducted to determine plasma fatty acid profiles in > 3000 subjects from 16 centers, who had also completed 24-h dietary recalls and dietary questionnaires. Plasma fatty acids were assessed by capillary gas chromatography. Ecological and individual correlations were calculated between fatty acids and select food groups. Results: The most important determinant of plasma fatty acids was region, which suggests that the variations across regions are largely due to different food intakes. Strong ecological correlations were observed between fish intake and long-chain n-3 polyunsaturated fatty acids (r = 0.78, P < 0.01), olive oil and oleic acid (r = 0.73, P < 0.01), and margarine and elaidic acid (r = 0.76, P < 0.01). Individual correlations varied across the regions, particularly between olive oil and oleic acid and between alcohol and the saturation index, as an indicator of stearoyl CoA desaturase activity. Conclusions: These findings indicate that specific plasma phospholipid fatty acids are suitable biomarkers of some food intakes in the EPIC Study. Moreover, these findings suggest complex interactions between alcohol intake and fatty acid metabolism, which warrants further attention in epidemiologic studies relating dietary fatty acids to alcohol-related cancers and other chronic diseases. Am J Clin Nutr 2009; 89: 331-46.
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| 2. |
- Travis, Ruth C, et al.
(author)
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Serum vitamin D and risk of prostate cancer in a case-control analysis nested within the European Prospective Investigation into Cancer and Nutrition (EPIC).
- 2009
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In: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 169:10, s. 1223-1232
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Journal article (peer-reviewed)abstract
- Results from the majority of studies show little association between circulating concentrations of vitamin D and prostate cancer risk, a finding that has not been demonstrated in a wider European population, however. The authors examined whether vitamin D concentrations were associated with prostate cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (1994-2000). Serum concentrations of 25-hydroxyvitamin D were measured in 652 prostate cancer cases matched to 752 controls from 7 European countries after a median follow-up time of 4.1 years. Conditional logistic regression models were used to calculate odds ratios for prostate cancer risk in relation to serum 25-hydroxyvitamin D after standardizing for month of blood collection and adjusting for covariates. No significant association was found between 25-hydroxyvitamin D and risk of prostate cancer (highest vs. lowest quintile: odds ratio = 1.28, 95% confidence interval: 0.88, 1.88; P for trend = 0.188). Subgroup analyses showed no significant heterogeneity by cancer stage or grade, age at diagnosis, body mass index, time from blood collection to diagnosis, or calcium intake. In summary, the results of this large nested case-control study provide no evidence in support of a protective effect of circulating concentrations of vitamin D on the risk of prostate cancer.
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| 3. |
- van Bakel, Marit M E, et al.
(author)
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Methodological challenges in the application of the Glycemic Index in epidemiological studies using data from the European prospective investigation into cancer and nutrition
- 2009
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In: Journal of Nutrition. - : Elsevier BV. - 0022-3166 .- 1541-6100. ; 139:3, s. 568-575
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Journal article (peer-reviewed)abstract
- Associations between the glycemic index (GI) or glycemic load (GL) and diseases are heterogeneous in epidemiological studies. Differences in assigning GI values to food items may contribute to this inconsistency. Our objective was to address methodological issues related to the use of current GI and GL values in epidemiological studies. We performed ecological comparison and correlation studies by calculating dietary GI and GL from country-specific dietary questionnaires (DQ) from 422,837 participants from 9 countries participating in the European Prospective Investigation into Cancer and Nutrition study and single standardized 24-h dietary recalls (24-HDR) obtained from a representative sample (n = 33,404) using mainly Foster Powell's international table as a reference source. Further, 2 inter-rater and 1 inter-method comparison were conducted, comparing DQ GI values assigned by independent groups with values linked by us. The ecological correlation between DQ and 24-HDR was good for GL (overall r = 0.76; P < 0.005) and moderate for GI (r = 0.57; P < 0.05). Mean GI/GL differences between DQ and 24-HDR were significant for most centers. GL but not GI from DQ was highly correlated with total carbohydrate (r = 0.98 and 0.15, respectively; P < 0.0001) and this was higher for starch (r = 0.72; P < 0.0001) than for sugars (r = 0.36; P < 0.0001). The inter-rater and inter-method variations were considerable for GI (weighted kappa coefficients of 0.49 and 0.65 for inter-rater and 0.25 for inter-method variation, respectively) but only mild for GL (weighted kappa coefficients > 0.80). A more consistent methodology to attribute GI values to foods and validated DQ is needed to derive meaningful GI/GL estimates for nutritional epidemiology.
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