Abstract Aims The aim of this paper is to provide an overview of the current evidence for associations between dietary glycemic index (GI) and dietary glycemic load (GL), and the risk of various ...types of cancer, and to summarize mechanisms proposed to explain the associations found. Data synthesis Medline was searched for cohort studies, case-control studies, and meta-analyses, published up to February 2016, that examined associations between dietary GI/GL and cancer. Findings from the main meta-analyses showed a weak-to-moderate association of high dietary GI/GL with increased risk of some cancers. High dietary GI but not GL was significantly and consistently associated with increased colorectal cancer risk in both cohort and case-control studies. Dietary GL was directly associated with breast and endometrial cancer risk in cohort studies. Positive associations between dietary GI or GL and cancer risk were found more frequently in case-control studies than cohort studies. The main mechanism for these associations is thought to be chronic hyperinsulinemia. Insulin is itself a mitogen and also increases the bioactivity of insulin-like growth factors which can promote cancer by inhibiting apoptosis and stimulating cell proliferation. Conclusions The review has uncovered consistent evidence that high dietary GI is associated with increased risk of colorectal cancer, and that high dietary GL is associated with increased risk of breast and endometrial cancer. However the risk increases are small or moderate.
Factors linked to glucose metabolism are involved in the etiology of several cancers. High glycemic index (GI) or high glycemic load (GL) diets, which chronically raise postprandial blood glucose, ...may increase cancer risk by affecting insulin-like growth factor. We prospectively investigated cancer risk and dietary GI/GL in the EPIC-Italy cohort. After a median 14.9 years, 5112 incident cancers and 2460 deaths were identified among 45,148 recruited adults. High GI was associated with increased risk of colon and bladder cancer. High GL was associated with: increased risk of colon cancer; increased risk of diabetes-related cancers; and decreased risk of rectal cancer. High intake of carbohydrate from high GI foods was significantly associated with increased risk of colon and diabetes-related cancers, but decreased risk of stomach cancer; whereas high intake of carbohydrates from low GI foods was associated with reduced colon cancer risk. In a Mediterranean population with high and varied carbohydrate intake, carbohydrates that strongly raise postprandial blood glucose may increase colon and bladder cancer risk, while the quantity of carbohydrate consumed may be involved in diabetes-related cancers. Further studies are needed to confirm the opposing effects of high dietary GL on risks of colon and rectal cancers.
Abstract Background and aims The increase in breast cancer incidence over recent decades has been accompanied by an increase in the frequency of metabolic syndrome. Several studies suggest that ...breast cancer risk is associated with the components of metabolic syndrome (high serum glucose and triglycerides, low HDL-cholesterol, high blood pressure, and abdominal obesity), but no prospective study has investigated risk in relation to the presence of explicitly defined metabolic syndrome. We investigated associations between metabolic syndrome, its components, and breast cancer risk in a nested case–control study on postmenopausal women of the ORDET cohort. Methods and results After a median follow-up of 13.5 years, 163 women developed breast cancer; metabolic syndrome was present in 29.8%. Four matched controls per case were selected by incidence density sampling, and rate ratios were estimated by conditional logistic regression. Metabolic syndrome (i.e. presence of three or more metabolic syndrome components) was significantly associated with breast cancer risk (rate ratio 1.58 95% confidence interval 1.07–2.33), with a significant risk increase for increasing number of components ( P for trend 0.004). Among individual metabolic syndrome components, only low serum HDL-cholesterol and high triglycerides were significantly associated with increased risk. Conclusions This prospective study indicates that metabolic syndrome is an important risk factor for breast cancer in postmenopausal women. Although serum HDL-cholesterol and triglycerides had the strongest association with breast cancer, all components may contribute to increased risk by multiple interacting mechanisms. Prevention or reversal of metabolic syndrome by life-style changes may be effective in preventing breast cancer in postmenopausal women.
Summary Background Associations between circulating concentrations of oestrogens, progesterone, and androgens with breast cancer and related risk factors in premenopausal women are not well ...understood. We aimed to characterise these associations with a pooled analysis of data from seven studies. Methods Individual participant data for prediagnostic sex hormone and sex hormone-binding globulin (SHBG) concentrations were contributed from seven prospective studies. We restricted analyses to women who were premenopausal and younger than 50 years at blood collection, and to women with breast cancer diagnosed before age 50 years. We estimated odds ratios (ORs) with 95% CIs for breast cancer associated with hormone concentrations by conditional logistic regression in cases and controls matched for age, date of blood collection, and day of cycle, with stratification by study and further adjustment for cycle phase. We examined associations of hormones with risk factors for breast cancer in control women by comparing geometric mean hormone concentrations in categories of these risk factors, adjusted for study, age, phase of menstrual cycle, and body-mass index (BMI). All statistical tests were two-sided. Findings We included data for up to 767 women with breast cancer and 1699 controls in the risk analyses. Breast cancer risk was associated with a doubling in concentrations of oestradiol (OR 1·19, 95% CI 1·06–1·35), calculated free oestradiol (1·17, 1·03–1·33), oestrone (1·27, 1·05–1·54), androstenedione (1·30, 1·10–1·55), dehydroepiandrosterone sulphate (1·17, 1·04–1·32), testosterone (1·18, 1·03–1·35), and calculated free testosterone (1·08, 0·97–1·21). Breast cancer risk was not associated with luteal phase progesterone (doubling in concentration OR 1·00, 95% CI 0·92–1·09), and adjustment for other factors had little effect on any of these ORs. Cross-sectional analyses in control women showed several associations of sex hormones with breast cancer risk factors. Interpretation Circulating oestrogens and androgens are positively associated with the risk for breast cancer in premenopausal women. Funding Cancer Research UK.
Background: The European IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study was set up to determine the aetiology of overweight, ...obesity and related disorders in children, and to develop and evaluate a tailored primary prevention programme. Objective: This paper focuses on the aetiological element of the multicentre study, the measures and examinations, sociodemographic characteristics of the study sample and proportions of participation. Design: Prospective cohort study with an embedded intervention study that started with a baseline survey in eight countries in 2007–2008. Subjects and measurements: Baseline participants of the prospective cohort study were 16 224 children aged 2–9 years. Parents reported sociodemographic, behavioural, medical, nutritional and other lifestyle data for their children and families. Examinations of children included anthropometry, blood pressure, fitness, accelerometry, DNA from saliva and physiological markers in blood and urine. The built environment, sensory taste perception and other mechanisms of children's food choices and consumer behaviour were studied in subgroups. Results: Between 1507 and 2567, children with a mean age of 6.0 years and an even sex distribution were recruited from each country. Of them, 82% lived in two-parent families. The distribution of standardised income levels differed by study sample, with low-income groups being strongly represented in Cyprus, Italy and Germany. At least one 24-h dietary recall was obtained for two-thirds of the children. Blood pressure and anthropometry were assessed in more than 90%. A 3-day accelerometry was performed in 46%, motor fitness was assessed in 41%, cardiorespiratory fitness in 35% and ~11% participated in taste perception tests. The proportion of children donating venous blood, urine and saliva was 57, 86 and 88%, respectively. Conclusion: The IDEFICS cohort provides valuable data to investigate the interplay of social, environmental, genetic, physiological and behavioural factors in the development of major diet- and lifestyle-related disorders affecting children at present.
To investigate the reproducibility of food consumption frequencies derived from the food frequency section of the Children's Eating Habits Questionnaire (CEHQ-FFQ) that was developed and used in the ...IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) project to assess food habits in 2- to 9-year-old European children.
From a subsample of 258 children who participated in the IDEFICS baseline examination, parental questionnaires of the CEHQ were collected twice to assess reproducibility of questionnaire results from 0 to 354 days after the first examination. Weighted Cohen's kappa coefficients (κ) and Spearman's correlation coefficients (r) were calculated to assess agreement between the first and second questionnaires for each food item of the CEHQ-FFQ. Stratification was performed for sex, age group, geographical region and length of period between the first and second administrations. Fisher's Z transformation was applied to test correlation coefficients for significant differences between strata.
For all food items analysed, weighted Cohen's kappa coefficients (κ) and Spearman's correlation coefficients (r) were significant and positive (P<0.001). Reproducibility was lowest for diet soft drinks (κ=0.23, r=0.32) and highest for sweetened milk (κ=0.68, r=0.76). Correlation coefficients were comparable to those of previous studies on FFQ reproducibility in children and adults. Stratification did not reveal systematic differences in reproducibility by sex and age group. Spearman's correlation coefficients differed significantly between northern and southern European countries for 10 food items. In nine of them, the lower respective coefficient was still high enough to conclude acceptable reproducibility. As expected, longer time (>128 days) between the first and second administrations resulted in a generally lower, yet still acceptable, reproducibility.
Results indicate that the CEHQ-FFQ gives reproducible estimates of the consumption frequency of 43 food items from 14 food groups in European children.
A carbohydrate‐rich diet, resulting in high blood glucose and insulin, has been hypothesized as involved in colorectal cancer etiology. We investigated dietary glycemic index (GI) and glycemic load ...(GL), in relation to colorectal cancer, in the prospectively recruited EPIC‐Italy cohort. After a median 11.7 years, 421 colorectal cancers were diagnosed among 47,749 recruited adults. GI and GL were estimated from validated food frequency questionnaires. Multivariable Cox modeling estimated hazard ratios (HRs) for associations between colorectal cancer and intakes of total, high GI and low GI carbohydrate and GI and GL. The adjusted HR of colorectal cancer for highest versus lowest GI quartile was 1.35; 95% confidence interval (CI) 1.03–1.78; p trend 0.031. Increasing high GI carbohydrate intake was also significantly associated with increasing colorectal cancer risk (HR 1.45; 95% CI 1.04–2.03; p trend 0.034), whereas increasing low GI carbohydrate was associated with reducing risk (HR 0.73; 95% CI 0.54–0.98; p trend 0.033). High dietary GI and high GI carbohydrate were associated with increased risks of cancer at all colon sites (HR 1.37; 95% CI 1.00–1.88, HR 1.80; 95% CI 1.22–2.65, respectively), whereas high GI carbohydrate and high GL were associated with increased risk of proximal colon cancer (HR 1.94; 95% CI 1.18–3.16, HR 2.01; 95% CI 1.08–3.74, respectively). After stratification for waist‐to‐hip ratio (WHR), cancer was significantly associated with GI, and high GI carbohydrate, in those with high WHR. These findings suggest that high dietary GI and high carbohydrate intake from high GI foods are associated with increased risk of colorectal cancer.
What's new?
Diets rich in carbohydrate trigger increases in blood glucose and insulin levels, events that may be involved in the etiology of colorectal cancer. But carbohydrates vary in their impact on blood glucose levels, reflected in their glycemic index (GI) values, and whether high GI carbohydrates raise cancer risk remains much debated. Here, high dietary GI and elevated intake of carbohydrates from high GI foods were associated with increased risk of colorectal cancer. A diet rich in low GI carbohydrates, by contrast, was associated with a reduced risk of disease.
Longitudinal studies investigating dietary patterns (DPs) and their association with childhood overweight/obesity are lacking in Europe. We identified DPs and investigated their association with ...overweight/obesity and changes in body mass index (BMI) in a cohort of European children.
Children aged 2-10 from eight European countries were recruited in 2007-2008. Food frequency questionnaires were collected from 14 989 children. BMI and BMI z-scores were derived from height and weight and were used to identify overweight/obese children. After 2 years (mean), anthropometric measurements were repeated in 9427 children. Principal component analysis was used to identify DPs. Simplified DPs (SDPs) were derived from DPs. Adjusted odds ratios (ORs) for overweight/obesity with increasing DP intake were estimated using multilevel logistic regression. Associations of BMI change with DP and SDP were assessed by multilevel mixed regression. Models were adjusted for baseline BMI, age, sex, physical activity and family income.
Four DPs were identified that explained 25% of food intake variance: snacking, sweet and fat, vegetables and wholemeal, and protein and water. After 2 years, 849(9%) children became overweight/obese. Children in the highest vegetables and wholemeal tertile had lower risk of becoming overweight/obese (OR: 0.69, 95% confidence intervals (CIs): 0.54-0.88). Children in the highest SDP tertile of vegetables and wholemeal had similarly lower risk of becoming overweight/obese (OR: 0.64, 95% CIs: 0.51-0.82), and their BMI increased by 0.7 kg/m(2) over the study period-significantly less than the increase in the lowest tertile (0.84 kg/m(2)).
Our findings suggest that promoting a diet rich in vegetables and wholemeal cereals may counteract overweight/obesity in children.
Aims/hypothesis
A diet rich in meat has been reported to contribute to the risk of type 2 diabetes. The present study aims to investigate the association between meat consumption and incident type 2 ...diabetes in the EPIC-InterAct study, a large prospective case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) study.
Methods
During 11.7 years of follow-up, 12,403 incident cases of type 2 diabetes were identified among 340,234 adults from eight European countries. A centre-stratified random subsample of 16,835 individuals was selected in order to perform a case-cohort design. Prentice-weighted Cox regression analyses were used to estimate HR and 95% CI for incident diabetes according to meat consumption.
Results
Overall, multivariate analyses showed significant positive associations with incident type 2 diabetes for increasing consumption of total meat (50 g increments: HR 1.08; 95% CI 1.05, 1.12), red meat (HR 1.08; 95% CI 1.03, 1.13) and processed meat (HR 1.12; 95% CI 1.05, 1.19), and a borderline positive association with meat iron intake. Effect modifications by sex and class of BMI were observed. In men, the results of the overall analyses were confirmed. In women, the association with total and red meat persisted, although attenuated, while an association with poultry consumption also emerged (HR 1.20; 95% CI 1.07, 1.34). These associations were not evident among obese participants.
Conclusions/interpretation
This prospective study confirms a positive association between high consumption of total and red meat and incident type 2 diabetes in a large cohort of European adults.
PDF
