Dietary and serum vitamins A and E and colorectal cancer risk in Chinese population: a case–control study

The role of vitamin C in the prevention of pancreatic cancer: a systematic-review

Introduction and aim

The aim of this systematic review was to assess the role of vitamin C in the prevention of pancreatic cancer (PC).

Methods

A comprehensive literature search was performed in PubMed, Embase and Web of Science up to August 2023, to identify randomized controlled trials (RCT), cohort studies and mendelian randomization studies based on prospective databases assessing the role of vitamin C in PC prevention.

Results

A total of twelve studies including European and North-American participants were included: two RCT, three mendelian randomization (MR) studies and seven cohort studies. Both RCT showed high quality in Cochrane risk of bias tool. Only one cohort study had <7 points in Newcastle Ottawa Scale. Both RCT found no association between the intake of 500 mg/day of vitamin C and the incidence of PC. Only one prospective cohort study found an association between vitamin C serum levels and a lower incidence of PC. The remaining cohort studies and MR studies found no association between dietary/supplements intake of vitamin C or circulating vitamin C levels and the incidence of PC.

Conclusion

There is no supporting evidence that vitamin C prevents PC development. Future prospective quality studies including high-risk populations are needed.

The Role of Dietary Vitamins and Antioxidants in Preventing Colorectal Cancer: A Systematic Review

The role of dietary vitamins and antioxidants in preventing colorectal cancer (CRC) is a significant area of research within nutritional oncology. However, the relationship between these nutrients and CRC prevention is complex and influenced by factors such as dosage, timing, and individual health status. This review aims to comprehensively analyze and synthesize the existing scientific literature on the potential role of dietary vitamins and antioxidants in preventing CRC. A comprehensive literature review was conducted by searching electronic databases to identify studies examining the prospected impacts of dietary vitamins and antioxidants on the prevention of CRC. According to the outcomes of this review, this research review shows a complex link between vitamins and CRC. While some vitamins such as B2, B6, and D seemed helpful, others such as A and E had mixed results. Vitamin C deficiency was even linked to worse outcomes in cancer patients. Overall, the studies suggest focusing on a balanced diet rich in various vitamins rather than relying solely on individual supplements to prevent CRC. On the other hand, the results of our review suggest that the relationship between antioxidant intake and CRC is more intricate than previously thought. Data from this review indicates that taking specific antioxidant supplements such as selenium and vitamin E does not seem to offer the same protection. This suggests that a balanced diet with a variety of antioxidants is more helpful than focusing on single supplements. While we did not observe a direct association, future studies could investigate how different types and combinations of antioxidants might influence CRC development. In conclusion, the present systematic review highlights the need for more research on the relationship between vitamins, antioxidants, and CRC. We need to understand how these nutrients affect both the survival of people with CRC and the prevention of the disease. This will help us determine the best ways to use vitamins and antioxidants in CRC management and prevention.

Interaction between vitamin E intake and a COMT gene variant on colorectal cancer risk among Korean adults: a case-control study

OBJECTIVES

Previous human trials have not supported the anticarcinogenic effect of vitamin E despite biological plausibility and considerable epidemiological evidence. A possible explanation for this inconsistency is the interactive effect of the catechol-O-methyltransferase (COMT) gene and supplemental vitamin E on cancer. We examined whether a COMT gene variant modulates the effect of dietary vitamin E intake on colorectal cancer (CRC) risk.

METHODS

In this case-control study of Korean adults (975 cases and 975 age- and sex-matched controls), dietary vitamin E density (mg/1,000 kcal) was measured using a semiquantitative food frequency questionnaire, COMT single nucleotide polymorphism (SNP) rs740603 (A>G) was genotyped, and CRC was verified histologically. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models with adjustments for potential confounders.

RESULTS

Higher vitamin E density was associated with a lower risk of CRC (highest vs. lowest quartiles: OR, 0.72; 95% CI, 0.55 to 0.96; p-for-trend=0.002). When stratified by COMT SNP rs740603 genotype, the inverse association between vitamin E density and CRC risk was confined to those with at least 1 A allele (≥median vs.

CONCLUSIONS

Our findings support a role for a genetic polymorphism in COMT in modifying the association between dietary vitamin E intake and CRC.

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Key Words

• Case-control studies
• Catechol-O-methyltransferase
• Colorectal cancer
• Gene-environment interaction
• Single nucleotide polymorphism
• Vitamin E

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MESH Headings

• Adult
• Humans
• Catechol O-Methyltransferase/genetics
• Case-Control Studies
• Polymorphism, Single Nucleotide
• Vitamin E
• Logistic Models
• Colorectal Neoplasms/epidemiology
• Colorectal Neoplasms/genetics
• Republic of Korea/epidemiology
• Risk Factors

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Grants

• National Research Foundation of Korea
• 2021R1A6A3A01087058 Ministry of Education
• 2021R1A2C2008439 Ministry of Science and ICT

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Affiliation(s)

Shinyoung Jun Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea
Madhawa Gunathilake Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea
Jeonghee Lee Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea
Jae Hwan Oh Center for Colorectal Cancer, National Cancer Center, Goyang, Korea
Hee Jin Chang Center for Colorectal Cancer, National Cancer Center, Goyang, Korea
Dae Kyung Sohn Center for Colorectal Cancer, National Cancer Center, Goyang, Korea
Aesun Shin Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea Cancer Research Institute, Seoul National University, Seoul, Korea
Jeongseon Kim Department of Cancer, AI & Digital Health, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, Korea

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Interaction between retinol intake and ISX rs5755368 polymorphism in colorectal cancer risk: a case-control study in a Korean population

This study aimed to examine whether the ISX rs5755368 genotypes are associated with the effect of dietary retinol consumption on CRC risk. We recruited 923 CRC patients and 1846 controls to identify the association between dietary retinol and CRC risk. Dietary retinol intake was assessed using a semiquantitative food frequency questionnaire. Genotype data were available for 1419 patients (600 cases and 819 controls) of the total study population. Genotyping was performed using an Illumina MEGA Expanded Array. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using unconditional logistic regression models. Retinol intake was inversely associated with CRC (OR = 0.49; 95% CI = 0.37-0.63). Participants with AA genotype showed lower CRC risk than subjects carrying the G allele (AG + GG) (OR = 0.76; 95% CI = 0.58-0.99). A 68% reduced risk of CRC was related to subjects who had the highest retinol intake and carrying AA genotype compared to the risk of participants consumed the lowest retinol intake and carrying the G allele (OR = 0.32; 95% CI = 0.20-0.53; P interaction = 0.026). Retinol intake could be a protective factor for CRC risk while this association could be strengthened among individuals carrying the homozygous AA genotype.

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.

Dietary intake and serum concentrations of vitamin A and vitamin E and pre-eclampsia risk in Chinese pregnant women: A matched case-control study

Background

Many studies have suggested that the serum concentrations of vitamin A (VA) and vitamin E (VE) influence preeclampsia (PE) risk in pregnant women. However, few studies have assessed whether dietary intake and serum concentrations of VA and VE are correlated with PE risk.

Methods

A 1:1 matched case-control study was conducted to explore the association between the dietary intake and serum concentrations of VA and VE and the risk of PE in pregnant Chinese women. A total of 440 pregnant women with PE and 440 control pregnant women were included in the study. Dietary information was obtained using a 78-item semi-quantitative food frequency questionnaire. Serum concentrations of VA and VE were measured by liquid chromatography-tandem mass spectrometry.

Results

Compared with the lowest quartile, the multivariate-adjusted odds ratios [95% confidence interval (CI)] of the highest quartiles were 0.62 (95% CI: 0.40-0.96, P trend = 0.02) for VA, 0.51 (95% CI: 0.33–0.80, P trend =0.002) for β-carotene, and 0.70 (95% CI: 0.45–1.08, P trend = 0.029) for retinol. Additionally, for serum VA and VE concentrations, the multivariate-adjusted odds ratios (95% CI) were 2.75 (95% CI: 1.24–6.13, P trend = 0.002) and 11.97 (95% CI: 4.01–35.77, P trend &lt; 0.001), respectively. No significant association was seen between VE intake and PE risk.

Conclusions

Dietary VA intake was negatively correlated with PE risk, and serum VA and VE concentrations were positively correlated with PE risk among pregnant Chinese women.

Association between pre-diagnostic dietary antioxidant vitamin consumption and ovarian cancer survival: a prospective cohort study

Background: Epidemiological evidence regarding the relationship between dietary antioxidant vitamin intake and ovarian cancer (OC) survival is not clear. Herein, we aimed to first evaluate this topic in a prospective cohort study in China. Methods: The present study included participants from the Ovarian Cancer Follow-Up Study, which was a hospital-based prospective cohort study including OC patients who were aged 18 to 79 years during 2015-2020. The information on the intake of antioxidant vitamins, consisting of vitamin A, retinol, α-carotene, β-carotene, vitamin C, and vitamin E, and other diet information was obtained through a 111-item food frequency questionnaire. Deaths were recorded until March 31, 2021. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival were evaluated using Cox proportional hazards models. Results: There were 130 (18.49%) deaths among 703 OC patients during a median 37.19 months follow-up. In the multivariable-adjusted model, the highest tertile of dietary vitamin C (HR = 0.43, 95% CI = 0.25-0.75, P for trend <0.05) and β-carotene intake (HR = 0.52, 95% CI = 0.31-0.87, P for trend <0.05) was inversely associated with the overall survival of OC when compared with the lowest tertile group. Retinol, vitamin A, vitamin E, and α-carotene consumption showed no association with OC survival. Of note is that the multiplicative interaction was identified between vitamin C intake and residual lesions in OC survival (P for interaction <0.05). Conclusion: Our findings indicate that pre-diagnostic higher vitamin C and β-carotene intake was associated with improved OC survival.

Oxidative imbalance increases the risk for colonic polyp and colorectal cancer development

BACKGROUND

The role of oxidative stress in the pathogenesis of colorectal carcinoma (CRC) has garnered considerable interest recently. Specific oxidative factors have been implicated in the pathogenesis of adenomatous polyps and ultimately adenocarcinoma.

AIM

To evaluate the effect of oxidative imbalance as quantified by specific serological markers in the development of sporadic colon adenocarcinoma.

METHODS

A total of 170 patients that underwent endoscopy of the lower gastrointestinal tract in a tertiary center within 3 years were included in the study. They were allocated in three groups; those with sporadic colon adenocarcinoma (n = 56, 32.9%), those with colonic polyps (n = 33, 19.4%) and healthy controls (n = 81, 47.7%). All patients were evaluated for oxidant activity and antioxidant capacity with serum measurements of specific markers such as vitamins A, 25(OH) D3, E, C, B12, folic acid, glutathione, selenium (Se), zinc (Zn), free iron (Fe²⁺), and malondialdehyde and results were compared between groups.

RESULTS

Serum levels of vitamins C, E, D, Se, Zn, vitamin B12 and total antioxidant capacity were significantly lower in the combined neoplasia/polyp group than in the control group (P = 0.002, P = 0.009, P < 0.001, P < 0.001, P < 0.001, P = 0.020 and P < 0.001, correspondingly). Increased levels of vitamin E (P = 0.004), vitamin D (P < 0.001), Se (P < 0.001) and Zn (P < 0.001) seem to bestow a protective effect on the development of CRC. For vitamin D (P < 0.001) and Zn (P = 0.036), this effect seems to extend to the development of colon polyps as well. On the other hand, elevated serum levels of malondialdehyde are associated with a higher risk of CRC (OR = 2.09 compared to controls, P = 0.004). Regarding colonic polyp development, increased concentrations of vitamin Α and Fe²⁺ are associated with a higher risk, whereas lower levels of malondialdehyde with a lower risk.

CONCLUSION

Increased oxidative stress may play an important role in the pathogenesis and progression of CRC. Antioxidants’ presence may exert a protective effect in the very early stages of colon carcinogenesis.

Association between Dietary Fatty Acid Patterns and Colorectal Cancer Risk: A Large-Scale Case-Control Study in China

Associations of dietary fatty acids with the risk of colorectal cancer (CRC) remain controversial. The objective of this study was to examine whether dietary-derived fatty acid patterns were related to CRC risk among Chinese people. A total of 2806 CRC patients and 2806 frequency-matched controls were interviewed in this case-control study between July 2010 and May 2021. A food frequency questionnaire was used to gather information on dietary intake. Four fatty acid patterns were identified using factor analysis. The even-long-chain fatty acid pattern had no statistically significant association with CRC risk (adjusted Odds ratio (aOR), 1.16; 95% confidence interval (CI), 0.97-1.39; ptrend = 0.129). However, significant inverse associations were found between the medium-chain and long-chain saturated fatty acid (SFA) pattern (aOR, 0.34; 95%CI, 0.27-0.42), the highly unsaturated fatty acid pattern (aOR, 0.73; 95%CI, 0.60-0.88), the odd-chain fatty acid pattern (aOR, 0.69; 95%CI, 0.57-0.83), and CRC risk. The interaction between fatty acid patterns and sex was observed, and the association between the highly unsaturated fatty acid pattern and CRC risk differed by subsite. In conclusion, increasing the intakes of foods rich in medium-chain SFAs, highly unsaturated fatty acids, and odd-chain fatty acids may be related to a lower risk of CRC.

Vitamin E and Non-Communicable Diseases: A Review

Vitamin E, a nutrient found in several foods, comprises eight lipophilic vitamers, the α-, β-, γ- and δ-tocopherols and the α-, β-, γ- and δ-tocotrienols. This vitamin is capable of exerting antioxidant and anti-inflammatory activities, and acting as immunomodulators. Despite these well-known biological activities, the findings regarding the ability of vitamin E and its serum metabolites to prevent and/or control chronic disease are often conflicting and inconsistent. In this review, we have described the metabolism of vitamin E and its interaction with the gut microbiota, considering that these factors may be partially responsible for the divergent results obtained. In addition, we focused on the correlations between vitamin E serum levels, dietary intake and/or supplementation, and the main non-communicable diseases, including diabetes mellitus, asthma, cardiovascular diseases, and the four most common cancers (breast cancer, lung cancer, colorectal cancer, and prostate cancer) with the intention of providing an overview of its health effects in the non-communicable-diseases prevention.

Diet-Derived Circulating Antioxidants and Risk of Digestive System Tumors: A Mendelian Randomization Study

Previous observational case-control studies have shown significant controversy over the impact of dietary intake-related circulating antioxidants on the risk of digestive system tumors. We conducted a two-sample Mendelian randomized (MR) analysis to determine whether there was a significant causal relationship between increased levels of circulating antioxidants and digestive system tumors. Our circulating antioxidants (vitamin C, carotenoids, vitamin A, and vitamin E) were derived from absolute circulating antioxidants and circulating antioxidant metabolites, and their corresponding instrumental variables were screened from published studies. The digestive system tumors we studied included colorectal, gastric, pancreatic, liver, and esophageal cancer, and the corresponding summary GAWS (genome-wide association study) data were obtained from the UK Biobank database. We first evaluated the causal relationship between each tumor and circulating antioxidants and then used meta-analysis to summarize the results of MR analysis of different tumors. No significant associations were noted for genetically predicted circulating antioxidants and higher risk of digestive system tumors in our study. The pooled ORs (odds ratio) are 0.72 (95% CI: 0.46-1.11; β-carotene), 0.93 (95% CI: 0.81-1.08; lycopene), 2.12 (95% CI: 0.31-14.66; retinol), and 0.99 (95% CI: 0.96-1.02; ascorbate) for absolute circulating antioxidants; for circulating antioxidant metabolites, the pooled ORs for digestive system tumors risk per unit increase of antioxidants were 1.29 (95% CI: 0.39-4.28; α-tocopherol), 1.72 (95% CI: 0.85-3.49; γ-tocopherol), 1.05 (95% CI: 0.96-1.14; retinol), and 1.21 (95% CI: 0.97-1.51; ascorbate), respectively. Our study suggested that increased levels of dietary-derived circulating antioxidants did not reduce the risk of digestive system tumors.

Dietary and serum vitamin D and preeclampsia risk in Chinese pregnant women: a matched case-control study

The effect of vitamin D (VD) on the risk of preeclampsia (PE) is uncertain. Few of previous studies focused on the relationship between dietary VD intake and PE risk. Therefore, we conducted this 1:1 matched case-control study to explore the association of dietary VD intake and serum VD concentrations with PE risk in Chinese pregnant women. A total of 440 pairs of participants were recruited during March 2016 to June 2019. Dietary information was obtained using a seventy-eight-item semi-quantitative FFQ. Serum concentrations of 25(OH)D₂ and 25(OH)D₃ were measured by liquid chromatography-tandem MS. Multivariate conditional logistic regression was used to estimate OR and 95 % CI. Restricted cubic splines (RCS) were plotted to evaluate the dose-response relationship of dietary VD intake and serum VD concentrations with PE risk. Compared with the lowest quartile, the OR of the highest quartile were 0·45 (95 % CI 0·29, 0·71, P_trend = 0·001) for VD dietary intake and 0·26 (95 % CI 0·11, 0·60, P_trend = 0·003) for serum levels after adjusting for confounders. In addition, the RCS analysis suggested a reverse J-shaped relationship between dietary VD intake and PE risk (P-nonlinearity = 0·02). A similar association was also found between serum concentrations of total 25(OH)D and PE risk (P-nonlinearity = 0·02). In conclusion, this study provides evidence that higher dietary intake and serum levels of VD are associated with the lower risk of PE in Chinese pregnant women.

Association of Retinol and Carotenoids Content in Diet and Serum With Risk for Colorectal Cancer: A Meta-Analysis

Background

Colorectal cancer (CRC) risk is linked to serum and dietary retinol and carotenoids, according to clinical and epidemiological research. However, the findings are not consistent. As a result, we did this meta-analysis to determine the link between them.

Methods

From 2000 through 2022, the PubMed, Web of Science, and Embase databases, as well as pertinent article references, were searched and filtered based on inclusion and exclusion criteria and literature quality ratings. High and low intake were used as controls, and OR (odds ratio) or RR (relative risk) and 95% confidence interval were extracted. The extracted data were plotted and analyzed using Stata12.0 software.

Results

A total of 22 relevant studies were included, including 18 studies related to diet and 4 studies related to serum. For high and low intake or concentration controls, the pooled OR was as follows: β-carotene (OR = 0.89, 95% CI: 0.78–1.03), α-carotene (OR = 0.87, 95% CI: 0.72–1.03), lycopene (OR = 0.93, 95% CI: 0.81–1.07), lutein/zeaxanthin (OR = 0.96, 95% CI: 0.87–1.07), β-cryptoxanthin (OR = 0.70, 95% CI: 0.48–1.01), total carotenoids (OR = 0.97, 95% CI: 0.81–1.15), retinol (OR = 0.99, 95% CI: 0.89–1.10), serum carotenoids (OR = 0.73, 95% CI: 0.58–0.93), serum retinol (OR = 0.62, 95% CI: 0.26–1.49). Subgroup analysis was performed according to tumor type, study type and sex.

Conclusion

Total carotenoid intake and Lutein/Zeaxanthin intake were not associated with CRC risk. High β-carotene, α-carotene, lycopene, and β-cryptoxanthin all tended to reduce CRC risk. Serum carotenoid concentrations were significantly inversely associated with CRC risk.

Downregulation of LRRC19 Is Associated with Poor Prognosis in Colorectal Cancer

Objective. Colorectal cancer (CRC) is globally one of the most often diagnosed cancers with high mortality rates. This study aimed to explore novel biomarkers for the diagnosis and prognosis of CRC. Methods. We collected 4 datasets about CRC in GEO and sought differentially expressed genes (DEGs) with GEO2R. Leucine-rich repeat-containing protein 19 (LRRC19) expression was assessed through the Oncomine and TIMER database analyses, which was further confirmed by qRT-PCR of CRC samples. We used online survival analysis tools (GEPIA, PrognoScan, and Kaplan–Meier plotter) to examine the prognostic value of LRRC19 in CRC and other malignancies. GO and KEGG enrichment analyses were employed to explore the biological functions of LRRC19. Finally, we conducted network prediction by STRING and further validation on the GEPIA to discover other molecules that might interact with LRRC19. Results. A total of 21 upregulated and 46 downregulated DEGs were identified from the 4 datasets. The TIMER and Oncomine online analyses showed lower mRNA of LRRC19 in CRC tissues compared with adjacent normal tissues, which was validated by qRT-PCR in CRC patient samples. The survival analysis through the GEPIA and PrognoScan websites revealed that low LRRC19 expression was significantly correlated with poor prognosis in CRC patients. The Kaplan–Meier plotter survival analysis indicated that low LRRC19 expression was significantly associated with the disease progression of patients with ovarian cancer, gastric cancer, breast cancer, and lung cancer. The enrichment analysis suggested that low expression of LRRC19 could be involved in the retinol metabolism and the zymogen granule membrane. Through STRING and GEPIA, it was found that LRRC19 is clearly associated with ZCCHC10, MOB3B, IMMP2L, and TRMT11. Conclusion. LRRC19 mRNA was prominently decreased in human CRC tissues and was significantly associated with shorter survival in CRC patients. LRRC19 might serve as a possible target for early diagnosis and prognosis assessment in CRC.

Soybean-derived gma-miR159a alleviates colon tumorigenesis by suppressing TCF7/MYC in mice

Previous reports have shown that plant-derived microRNAs (miRNAs) regulate mammalian gene expression through dietary intake. Our prior study found that gma-miR159a, which is abundant in soybean, significantly inhibited the proliferation of colon cancer cells. In the current study, dietary gma-miR159a was utilized to study its anti-colon cancer function in azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon cancer mice. Under processing conditions, gma-miR159a exhibited excellent stability in cooked soybean. In vitro, gma-miR159a suppressed the expression of the oncogene MYC downstream of the Wnt signaling pathway by targeting the TCF7 gene, significantly inhibiting the growth of colon cancer cells. The in vivo experiments showed that gma-miR159a and soybean RNA (total RNA extracted from soybean) significantly reduced tumor growth in AOM/DSS-induced colon cancer mice by gavage. This effect disappeared when anti-miR159a was present. In addition, gma-miR159a and soybean RNA significantly attenuated inflammation in colon cancer mice. These results showed that long-term dietary intake of soybean-derived gma-miR159a effectively prevented the occurrence of colon cancer and colitis, which provides novel evidence for the prevention function of soybean.

Risk of Colorectal Cancer in a Brazilian Population is Differentially Associated with the Intake of Processed Meat and Vitamin E

The incidence and mortality rates of colorectal cancer (CRC) in Northeast Brazil are increasing. To study the association between CRC and diet, data were obtained from 64 patients with CRC and 123 sex- and age-matched controls. The dietary details were recorded using a validated food frequency questionnaire. Nutrient intake was calculated using Dietsys software (National Cancer Institute, Maryland, USA). In a binary logistic regression model of dietary components (model 1), the chance of CRC increased by 0.2% (odds ratio [OR] = 1.002; 95% confidence interval [CI]: 1.000-1.004) for each gram of processed meat intake per week (p < 0.010). Consumption of eggs decreased the chance by 0.1% per gram (OR = 0.999; 95% CI: 0.998-1.000; p < 0.050). The use of oil (including olive oil) for served food decreased the chance by 1.8% (OR = 0.982; 95% CI: 0.970-0.992) for each time consumed (p < 0.010). In a model of nutritional factors (model 2), intake of vitamin E decreased the chance by 16.8% (OR = 0.832; 95% CI: 0.725-0.940) for each milligram intake per week (p < 0.010). In model 1 and 2 smoking increased the chance of CRC by 10.294 (95%CI: 4.240-27.670) and 2.496 (95% CI: 1.425-3.566) times (p < 0.010; p < 0.010), respectively.

Pretreatment serum vitamin level predicts severity of radiation-induced oral mucositis in patients with nasopharyngeal carcinoma

BACKGROUND

Radiation-induced mucositis (RIOM) is a common radiotherapy toxicity. We aimed to evaluate the relationship of serum vitamin status with RIOM among nasopharyngeal carcinoma (NPC) patients who underwent radiotherapy.

METHODS

NPC patients who underwent concurrent chemoradiotherapy with available pretreatment serum vitamin values were included. Serum vitamin levels and clinical characteristics were collected. Logistic regression analysis and receiver operating characteristic curves were conducted to explore the potential risk factors and corresponding cut-off values for severe RIOM.

RESULTS

Two hundred and forty NPC patients were enrolled. Multivariate regression analysis showed that mean oral cavity radiation dose (OR = 2.042; 95% CI = 1.585-2.630; P < .001), weekly concurrent chemotherapy (OR = 3.898; 95% CI = 1.085-14.004; P = .037), lower serum level of vitamin B2 (OR = 0.951; 95% CI = 0.924-0.978; P < .001), and vitamin C (OR = 0.455; 95% CI = 0.346-0.598; P < .001) were independent risk factors for developing severe RIOM.

CONCLUSIONS

The findings of this study revealed that serum vitamin status could predict the severity of RIOM, providing a theoretical basis for the prevention and treatment of RIOM.

Vitamin E and cancer prevention: Studies with different forms of tocopherols and tocotrienols

α-Tocopherol (α-T) is the major form of vitamin E (VE) in animals and has the highest activity in carrying out the essential antioxidant functions of VE. Because of the involvement of oxidative stress in carcinogenesis, the cancer prevention activity of α-T has been studied extensively. Lower VE intake or nutritional status has been shown to be associated with increased cancer risk, and supplementation of α-T to populations with VE insufficiency has shown beneficial effects in lowering the cancer risk in some intervention studies. However, several large intervention studies with α-T conducted in North America have not demonstrated a cancer prevention effect. More recent studies have centered on the γ- and δ-forms of tocopherols and tocotrienols (T3). In comparison with α-T, these forms have much lower systemic bioavailability but have shown stronger cancer-preventive activities in many studies in animal models and cell lines. γ-T3 and δ-T3 generally have even higher activities than γ-T and δ-T. In this article, we review recent results from human and laboratory studies on the cancer-preventive activities of different forms of tocopherols and tocotrienols, at nutritional and pharmacological levels. We aim to elucidate the possible mechanisms of the preventive actions and discuss the possible application of the available information for human cancer prevention by different VE forms.

Association of Serum Alpha-Tocopherol and Retinol with the Extent of Coronary Lesions in Coronary Artery Disease

Background and aims: Fat-soluble vitamins play an important role in the pathogenesis of cardiovascular disease and progression of atherosclerosis. This study aimed at investigating the relationship of the serum levels of alpha-tocopherol and retinol with the extent of coronary lesions in patients with coronary artery disease. Methods. Patients with coronary artery disease (n=177) aged 30-74 years, who underwent their first coronary angiography, were enrolled. The extent of coronary lesions was assessed using the Friesinger index (FI). Accordingly, patients were grouped as follows: FI = 0-4 (n=90), FI = 5-9 (n=50), and FI = 10-15 (n=37). Serum levels of vitamins were ‬determined via high-performance liquid chromatography and serum biochemical analysis. Results. Assessment of FI-based groups revealed that 50.8% patients had a coronary artery lesion to a low extent (FI 0-4). Individuals in this group were younger and had lower glucose and serum alpha-tocopherol levels than the other groups (p < 0.05). Low levels of alpha-tocopherol were more frequent in the FI 0-4 group than that in the other groups (p=0.03). No difference was observed between the mean serum retinol levels among the FI-based groups (n=0.492), and the low frequency of retinol was consistent among the FI groups (n=0.348). Conclusions. The low level of alpha-tocopherol together with the presence of dyslipidemia is probably associated with the initial events in atherosclerosis. Increased alpha-tocopherol levels in patients with more extensive coronary artery lesions may have resulted from altered vitamin E metabolism with increased oxidative stress.