Carbohydrate, dietary glycaemic index and glycaemic load, and colorectal cancer risk: a case-control study in China

Diet is Linked to Colorectal Cancer Risk among Asian Adults: A Scoping Review

This review aimed to map current evidence on the association between dietary factors and colorectal cancer (CRC) risk in Asia. This review was conducted based on Arksey and O'Malley methodological framework. Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) flow diagram was used to record the review process. For the purpose of searching for articles, three electronic databases namely PubMed, EBSCOHost and ScienceDirect were employed. The inclusion criteria for articles selection were articles with association analysis between diet and CRC risk among Asians, had adults as participants, articles were written in English, open-accessed and published between years 2009 and 2021. Thus, 35 out of 369 screened articles were eventually included in this review which covered 28 case-control studies, six prospective cohort studies and one randomised clinical trial. Foods such as meats, alcohol and westernised diet have been shown to be associated with increase of CRC risk while fruits, vegetables and traditional meals decreased the risk of CRC. Only a few interventional and dietary patterns studies were identified. Specific single foods and nutrients and dietary patterns have been found to increase the risk but also protected the Asian population against CRC. The findings of this review will guide health professionals, researchers and policy makers to conduct a suitable study design and topic for future research.

Carbohydrate quality indices and colorectal cancer risk: a case-control study

BACKGROUND

Colorectal cancer (CRC) is the fourth and third most common cancer in Iran and the world, respectively. Carbohydrates can lead to the proliferation of cancer cells, including CRC. The current study aimed to investigate the association between glycemic load (GL), insulin load (IL), glycemic index (GI), insulin index (II), low-carbohydrate diet score (LCDS), and carbohydrate quality index (CQI) with CRC odds.

METHODS

The present case-control study was performed on 71 CRC cases and 142 controls in the Hospital Cancer Organization and three general hospitals in Tehran, Iran. We calculated the dietary GI, GL, IL, II, CQI, and LCDS by a validated food frequency questionnaire.

RESULTS

The results indicated that people who were in the highest tertile of the GI had higher odds of CRC compared to the lower tertile (in the adjusted model: odds ratio (OR) = 3.89; 95% confidence interval (CI): 1.71-8.84). On the contrary, people who were in the highest tertile of the CQI and LCDS had significantly lower odds of CRC compared to the lower tertile (in the adjusted model: tertile (T) ₂-OR = 0.24; 95% CI: 0.11-0.53 and T₃-OR = 0.15; 95% CI: 0.06-0.39 for CQI and T₂-OR = 0.33; 95% CI: 0.13-0.79 and T₃-OR = 0.28; 95% CI: 0.10-0.82 for LCDS). Also, IL was positively associated with the odds of CRC after adjusting for confounding factors (T₂-OR = 2.46; CI: 1.08-5.61 and T₃- OR = 2.80; 95% CI: 1.07-7.31). Regarding the GL, only individuals who were in the second tertile had significantly higher odds of CRC compared to the first tertile (OR = 2.42; CI: 1.07-5.47).

CONCLUSION

According to the findings, it is recommended to use a diet with high-quality carbohydrates and low GI and GL to minimize the odds of developing CRC. People should also be encouraged to have a balanced carbohydrate intake.

Serum Saturated Fatty Acids including Very Long-Chain Saturated Fatty Acids and Colorectal Cancer Risk among Chinese Population

The association between circulating saturated fatty acids (SFAs) including very long-chain SFAs (VLCSFAs) and colorectal cancer (CRC) risk has not been clearly established. To investigate the association between serum SFAs and CRC risk in Chinese population, 680 CRC cases and 680 sex and age-matched (5-year interval) controls were recruited in our study. Serum levels of SFAs were detected by gas chromatography. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between serum SFAs and CRC risk. Results showed that total SFAs were positively associated with the risk of CRC (adjusted OR _{quartile 4 vs. 1} = 2.64, 95%CI: 1.47-4.74). However, VLCSFAs were inversely associated with CRC risk (adjusted OR _{quartile 4 vs. 1} = 0.51, 95%CI: 0.36-0.72). Specifically, lauric acid, myristic acid, palmitic acid, heptadecanoic acid, and arachidic acid were positively associated with CRC risk, while behenic acid and lignoceric acid were inversely associated with CRC risk. This study indicates that higher levels of total serum SFAs and lower levels of serum VLCSFAs were associated with an increased risk of CRC in Chinese population. To reduce the risk of CRC, we recommend reducing the intake of foods containing palmitic acid and heptadecanoic acid such as animal products and dairy products, and moderately increasing the intake of foods containing VLCSFAs such as peanuts and canola oil.

Glycemic index, glycemic load, and lung cancer risk: A meta-analysis of cohort and case-control studies

Objective

Glycemic index (GI) or glycemic load (GL) has been investigated in the field of cancer research for several years. However, the relationship between GI or GL and lung cancer risk remains inconsistent. Therefore, this study aimed to summarize previous findings on this relationship.

Methods

PubMed, Embase, Scopus, Web of Science databases, and Cochrane Library were searched by July 2021. This review was conducted in accordance with the PRISMA guidelines. A fixed or random-effects model was adopted for meta-analysis to compute the pooled relative risks (RR) and their corresponding 95% confidence intervals (CIs). Subgroup analyses, sensitivity analyses, and publication bias analyses were also performed.

Results

In total, nine articles were included, with four case-control studies and five cohort studies, including 17,019 cases and 786,479 controls. After merging the studies, pooled multivariable RRs of lung cancer based on the highest versus the lowest intake were 1.14 (95%CI: 1.03–1.26) and 0.93 (95%CI: 0.84–1.02) for GI and GL. Results persisted in most stratifications after stratifying by potential confounders in the relationship between GI and lung cancer risk. There was a non-linear dose response relation for GI with lung caner risk.

Conclusion

GI typically has a positive relationship with lung cancer risk. However, no associations between GL and lung cancer risk were observed based on current evidence, suggesting that this issue should be studied and verified further to substantiate these findings.

The Association Between Different Types of Dietary Carbohydrates and Colorectal Cancer: A Case-Control Study

Background

Several factors such as genetics and dietary intake are involved in the development of colorectal cancer (CRC). Higher intake of dietary carbohydrates may be associated with an increased risk of CRC. This study aimed to investigate the association between different types of dietary carbohydrates and CRC.

Methods

This hospital-based case–control study was carried out from June 2020 to May 2021 on 480 randomly selected participants including 160 CRC patients and 320 healthy controls aged 35–70 years in Firoozgar hospital, Tehran, Iran. Dietary intake was assessed using Food Frequency Questionnaire (FFQ). Nutritionist IV software was used to determine the intake of calorie and various forms of dietary carbohydrates including total carbohydrate, simple sugar, glucose, fructose, galactose, sucrose, lactose, and maltose.

Results

The average daily intake of calorie, carbohydrates, sugar, glucose, fructose, sucrose, and maltose were significantly higher among CRC cases compared to the controls (All P < 0.05). The logistic regression found significant associations between CRC with dietary intake of carbohydrates (OR = 1.009, CI 95%: 1.003–1.01, P = 0.002), sugar (OR = 1.02, CI 95%: 1.01–1.03, P < 0.001), glucose (OR = 1.06, CI 95%: 1.01–1.11, P = 0.009), fructose (OR = 1.31, CI 95%: 1.19–1.43, P < 0.001), sucrose (OR = 1.19, CI 95%: 1.12.−1.25, P < 0.001), maltose (OR = 9.03, CI 95%: 3.93–20.78, P < 0.001), galactose (OR = 1.31, CI 95%: 1.07–1.6, P = 0.008), and lactose (OR = 1.009, CI 95%: 1.01–1.18, P = 0.02). This association remained significant after adjustment for sex and age (except for galactose and lactose), and additional adjustment for sleep, tobacco, and alcohol level, and further adjustment for calorie intake and body mass index (BMI) (except for glucose).

Conclusions

A positive association was found between CRC and dietary intake of carbohydrates, sugar, fructose, sucrose, and maltose. Following a low-carbohydrate, low-sugar diet may help prevent CRC. Future longitudinal studies are warranted to confirm these findings.

The interaction between glycemic index, glycemic load, and the genetic variant ADIPOQ T45G (rs2241766) in the risk of colorectal cancer: a case-control study in a Korean population

PURPOSE

The glycemic index (GI), glycemic load (GL), and adiponectin level contribute to glycemic response and insulin sensitivity in the body. Studies have shown that tumor development is related to glycemic disorders; however, the results are contradictory. We aimed to investigate the association of GI and GL with colorectal cancer (CRC) risk in a Korean population and their possible interactions with the genetic variant ADIPOQ T45G.

METHODS AND RESULTS

A case-control study including 2096 participants with 695 CRC cases was conducted. The results showed that diets with high GI or GL were significantly associated with an increased risk of CRC [odds ratio (OR) = 5.44, 95% confidence interval (CI) 3.85-7.68; OR = 4.43, 95% CI 3.18-6.15, respectively; all p-trends < 0.001]. Moreover, even with a low-GI and low-GL diet, G/G genotype carriers may have 2.93-fold and 3.77-fold higher risk of rectal cancer compared to carriers of other genotypes (T/T + T/G), (OR = 2.93, 95% CI 1.01-8.59, p-interaction = 0.011 for GI; OR = 3.77, 95% CI 1.46-9.77, p-interaction = 0.025 for GL).

CONCLUSIONS

Overall, our study suggests positive associations of GI and GL with CRC risk. Moreover, the associations of GI and GL with rectal cancer risk could be modified by ADIPOQ T45G in a Korean population. Further studies with larger sample sizes are needed to confirm our findings.

Dietary Polyamines Intake and Risk of Colorectal Cancer: A Case-Control Study

Polyamines (including putrescine, spermidine, and spermine) are small, cationic molecules that are necessary for cell proliferation and differentiation. Few studies have examined the association of dietary polyamines intake with colorectal cancer risk. The aim of this study was to evaluate total polyamines, putrescine, spermidine, and spermine intake in relation to colorectal cancer risk in China. In total, 2502 colorectal cancer cases and 2538 age-(5-year interval) and sex-matched controls were recruited from July 2010 to April 2019. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated by multivariable unconditional logistic regression after adjustment for various potential confounding factors. Higher intake of total polyamine, putrescine and spermidine was significantly associated with reduced risk of colorectal cancer. The adjusted ORs for the highest compared with the lowest quartile of intake were 0.60 (95% CI 0.50, 0.72; P_trend < 0.001) for total polyamines, 0.35 (95% CI 0.29, 0.43; P_trend < 0.001) for putrescine and 0.79 (95% CI 0.66, 0.95; P_trend = 0.001) for spermidine, respectively. However, higher intake of spermine was associated with increased risk of colorectal cancer, with an adjusted OR of 1.58 (95% CI 1.29, 1.93; P_trend < 0.001). This data indicate that higher intake of total polyamines, putrescine and spermidine, as well as lower intake of spermine, is associated with a decreased risk of colorectal cancer.

Resistant starch supplementation increases crypt cell proliferative state in the rectal mucosa of older healthy participants

There is strong evidence that foods containing dietary fibre protect against colorectal cancer, resulting at least in part from its anti-proliferative properties. This study aimed to investigate the effects of supplementation with two non-digestible carbohydrates, resistant starch (RS) and polydextrose (PD), on crypt cell proliferative state (CCPS) in the macroscopically normal rectal mucosa of healthy individuals. We also investigated relationships between expression of regulators of apoptosis and of the cell cycle on markers of CCPS. Seventy-five healthy participants were supplemented with RS and/or PD or placebo for 50 d in a 2 × 2 factorial design in a randomised, double-blind, placebo-controlled trial (the Dietary Intervention, Stem cells and Colorectal Cancer (DISC) Study). CCPS was assessed, and the expression of regulators of the cell cycle and of apoptosis was measured by quantitative PCR in rectal mucosal biopsies. SCFA concentrations were quantified in faecal samples collected pre- and post-intervention. Supplementation with RS increased the total number of mitotic cells within the crypt by 60 % (P = 0·001) compared with placebo. This effect was limited to older participants (aged ≥50 years). No other differences were observed for the treatments with PD or RS as compared with their respective controls. PD did not influence any of the measured variables. RS, however, increased cell proliferation in the crypts of the macroscopically-normal rectum of older adults. Our findings suggest that the effects of RS on CCPS are not only dose, type of RS and health status-specific but are also influenced by age.

Role of diet on intestinal metabolites and appetite control factors in SD rats

The present study aimed to investigate changes in the levels of metabolites and appetite control factors caused by different dietary interventions in Sprague Dawley (SD) rats. A total of 35 male SD rats were weaned and immediately randomly assigned to five groups. The control group was given ad libitum access to a normal chow diet, and the other groups received a high-fat diet (FAT group), high-sugar diet, high-fibre or high-protein diet (PRO group) for 4 weeks. The high-fat diet contributed to weight gain and adipose tissue formation, and affected lipid indexed. The FAT group had a higher body weight, Lee's index, adipose mass and glucose tolerance than all of the other groups. The opposite effect was observed in the PRO group. High-performance liquid chromatography revealed that short-chain fatty acid and amino acid formation were affected by the various diets. In addition, differences in the mRNA expression levels of leptin, ghrelin and associated receptors were determined in the gastrointestinal, adipose and hypothalamus tissues. The present study provides further evidence of the role of diet in obesity development and prevention. It also highlights the role of intestinal metabolites and appetite control factor expression in the pathogenesis of obesity in SD rats.

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.

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.