Glycemic index, glycemic load and risk of gastric cancer

Daily Diet and Nutrition Risk Factors for Gastric Cancer Incidence in a Japanese Population

Background/Aims

: Nutritional factors associated with gastric cancer (GC) are not completely understood. We aimed to determine the effect of nutrient intake on the incidence of GC.

Methods

: This was a post hoc analysis of a prospective trial that evaluated modalities for GC screening in participants aged 30 to 74 years living in high-risk areas for GC in Japan between June 2011 and March 2013. The patients were followed up for GC incidence for 6 years. All participants completed a self-administered food frequency questionnaire (FFQ) upon enrollment before GC screening. Daily nutrient intake was calculated from the FFQ and dichotomized at each cutoff value using receiver operating characteristic analysis. Risk factors associated with GC incidence were investigated in terms of nutrient intake and participant characteristics using Cox proportional hazards regression analysis.

Results

: Overall, 1,147 participants were included in this analysis. The median age was 62 years, and 50.7% of the participants were men. The median follow-up period was 2,184 days. GC was detected in 25 participants during the follow-up. Multivariate Cox proportional hazards regression analysis revealed that the intake of sodium (adjusted hazards ratio [aHR], 3.905; 95% confidence interval [CI], 1.520 to 10.035; p=0.005) and vitamin D (aHR, 2.747; 95% CI, 1.111 to 6.788, p=0.029) were positively associated with GC incidence, whereas the intake of soluble dietary fiber (aHR, 0.104; 95% CI, 0.012 to 0.905; p=0.040) was inversely associated with GC incidence.

Conclusions

: Daily high intake of sodium and vitamin D and low soluble dietary fiber intake are associated with GC incidence.

Association between priori and posteriori dietary patterns and gastric cancer risk: an updated systematic review and meta-analysis of observational studies

An increasing number of epidemiological studies have explored the relationship between the risk of gastric cancer and specific dietary patterns, but the findings remain inconclusive. We, therefore, performed this comprehensive systematic review and meta-analysis to analyze the available evidence regarding the associations between a priori and a posteriori dietary patterns and the risk of gastric cancer. A systematic search of six electronic databases, including PubMed, Web of Science, EBSCO, Scopus, China National Knowledge Infrastructure (CNKI), and Wanfang Data, was carried out to retrieve the relevant articles published up to March 2024. Thirty-six studies (10 cohort and 26 case-control studies) with a total of 2 181 762 participants were included in the final analyses. Combining 15 effect sizes extracted from 12 articles, we observed a reduced risk of gastric cancer in the highest versus the lowest categories of the Mediterranean diet [relative risk (RR), 0.72; 95% confidence interval (CI), 0.61-0.85; P < 0.001]. Combining 11 effect sizes from 10 articles (involving 694 240 participants), we found that the highest Dietary Inflammatory Index scores were significantly associated with an increased risk of gastric cancer (RR, 1.32; 95% CI, 1.11-1.57; P < 0.001). A reduced risk of gastric cancer was shown for the highest compared with the lowest categories of healthy dietary pattern (RR, 0.78; 95% CI, 0.67-0.91; P = 0.002). Conversely, the highest adherence to the Western dietary pattern was associated with an increased risk of gastric cancer (RR, 1.33; 95% CI, 1.19-1.49; P < 0.001). Our study demonstrated that the Mediterranean diet and a healthy dietary pattern were associated with a decreased risk of gastric cancer. Conversely, the Dietary Inflammatory Index and Western dietary pattern were associated with an increased risk of gastric cancer.

Glycemic Index, Glycemic Load, and FAS rs6586161 Polymorphism in Relation to Gastric Cancer Risk: A Case-Control Study in Korea

Many dietary and genetic factors have been confirmed to be associated with gastric cancer risk. This research investigated gastric cancer risk with regard to the glycemic index, glycemic load, and FAS rs6586161 polymorphism. A total of 232 matched pairs were included in this case-control study. Data collection was conducted at two hospitals in Korea from 2002 to 2006. Dietary information was obtained from a food frequency questionnaire, and genotypes of FAS rs6586161 polymorphism were TT, TA, and AA type. Gastric cancer risk was increased for the highest tertile of glycemic index (vs. lowest tertile, OR = 1.84, 95% CI = 1.07-3.18), the highest tertile of glycemic load (vs. lowest tertile, OR = 2.14, 95% CI = 1.23-3.75), and the AA type of FAS rs6586161 polymorphism (vs. TT types, OR = 1.95, 95% CI = 1.13-3.39). Furthermore, gastric cancer risk was significantly elevated for the participants with the highest glycemic load and AA type of FAS rs6586161 polymorphism (vs. the lowest glycemic load and TT type, OR = 5.53, 95% CI = 2.01-15.21). Both the high glycemic load and AA type of FAS rs6586161 polymorphism increased gastric cancer risk; however, the interactions between these two elevated the risk of gastric cancer even more.

Neuroendocrine Tumors: A Comprehensive Review on Nutritional Approaches

Neuroendocrine neoplasms are a heterogeneous group of neoplasms with increasing incidence, high prevalence, and survival worldwide. About 90% of cases are well differentiated forms, the so-called neuroendocrine tumors (NETs), with slow proliferation rates and prolonged survival but frequent development of liver metastases and endocrine syndromes. Both the tumor itself and systemic therapy may have an impact on patient nutrition. Malnutrition has a negative impact on outcome in patients with NETs, as well as obesity. In addition, obesity and metabolic syndrome have been shown to be risk factors for both the development and prognosis of NET. Therefore, dietary assessment based on body composition and lifestyle modifications should be an integral part of the treatment of NET patients. Nutrition plans, properly formulated by a dietician, are an integral part of the multidisciplinary treatment team for patients with NETs because they allow an improvement in quality of life, providing a tailored approach based on nutritional needs and nutritional manageable signs and/or symptoms related to pharmacological treatment. The aim of this review is to condense the latest evidence on the role of the most used dietary models, the Mediterranean diet, the ketogenic diet, and intermittent fasting, in the context of NETs, while considering the clinical and molecular mechanisms by which these dietary models act.

Cruciferous vegetable consumption and multiple health outcomes: an umbrella review of 41 systematic reviews and meta-analyses of 303 observational studies

Background: Epidemiological studies evaluating the associations between the consumption of cruciferous vegetables (CV) and diverse health outcomes have generated inconsistent findings. Therefore, we carried out an umbrella review to systematically summarize existing evidence on this topic. Methods: This study had been registered at PROSPERO (no. CRD42021262011). Relevant systematic reviews and meta-analyses of observational studies were identified by searching PubMed, Web of science, and Embase databases from inception up to March 15, 2021. Observational studies investigating the association between CV intake and multiple health outcomes in humans were eligible for inclusion. The validated AMSTAR (A Measurement Tool to Assess Systematic Reviews) instrument was utilized for assessing the methodological quality of the included systematic reviews. For each meta-analysis, we assessed the summary effect size by using fixed and random effects models, 95% prediction intervals, heterogeneity, evidence of small-study effects, and excess significance bias. Results: Our umbrella review included 41 meta-analyses of 303 individual studies involving 13 394 722 participants. Twenty-four health outcomes including cancers (n = 23), cardiovascular disease (n = 12), mortality (n = 5), and metabolic diseases (n = 1) were evaluated. The summary random effects estimates were significant at P < 0.05 in 24 meta-analyses - all of which reported decreased risks of health outcomes. All were of moderate methodological quality in our study. Of the 41 meta-analyses, we observed suggestive evidence for beneficial associations between gastric cancer, lung cancer, endometrial cancer, and all-cause mortality. Moreover, 16 associations were supported by weak evidence, including breast cancer, lung cancer, renal cell carcinoma, bladder cancer, prostate cancer, ovarian cancer, endometrial cancer, colon cancer, colorectal adenoma, colorectal neoplasm, non-Hodgkin lymphoma, and total cancer. Conclusions: It revealed that CV intake might be associated with beneficial effects on several health-related outcomes (gastric cancer, lung cancer, endometrial cancer, and all-cause mortality). Other associations could be genuine, but substantial uncertainty remains. Additional studies are needed to evaluate the relationship between the consumption of CV and various health outcomes as well as robust randomized controlled trials in the future.

Fasting Plasma Glucose Variability and Gastric Cancer Risk in Individuals Without Diabetes Mellitus: A Nationwide Population-Based Cohort Study

Long-term glycemic variability is associated with various adverse health outcomes in patients with diabetes mellitus (DM). However, the relationship between glycemic variability and gastric cancer remains unclear. We aimed to investigate the association between glycemic variability and gastric cancer incidence in individuals without DM.

Adherence to low-carbohydrate diet in relation to gastric cancer: findings from a case-control study in Iran

This study examined the association between adherence to low carbohydrate diet (LCD) and risk of gastric cancer (GC). This hospital-based case-control study was conducted in Iran Cancer Institute, Tehran, Iran between 2010 and 2012. Totally, 178 patients with GC and 276 apparently healthy controls participated in this study. Cases were histo-pathologically confirmed GC patients aged ≥40 years diagnosed with GC in the last year. Dietary intakes were assessed using a validated 146-item Diet History Questionnaire. We computed the LCD score trough the protocol explained by Halton. Patients with GC were older (60.8 vs. 53.2 years, P < 0.001) and more likely to be male (74.2 vs. 63.8%, P = 0.02), married (97.8 vs. 86.6%, P < 0.001) and illiterate (62.4% vs. 26.1%, P < 0.001) than controls. Before adjusting for covariates, adherence to LCD-diet was not associated with risk of GC [odds ratio (OR) 1.31; 95% confidence interval (CI) 0.82-2.09 for highest vs. lowest tertile; Ptrend < 0.26]. Adjustments for several potential confounders including H-pylori infection and BMI, participants in the highest tertile of LCD score were 7% more likely to have GC than those in the lowest tertile; however, it was not statistically significant (OR 1.07; 95% CI 0.59-1.95 for highest vs. lowest tertile; Ptrend < 0.79). No significant association was also seen between adherence to animal- or vegetable-based LCD diet and risk of GC. In conclusion, we failed to find any evidence on the association between consumption of LCD and odds of GC. Further studies, in particular of prospective design, are required to confirm these findings.

Associations of Dietary Glycemic Index, Glycemic Load and Carbohydrate with the Risk of Cervical Intraepithelial Neoplasia and Cervical Cancer: A Case-Control Study

BACKGROUND

The association of dietary glycemic index (GI) and glycemic load (GL) with the risk of cervical cancer has never been investigated. Thus, we aimed to find evidence of any association of GI and GL with the risk of cervical intraepithelial neoplasia (CIN) and cervical cancer.

METHODS

In this hospital-based case-control study, we included 1340 women (670 controls and 262, 187 and 221 patients with CIN1, CIN2/3, and cervical cancer, respectively) from the Korean human papillomavirus cohort study. Completed demographic questionnaires and semi-quantitative food-frequency questionnaires were collected. The association of dietary GI and GL with CIN and cervical cancer was estimated using a logistic regression model.

RESULTS

The multivariate odds ratios (OR) of the highest compared with the lowest quintile of GL for CIN1 were 2.8 (95% confidence interval (CI) = 1.33-5.88). Dietary GI and GL were not associated with CIN2/3 and cervical cancer. Stratified analyses by body mass index (BMI) indicated a positive association between GI and GL and CIN 1 risk among women with a BMI (in kg/m2) <23 (OR = 2.94; 95% CI = 1.32-6.53; p for trend = 0.031 for GI and OR = 3.15; 95% CI = 1.53-6.52; p for trend = 0.013 for GL), but not among those with a BMI of ≥23. A stratification analysis by menopausal status showed that the highest quintile of GI and GL was significantly associated with the risk of CIN1 (OR = 2.91; 95% CI = 1.43-5.96; p for trend = 0.005) (OR = 2.96; 95% CI = 1.53-5.69; p for trend = 0.023) among premenopausal women. Also, in HPV positive women, dietary GL showed significant CIN1 risk (OR = 2.61; 95% CI = 1.09-6.24; p for trend = 0.087).

CONCLUSION

Our case-control study supports the hypothesized associations of dietary GI and GL with increased risk of CIN1. Thus, the consumption of low GI and GL foods plays a significant role in the prevention of cervical carcinogenesis.

Dietary carbohydrate intake, glycaemic index, glycaemic load and digestive system cancers: an updated dose-response meta-analysis

Several studies analysed the associations between dietary carbohydrate intake, glycaemic index (GI) and glycaemic load (GL) and digestive system cancers; however, the results remain controversial. This study was to perform a meta-analysis evaluating the quantitative and dose-response associations between carbohydrate intake, GI and GL, and risk of digestive system cancers. We searched medical and biological databases up to June 2018 and identified twenty-six cohort studies and eighteen case-control studies. Meta-analytic fixed or random effects models were applied to process data. We also performed dose-response analysis, meta-regression and subgroup analyses. We found that high levels of GI were significantly associated with the risk of digestive system cancers at the highest compared with the lowest categories from cohort studies (summary relative risk (RR)=1·10, 95 % CI 1·05, 1·15). Similar effects were observed from case-control studies of the comparison between the extreme categories, but the difference did not reach statistical significance (summary OR=1·28, 95 % CI 0·97, 1·69). We also observed significant dose-response association between GI and digestive system cancers, with every 10-unit increase in GI (summary RR=1·003; 95 % CI 1·000, 1·012 for cohort studies; summary OR=1·09; 95 % CI 1·06, 1·11 for case-control studies). In addition, both cohort studies and case-control studies indicated that neither dietary carbohydrate intake nor GL bore any statistical relationship to digestive system cancers from the results of the highest compared with the lowest categories analyses and dose-response analyses. The results suggest a moderate association between high-GI diets and the risk of digestive system cancers.

Cohort study of oncologic emergencies in patients with head and neck cancer

BACKGROUND

Treatments for head and neck squamous cell carcinoma (HNSCC) are associated with toxicities that lead to emergency department presentation.

METHODS

We utilized data from an ongoing prospective cohort of newly diagnosed, previously untreated patients (N = 298) with HNSCC to evaluate the association between clinical and epidemiologic factors and risk for and frequency of emergency department presentation. Time to event was calculated from the date of treatment initiation to emergency department presentation, date of death, or current date. Frequency of emergency department presentation was the sum of emergency department visits during the follow-up time.

RESULTS

History of hypertension, normal/underweight body mass index (BMI), and probable depression predicted increased risk for emergency department presentation. BMI and severe pain were associated with higher frequency of emergency department presentations.

CONCLUSION

Clinical and epidemiologic factors can help predict patients with HNSCC who will present to the emergency department. Such knowledge may improve treatment-related patient outcomes and quality of life. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1195-1204, 2017.

Dietary glycemic index, glycemic load and cancer: An overview of the literature

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.

Glycemic Index, Glycemic Load, and Lung Cancer Risk in Non-Hispanic Whites

BACKGROUND

Postprandial glucose (PPG) and insulin responses play a role in carcinogenesis. We evaluated the association between dietary glycemic index (GI) and glycemic load (GL), markers of carbohydrate intake and PPG, and lung cancer risk in non-Hispanic whites.

METHODS

GL and GI were assessed among 1,905 newly diagnosed lung cancer cases recruited from the University of Texas MD Anderson Cancer Center (Houston, TX) and 2,413 healthy controls recruited at Kelsey-Seybold Clinics (Houston, TX). We assessed associations between quintiles of GI/GL and lung cancer risk and effect modification by various risk factors. ORs and 95% confidence intervals (CI) were estimated using multivariable logistic regression.

RESULTS

We observed a significant association between GI [5th vs. 1st quintile (Q) OR = 1.49; 95% CI, 1.21-1.83; P(trend) <0.001] and lung cancer risk and GI(ac) (5th vs. 1st Q OR = 1.48; 95% CI, 1.20-1.81; P(trend) = 0.001) and lung cancer risk. We observed a more pronounced association between GI and lung cancer risk among never smokers (5th vs. 1st Q OR = 2.25; 95% CI, 1.42-3.57), squamous cell carcinomas (SCC; 5th vs. 1st Q OR = 1.92; 95% CI, 1.30-2.83), and those with less than 12 years of education (5th vs. 1st Q OR = 1.75; 95% CI, 1.19-2.58, P(interaction) = 0.02).

CONCLUSION

This study suggests that dietary GI and other lung cancer risk factors may jointly and independently influence lung cancer etiology.

IMPACT

Understanding the role of GI in lung cancer could inform prevention strategies and elucidate biologic pathways related to lung cancer risk.

Association between dietary carbohydrate intake, glycemic index and glycemic load, and risk of gastric cancer

PURPOSE

The association between dietary carbohydrate intake, glycemic index (GI) and glycemic load (GL), and risk of gastric cancer (GC) has been investigated by many studies. However, the results of these studies were controversial. The aim of our study was to systematically assess this issue.

METHODS

PUBMED and EMBASE were searched up to March 2015, and either a fixed- or a random-effects model was adopted to estimate overall relative risks (RRs). Dose-response, meta-regression, subgroup, and publication bias analyses were applied.

RESULTS

Twenty-six studies with approximately 540,000 participants were finally included in this meta-analysis. High level of dietary carbohydrate intake (pooled RR 1.17, 95 % CI 0.91-1.50), GI (pooled RR 1.17, 95 % CI 0.80-1.69), and GL (pooled RR 1.06, 95 % CI 0.90-1.26) were all nonsignificantly associated with incidence of GC. In addition, no significant dose-response relationship was observed between carbohydrate intake, GI and GL, and the risk of GC. However, further subgroup analyses based on gender and geographic region suggested a significant association between higher carbohydrate intake (pooled RR 1.52, 95 % CI 1.10-2.08), GL (pooled RR 1.41, 95 % CI 1.04-1.92), and GC risk in males subgroup, and between higher carbohydrate intake (pooled RR 1.69, 95 % CI 1.36-2.09) and GC risk in Asian studies.

CONCLUSIONS

No significant association was found between dietary carbohydrate intake, GI and GL, and risk of GC. However, significantly positive association was observed in the males subgroup and Asian studies.

At the crossroad between obesity and gastric cancer

Obesity has reached epidemic proportions worldwide with disproportionate prevalence in different communities and ethnic groups. Recently, the American Medical Association recognized obesity as a disease, which is a significant milestone that opens the possibilities of treating obesity under standardized health plans. Obesity is an inflammatory disease characterized by elevated levels of biomarkers associated with abnormal lipid profiles, glucose levels, and blood pressure that lead to the onset of metabolic syndrome. Interestingly, inflammatory biomarkers, in particular, have been implicated in the risk of developing several types of cancer. Likewise, obesity has been linked to esophageal, breast, gallbladder, kidney, pancreatic, and colorectal cancers. Thus, there exists a link between obesity status and tumor appearance, which may be associated to the differential levels and the circulating profiles of several inflammatory molecules. For example, mediators of the inflammatory responses in both obesity and gastric cancer risk are the same: pro-inflammatory molecules produced by the activated cells infiltrating the inflamed tissues. These molecules trigger pathways of activation shared by obesity and cancer. Therefore, understanding how these different pathways are modulated would help reduce the impact that both diseases, and their concomitant existence, have on society.

Glycemic index of American-grown jasmine rice classified as high

The primary objective was to determine the glycemic index (GI) of jasmine rice grown in the United States (US). Secondary objective was to compare the GI of US grown jasmine rice to those grown in Thailand. Twelve healthy subjects were served all four brands of jasmine rice and a reference food (glucose), each containing 50 g of available carbohydrate. Fingerstick blood glucose was measured at 0, 15, 30, 45, 60, 90, and 120 min after consumption following a fasting state. The GI was calculated using the standard equation. The GI values for test foods ranged from 96 to 116 and were all classified as high GI foods. No difference in GI was found between American-grown and Thailand-grown jasmine rice. Although not statistically significant, observations show glycemic response among Asian American participants may be different. GI should be considered when planning meals with jasmine rice as the main source carbohydrate.

Adherence to the Mediterranean diet and gastric cancer risk in Italy

We investigated gastric cancer risk in relation to the adherence to the Mediterranean diet using data from two case-control studies conducted in Italy between 1985 and 2007, including 999 incidents, histologically confirmed gastric cancers and 2,628 controls admitted to hospital for acute non-neoplastic diseases. Adherence to the Mediterranean diet was assessed using the Mediterranean Diet Score (MDS) based on nine of the major characteristics of the Mediterranean diet in the overall dataset. The Mediterranean Dietary Pattern adherence index (MDP) and the Mediterranean Adequacy Index (MAI) were considered in the second study only. We estimated odds ratios (OR) and corresponding 95% confidence intervals (CI) of gastric cancer for categories of the three scores using multiple logistic regression models. We found a reduced risk of gastric cancer for increasing levels of the MDS: as compared to subjects in the lowest category of the MDS, the ORs were 0.78, 0.61 and 0.57 in subsequent levels of MDS, with a significant trend in risk. Risk estimates were consistent across strata of age, sex, education, smoking, body mass index, and family history of gastric cancer. We also observed a decreased risk of gastric cancer for the highest versus the lowest quintile for MDP and MAI, with OR of 0.58 and 0.71, respectively. Our study provides convincing evidence of a beneficial role of the Mediterranean diet on gastric cancer.

Intake of specific nonfermented soy foods may be inversely associated with risk of distal gastric cancer in a Chinese population

Because the association between soy consumption and gastric cancer is inconsistent, we evaluated the putative preventive effect of soy food on gastric cancer risk in the Shanghai Women's and Men's Health Studies, comprising a total of 128,687 participants. Intake of nonfermented soy foods was estimated using 2 validated food-frequency questionnaires. HRs were calculated with 95% CIs for intake amounts of total nonfermented soy food intake, soy protein, and isoflavones as well as individual soy food groups using Cox proportional hazards regression. A total of 493 distal gastric cancer cases were identified by 2010. Although all risk estimates for summary measures of soy food intake above the lowest quartile (quartile 1) were suggestive of a protective effect, no statistically significant associations with risk of distal gastric cancer were found. Among the separate soy food groups, significant reductions in risk of distal gastric cancer by increasing intake of tofu were found in men in quartile 2 (HR: 0.59; 95% CI: 0.40, 0.86), quartile 3 (HR: 0.62; 95% CI: 0.44, 0.88), and quartile 4 (HR: 0.64; 95% CI: 0.42, 0.99), resulting in a significant trend (P-trend = 0.02). Dry bean intake was also inversely associated with decreased risk of gastric cancer, but in postmenopausal women only [quartile 2 (HR: 0.54; 95% CI: 0.30, 0.96); quartile 3 (HR: 0.90; 95% CI: 0.64, 1.27); and quartile 4 (HR: 0.63; 95% CI: 0.43, 0.91)], resulting in a significant trend (P-trend = 0.03). Overall, our study found no statistically significant association between nonfermented soy food intake and distal gastric cancer risk, though the data supported the hypothesis that tofu may protect against distal gastric cancer in men and dry bean consumption may decrease the risk of gastric cancer in postmenopausal women.

Dietary patterns and stomach cancer: a meta-analysis

Investigation of the relationship between dietary patterns and some chronic diseases becomes appealing in nutrition epidemiology. Many studies reported potential associations between different dietary patterns and the risk of stomach cancer, however, a consistent perspective hasn't been established to date. Herein, we carried this meta-analysis to identify the associations between different dietary patterns and the risk of stomach cancer. A total of 23 studies met the inclusion criteria and were included in this meta-analysis. A decreased risk of stomach cancer was shown for the highest compared with the lowest category of a "healthy" dietary pattern [odds ratio (OR) = 0.69; confidence interval (CI): 0.53, 0.89; P = 0.005). There were evidence of the increased risk of stomach cancer in the highest compared with the lowest categories of Western-style pattern (OR = 1.59; CI: 1.25, 2.04; P = 0.0002) and alcohol-drinking pattern (OR = 1.37; CI: 1.11, 1.70; P = 0.004). The results of this meta-analysis indicate that healthy dietary pattern may decrease the risk of stomach cancer, whereas Western-style and alcohol-drinking dietary patterns may increase the risk of stomach cancer.

Cruciferous vegetable consumption and gastric cancer risk: a meta-analysis of epidemiological studies

The relationship between consumption of cruciferous vegetables (CV) and risk of gastric cancer has been investigated by many studies, but remains controversial. We carried out a meta-analysis to summarize available evidence from epidemiological studies on this point. Relevant published reports of CV intake and gastric cancer were identified using MEDLINE (PubMed), EMBASE, and Web of Science databases through to the end of September 2012. We pooled the relative risk from individual studies using a fixed- or random-effects model and carried out heterogeneity and publication bias analyses. Sixteen case-control and six prospective studies were included in our analysis. When all studies were pooled, we yielded a significantly inverse association between CV (relative risk = 0.81; 95% confidence interval, 0.75-0.88) intake and gastric cancer risk, with little heterogeneity (Q = 27.27, P = 0.292, I(2) = 12.0%). Specific analysis for cabbage intake yielded similar result. When separately analyzed, case-control studies of CV intake yielded significant results and the results of prospective studies showed borderline statistical significance. Moreover, significant results were consistent for high-quality studies, for North American, European, and Asian studies, for studies on males, and for studies on non-cardia gastric cancer. Findings from this meta-analysis provide evidence that high intake of CV was inversely associated with the risk of gastric cancer and non-cardia gastric cancer in humans. Further studies on other specific CV, food preparation methods, and stratified results by anatomic cancer site and histological type should be extended in the future.

Phaseolus beans: impact on glycaemic response and chronic disease risk in human subjects

Consumption of Phaseolus vulgaris bean species such as pinto, black, navy or kidney may be beneficial in the prevention and treatment of chronic diseases. In particular, conditions that are promoted by increased glycaemic stress (hyperglycaemia and hyperinsulinaemia) including diabetes, CVD and cancer seem to be reduced in individuals who eat more of these beans. The present paper discusses the influence of P. vulgaris species on glycaemic response and the impact that relationship may have on the risk of developing diabetes, CVD and cancer.

Glycemic index, glycemic load and cancer risk

BACKGROUND

Dietary glycemic index (GI) and glycemic load (GL) have been related to the risk of selected cancers, but the issue remains open.

PATIENTS AND METHODS

Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces for incident, histologically confirmed cases of the stomach (n=1182), colon (n=1727), rectum (n=1447), liver (n=309), pancreas (n=628), lung (n=3341), breast (n=2362), ovary (n=442), prostate (n=1799), testis (n=686), kidney (n=1345), bladder (n=1029), brain (n=1009), non-Hodgkin's lymphomas (NHL, n=1666), leukemias (n=1069), multiple myelomas (n=343), and 5039 population controls. Dietary information on eating habits 2 years before participants' enrollment in the study was obtained using a validated food frequency questionnaire (FFQ). Odds ratios (ORs) and 95% confidence intervals (CI) were derived by unconditional logistic regression including recognized confounding factors.

RESULTS

Dietary GI was positively associated with the risk of prostate cancer (OR, 1.26 for the highest versus the lowest quartile). A higher dietary GL significantly increased the risk of colorectal (OR, 1.28), rectal (OR, 1.44) and pancreatic (OR, 1.41) cancers. No other significant associations were found.

CONCLUSIONS

Our findings suggest that a diet high in GI and GL is associated with increased risk of selected cancers.

Decreased oral cancer risk by moderate alcohol consumption in non-smoker postmenopausal women

OBJECTIVE

Alcohol consumption is a strong risk factor for oral cancer however; an ambiguous biphasic impact of moderate and excessive alcohol intake on the risk of upper aerodigestive tract cancers has also been published. The aim of the present study was to clarify the dose-related risk of alcohol consumption for oral cancer, in male and female cases.

MATERIALS AND METHODS

Six-hundred and eight non-smoker patients (466 males and 142 females) with squamous cell oral carcinomas (OCs) and 406 non-smoker tumor free controls (264 males and 142 females) were included into the study. Data of three groups; abstinent cases, moderate and excessive alcohol consumers were recorded according to the drinking habits of both OC cases and their controls. Blood glucose levels in male and female cases and menopausal state of women were also registered.

RESULTS

Mean age of female patients was significantly higher than of male cases (p<0.01). Excessive alcohol consumption was a strong risk factor for both sexes, however moderate alcohol intake proved to be an OC risk for men (OR: 1.4) and decreased the OC risk for women (OR: 0.7). Elevated blood glucose level proved to be an OC risk factor for the predominantly postmenopausal women (OR: 1.6), whereas did not affect the OC risk among men.

CONCLUSION

The presented findings are controversial to the hypothesis that women are more vulnerable to alcohol-induced carcinogenesis as compared with men. Increased insulin sensitivity and higher estrogen levels are advantageous systemic effects of moderate ethanol intake and they might reduce the risk for OC in postmenopausal women.

Relationship between plasma glucose levels and malignant uterine cervical neoplasias

Background:

There is a direct correlation between glycemic load and the risk of developing many malignant neoplasms.

Aims:

The aim of this study was to determine the plasma glucose levels in women with cervical cancer.

Methods:

The study included 177 women with anatomopathologically diagnosed uterine cervical cancer (stages 0–IV) treated between 1980 and 2008 at the Gynecology and Obstetrics outpatient service of the UFTM, Brazil. The plasma glucose levels of all patients were assayed at the time of diagnosis and correlated with tumor staging.

Results:

We statistically compared the plasma glucose levels of group 1 (cervical intraepithelial neoplasia 2–3), group 2 (stage I–II), group 3 (stage III–IV), and group 4 (control group: leiomyomas). Patient groups with poor prognosis (groups 2 and 3) showed significantly higher plasma glucose levels (P < 0.05) than those with less aggressive lesions (group 1). Plasma glucose levels were significantly higher in groups 2 and 3 than in group 4 (P < 0.05). The comparison of number of patients with plasma glucose level >90 mg/dl showed CIN versus I/II: P = 0.0753; OR = 2.018; (95% CI: 0.9236 to 4.410) and CIN versus III/IV: P = 0.0975; OR = 2.400; (95% CI: 0.8335 to 6.911).

Conclusion:

We observed an association between high plasma glucose levels and cervical cancer cases with poor prognoses. Plasma glucose tests should be routinely used as additional prognostic parameters in patients with cervical neoplasias.

Polymorphisms affecting micro-RNA regulation and associated with the risk of dietary-related cancers: a review from the literature and new evidence for a functional role of rs17281995 (CD86) and rs1051690 (INSR), previously associated with colorectal cancer

In this review, we focus on the genetic variations (single nucleotide polymorphisms, SNPs) known to occur in microRNAs and in their binding sites and the susceptibility to cancers of the gastro-intestinal (GI) tract in humans. Since the sequence complementarity and the thermodynamics of binding play an essential role in the interaction of miRNA with its target mRNA, sequence variations in the miRNA-binding seed regions or in miRNA genes (either within pre-, pri-, or mature miRNA regions) should reinforce, weaken, or disrupt the miRNA-mRNA interaction and affect the expression of mRNA targets. Indirect evidences supporting these hypotheses are reported in the literature, essentially coming from case-control association studies. Several studies have been published on the association between miR-SNPs or SNPs within their binding sites and the risk of oesophageal, gastric, or colorectal cancer. Unfortunately, functional studies are lacking. Besides reviewing the available literature, we present here for the first time two SNPs (rs17281995 in CD86 and rs1051690 in INSR) previously associated with the risk of CRC in a Czech population are also associated with the risk in a Spanish population. Moreover, we show for the first time that both these alleles regulate differentially the amount of a reporter gene (luciferase) in an in vitro assay on HeLa cells. These findings suggest that both these SNPs may have a functional role in regulating the expression of CD-86 and INSR proteins acting at the level of the 3'UTR. More functional studies are needed in order to better understand the role of polymorphic regulatory sequences at the 3'UTR of genes.

Selected aspects of Mediterranean diet and cancer risk

European Mediterranean populations have a high life expectancy. Several aspects of their diet are considered favorable on health. We considered the role of various aspects of the Mediterranean diet on cancer risk in a series of Italian case-control studies including about 10,000 cases of cancer at 13 different sites and over 17,000 controls. For most epithelial cancers, the risk decreased with increasing vegetable consumption. Allium vegetables were also favorably related to cancer risk. Fruit intake was inversely associated with digestive tract and laryngeal cancers. For digestive tract cancers, the population attributable risks for low intake of vegetables and fruit ranged between 15% and 40%. Olive oil and unsaturated fats, which are typical aspects of the Mediterranean diet, were inversely related to the risk of several cancers, particularly of the upper aerodigestive tract. Whole grain food (and hence possibly fiber) intake was also related to reduced risk of various cancers. In contrast, refined grains and, consequently, glycemic load and index were associated to increased risks. Several micronutrients and food components (including folate, flavonoids, and carotenoids) showed inverse relations with cancer risk, but the main component(s) responsible for the favorable effect of a diet rich in vegetables and fruit remain undefined.

Glycemic index and glycemic load of selected Chinese traditional foods

AIM: To determine the glycemic index (GI) and glycemic load (GL) values of Chinese traditional foods in Hong Kong.

METHODS: Fifteen healthy subjects (8 males and 7 females) volunteered to consume either glucose or one of 23 test foods after 10-14 h overnight fast. The blood glucose concentrations were analyzed immediately before, 15, 30, 45, 60, 90 and 120 min after food consumption using capillary blood samples. The GI value of each test food was calculated by expressing the incremental area under the blood glucose response curve (IAUC) value for the test food as a percentage of each subject’s average IAUC value for the glucose. The GL value of each test food was calculated as the GI value of the food multiplied by the amount of the available carbohydrate in a usual portion size, divided by 100.

RESULTS: Among all the 23 Chinese traditional foods tested, 6 of them belonged to low GI foods (Tuna Fish Bun, Egg Tart, Green Bean Dessert, Chinese Herbal Jelly, Fried Rice Vermicelli in Singapore-style, and Spring Roll), 10 of them belonged to moderate GI foods (Baked Barbecued Pork Puff, Fried Fritter, “Mai-Lai” Cake, “Pineapple” Bun, Fried Rice Noodles with Sliced Beef, Barbecue Pork Bun, Moon Cakes, Glutinous Rice Ball, Instant Sweet Milky Bun, and Salted Meat Rice Dumpling), the others belonged to high GI foods (Fried Rice in Yangzhou-Style, Sticky Rice Wrapped in Lotus Leaf, Steamed Glutinous Rice Roll, Jam and Peanut Butter Toast, Plain Steamed Vermicelli Roll, Red Bean Dessert, and Frozen Sweet Milky Bun).

CONCLUSION: The GI and GL values for these Chinese traditional foods will provide some valuable information to both researchers and public on their food preference.

Evaluation of a glucose meter in determining the glycemic index of chinese traditional foods

BACKGROUND

The purpose of this study was to evaluate whether the Glucometer Elite((R)) meter (Bayer Diagnostics, Kyoto, Japan) (POG) could be used for determining the glycemic index (GI) values of Chinese traditional foods, compared with the YSI (Yellow Springs, OH) glucose analyzer (YSI).

METHODS

After consumption of either glucose or one of 11 test foods, the 2-h postprandial glucose responses were measured separately by POG and YSI. GI values and incremental area under the blood glucose response curve (IAUC) values were then calculated to make comparisons between POG and YSI.

RESULTS

The mean glucose concentration measured by POG was higher than that measured by YSI (5.54 +/- 0.03 vs. 5.30 +/- 0.03 mmol/L, P < 0.01). The mean IAUC calculated by POG data was also higher than that calculated by YSI data (112.93 +/- 4.04 vs. 106.76 +/- 4.06 mmol.min/L, P < 0.01). However, there were no differences in the mean GI value determined by POG and YSI data for each test food.

CONCLUSIONS

Although the glucose concentrations measured by POG were higher than that measured by YSI glucose analyzer, it seemed to be an appropriate instrument to determine the GI values of Chinese traditional foods. However, this conclusion should be cautiously applied to other kinds of glucose meters.

Diet and cancer in Mediterranean countries: carbohydrates and fats

Objective

Several aspects of the diet characteristic of the Mediterranean countries are considered favourable not only on cardiovascular disease, but also on cancer risk. We considered some aspects of the Mediterranean diet (including, in particular, the consumption of olive oil and carbohydrates) on cancer risk.

Design, Setting and Subjects

Data were derived from a series of case-control studies, conducted in Italy since the early 1990s, on over 10 000 cases of thirteen cancer sites and over 17 000 controls.

Results

Olive oil, and other mono- and unsaturated fats, appear to be favourable indicators of breast, ovarian, colorectal, but mostly of upper aero-digestive tract cancers. Whole grain foods are also related to reduced risk of upper aero-digestive tract and various other cancers. In contrast, refined grain intake and, consequently, glycaemic index and glycaemic load were associated to increased risk for several cancer sites. Fish, and hence a diet rich in n-3 polyunsaturated fatty acids, tended to be another favourable diet indicator, while frequent red meat intake was directly related to some common neoplasms. An a priori defined Mediterranean diet score was inversely related to upper digestive and respiratory tract cancers.

Conclusions

These data provide additional evidence that major characteristics of the Mediterranean diet favourably affect cancer risk.

Association between Mediterranean dietary patterns and cancer risk

To evaluate the association between diet and cancer risk in Mediterranean countries, data presented from a series of case-control studies conducted in Italy were reviewed. The series comprised over 20,000 cases affecting 20 cancer sites and included 18,000 controls. For most epithelial cancers, risk decreased with increasing vegetable and fruit consumption. Fish and whole grains (but not refined grains) were also favorable diet indicators. Olive oil and other monounsaturated and unsaturated fats were inversely related to cancer risk at several sites. A Mediterranean diet pattern appears to be favorable for a reduced cancer risk, indicating the importance of dietary patterns.

Glycemic index, glycemic load and renal cell carcinoma risk

BACKGROUND

The risk of renal cell carcinoma (RCC) has been related to refined cereals and starchy foods, but the association has not been studied in terms of glycemic index (GI) and glycemic load (GL). To provide information on this issue, we analyzed data from an Italian multicentric case-control study.

MATERIALS AND METHODS

Cases were 767 patients with histologically confirmed, incident RCC. Controls were 1534 subjects admitted to the same hospitals as cases for a wide spectrum of acute, non-neoplastic conditions, unrelated to known risk factors for RCC. Information on dietary habits was derived through a food-frequency questionnaire. Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) for GI and GL intake were adjusted for major relevant covariates.

RESULTS

Compared with the lowest quintile, the ORs for the highest quintile were 1.43 (95% CI 1.05-1.95) for GI and 2.56 (95% CI 1.78-3.70) for GL, with significant trends in risk. Compared with the lowest quintile, the risk of RCC for all subsequent levels of GL was higher in never drinkers than in ever drinkers.

CONCLUSIONS

We found direct relations between dietary levels of GI and GL and RCC risk. This can be related to mechanisms linked to insulin resistance and sensitivity.

Coffee, black tea and risk of gastric cancer

BACKGROUND

To provide information about the association of coffee, black tea with gastric cancer risk.

METHODS

Between 1985 and 2007, we conducted two case-control studies in northern Italy. Overall, cases were 999 subjects with incident, histologically confirmed gastric cancer and controls were 2,628 patients admitted to the same network of hospitals for acute non-neoplastic diseases. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) for coffee (mostly espresso and mocha) and black tea consumption were estimated after allowance for socio-demographic data, smoking, and other major covariates of interest.

RESULTS

When compared with non-coffee drinkers, the OR was 0.94 (95% CI: 0.73-1.22) for drinkers of one cup of coffee per day, 1.03 (95% CI: 0.80-1.32) for two, 1.07 (95% CI: 0.82-1.40) for three, and 1.24 (95% CI: 0.94-1.65) for four or more cups per day. No association was found with reference to duration of coffee consumption, or consumption of decaffeinated coffee. When compared with non-black-tea drinkers, the OR was 0.89 (95% CI: 0.56-1.42) for drinkers of two or more cups of black tea per day.

CONCLUSIONS

Our investigation, based on a uniquely large dataset, provides convincing evidence that coffee and black tea consumption is unlikely to be strongly associated with gastric cancer risk.

Food groups and alcoholic beverages and the risk of stomach cancer: a case-control study in Italy

To investigate the role of a wide range of foods and beverages on the risk of stomach cancer, we analyzed data from a case-control study carried out in Italy between 1997 and 2007 on 230 subjects with incident histologically confirmed stomach cancer (143 men and 87 women, age range 22-80 yr) and 547 controls (286 men and 261 women, age range 22-80 yr) admitted to hospital for acute, non-neoplastic diseases. Odds ratios (OR) of stomach cancer and their corresponding 95% confidence intervals (CI) were estimated using unconditional multiple logistic regression models, adjusted for age, sex, energy intake, and other selected variables. A direct association with stomach cancer risk was observed for cereals (OR = 2.07, 95% CI = 1.01-4.24, for the highest compared to the lowest quintile of intake, P for trend = 0.03), soups (OR = 1.94, 95% CI = 1.10-3.42, P for trend = 0.05), and potatoes (OR = 2.04, 95% CI = 1.05-3.98, P for trend = 0.04). Conversely, inverse trends in risk were observed with vegetables (OR = 0.47, 95% CI = 0.27-0.81, P for trend = 0.01) and fruit intake (OR = 0.53, 95% CI = 0.30-0.93, P for trend = 0.08). The results of this study confirm a protective role of vegetables and fruit against stomach cancer and suggest a detrimental effect of (refined) cereals on this neoplasm.

Dietary glycemic load and gastric cancer risk in Italy

We investigated gastric cancer risk in relation to dietary glycemic index (GI) and glycemic load (GL), which represent indirect measures of carbohydrate absorption and consequently of dietary insulin demand, in a case-control study conducted in northern Italy between 1997 and 2007, including 230 patients with the incident, histologically confirmed gastric cancer and 547 frequency matched controls, admitted to the same hospitals as cases with acute non-neoplastic conditions. We used conditional logistic regression models, including terms for major recognised gastric cancer risk factors and non-carbohydrate energy intake. The odds ratios (ORs) in the highest vs lowest quintile were 1.9 (95% CI: 1.0–3.3) for GI and 2.5 (95% CI: 1.3–4.9) for GL. Compared with participants reporting low GL and high fruits/vegetables intake, the OR rose across strata of high GL and low fruits/vegetables, to reach 5.0 (95% CI: 2.2–11.5) for those reporting low fruits/vegetables intake and high GL. Our study may help to explain the direct relation observed in several studies between starchy foods and gastric cancer risk.

Glycemic index, glycemic load, and risk of digestive tract neoplasms: a systematic review and meta-analysis

BACKGROUND

Habitual consumption of diets with a high glycemic index (GI) and a high glycemic load (GL) may influence cancer risk via hyperinsulinemia and the insulin-like growth factor axis.

OBJECTIVE

The objective was to conduct a systematic review to assess the association between GI, GL, and risk of digestive tract cancers.

DESIGN

Medline and Embase were searched for relevant publications from inception to July 2008. When possible, adjusted results from a comparison of cancer risk of the highest compared with the lowest category of GI and GL intake were combined by using random-effects meta-analyses.

RESULTS

Cohort and case-control studies that examined the risk between GI or GL intake and colorectal cancer (n = 12) and adenomas (n = 2), pancreatic cancer (n = 6), gastric cancer (n = 2), and squamous-cell esophageal carcinoma (n = 1) were retrieved. Most case-control studies observed positive associations between GI and GL intake and these cancers. However, pooled cohort study results showed no associations between colorectal cancer risk and GI intake [relative risk (RR): 1.04; 95% CI: 0.92, 1.12; n = 7 studies] or GL intake (RR: 1.06; 95% CI: 0.95, 1.17; n = 8 studies). Furthermore, no significant associations were observed in meta-analyses of cohort study results of colorectal cancer subsites and GI and GL intake. Similarly, no significant associations emerged between pancreatic cancer risk and GI intake (RR: 0.99; 95% CI: 0.83, 1.19; n = 5 studies) or GL intake (RR: 1.01; 95% CI: 0.86, 1.19; n = 6 studies) in combined cohort studies.

CONCLUSIONS

The findings from our meta-analyses indicate that GI and GL intakes are not associated with risk of colorectal or pancreatic cancers. There were insufficient data available regarding other digestive tract cancers to make any conclusions about GI or GL intake and risk.

Glycemic index, glycemic load, and cancer risk: a meta-analysis

BACKGROUND

Factors linked to glucose metabolism play an important role in the development of cancers, and both glycemic index (GI) and glycemic load (GL) have been investigated as potential etiologic factors.

OBJECTIVE

A meta-analysis was performed to explore the association between GI and GL and cancer risk from published studies.

DESIGN

A comprehensive, systematic bibliographic search of the medical literature was conducted to identify relevant studies. Case-control and cohort studies published before October 2007 that reported cancer risk estimates for GI and GL were included. Pooled relative risks (RRs) were estimated for breast, colorectal, endometrial, and pancreatic cancer.

RESULTS

Thirty-nine studies were included in the meta-analysis. The interquantile ranges of GL were significantly wider in case-control studies, most of which were conducted in European countries, than in cohort studies. Cohort studies that presented lower ranges of GL also reported lower risk estimates. Overall, both GL and GI were significantly associated with a greater risk of colorectal (summary RR = 1.26; 95% CI: 1.11, 1.44 and RR = 1.18; 95% CI: 1.05, 1.34, respectively) and endometrial (RR = 1.36; 95% CI: 1.14, 1.62 and RR = 1.22; 95% CI: 1.01, 1.49) cancer than of breast and pancreatic cancer. There was, however, a significant between-study heterogeneity for colorectal cancer (P < 0.0001). The association between GL and breast cancer disappeared when publication bias was taken into account. No association was found for pancreatic cancer.

CONCLUSION

This comprehensive meta-analysis of GI and GL and cancer risk suggested an overall direct association with colorectal and endometrial cancer.

State of the Art Reviews: Glycemic Index, Obesity, and Chronic Disease

There is increasing evidence that both the amount and type of carbohydrate play an important role in weight management and risk of chronic disease. Classifying carbohydrates according to their post-prandial glycemic effect (ie, the glycemic index of foods) has yielded more useful insights than the historical distinctions of simple versus complex chemical structure. Diets based on carbohydrate foods that are more slowly digested and absorbed (ie, low glycemic index diets) have been independently linked to reduced risk of type 2 diabetes, cardiovascular disease, and some types of cancer. In individuals with diabetes, intervention studies have shown improvements in insulin sensitivity and glycated hemoglobin concentration with low glycemic index diets. Research also suggests that low glycemic index diets may assist with weight management through effects on satiety and fuel partitioning. Although ongoing research is needed, the current findings, together with the fact that there are no demonstrated negative effects of a low glycemic index diet, suggest that the glycemic index should be an important consideration in the dietary management and prevention of obesity and chronic disease.

Measuring the glycemic index of foods: interlaboratory study

BACKGROUND

Many laboratories offer glycemic index (GI) services.

OBJECTIVE

We assessed the performance of the method used to measure GI.

DESIGN

The GI of cheese-puffs and fruit-leather (centrally provided) was measured in 28 laboratories (n=311 subjects) by using the FAO/WHO method. The laboratories reported the results of their calculations and sent the raw data for recalculation centrally.

RESULTS

Values for the incremental area under the curve (AUC) reported by 54% of the laboratories differed from central calculations. Because of this and other differences in data analysis, 19% of reported food GI values differed by >5 units from those calculated centrally. GI values in individual subjects were unrelated to age, sex, ethnicity, body mass index, or AUC but were negatively related to within-individual variation (P=0.033) expressed as the CV of the AUC for repeated reference food tests (refCV). The between-laboratory GI values (mean+/-SD) for cheese-puffs and fruit-leather were 74.3+/-10.5 and 33.2+/-7.2, respectively. The mean laboratory GI was related to refCV (P=0.003) and the type of restrictions on alcohol consumption before the test (P=0.006, r2=0.509 for model). The within-laboratory SD of GI was related to refCV (P<0.001), the glucose analysis method (P=0.010), whether glucose measures were duplicated (P=0.008), and restrictions on dinner the night before (P=0.013, r2=0.810 for model).

CONCLUSIONS

The between-laboratory SD of the GI values is approximately 9. Standardized data analysis and low within-subject variation (refCV<30%) are required for accuracy. The results suggest that common misconceptions exist about which factors do and do not need to be controlled to improve precision. Controlled studies and cost-benefit analyses are needed to optimize GI methodology. The trial was registered at clinicaltrials.gov as NCT00260858.

Dietary glycemic index, glycemic load, and the risk of breast cancer in an Italian prospective cohort study

BACKGROUND

Interest in the roles of glycemic index (GI) and glycemic load (GL) in breast cancer etiology has been stimulated by indications that disease risk is linked to insulinemia, sex hormone bioavailability, and insulin-like growth factor 1.

OBJECTIVE

We aimed to determine whether GI and GL were associated with the risk of breast cancer in a cohort of Italian women volunteers from Northern Italy, who enrolled between 1987-1992 in the Hormones and Diet in the Etiology of Breast Tumors Study (ORDET Study).

DESIGN

Volunteers completed a semiquantitative food-frequency questionnaire, and anthropometric and lifestyle data were collected. Dietary GI and GL in relation to breast cancer risk were examined in 8926 cohort women, including 289 with breast cancer identified after a mean follow-up of 11.5 y.

RESULTS

The relative risk (RR) of breast cancer in the highest (versus lowest) quintiles of GI and GL was 1.57 (95% CI: 1.04, 2.36; P for trend = 0.040) and 2.53 (95% CI: 1.54, 4.16; P for trend = 0.001), respectively. Total carbohydrate intake was not associated with greater breast cancer risk, but high carbohydrate from high-GI foods was. When women were categorized by baseline menopausal status and body mass index (BMI; in kg/m(2)), the increased risk of dietary GL was confined to those who were premenopausal (RR = 3.89; 95% CI: 1.81, 8.34) and who had normal BMI (ie, <25) (RR = 5.79; 95% CI: 2.60, 12.90) (P for trend = 0.001 for both).

CONCLUSIONS

A high-GL diet may increase the risk of breast cancer in Italian women. The effect is particularly evident in premenopausal women and those with BMI < 25.

Diet and cancer risk in Mediterranean countries: open issues

Objective

To analyse various aspects of the Mediterranean diet in relation to the risk of several common cancers in Italy.

Design

Data from a series of case-control studies conducted in northern Italy between 1983 and 2004 on over 20 000 cases of several major cancers and 18 000 controls.

Results

For most digestive tract cancers, the risk decreased with increasing vegetable and fruit consumption, with relative risks between 0.3 and 0.7 for the highest level of intake, and the population-attributable risks for low intake of vegetables and fruit ranged between 15 and 40%. Less strong inverse relations were observed for other (epithelial) cancers, too. A number of micronutrients contained in vegetables and fruit showed an inverse relation with cancer risk. In particular, flavones, flavonols and resveratrol were inversely related to breast cancer risk. Olive oil, which is a typical aspect of the Mediterranean diet, has also been inversely related to cancers of the colorectum and breast, and mainly of the upper digestive and respiratory tract. Consumption of pizza, one of the most typical Italian foods, was related to a reduced risk of digestive tract cancers, although pizza may simply be an aspecific indicator of the Italian diet.

Conclusions

Adherence to the Mediterranean diet is a favourable indicator of the risk of several common epithelial cancers in Italy. A score summarising the major characteristics of the Mediterranean diet was related to a priori defined reduced risks of several digestive tract neoplasms by over 50%.