Carbohydrate nutrition and risk of adiposity-related cancers: results from the Framingham Offspring cohort (1991-2013)

Anti-melanoma and antioxidant properties of the methanol extract from the leaves of Phragmenthera capitata (Spreng.) Balle and Globimetula braunii (Engl.) Van Tiegh

OBJECTIVES

Phragmenthera capitata (Spreng.) Balle and Globimetula braunii (Engler.) Van Tiegh are African mistletoe traditionally used in cancers treatment. Thus, the aim of the study was to assess the anti-melanoma potential of the methanol extract of Phragmenthera capitata (Spreng.) Balle (PCMe-OH) and Globimetula braunii (Engler.) (GBMe-OH) Van Tiegh.

METHODS

Antioxidant potential was evaluated using DPPH, FRAP and hydroxyl assays. Total flavonoid and phenolic contents was also determined. MTT assay was used to estimate the effects on cell viability using SK-MLE28 and B16-F10 cell lines. Colony formation and wound healing were also assessed. Fluorometry methods were used for qualitative analysis of apoptosis and estimate ROS production. Western blot analysis was used for protein expression.

RESULTS

Phragmenthera capitata (PCMe-OH) showed the highest antioxidant activity and possess the highest phenolic contents (1,490.80 ± 55 mgGAE/g extract) in comparison with G. braunii (GBMe-OH) and (1,071.40 ± 45 mgGAE/g extract). Flavonoid content was similar in both extracts (11.63 ± 5.51 mg CATE/g of extract and 12.46 ± 2.58 mg CATE/g of extract respectively). PC-MeOH showed the highest cytotoxicity effect (IC50 of 55.35 ± 1.17 μg/mL) and exhibited anti-migrative potential on B16-F10 cells. Furthermore, PC-MeOH at 55.35 and 110.7 μg/mL; promoted apoptosis-induced cell death in B16-F10 cells by increasing intracellular ROS levels and reducing Bcl-2 expression level at 110.7 μg/mL. Significant upregulation of P-PTEN expression was recorded with PC-MeOH at 110.7 μg/mL; inhibiting therefore PI3K/AKT/m-Tor signaling pathway. Moreover, at 55.37 μg/mL significant reduction of c-myc and cyclin D1 was observed; dysregulating the MAPK kinase signaling pathway and cell cycle progression.

CONCLUSIONS

Phragmenthera capitata may be developed into selective chemotherapy to fight against melanoma.

Dietary Approach of Patients with Hormone-Related Cancer Based on the Glycemic Index and Glycemic Load Estimates

Hormone-related cancers, namely breast, endometrial, cervical, prostate, testicular, and thyroid, constitute a specific group of cancers dependent on hormone levels that play an essential role in cancer growth. In addition to the traditional risk factors, diet seems to be an important environmental factor that partially explains the steadily increased prevalence of this group of cancer. The composition of food, the dietary patterns, the endocrine-disrupting chemicals, and the way of food processing and preparation related to dietary advanced glycation end-product formation are all related to cancer. However, it remains unclear which specific dietary components mediate this relationship. Carbohydrates seem to be a risk factor for cancer in general and hormone-related cancers, in particular, with a difference between simple and complex carbohydrates. Glycemic index and glycemic load estimates reflect the effect of dietary carbohydrates on postprandial glucose concentrations. Several studies have investigated the relationship between the dietary glycemic index and glycemic load estimates with the natural course of cancer and, more specifically, hormone-related cancers. High glycemic index and glycemic load diets are associated with cancer development and worse prognosis, partially explained by the adverse effects on insulin metabolism, causing hyperinsulinemia and insulin resistance, and also by inflammation and oxidative stress induction. Herein, we review the existing data on the effect of diets focusing on the glycemic index and glycemic load estimates on hormone-related cancers.

Dietary glycemic index, glycemic load and cancer risk: a meta-analysis of prospective cohort studies

PURPOSE

There is considerable inconsistency in results regarding the association of dietary glycemic index (GI) and glycemic load (GL) with cancer risk. We therefore conducted this systematic review and dose-response meta-analysis of prospective cohort studies to evaluate the relationship between dietary GI/GL and cancer risk.

METHODS

We searched PubMed and Web of Science for prospective cohort studies of dietary GI/GL in relation to risks of all types of cancer up to 31 March 2021. We used a random-effect model to calculate summary relative risks (RR) and 95% confidence intervals (CI). The certainty of evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. This study was registered at PROSPERO (CRD42020215338).

RESULTS

Overall, 55 cohorts were included in the meta-analysis. We assessed the relationship between dietary GI or GL and risks of 23 cancer types, including hormone-related cancers, cancers from digestive system, respiratory system, urinary system and other cancer sites. High GI diet increased overall risk of cancer with low certainty of evidence (highest vs lowest categories, n = 3, RR 1.04, 95% CI 1.01-1.07). For site-specific cancers, high GI diet increased risks of lung cancer (highest vs lowest categories, n = 5, RR 1.08, 95% CI 1.01-1.18) and breast cancer (highest vs lowest categories, n = 14, RR 1.05, 95% CI 1.01-1.09), especially for postmenopausal breast cancer (highest vs lowest categories, n = 10, RR 1.06, 95% CI 1.00-1.13), all with low certainty of evidence. Additionally, dietary GI was positively related to risk of bladder cancer with low certainty of evidence (highest vs lowest categories, n = 3, RR 1.23, 95% CI 1.09-1.40), as well as negatively related to ovarian cancer risk with very low certainty of evidence (highest vs lowest categories, n = 4, RR 0.83, 95% CI 0.69-1.00) and lymphoma risk with low certainty of evidence (highest vs lowest categories, n = 2, RR 0.84, 95% CI 0.72-0.98). Besides, we found an inverse association of dietary GL with lung cancer risk with low certainty of evidence (highest vs lowest categories, n = 5, RR 0.87, 95% CI 0.80-0.94).

CONCLUSION

High dietary GI increased overall cancer risk with low certainty of evidence. For site-specific cancers, high GI diet increased the risks of breast cancer with low certainty of evidence and lung cancer with low certainty of evidence. Dietary GL was inversely associated with lung cancer risk with low certainty of evidence.

Dietary insulin index and load with risk of breast cancer in a case-control study

OBJECTIVE

Circulating insulin levels have been positively associated with risk of breast cancer (BrCa); however, it remains unclear whether a diet inducing an elevated insulin response influences Breast risk.

METHODS

In this study, 250 newly diagnosed breast cancer patients and 250 hospitalised controls were recruited using convenience sampling. The dietary insulin index (DII) was calculated by dividing the dietary insulin load by the total energy intake.

RESULTS

Compared with those in the lowest tertiles of DII and dietary insulin load (DIL), subjects in the highest tertile were more likely to be overweight, have a family history of breast and other types of cancer and a history of benign breast diseases. After controlling for multiple potential confounders, a significantly increased BrCa odds was observed in the highest tertiles of DII and DIL score compared with the lowest tertiles (odds ratio (OR): 1.46; 95% CI: 0.67-3.19, P = .006) and (OR: 1.87; 95% CI: 0.92-3.80, P = .038), respectively.

CONCLUSIONS

Our findings suggest that a diet that induces an elevated postprandial insulin response, indicated by higher DII and DIL scores, may increase the odds of BrCa, especially among women.

Glycaemic index, glycaemic load and cancer risk: results from the prospective NutriNet-Santé cohort

BACKGROUND

Evidence is accumulating that high dietary glycaemic index (GI) and glycaemic load (GL) are potential risk factors for several metabolic disorders (e.g. type-2 diabetes, cardiovascular diseases), but remains limited concerning cancer risk. Although, mechanistic data suggest that consuming high-GI foods may contribute to carcinogenesis through elevated blood glucose levels, insulin resistance or obesity-related mechanisms. Our objective was to study the associations between dietary GI/GL and cancer.

METHODS

In total, 103 020 French adults (median age = 40.2 years) from the NutriNet-Santé cohort (2009-2020) with no cancer or diabetes at baseline were included (705 137 person-years, median follow-up time = 7.7 years). Repeated 24-h dietary records linked with a detailed food-composition table (>3500 food/beverage items). We computed the average dietary GI and GL at the individual level. Associations between GI, GL, contribution of low- and medium/high-GI foods to energy and carbohydrate intake and cancer risk (overall, breast, prostate and colorectal) were assessed using multivariable Cox proportional-hazard models.

RESULTS

Higher dietary GL was associated with higher overall cancer risk [n = 3131 cases, hazard ratios (HRs) for sex-specific quintile 5 vs 1 = 1.25, 95% confidence interval (CI) = 1.03-1.52; Ptrend = 0.008] and specifically postmenopausal breast cancer (n = 924, HRQ5vs.Q1 = 1.64, 95% CI = 1.06-2.55; Ptrend = 0.03). A higher contribution of low-GI food/beverages to energy intake was associated with lower cancer risk whereas a higher contribution of medium/high-GI items to energy intake was positively associated with higher risk of overall, breast and postmenopausal breast cancers (Ptrend ≤ 0.02).

CONCLUSIONS

These results support a possible impact of GI/GL on cancer risk. If confirmed in other populations and settings, dietary GI/GL could be considered as modifiable risk factors for primary cancer prevention.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03335644.

Dietary Carbohydrate Intake Glycemic Index and Glycemic Load and the Risk of Prostate Cancer among Iranian Men: A Case-Control Study

Previous studies have presented a few evidences on the relationship between dietary carbohydrate intake, glycemic index (GI), glycemic load (GL), with the prostate cancer risk. We performed a case-control study to evaluate these associations in 50 men with histologically confirmed prostate cancer and 100 control men. Odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) were derived using logistic regression. The fully adjusted ORs for the top vs. the bottom quartile were 15.02 (P trend = 0.004), 1.04 (P trend = 0.003), and 10.35 (P trend = 0.002) for carbohydrate intake, GI and GL, respectively. Significant associations with prostate cancer remained only among men with reduced fiber intake for carbohydrate intake, GI and GL and among those had increased fiber intake for GI. These findings support the hypothesis that diet with high carbohydrate, GI and GL enhance risk of prostate cancer.

Glycemic Index, Glycemic Load, and Risk of Ovarian Cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cohort

BACKGROUND

Ovarian cancer is the fifth most common cause of cancer death among women in the US, yet few modifiable risk factors have been established. Diets high in glycemic index (GI) and glycemic load (GL) have been linked to several cancers, but epidemiologic studies of ovarian cancer have yielded inconsistent results.

OBJECTIVE

In this study, we aimed to examine associations between GI or GL and ovarian cancer.

METHODS

We used prospective data from the Prostate, Lung, Colorectal, and Ovarian cohort. GI and GL were calculated from validated FFQs. Participants were women who were aged 60 to 74 y, did not have a history of cancer, and had both ovaries. Cox proportional hazard models were used to calculate HRs and 95% CIs for risk of ovarian cancer associated with quartiles of GI and GL. Analyses were performed separately for those who completed the dietary questionnaire at baseline (DQX) or later in the study (DHQ).

RESULTS

From the DQX sample set, 181 cases were identified among 24,633 women with median follow-up of 12.1 y; there were 211 cases among 42,410 women in the DHQ set, with median follow-up of 8.9 y. After adjusting for age at dietary questionnaire completion, year of randomization, year of questionnaire, study center, and oral contraceptive use, the risk of ovarian cancer decreased by 43% (HR: 0.57; 95% CI: 0.37, 0.88) among those in the highest compared with those in the lowest quartile of GL (DQX). Those in the highest compared with those in the lowest quartile of GI (DHQ), had a 38% lower risk (HR: 0.62; 95% CI: 0.42, 1.00).

CONCLUSIONS

We observed lower risk of ovarian cancer associated with higher GI and GL. Results should be interpreted with caution as they may have been influenced by limitations including lack of variability in dietary intake. Additional studies are needed to better understand what is driving these associations.

Anticancer Activity of Combretum fragrans F. Hoffm on Glioblastoma and Prostate Cancer Cell Lines

BACKGROUND

Cancer incidence has been growing in an alarming rate worldwide and new therapeutics are needed, particularly for intractable and chemoresistant cases. We evaluated the cytotoxic effects of Combretum fragrans F. Hoffm (Combretaceae) on glioblastoma (U87MG and C6) and prostate (PC-3) cancer cell lines.

METHODS

The cytotoxic effect of the methanolic extract of the stem bark of Combretum fragrans was assessed using XTT (2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide) test. Expressions of Akt and ERK1/2 were determined using Western blot technique, while Caspase-3/7 kits were used to evaluate caspase-3/7 activity.

RESULTS

C. fragrans extract inhibited the proliferation of U87 (IC50 = 20.13 µg/mL), C6 (IC50 = 12.17 µg/mL), and PC-3 (IC50 = 11.50 µg/mL) cells. Treatment with the extract resulted in lower levels (p < 0.001) of phospho-ERK1/2 and phospho-Akt in U87 cells, and instead, higher levels of phospho-ERK1/2 (p < 0.001) in C6 and PC-3 cells. An increase in caspase-3/7 activity was observed, mainly after 24 hours of treatment, indicating the activation of apoptotic processes.

CONCLUSION

Altogether, these results suggest that C. fragrans have potent anticancer properties. This plant should be further investigated for developing new anticancer drugs.

Hyperglycemia-Induced miR-467 Drives Tumor Inflammation and Growth in Breast Cancer

The tumor microenvironment contains the parenchyma, blood vessels, and infiltrating immune cells, including tumor-associated macrophages (TAMs). TAMs affect the developing tumor and drive cancer inflammation. We used mouse models of hyperglycemia and cancer and specimens from hyperglycemic breast cancer (BC) patients to demonstrate that miR-467 mediates the effects of high blood glucose on cancer inflammation and growth. Hyperglycemic patients have a higher risk of developing breast cancer. We have identified a novel miRNA-dependent pathway activated by hyperglycemia that promotes BC angiogenesis and inflammation supporting BC growth. miR-467 is upregulated in endothelial cells (EC), macrophages, BC cells, and in BC tumors. A target of miR-467, thrombospondin-1 (TSP-1), inhibits angiogenesis and promotes resolution of inflammation. Systemic injections of a miR-467 antagonist in mouse models of hyperglycemia resulted in decreased BC growth (p < 0.001). Tumors from hyperglycemic mice had a two-fold increase in macrophage accumulation compared to normoglycemic controls (p < 0.001), and TAM infiltration was prevented by the miR-467 antagonist (p < 0.001). BC specimens from hyperglycemic patients had increased miR-467 levels, increased angiogenesis, decreased levels of TSP-1, and increased TAM infiltration in malignant breast tissue in hyperglycemic vs. normoglycemic patients (2.17-fold, p = 0.002) and even in normal breast tissue from hyperglycemic patients (2.18-fold increase, p = 0.04). In malignant BC tissue, miR-467 levels were upregulated 258-fold in hyperglycemic patients compared to normoglycemic patients (p < 0.001) and increased 56-fold in adjacent normal tissue (p = 0.008). Our results suggest that miR-467 accelerates tumor growth by inducing angiogenesis and promoting the recruitment of TAMs to drive hyperglycemia-induced cancer inflammation.

A nutrient-wide association study for risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition and the Netherlands Cohort Study

PURPOSE

The evidence from the literature regarding the association of dietary factors and risk of prostate cancer is inconclusive.

METHODS

A nutrient-wide association study was conducted to systematically and comprehensively evaluate the associations between 92 foods or nutrients and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC). Cox proportional hazard regression models adjusted for total energy intake, smoking status, body mass index, physical activity, diabetes and education were used to estimate hazard ratios and 95% confidence intervals for standardized dietary intakes. As in genome-wide association studies, correction for multiple comparisons was applied using the false discovery rate (FDR < 5%) method and suggested results were replicated in an independent cohort, the Netherlands Cohort Study (NLCS).

RESULTS

A total of 5916 and 3842 incident cases of prostate cancer were diagnosed during a mean follow-up of 14 and 20 years in EPIC and NLCS, respectively. None of the dietary factors was associated with the risk of total prostate cancer in EPIC (minimum FDR-corrected P, 0.37). Null associations were also observed by disease stage, grade and fatality, except for positive associations observed for intake of dry cakes/biscuits with low-grade and butter with aggressive prostate cancer, respectively, out of which the intake of dry cakes/biscuits was replicated in the NLCS.

CONCLUSIONS

Our findings provide little support for an association for the majority of the 92 examined dietary factors and risk of prostate cancer. The association of dry cakes/biscuits with low-grade prostate cancer warrants further replication given the scarcity in the literature.

Longitudinal dimensions of alcohol consumption and dietary intake in the Framingham Heart Study Offspring Cohort (1971-2008)

Existing studies addressing alcohol consumption have not captured the multidimensionality of drinking patterns, including drinking frequency, binge drinking, beverage preference and changes in these measures across the adult life course. We examined longitudinal trends in drinking patterns and their association with diet over four decades in ageing US adults from the Framingham Offspring Study (n 4956; baseline mean age 36·2 years). Alcohol intake (drinks/week, drinking frequency, beverage-specific consumption, drinks/occasion) was assessed quadrennially from examinations 1 to 8. Participants were classified as binge drinkers, moderate drinkers or heavy drinkers (4+ and 5+ drinks/occasion; ≤1 and ≤2 drinks/d and >7 and >14 drinks/week for women and men, respectively). Dietary data were collected by a FFQ from examinations 5 to 8 (1991-2008). We evaluated trends in drinking patterns using linear mixed effect models and compared dietary intake across drinking patterns using heterogeneous variance models. Alcohol consumption decreased from 1971 to 2008 (3·7 v. 2·2 oz/week; P < 0·05). The proportion of moderate (66 v. 59·3 %), heavy (18·4 v. 10·5 %) and binge drinkers (40·0 v. 12·3 %) declined (P < 0·05). While average wine consumption increased (1·4 v. 2·2 drinks/week), beer (3·4 v. 1·5 drinks/week) and cocktail intake (2·8 v. 1·2 drinks/week) decreased. Non-binge drinkers consumed less sugary drinks and more whole grains than binge drinkers, and the latter consumed more total fat across all examinations (P < 0·05). There was a significant difference in consumption trends of total grains by drinking level (P < 0·05). In conclusion, alcohol drinking patterns are unstable throughout adulthood. Higher intakes were generally associated with poorer diets. These analyses support the nuanced characterisation of alcohol consumption in epidemiological studies.

Association between dietary sugar intake and colorectal adenoma among cancer screening examinees in Japan

Although intake of highly sugary foods is considered to be a potential risk factor for colorectal cancer through hyperinsulinemia, the association of sugar intake and colorectal adenoma, a precursor lesion to most colorectal cancer, is poorly understood, particularly in Asian populations. We undertook a cross‐sectional study in a Japanese population to investigate the association between dietary sugar intake and the prevalence of colorectal adenoma. Study subjects were selected from participants who underwent magnifying colonoscopy with dye spraying as part of a cancer screening program and who responded to a self‐administered questionnaire before the colonoscopy. A total of 738 cases with colorectal adenoma and 697 controls were enrolled. Dietary intakes of glucose, fructose, galactose, sucrose, maltose, lactose, and total sugars (sum of these six mono‐ or disaccharides) were calculated from a food frequency questionnaire, and divided into quartiles based on the distribution among controls. Odds ratios and 95% confidence intervals of colorectal adenoma were estimated using unconditional logistic regression models, with adjustment for potential confounding factors. Total sugar intake was not significantly associated with the prevalence of colorectal adenoma (odds ratio for the highest intake group compared to reference group = 1.18; 95% confidence interval, 0.81‐1.73; P for trend = .34). Furthermore, no statistically significant positive associations were observed for any of the six mono‐ or disaccharides. Findings were similar on additional analyses by site, size, and number of adenomas. Our findings do not support an association between high sugar intake and increased odds ratios of colorectal adenoma.

Influence of Diet and Nutrition on Prostate Cancer

The incidence of prostate cancer (PCa) displays widespread regional differences, probably owing to differences in dietary habits. Nutrients, including fat, protein, carbohydrates, vitamins (vitamin A, D, and E), and polyphenols, potentially affect PCa pathogenesis and progression, as previously reported using animal models; however, clinical studies have reported controversial results for almost all nutrients. The effects of these nutrients may be manifested through various mechanisms including inflammation, antioxidant effects, and the action of sex hormones. Dietary patterns including the Western and Prudent patterns also influence the risk of PCa. Recent studies reported that the gut microbiota contribute to tumorigenesis in some organs. Diet composition and lifestyle have a direct and profound effect on the gut bacteria. Human studies reported an increase in the abundance of specific gut bacteria in PCa patients. Although there are few studies concerning their relationship, diet and nutrition could influence PCa, and this could be mediated by gut microbiota. An intervention of dietary patterns could contribute to the prevention of PCa. An intervention targeting dietary patterns may thus help prevent PCa.

Glycemic Index, Glycemic Load and Cancer Risk: An Updated Meta-Analysis

Diets high in glycemic index (GI) and glycemic load (GL) have been related to an increased risk of selected cancers, but additional quantification is required. We updated a systematic review and meta-analysis published in 2015 to May 2019 to provide quantitative information on GI/GL and cancer risk. Relative risks (RR) and the corresponding 95 % confidence intervals (CI) for the highest versus the lowest categories of GI and GL were extracted from selected studies and pooled using random-effects models. Twenty reports (>22,000 cancer cases) have become available after January 2015, and 15 were added to the meta-analyses by cancer sites, which considered a total of 88 investigations. The five additional reports were reviewed, but not included in the meta-analyses, since data were inadequate to be pooled. For hormone-related cancers, summary RRs for the highest versus lowest GI and GL intakes were moderately increased. They ranged from 1.04 (breast) to 1.12 (endometrium) for GI and from 1.03 (prostate) to 1.22 (ovary) for GL, of borderline significance. High GI was associated with small increased risks of colorectal (summary RR for GI: 1.20, 95% CI, 1.07–1.34—GL: 1.09, 95% CI, 0.97–1.22, 19 studies), bladder (GI: 1.25, 95% CI, 1.11–1.41—GL: 1.10, 95% CI, 0.85–1.42, four studies) and kidney cancers (GI: 1.16, 95% CI, 1.02–1.32—GL: 1.14, 95% CI, 0.81–1.60, five studies). GL was not significantly related to those cancer sites. Stomach, prostate and lung cancers were not associated with GI and GL. The present analysis, based on an updated comprehensive evaluation of the epidemiological literature, indicates moderate unfavorable effects of high versus low GI on colorectal, and possibly bladder and kidney cancers, and a possible moderate positive association between GL and endometrial cancer.

Association of the glycaemic index and glycaemic load with colorectal cancer in the population of Córdoba (Argentina): results of a case-control study using a multilevel modelling approach

The glycaemic index (GI) and glycaemic load (GL) are involved in the aetiology of different diseases, and they could be related to the development of colorectal cancer (CRC). The aim of this study was to evaluate the association between the quality and quantity indicators of carbohydrates consumed by the population of Córdoba (Argentina) and the odds of developing CRC in 2008-2016 period. A case-control study was conducted with 492 participants (161/331 cases/controls), interviewed through a validated FFQ. Multilevel logistic regression models were used to assess the effect of GI, GL and the quantity or weekly intake of high-GI foods on CRC occurrence, following adjustment for individual/first-level covariates, and using level of urbanisation as the contextual variable. The models were stratified by sex. Participants in the highest v. lowest tertile of dietary GL and weekly intake of high-GI foods had increased odds of CRC presence in the entire sample (OR 1·64, 95 % CI 1·16, 2·34 and OR 1·11, 95 % CI 1·09, 1·14, respectively) and in women (OR 1·98, 95 % CI 1·24, 3·18 and OR 1·41, 95 % CI 1·09, 1·83, respectively). In men, the second tertile of GL and weekly intake of high-GI foods were associated with CRC (OR 1·44, 95 % CI 1·04, 1·99 and OR 1·48, 95 % CI 1·32, 1·65, respectively). Also, GI was associated with CRC in women (highest v. lowest tertile OR 2·12, 95 % CI 1·38, 3·27). In addition to the quantity and quality of carbohydrates intake, it is important to consider the frequency of consumption of high-GI foods in CRC prevention.

Carbohydrate Nutrition and the Risk of Cancer

PURPOSE OF REVIEW

This review summarizes a selection of epidemiologic research assessing the associations between carbohydrate intake and cancer incidence and survival. Evidence for plausible biological mechanisms is also considered.

RECENT FINDINGS

The mechanistic paradigm explaining the relationship between carbohydrates and cancer risk has been contested by numerous observational studies. Carbohydrates have conventionally been ascribed a deleterious role in the field of cancer research due to previous preclinical findings. A breadth of studies suggests that complex carbohydrate intake is inversely associated with risk of a number of cancer types. Data from studies assessing simple carbohydrates and cancer risk are mixed. Furthermore, recommendations for subsequent studies are framed.

Dietary Glycemic Index and Glycemic Load and the Risk of Prostate Cancer: An Updated Systematic Review and Dose-Response Meta-Analysis

A meta-analysis in 2015 revealed no significant association between glycemic index (GI), glycemic load (GL), and prostate cancer. Moreover, until now, no study has examined the dose-response association of GI, GL, and prostate cancer yet. The online databases were searched by two independent researchers for relevant publications up to Jan. 2019, using relevant keywords. Nine studies including five prospective and four case-control studies were included in the current systematic review and meta-analysis. These studies have included 290,911 individuals. We found a significant positive dose-response association between dietary GI and prostate cancer (P_nonlinearity = 0.03). Comparing individuals in the highest category of GI with those in the lowest category, no significant association was found between GI and prostate cancer (combined effect size: 1.08, 95% CI: 0.97-1.19, P = 0.17). Furthermore, no significant association was seen between dietary GL and prostate cancer in both dose-response analysis and when comparing the highest versus lowest categories of GL (combined effect size: 1.03, 95% CI: 0.91-1.16, P = 0.65). In conclusion, we found a significant positive dose-response association between dietary GI and prostate cancer. However, significant association was not seen for dietary GL.

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.

A Sterol from Soft Coral Induces Apoptosis and Autophagy in MCF-7 Breast Cancer Cells

The peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor that plays a key role in regulating cellular metabolism, and is a therapeutic target for cancer therapy. To search for potential PPARγ activators, a compound library comprising 11 marine compounds was examined. Among them, a sterol, 3β,11-dihydroxy-9,11-secogorgost-5-en-9-one (compound 1), showed the highest PPARγ activity with an IC₅₀ value of 8.3 μM for inhibiting human breast adenocarcinoma cell (MCF-7) growth. Western blotting experiments showed that compound 1 induces caspase activation and PARP cleavage. In addition, compound 1 modulated the expression of various PPARγ-regulated downstream biomarkers including cyclin D1, cyclin-dependent kinase (CDK)6, B-cell lymphoma 2 (Bcl-2), p38, and extracellular-signal-regulated kinase (ERK). Moreover, compound 1 increased reactive oxygen species (ROS) generation, upregulated the phosphorylation and expression of H2AX, and induced autophagy. Interestingly, pre-treatment with the autophagy inhibitor 3-methyladenine rescued cells from compound 1-induced growth inhibition, which indicates that the cytotoxic effect of compound 1 is, in part, attributable to its ability to induce autophagy. In conclusion, these findings suggest the translational potential of compound 1 in breast cancer therapy.

Associations of Whole and Refined Grain Intakes with Adiposity-Related Cancer Risk in the Framingham Offspring Cohort (1991-2013)

Case-control studies suggest that higher whole grain and lower refined grain intakes are associated with reduced cancer risk, but longitudinal evidence is limited. The objective of this prospective cohort study is to evaluate associations between whole and refined grains and their food sources in relation to adiposity-related cancer risk. Participants were adults from the Framingham Offspring cohort (N = 3,184; ≥18 yr). Diet, measured using a food frequency questionnaire, medical and lifestyle data were collected at exam 5 (1991-95). Between 1991 and 2013, 565 adiposity-related cancers were ascertained using pathology reports. Cox proportional hazards models were used to estimate adjusted hazard ratios and 95% confidence intervals for associations of whole and refined grains with risk of adiposity-related cancers combined and with risk of breast and prostate cancers in exploratory site-specific analyses. Null associations between whole and refined grains and combined incidence of adiposity-related cancers were observed in multivariable-adjusted models (HR: 0.94; 95% CI: 0.71-1.23 and HR: 0.98; 95% CI: 0.70-1.38, respectively). In exploratory analyses, higher intakes of whole grains (oz eq/day) and whole grain food sources (servings/day) were associated with 39% and 47% lower breast cancer risk (HR: 0.61; 95% CI: 0.38-0.98 and HR: 0.53; 95% CI: 0.33-0.86, respectively). In conclusion, whole and refined grains were not associated with adiposity-related cancer risk. Whole grains may protect against breast cancer, but findings require confirmation within a larger sample and in other ethnic groups.

Consumption of Sugars, Sugary Foods, and Sugary Beverages in Relation to Adiposity-Related Cancer Risk in the Framingham Offspring Cohort (1991-2013)

Background: Higher sugar consumption may increase cancer risk by promoting insulin-glucose dysregulation, oxidative stress, hormonal imbalances, and excess adiposity. This prospective study investigates the association between dietary sugars (fructose and sucrose) and sugary foods and beverages in relation to combined and site-specific (breast, prostate, colorectal) adiposity-associated cancers.Methods: The analytic sample consisted of 3,184 adults, aged 26-84 years, from the Framingham Offspring cohort. Diet data were first collected between 1991 and 1995 using a food frequency questionnaire. Intakes of fructose, sucrose, sugary foods, and sugary beverages (fruit juice and sugar-sweetened beverages) were derived. Participants were followed up until 2013 to ascertain cancer incidence; 565 doctor-diagnosed adiposity-related cancers, including 124 breast, 157 prostate, and 68 colorectal cancers occurred. Multivariable-adjusted Cox proportional hazards models were used to evaluate associations. Tests for interaction with BMI and waist circumference were conducted.Results: No associations were observed between fructose, sucrose, sugary food consumption, and combined incidence of adiposity-related cancers or the examined site-specific cancers. While total consumption of sugary beverages was not associated with site-specific cancer risk, higher intakes of fruit juice were associated with 58% increased prostate cancer risk (HR: 1.58; 95% CI, 1.04-2.41) in multivariable-adjusted models. In exploratory stratified analyses, higher sugary beverage intakes increased overall adiposity-related cancer risk by 59% in participants with excessive central adiposity (HR: 1.59; 95% CI, 1.01-2.50; Ptrend = 0.057).Conclusions: In this cohort of American adults, higher sugary beverage consumption was associated with increased cancer risk among participants with central adiposity.Impact: These analyses suggest that avoiding sugary beverages represents a simple dietary modification that may be used as an effective cancer control strategy. Cancer Prev Res; 11(6); 347-58. ©2018 AACR.

Carbohydrate intake and the risk of prostate cancer

BACKGROUND

Prostate cancer (PCa) is one of the leading cause cancer among men worldwide. Many epidemiologic studies have reported an association between carbohydrate intake and PCa. However, the evidence from epidemiologic studies is inconsistent. We conducted a comprehensive meta-analysis to explore the associations between carbohydrate intake and PCa risk and to investigate potential dose-response relationships.

METHODS

We searched PubMed and EMBASE for studies published from 1980 to 2018. 21 studies were included with 98,739 participants and 11,573 cases. Multivariate-adjusted odds ratios (ORs) were pooled using random-effect models. Potential dose-response relationships were evaluated for PCa risk.

RESULTS

We did not detect an association about higher carbohydrate intake and PCa risk (OR:1.11, 95% confidence interval [CI]: 0.98-1. 26, I² = 62.7%), nor association was detected about higher carbohydrate intake with advanced PCa risk (OR:0.95, 95% CI: 0.78-1.16, I² = 14.1%) or non-advanced Pca risk (OR:1.01, 95% CI: 0.79-1.29, I² = 64.4%). There was not a significant dose-response association observed for carbohydrate intake with PCa risk and advanced PCa risk.

CONCLUSIONS

Our meta-analysis shows no association between carbohydrate intake and prostate cancer risk. Nor is association detected about carbohydrate intake with advanced or non-advanced Pca risk. More studies are needed for a further dose-response meta-analysis.

Influence of Obesity on the Course of Malignant Neoplastic Disease in Patients After Pulmonary Metastasectomy

BACKGROUND/AIM

The aim of the study was to determine whether increased body mass index (BMI) in patients operated on for lung metastases influences the course of the disease.

MATERIALS AND METHODS

The retrospective data of 97 patients previously operated on for different malignancies were analyzed. There were 40 obese patients (BMI >30 kg/m², mean 33.9±4.5) and 57 non-obese patients (BMI 25.8±2.7 kg/m², p<0.001). Disease-free interval (DFI), the overall survival (OS) and survival after pulmonary metastasectomy were analyzed.

RESULTS

DFI and OS were longer in obese than in non-obese patients (82.1±83.5 months vs. 43.0±44.4, p<0.01 and 110.7±81.3 months vs. 69.9±52.9 p<0.005, respectively). Survival after pulmonary metastasectomy was 27.2±25.6 months and was longer in obese and overweight patients than in normal weight patients (20.2±18.4 months vs. 29.4±26.5, p<0.05).

CONCLUSION

Being obese or overweight is a favorable prognostic factor in patients after surgical resection of lung metastases of different malignancies.