Dr Francesca Crowe
|Research Area:||Clinical Epidemiology|
|Keywords:||Epidemiology, Nutrition, Million Women Study, UK Biobank, Cancer and Oxford WebQ|
Francesca joined the Cancer Epidemiology Unit in 2007 as the NZ HRC/Girdlers’ Postdoctoral Research fellow at Green Templeton College after gaining a PhD in Human Nutrition from the University of Otago (New Zealand) and now fills the position of Nutritional Epidemiologist. She is the Principal Investigator for the unit’s online dietary questionnaire the Oxford WebQ that is currently being administered in two large epidemiological studies – the Million Women Study and UK Biobank. She also co-ordinates the cardiovascular research group for the EPIC-Oxford cohort of 65,000 participants based in the Cancer Epidemiology Unit. Francesca is particularly interested in the future of dietary assessment and the use of internet-based methods to measure diet in hundreds of thousands of people. She also has a keen research interest in the relation between dietary components and blood-based nutrient biomarkers (e.g. fatty acids, vitamin D) and the aetiology of diseases such as cardiovascular disease and prostate cancer.
There are no collaborations listed for this principal investigator.
Evidence from prospective studies is consistent in showing an inverse association between dietary fibre intake and risk of ischaemic heart disease (IHD), but whether dietary fibre from various food sources differ in their effect on IHD risk is less clear. The objective of this study was to assess the associations of total and food sources of dietary fibre with IHD mortality in the European Prospective Investigation into Cancer and Nutrition-Heart study. Hide abstract
A higher intake of fruits and vegetables has been associated with a lower risk of ischaemic heart disease (IHD), but there is some uncertainty about the interpretation of this association. The objective was to assess the relation between fruit and vegetable intake and risk of mortality from IHD in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heart study. Hide abstract
To examine the associations of a vegetarian diet and dietary fibre intake with risk of diverticular disease. Hide abstract
Vegetarians and vegans exclude certain food sources of vitamin D from their diet, but it is not clear to what extent this affects plasma concentrations of 25-hydroxyvitamin D (25(OH)D). The objective was to investigate differences in vitamin D intake and plasma concentrations of 25(OH)D among meat eaters, fish eaters, vegetarians and vegans. Hide abstract
Height and BMI are risk factors for several types of cancer and may be related to circulating concentrations of insulin-like growth factor-I (IGF-I), a peptide associated with increased cancer risk. Hide abstract
Vegans, and to a lesser extent vegetarians, have low average circulating concentrations of vitamin B12; however, the relation between factors such as age or time on these diets and vitamin B12 concentrations is not clear. The objectives of this study were to investigate differences in serum vitamin B12 and folate concentrations between omnivores, vegetarians and vegans and to ascertain whether vitamin B12 concentrations differed by age and time on the diet. Hide abstract
The use of serum fatty acid biomarkers in nutritional epidemiology is increasingly common; however, there is an absence of scientific evidence to substantiate whether the measurement of fatty acids as molecular percentages (which is the conventional approach) or as absolute concentrations is more informative. Hide 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. Hide abstract
Circulating concentrations of insulin-like growth factor I (IGF-I) and IGF binding proteins (IGFBP) have been associated with the risk of several types of cancer. Dietary correlates of IGF-I and IGFBPs are not yet well established. The objective of this study was to assess the association between dietary intake and serum concentrations of IGF-I, IGFBP-1, IGFBP-2, and IGFBP-3 in a cross-sectional analysis of 4,731 men and women taking part in the European Prospective Investigation into Cancer and Nutrition. Diet was assessed using country-specific validated dietary questionnaires. Serum concentrations of IGF-I, IGFBP-1, IGFBP-2 and IGFBP-3 were measured, and the associations between diet and IGF-I and IGFBPs were assessed using multiple linear regression adjusting for sex, age, body mass index, smoking status, and alcohol and energy intake. Each 1 SD increment increase in total and dairy protein and calcium intake was associated with an increase in IGF-I concentration of 2.5%, 2.4%, and 3.3%, respectively (P for trend <0.001 for all) and a decrease in IGFBP-2 of 3.5%, 3.5%, and 5.4% (P for trend <0.001 for all), respectively. There were no significant associations between the intake of protein or calcium from nondairy sources and IGF-I. The results from this large cross-sectional analysis show that either the intake of dairy protein or calcium is an important dietary determinant of IGF-I and IGFBP-2 concentrations; however, we suggest that it is more likely to be protein from dairy products. Hide abstract
Plausible biological mechanisms underlie possible associations between fatty acids in blood and risk of prostate cancer; epidemiologic evidence for an association, however, is inconsistent. Hide abstract
Am J Clin Nutr, 87 (5), pp. 1405-1413. Read abstract2008. Dietary fat intake and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition.
Findings from early observational studies have suggested that the intake of dietary fat might be a contributing factor in the etiology of prostate cancer. However, the results from more recent prospective studies do not support this hypothesis, and the possible association between different food sources of fat and prostate cancer risk also remains unclear. Hide abstract
Journal of Nutrition, 138 pp. 551-555-551-555. Read abstract2008. Lowering plasma homocysteine concentrations of older men and women with folate, vitamin B-12, and vitamin B-6 does not affect the proportion of (n-3) long chain polyunsaturated fatty acids in plasma phosphatidylcholine
There is evidence to suggest that folate, homocysteine, or both affect the (n-3) long chain PUFA composition of tissues; however, this evidence is derived largely from experiments with animals and small observational studies in humans. Results from randomized controlled trials are needed. The objective of this study was to determine whether homocysteine lowering with a B vitamin supplement affects the proportion of (n-3) long-chain PUFA in plasma phosphatidylcholine. We conducted a double-blind, placebo-controlled, randomized clinical trial involving 253 participants, 65 y or older, with plasma homocysteine concentrations of at least 13 μmol/L. Participants in the vitamin group (n= 127) took a daily supplement containing 1000 μg folate, 500 μg vitamin B-12, and 10 mg vitamin B-6 for 2 y. The fatty acid composition of plasma phosphatidylcholine was measured at baseline and at 2 y. Plasma homocysteine concentrations during the course of the study were 4.4μmol/L lower in the vitamin group than in the placebo group. The proportions of eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids in plasma phosphatidylcholine did not differ between the vitamin and placebo groups at 2 y; the mean differences after adjusting for baseline values and sex were 20.03 (99% CI: -0.22, 0.16), 0.03 (99% CI: -0.03, 0.09), and -0.02 (99% CI: -0.27, 0.24) mol%, respectively. Lowering plasma homocysteine concentrations of older men and women with folate, vitamin B-12, and vitamin B-6 had no effect on the proportion of (n-3) long-chain PUFA in plasma phosphatidylcholine. © 2008 American Society for Nutrition. Hide abstract
British Journal of Nutrition, 99 pp. 168-174-168-174. Read abstract2008. Serum n-3 long-chain PUFA differ by sex and age in a population-based survey of New Zealand adolescents and adults
A higher proportion of n-3 long-chain PUFA in tissue lipids has been associated with a lower risk of CVD and some cancers. Diet is an important predictor of n-3 long-chain PUFA composition; however, the importance of non-dietary factors such as sex and age is unclear. We measured the proportion of n-3 long-chain PUFA in serum phospholipid, cholesterol ester and TAG of 2793 New Zealanders 15 years or older who participated in the 1997 National Nutrition Survey to determine differences by sex and age. Women had lower proportions of EPA and docosapentaenoic acid in phospholipid, by 0.07 (P=0.004) and 0.10 (P<0.001) mol%, respectively, and a higher proportion of DHA by 0.16 mol% (P=0.001) compared with men. Intake of fish fat did not differ between men and women. There was a positive association between age and the proportion of EPA and DHA in phospholipid (P<0.001). The sex differences in EPA and DHA were similar at all ages. Similar sex and age differences in serum cholesterol ester n-3 long-chain PUFA were found; only age differences were found in serum TAG. Sex and age differences in n-3 long-chain PUFA occur in the general population. Men and women may need to be considered separately when examining the association between disease risk and biomarkers of n-3 fatty acids. © 2007 The Authors. Hide abstract
American Journal of Clinical Nutrition, 86 pp. 1278-1285-1278-1285. Read abstract2007. Serum phospholipid n-3 long-chain polyunsaturated fatty acids and physical and mental health in a population-based survey of New Zealand adolescents and adults
Background: Evidence from observational studies suggests that there is an association between n-3 long-chain polyunsaturated fatty acids and depression; however, this association has yet to be examined in a population-based study. Objective: The objective was to assess whether n-3 long-chain polyunsaturated fatty acids in serum phospholipids are associated with mental and physical well-being. Design: The fatty acid composition of serum phospholipids was measured in 2416 New Zealanders aged ≥ 15 y who took part in the 1997 National Nutrition Survey. The mental and physical component scores were assessed by using the short-form 36 health questionnaire. Results: After adjustment for a number of covariates, there was a significant positive trend in self-reported physical well-being across the quintiles of eicosapentaenoic acid (P for trend = 0.009) and the ratio of eicosapentaenoic to arachidonic acid (P for trend = 0.012). The differences in the physical component score between the first and fifth quintiles were 2.4 and 2.5 points, respectively. The results showed that neither the proportion of eicosapentaenoic acid nor that of docosahexaenoic acid was associated with the mental component score; however, there was a significant positive trend in mental well-being across the quintiles of the ratio of eicosapentaenoic to arachidonic acid (P for trend = 0.044). Conclusion: The results from this population-based survey of New Zealanders suggest a strong and consistent association between eicosapentaenoic acid in serum phospholipids and self-reported physical well-being; the association with mental well-being is less compelling. © 2007 American Society for Nutrition. Hide abstract
American Journal of Clinical Nutrition, 83 pp. 887-894-887-894. Read abstract2006. Serum fatty acids as biomarkers of fat intake predict serum cholesterol concentrations in a population-based survey of New Zealand adolescents and adults
Background: The results of randomized controlled trials indicate that the amount and type of dietary fat are important predictors of serum cholesterol concentrations. However, the results of observational studies show weak or no association between dietary fat intake and serum cholesterol. Serum fatty acids are valid biomarkers of fat intake and may improve dietary estimates. Objective: The objective was to ascertain whether serum fatty acids are associated with serum cholesterol concentrations in New Zealand adolescents and adults. Design: The current study was a cross-sectional, national, population-based survey of 2793 New Zealanders aged ≥15 y who participated in the 1997 National Nutrition Survey. The fatty acid composition of serum cholesterol esters, phospholipids, and triacylglycerols was measured. Results: A 1-SD increase in myristic acid (14:0) in serum cholesterol ester, phospholipids, and triacylglycerol corresponded with increases in serum cholesterol of 0.19, 0.13, and 0.10 mmol/L, respectively, after adjustment of the regression analysis for sex, age, body mass index, ethnicity, and smoking. The mean difference in cholesterol concentrations between persons in the highest and the lowest quintiles of serum cholesteryl-myristate was 0.48 mmol/L (P for trend < 0.001). A 1-SD increase in the proportion of linoleic acid (18:2n-6) in serum cholesterol ester, phospholipids, and triacylglycerol corresponded with decreases in serum cholesterol of 0.07, 0.07, and 0.05 mmol/L, respectively. The difference in mean serum cholesterol between the highest and lowest quintiles of cholesteryl-linoleate was 0.18 mmol/L (P for trend = 0.019). Conclusion: Saturated and polyunsaturated fat intakes, measured by using fatty acid biomarkers, are important predictors of serum cholesterol concentrations in New Zealand. © 2006 American Society for Nutrition. Hide abstract
Diet and blood-based biomarkers and risk of cardiovascular disease
Diet is thought to be of considerable importance for the prevention of cardiovascular disease (CVD) but in order to reliably establish any association between diet and CVD, it is essential that diet is measured in large groups of people with a wide variation in their diets. The EPIC-Oxford cohort is a prospective study of 65,500 people recruited in the United Kingdom between 1993 and 2000. The cohort comprises 34,000 meat eaters, 10,000 fish-eaters (eat fish but not meat), 19,000 vegetarians, ...