Prospective study of fruits and vegetables and risk of oral premalignant lesions in men

Assessing the Effect of Curcumin on the Oral Mucosal Cytomorphometry and Candidal Species Specificity in Tobacco Users: A Pilot Study

Objectives: Tobacco consumption is of major concern for public health. Compromised oral hygiene accentuated by tobacco leads to alteration in the oral mucosa and microbiome, including Candida, and its species can be identified rapidly using CHROMagar. Curcumin, a naturally available compound possesses antioxidant, anti-inflammatory, anti-microbial, anti-carcinogenic, anti-fungal, and immunomodulatory properties. Hence, a comprehensive study was planned. Aim: To evaluate and compare cytomorphometric analysis and Candida colonization and speciation in tobacco users before and after the use of curcumin gel. Materials and Methods: The study comprised a total of 120 participants (the study (tobacco habit) group, n = 60 and control (healthy) group, n = 60). The intervention was the application of curcumin gel over the lesion area three times daily for 2 months. All participants’ oral health status was assessed, followed by cytomorphometric analysis and Candida colonization and speciation using CHROMagar. Results: Cytomorphometric analysis showed statistically significant differences in the control and study group for cell diameter (CD), nuclear diameter (ND), CD:ND ratio, and micronuclei (p = 0.0001). Candida colonization had a significantly higher number of colonies in the habit group when compared to the control group. Candida tropicalis was predominant in the study group, whereas Candida albicans was predominant in the control group. In the study group, after intervention with curcumin, a statistically significant difference was seen in nuclear diameter, CD:ND ratio, and micronuclei. There was a reduction in the number of Candida colonies, and Candida albicans was the predominant species observed in the study group after the intervention of curcumin and discontinuation of habit. Conclusion: Curcumin was found to reduce the number of micronuclei and also decreased Candida colonization, along with the discontinuation of habit in tobacco users.

Retraction: Oral leukoplakia, a clinical-histopathological study in 412 patients

The authors detected some minor errors in the published manuscript (Rubert A, Bagán L, Bagán JV. Oral leukoplakia, a clinical-histopathological study in 412 patients. J Clin Exp Dent. 2020 Jun 1;12(6):e540-e546. doi: 10.4317/jced.57091. PMID: 32665812; PMCID: PMC7335600.) and have requested that the entire article be republished with these errors already rectified.

Background

A retrospective clinical-histopathological study was made of the evolution of oral leukoplakia over time, staging the disease according to the classification of van der Waal.

Material and Methods

A study was made of 412 patients with oral leukoplakia, analyzing the corresponding clinical factors and histopathological findings; assessing associations between the different clinical presentations and epithelial dysplasia; and evaluating the factors influencing malignant transformation of the lesions.

Results

Clinically, homogeneous presentations were seen to predominate (n = 336, 81.6%), while histologically most of the lesions exhibited no dysplastic changes (n = 271; 65.7%). Stage 1 of the van der Waal classification was the most common presentation (n = 214; 51.9%). The lesion malignization rate was 8.5%, and the factors associated to a significantly increased malignization risk were non-homogeneous OL lesions (p=0.00), lesion location in the tongue (p=0.00), and the presence of epithelial dysplasia (p=0.00).

Conclusions

In our series of patients with oral leukoplakia, malignization was associated to the less common clinical presentations of the disease, i.e., non-homogeneous lesions, and the latter tended to exhibit high grade epithelial dysplasia. Key words:Oral leukoplakia, potentially malignant disorders, malignant transformation.

Grapefruit-Derived Micro and Nanovesicles Show Distinct Metabolome Profiles and Anticancer Activities in the A375 Human Melanoma Cell Line

Fruit juice is one of the most easily accessible resources for the isolation of plant-derived vesicles. Here we found that micro- and nano-sized vesicles (MVs and NVs) from four Citrus species, C. sinensis, C. limon, C. paradisi and C. aurantium, specifically inhibit the proliferation of lung, skin and breast cancer cells, with no substantial effect on the growth of non-cancer cells. Cellular and molecular analyses demonstrate that grapefruit-derived vesicles cause cell cycle arrest at G2/M checkpoint associated with a reduced cyclins B1 and B2 expression levels and the upregulation of cell cycle inhibitor p21. Further data suggest the inhibition of Akt and ERK signalling, reduced intercellular cell adhesion molecule-1 and cathepsins expressions, and the presence of cleaved PARP-1, all associated with the observed changes at the cellular level. Gas chromatography-mass spectrometry-based metabolomics reveals distinct metabolite profiles for the juice and vesicle fractions. NVs exhibit a high relative amount of amino acids and organic acids whereas MVs and fruit juice are characterized by a high percentage of sugars and sugar derivatives. Grapefruit-derived NVs are in particular rich in alpha–hydroxy acids and leucine/isoleucine, myo-inositol and doconexent, while quininic acid was detected in MVs. Our findings reveal the metabolite signatures of grapefruit-derived vesicles and substantiate their potential use in new anticancer strategies.

Effect of metabolic syndrome on incidence of oral potentially malignant disorder: a prospective cohort study in Taiwan

OBJECTIVES

We aimed to assess the effect of metabolic syndrome (MetS) on incident oral potentially malignant disorder (OPMD).

DESIGN

We conducted a prospective cohort study of the Changhua community-based integrated screening (CHCIS) programme and nationwide oral cancer screening programme during the period between 2005 and 2014.

SETTING

CHCIS, Taiwan.

PARTICIPANTS

We enrolled 17 590 participants aged 30 years and older.

MAIN OUTCOMES AND MEASURES

We assessed the impact of MetS on the outcome measured by incident OPMD.

RESULTS

The incidences of OPMD among subjects with and without MetS were 7.68 ‰ and 5.38 ‰, respectively. After adjusting for confounders, subjects with MetS exhibited a statistically greater risk of developing OPMD compared with those who were free of MetS by 33% (adjusted rate ratio, aRR=1.33, 95% CI 1.14 to 1.55). Individual components of MetS still remained significant, including central obesity (aRR=1.22, 95% CI 1.04 to 1.44), hypertriglyceridaemia (aRR=1.26, 95% CI 1.07 to 1.49) and hyperglycaemia (aRR=1.20, 95% CI 1.02 to 1.41). Central obesity and hypertriglyceridaemia were also statistically associated with a subtype of OPMD, namely, leukoplakia.

CONCLUSION

The temporal influence of MetS on the risk of incident OPMD was noted in our prospective cohort study. Therefore, promoting an MetS prevention and control programme might reduce the occurrence of OPMD and oral cancer.

Oral leukoplakia, a clinical-histopathological study in 412 patients

Background

A retrospective clinical-histopathological study was made of the evolution of oral leukoplakia over time, staging the disease according to the classification of van der Waal.

Material and Methods

A study was made of 412 patients with oral leukoplakia, analyzing the corresponding clinical factors and histopathological findings; assessing associations between the different clinical presentations and epithelial dysplasia; and evaluating the factors influencing malignant transformation of the lesions.

Results

Clinically, homogeneous presentations were seen to predominate (n = 336, 81.6%), while histologically most of the lesions exhibited no dysplastic changes (n = 271; 65.7%). Stage 1 of the van der Waal classification was the most common presentation (n = 214; 51.9%). The lesion malignization rate was 8.3%, and the factors associated to a significantly increased malignization risk were non-homogeneous OL lesions (p=0.00), lesion location in the tongue (p=0.00), and the presence of epithelial dysplasia (p=0.00).

Conclusions

In our series of patients with oral leukoplakia, malignization was associated to the less common clinical presentations of the disease, i.e., non-homogeneous lesions, and the latter tended to exhibit high grade epithelial dysplasia.

Key words:Oral leukoplakia, potentially malignant disorders, malignant transformation.

Oral Potentially Malignant Disorders

Oral potentially malignant disorders (OPMDs) are precursor lesions that may undergo malignant transformation to oral cancer. These lesions most commonly present clinically as white patches (leukoplakia). However, they may also be red (erythroplakia), or red and white (erythroleukoplakia). There are many risk factors associated with the development of an OPMD, and with the risk of malignant transformation of the lesion. A biopsy with subsequent microscopic examination from the lesional tissue is necessary in identification of OPMD. This article reviews the clinical appearance of OPMDs, associated risk factors, diagnosis and histologic appearance, and treatment.

Anticancer Potential of Citrus Juices and Their Extracts: A Systematic Review of Both Preclinical and Clinical Studies

Background: During the last decades, a huge body of evidence has been accumulated suggesting that Citrus fruits and their juices might have a role in preventing many diseases including cancer.

Objective: To summarize the numerous evidences on the potential of Citrus juices and their extracts as anticancer agents.

Data sources: A systematic review of articles written in English using MEDLINE (1946-present), EMBASE (1974-present) and Web of Sciences (1970-present) was performed independently by two reviewers. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, cancer, neoplasm, neoplasia, tumor, metastasis, carcinogenesis, proliferation. The last search was performed on March 16th, 2017.

Study selection: Study selection and systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Prior to the beginning of the review, Authors defined a checklist for inclusion criteria, thus including articles which meet the following: (i) published on peer-reviewed scientific journals; (ii) Citrus juice used alone; (iii) extracts derived from Citrus juice; (iii) for preclinical studies, an exposure time to Citrus juices and their extracts more than 24 h. Reviews, meta-analyses, conference abstracts and book chapters were excluded.

Data extraction: Three reviewers independently performed the extraction of articles.

Data synthesis: 22 papers met our inclusion criteria and were eligible for inclusion in the final review. According to the kind of study, the selected ones were further divided in preclinical (n = 20) and observational (n = 2) studies.

Conclusion: The studies discussed in this review strongly corroborate the role of Citrus juices and their derivatives as potential resource against cancer.

Chemopreventive Agents and Inhibitors of Cancer Hallmarks: May Citrus Offer New Perspectives?

Fruits and vegetables have long been recognized as potentially important in the prevention of cancer risk. Thus, scientific interest in nutrition and cancer has grown over time, as shown by increasing number of experimental studies about the relationship between diet and cancer development. This review attempts to provide an insight into the anti-cancer effects of Citrus fruits, with a focus on their bioactive compounds, elucidating the main cellular and molecular mechanisms through which they may protect against cancer. Scientific literature was selected for this review with the aim of collecting the relevant experimental evidence for the anti-cancer effects of Citrus fruits and their flavonoids. The findings discussed in this review strongly support their potential as anti-cancer agents, and may represent a scientific basis to develop nutraceuticals, food supplements, or complementary and alternative drugs in a context of a multi-target pharmacological strategy in the oncology.

Anti-carcinogenic and Anti-bacterial Properties of Selected Spices: Implications in Oral Health

"Let food be thy medicine and medicine be thy food", as said by the father of medicine, Hippocrates in 431 B.C. Nature has provided us with a variety of treatment modalities in the form of food. For the first 5,000 years of civilization, humans relied on herbs and foods for medicine. Only in the past 60 years have we forgotten our medicinal "roots" in favor of patented medicines. While pharmaceutical ingredients have their value, we should not overlook the well-documented, non-toxic and inexpensive healing properties of food. As an individual we consume food several times a day without a complete understanding of its innate qualities. As part of a daily diet, food plays a significant role in helping our bodies function at their best. There are hundreds of extremely nutritious foods, but the items in this article do more than providing healthy nutrients. Many of them consist of ingredients with hidden pharmaceutical qualities ranging from anti-inflammatory to anti-carcinogenic agent. They not only boost our innate immunity but also act as an adjunct to medicines for specific treatment. Prevention and management of symptoms can often be improved significantly through the foods we consume regularly. This paper overviews these beneficial traits of food ingredients, consumed on a daily basis, in various oral diseases.

Rapid identification of polymethoxylated flavonoids in traditional Chinese medicines with a practical strategy of stepwise mass defect filtering coupled to diagnostic product ions analysis based on a hybrid LTQ-Orbitrap mass spectrometer

INTRODUCTION

The methodology of stepwise mass defect filtering (MDF) approach coupled to diagnostic product ions (DPIs) analysis on a hybrid linear trap quadrupole (LTQ)/orbitrap mass spectrometer was the first to be established to screen and identify structural analogues from complex herbal extracts.

OBJECTIVE

To develop an analytical methodology that could be adopted to screen and identify structural analogues in traditional Chinese medicines (TCMs) rapidly and accurately.

METHODS

Taking polymethoxylated flavonoids (PMFs) in the leaves of Citrus reticulata Blanco as an example, high-resolution mass data were acquired by high-performance liquid chromatography (HPLC) coupled with a LTQ/orbitrap mass spectrometer. The stepwise MDF with multiple mass defect windows or mass windows enabled the original data to be analysed much faster and more accurately by reducing the potential interferences of matrix ions. Additionally, analysis of DPIs could provide a criterion to classify the target constituents detected into certain chemical families.

RESULTS

In total, 81 PMFs, including 50 polymethoxyflavones and 31 polymethoxyflavanones or polymethoxychalcones, were screened and identified from the original data and preliminarily identified.

CONCLUSION

The analytical methodology developed could be used as a rapid, effective technique to screen and identify compounds from TCM extracts and other organic matter mixtures with compounds that can also be classified into families based on the common carbon skeletons.

Oral and pharyngeal cancer in women

Although in the United States the incidence of oral and pharyngeal cancer (OPC) has been significantly higher in men than in women, the identification of human papilloma virus as a risk factor for OPC has focused new scrutiny on who may develop OPC. One surprising element is that non-Hispanic white women have a higher incidence of OPC than of cervical cancer. OPC is thus a woman's disease, and diligence is needed to ensure that the occurrence of OPC in women does not go undetected by their oral health care providers.

Characterization of polymethoxylated flavonoids (PMFs) in the peels of 'Shatangju' mandarin ( Citrus reticulata Blanco) by online high-performance liquid chromatography coupled to photodiode array detection and electrospray tandem mass spectrometry

A sensitive HPLC-DAD-ESI-MS/MS method was established to screen and identify the polymethoxylated flavonoids (PMFs) in the peels of 'Shatangju' mandarin ( Citrus reticulata Blanco). Eight PMF standards, including four polymethoxylated flavones, two polymethoxylated flavanones, and two polymethoxylated chalcones, were first to be analyzed in positive mode by CID-MS/MS. On the basis of the ESI-MS(n) characteristics of PMFs and the results of EIC-MS/MS experiment, 32 PMFs including 24 flavones and 8 flavanones or chalcones were screened from the complex extract of the peels of 'Shatangju' mandarin. Among them, 10 PMFs were hydroxylated polymethoxyflavonoids (OH-PMFs), and the rest were all permethoxylated PMFs. This was the first systematic report of the presence of PMFs in the peels of 'Shatangju' mandarin, especially for polymethoxylated flavanones and chalcones. Meanwhile, the contents of the three main PMFs and total flavonoids in the peels of 'Shatangju' were determined by HPLC and UV spectrophotometry, respectively. The results indicated that the developed analytical method could be employed as an effective technique for the characterization of PMFs.

Diet and prevention of oral cancer: strategies for clinical practice

BACKGROUND

Oral health care professionals can play an important role in preventing oral cancer by performing oral mucosal examinations to detect pre-cancerous changes and by educating patients about oral cancer prevention strategies, including dietary approaches.

CONCLUSIONS

Current evidence supports a diet high in fruits, vegetables and plant-based foods for prevention of oral cancer. Dietary supplements-including vitamins and minerals-have not been shown to be effective as substitutes for a diet high in fruits and vegetables.

CLINICAL IMPLICATIONS

In addition to discussing tobacco and alcohol use with patients (and, if relevant, betel nut and gutka consumption), as well as the risk of sexual transmission of human papillo-mavirus, clinicians should provide dietary advice for the prevention of oral cancer as part of routine patient education practices.

Tooth loss, chewing habits, and food choices among older Nigerians in Plateau State: a preliminary study

OBJECTIVE

To determine the association between tooth loss, chewing habits, and food choices among older Nigerians.

METHODS

A questionnaire was administered by an interviewer to 500 randomly selected Nigerians, aged 50 and above, drawn from households in Plateau State in the North Central part of Nigeria. Intake of fruits/vegetables, and hard food items such as nuts, roast corn and nontender meat, was assessed. The subjects were then examined clinically to chart their dentitions.

RESULTS

The sample comprised of approximately equal numbers of men and women from predominantly rural and semi-urban communities. Those participants who had more than 20 teeth selected fruits/vegetables more frequently than those with fewer teeth; in addition, they chewed hard foods more frequently. On the other hand, a larger proportion of people with 20 or fewer teeth indicated that they avoided certain food items because of their teeth/mouth conditions. One-way anova showed that the people who selected fruits/vegetables daily or weekly compared to occasionally or rarely had significantly more teeth on average. Multivariable logistic regression analysis, controlling for age, gender, income, and education showed that the number of remaining teeth was significantly associated with the selection of vegetables/fruits and other hard food items.

CONCLUSION

Tooth loss affects selection of specific foods by older Nigerians in Plateau State and thus, could impact on the nutritional status of these individuals.

Associations of dietary dark-green and deep-yellow vegetables and fruits with cervical intraepithelial neoplasia: modification by smoking

Smoking has been positively and fruit and vegetable intake has been negatively associated with cervical cancer, the second most common cancer among women worldwide. However, a lower consumption of fruits and reduced serum carotenoids have been observed among smokers. It is not known whether the smoking effect on the risk of cervical neoplasia is modified by a low intake of fruits and vegetables. The present study examined the combined effects of tobacco smoking and diet using a validated FFQ and serum carotenoid and tocopherol levels on cervical intraepithelial neoplasia grade 3 (CIN3) risk in a hospital-based case–control study conducted in São Paulo, Brazil, between 2003 and 2005. The sample comprised 231 incident, histologically confirmed cases of CIN3 and 453 controls. A low intake ( ≤ 39 g) of dark-green and deep-yellow vegetables and fruits without tobacco smoking had a lesser effect on CIN3 (OR 1·14; 95 % CI 0·49, 2·65) than among smokers with higher intake ( ≥ 40 g; OR 1·83; 95 % CI 0·73, 4·62) after adjusting for confounders. The OR for the joint exposure of tobacco smoking and low intake of vegetables and fruits was greater (3·86; 95 % CI 1·74, 8·57; P for trend < 0·001) compared with non-smokers with higher intake after adjusting for confounding variables and human papillomavirus status. Similar results were observed for total fruit, serum total carotene (including β-, α- and γ-carotene) and tocopherols. These findings suggest that the effect of nutritional factors on CIN3 is modified by smoking.

Nutrition and health: guidelines for dental practitioners

Good nutrition is vital to overall health, and poor diet and a sedentary lifestyle are major causes of morbidity and mortality worldwide. Nutritional factors are implicated in many oral and systemic diseases and conditions, including obesity, hypertension, dyslipidemia, type II diabetes, cardiovascular disease, osteoporosis, dental caries and some cancers including oral cancers. This review focuses on the evidence for the relations between key nutritional factors and health. Energy intake is related to body weight and obesity, highlighting the importance of lower-energy diets and regular physical activity for body weight maintenance and for preventing obesity. Evidence is presented for the health benefits of high quality carbohydrates, such as whole grain products, and fruits and vegetables, in reducing the risk of cardiovascular disease and cancer. The adverse effects of sugar, sweetened beverages, and trans and saturated fats on several diseases including caries, diabetes and cardiovascular disease are described. The health benefits of unsaturated fats, antioxidants, B vitamins and vitamin D in cardiovascular disease, periodontitis, cancer, and other conditions are documented. Both benefits and harmful effects of dairy product intake on health are discussed. Based on the evidence, nutritional guidelines are provided, as well as key recommendations for preventing obesity. Dentists can play a critical role in motivating and enabling healthy food choices.

UPLC/Q-TOFMS/MS as a powerful technique for rapid identification of polymethoxylated flavones in Fructus aurantii

Polymethoxylated flavones (PMFs), as potential cancer chemopreventive agents, are widely distributed in Citrus genus. In this study, a selected ion monitoring-tandem mass (SIM-MS/MS) method for the rapid identification of PMFs in Fructus aurantii (F. aurantii) with ultra-performance liquid chromatography (UPLC) coupled to quadrupole, hybrid orthogonal acceleration time-of-flight tandem mass spectrometer (Q-TOFMS/MS) was proposed. The MS data for candidates, containing accurate mass and isotopic patterns for both precursors and their fragment ions, were acquired selectively. Based on the MS data, the mass spectrometric fingerprint (MSFP) for candidates, consisting of chemical formula and dissociation pattern, was determined. Comparing the MSFPs of the observed compounds with the diagnostic MSFP of the species, 44 PMFs were tentatively identified. The method was validated by tangeretin and sinensetin, two representative compounds of PMFs, and was considered to be suitable for the rapid screening of PMFs in crude and partially purified samples.

Absorption, metabolism and excretion of flavanones from single portions of orange fruit and juice and effects of anthropometric variables and contraceptive pill use on flavanone excretion

Oranges are rich sources of flavonoids that are bioactive and may protect against age-related diseases. The absorption of orange flavanones may be affected by factors such as processing and subject anthropometric variables, and the bioactivity of the absorbed phytochemicals depends on how they are metabolised during absorption. In a randomised cross-over study, twenty subjects consumed a single portion of orange fruit (150 g) or juice (300 g) that contained the flavanones narirutin and hesperidin, and an additional 109 subjects across a broad age range (18-80 years) consumed the juice. Flavanone metabolites were measured in regularly collected samples of plasma and urine. After consumption of fruit or juice, flavanone conjugates, but not the aglycones, were detected in plasma and urine. The flavanone conjugates were shown to include the 7- and 4'-O-monoglucuronides of naringenin, the 7- and 3'-O-monoglucuronides of hesperetin, two hesperetin diglucuronides and a hesperetin sulfo-glucuronide, but no aglycones or rutinosides. Analysis of the plasma pharmacokinetic and urinary excretion data on a dose-adjusted basis indicated no difference in absorption or excretion of either flavanone between the fruit and juice matrices. In the extended urinary excretion dataset the individual variation was very large (range 0-59 % urinary yield). There was a small but significant (P < 0.05) decrease in the excretion of hesperetin (but not naringenin) with increasing age (P < 0.05), but the effects of sex, BMI and contraceptive pill use were shown not to be associated with the variation in flavanone excretion.

Human papillomavirus-16 modifies the association between fruit consumption and head and neck squamous cell carcinoma

Human papillomavirus-16 (HPV-16) is a risk factor for head and neck squamous cell carcinoma (HNSCC). HPV-positive cancers have distinct disease cofactors and improved survival following treatment. There is conflicting evidence of a protective association of fruit consumption with HNSCC. As HPV-related disease is clinically distinct, we investigated whether the association between fruit consumption and HNSCC risk was modified by exposure to HPV-16. We studied 270 cases and 493 controls with fruit intake information and known HPV-16 antibody status. Cases were identified at nine Boston-area medical facilities between 1999 and 2003. Controls were randomly selected from the greater population and frequency matched to cases by age, gender, and town of residence. Controlling for age, gender, race, smoking, alcohol, total energy intake, body mass index, and education, the seronegative individuals had a significantly lower risk of HNSCC with increasing total fruit consumption [odds ratio (OR)(tertile 2), 0.60; 95% confidence interval (95% CI), 0.38-0.95; OR(tertile 3), 0.57; 95% CI, 0.35-0.95] and specifically increasing citrus fruit consumption (OR(tertile 2), 0.61; 95% CI, 0.39-0.97; OR(tertile 3), 0.59; 95% CI, 0.37-0.96). However, among the seropositive, risk increased with greater fruit consumption (OR(tertile 2), 2.27; 95% CI, 0.92-5.58; OR(tertile 3), 1.40; 95% CI, 0.55-3.59) and citrus fruit consumption (OR(tertile 2), 3.35; 95% CI, 1.36, 8.24; OR(tertile 3), 3.15; 95% CI, 1.23-8.08). This interaction was statistically significant (P < 0.05), showing that fruit consumption was associated with a reduced HNSCC risk among HPV-16-seronegative individuals but an increased HNSCC risk among the HPV-16-seropositive individuals. These findings suggest that dietary factors dramatically alter the pattern of occurrence of HPV-associated HNSCC and show that viral-related disease is clinically and etiologically distinct.

Is dental care utilization associated with oral cavity cancer in a large sample of community-based United States residents?

OBJECTIVES

Cancer of the oral cavity and pharynx remains one of the 10 leading causes of cancer deaths in US. Besides smoking and alcohol consumption, there are no well-established risk factors. While poor dental care had been implicated, it is unknown if lack of dental care, implying poor dental hygiene predisposes to oral cavity cancer. This study aimed to assess the relationship between dental care utilization during the past 12 months and the prevalence of oral cavity cancer.

METHODS

A cross-sectional design of the National Health Interview Survey of Adult, noninstitutionalized US residents (n=30 475) was used to assess the association between dental care utilization and self-reported diagnosis of oral cavity cancer. Chi-square statistic was used to examine the crude association between the explanatory variable, dental care utilization and other covariates, while unconditional logistic regression was used to assess the relationship between oral cavity cancer and dental care utilization.

RESULTS

There were statistically significant differences between those who utilized dental care during the past 12 months and those who did not with respect to education, income, age, marital status, and gender (P<0.05), but not health insurance coverage (P=0.53). In addition, those who utilized dental care relative to those who did not were 65% less likely to present with oral cavity cancer, prevalence odds ratio (POR), 0.35, 95% confidence interval (CI), 0.12-0.98. Further, higher income, advanced age, people of African heritage, and unmarried status were statistically significantly associated with oral cavity cancer (P<0.05), but health insurance coverage, alcohol use, and smoking were not, P>0.05. After simultaneously controlling for the relevant covariates, the association between dental care and oral cavity cancer did persist but imprecise. Thus, when compared with those who did not use dental care, those who did were 62% less likely to be diagnosed with oral cavity cancer, adjusted POR, 0.38, 95% CI, and 0.13-1.10.

CONCLUSIONS

Among US adults residing in community settings, use of dental care during the past 12 months was marginally statistically significantly associated with oral cavity cancer, but clinically relevant in assessing oral cavity cancer prevalence in this sample. However, because of the nature of our data, which restricts temporal sequence, a large sample prospective study that may identify modifiable factors associated with oral cavity cancer development, namely poor dental care is needed.

Dairy products, leanness, and head and neck squamous cell carcinoma

BACKGROUND

As part of a population-based case-control study, we investigated the association of food groups and micronutrients estimated from a validated food frequency questionnaire (FFQ) with the risk of development of head and neck squamous cell carcinoma (HNSCC).

METHODS

Incident cases were accrued through Boston area hospitals from 1999 to 2003, and neighborhood controls were selected and matched by location, age, and sex. There were 504 cases and 717 controls enrolled, who completed the FFQ.

RESULTS

We observed a positive association between the consumption of dairy products and HNSCC. The odds of HNSCC in the highest quintile of dairy intake was 1.64 (95% CI: 1.09-2.46), compared with subjects in the lowest quintile. There was a significant association between leanness with HNSCC. The odds of cancer among the leanest subjects was 5.8 (95%CI: 3.2-10.6) compared with a healthy BMI. Finally, intake of animal fat was positively associated with an elevation in cancer risk. The odds of HNSCC for high animal fat intake were 1.50 (0.99-2.27).

CONCLUSIONS

Our data suggest that consumption of fruits and vegetables is not universally protective for HNSCC and that other food groups and nutrients may influence the risk for developing this disease.

Zyflamend reduces LTB4 formation and prevents oral carcinogenesis in a 7,12-dimethylbenz[alpha]anthracene (DMBA)-induced hamster cheek pouch model

Aberrant arachidonic acid metabolism, especially altered cyclooxygenase and 5-lipoxygenase (LOX) activities, has been associated with chronic inflammation as well as carcinogenesis in human oral cavity tissues. Here, we examined the effect of Zyflamend, a product containing 10 concentrated herbal extracts, on development of 7,12-dimethylbenz[alpha]anthracene (DMBA)-induced inflammation and oral squamous cell carcinoma (SCC). A hamster cheek pouch model was used in which 0.5% DMBA was applied topically onto the left cheek pouch of male Syrian golden hamsters either three times per week for 3 weeks (short term) or 6 weeks (long term). Zyflamend was then applied topically at one of three different doses (25, 50 and 100 microl) onto the left cheek pouch three times for 1 week (short-term study) or chronically for 18 weeks. Zyflamend significantly reduced infiltration of inflammatory cells, incidence of hyperplasia and dysplastic lesions, bromodeoxyuridine-labeling index as well as number of SCC in a concentration-dependent manner. Application of Zyflamend (100 microl) reduced formation of leukotriene B(4) (LTB(4)) by 50% compared with DMBA-treated tissues. The reduction of LTB(4) was concentration dependent. The effect of Zyflamend on inhibition of LTB(4) formation was further confirmed with in vitro cell-based assay. Adding LTB(4) to RBL-1 cells, a rat leukemia cell line expressing high levels of 5-LOX and LTA(4) hydrolase, partially blocked antiproliferative effect of Zyflamend. This study demonstrates that Zyflamend inhibited LTB(4) formation and modulated adverse histopathological changes in the DMBA-induced hamster cheek pouch model. The study suggests that Zyflamend might prevent oral carcinogenesis at the post-initiation stage.

Dietary risk factors for hypopharyngeal cancer in India

OBJECTIVE

The Indian subcontinent has among the highest rates of hypopharyngeal cancer worldwide. The purpose of this study was to examine the associations between the Indian diet and hypopharyngeal cancer.

METHODS

We used data from a hospital-based case-control study of 513 incident hypopharyngeal cancers and 718 controls from four centers in India. Dietary information was assessed using a 67-item semi-quantitative food frequency questionnaire. Intakes of related foods were combined across food groups and were categorized by quartile. We used unconditional logistic regression modeling, stratified by ever tobacco use, to analyze the association between food intakes and hypopharyngeal cancer.

RESULTS

Among persons who had ever smoked or chewed tobacco, protective associations were seen at the highest quartiles of total fruit intake (OR = 0.37, 0.20-0.69), curds (OR = 0.35, 0.17-0.69), and leafy green (OR = 0.25, 95% CI 0.13-0.51), root (OR = 0.22, 95% CI 0.11-0.43), and cruciferous vegetable intakes (OR = 0.41, 0.20-0.84). Results were similar, although not as robust, among persons who had never smoked or chewed tobacco. An increased risk of disease was seen among tobacco users who drank milk daily (OR = 1.84, 1.14-2.98).

CONCLUSIONS

Dietary factors might contribute to the high risk of hypopharyngeal cancer observed in India.

Fruit and vegetable intake and head and neck cancer risk in a large United States prospective cohort study

Squamous head and neck cancers include cancers of the oral cavity, pharynx and larynx are the sixth leading cause of cancer mortality worldwide, resulting in more than 350,000 deaths annually. Intake of fruit and vegetables may protect against head and neck cancer incidence, although few prospective studies have examined this association. We investigated this relation in 490,802 United States participants of the NIH-AARP Diet and Health cohort using Cox proportional hazard models adjusted for potential confounders. During 2,193,751 person years of follow-up from 1995/1996-2000, 787 participants were diagnosed with head and neck cancer. We found an inverse association between total fruit and vegetable intake and head and neck cancer risk (per serving/day/1,000 calories, Hazard Ratio, 95% Confidence interval: 0.94, 0.89-0.99). In models mutually adjusted for fruit and vegetable intake, the association was stronger for vegetables (fifth vs. first quintile: 0.65, 0.50-0.85) than for fruits (fifth vs. first quintile: 0.87, 0.68-1.11). When further subclassified into botanical groups, those in the highest tertile of leguminosae (dried beans, string beans and peas, 0.80, 0.67-0.96), rosaceae (apples, peach, nectarines, plums, pears and strawberries, 0.60, 0.49-0.73), solanaceae (peppers and tomatoes, 0.82, 0.69-0.98) and umbelliferae (carrots, 0.73, 0.60-0.89) had decreased risk of head and neck cancer, but no significant associations were seen for 9 other botanical groups. Results from this large prospective observational study are consistent with previous case-control studies and support the hypothesis that total fruit and vegetable intake is associated with reduced risk of head and neck cancer.

Maternal diet during pregnancy and islet autoimmunity in offspring

BACKGROUND

Recent studies on the etiology of type 1 diabetes mellitus (T1DM) suggest that the components of the infant diet are associated with islet autoimmunity (IA), a precursor of T1DM. The role of prenatal nutritional exposures has not been thoroughly investigated.

METHODS

The Diabetes Autoimmunity Study in the Young has enrolled newborns from 1993 to 2004 at increased risk for T1DM based on human leukocyte antigen (HLA) genotype and family history of T1DM. The child is tested for islet autoantibodies at 9 and 15 months, 2 yr, and annually thereafter. We conducted a cohort study of 642 subjects for whom a Willett food frequency questionnaire for the mother's third trimester diet was completed. A case is defined as a subject who tests positive for islet autoantibodies at two consecutive blood draws and is still positive (or diabetic) at last follow-up (n = 27). Maternal consumption frequencies of potatoes, other root vegetables, gluten-containing foods, non-gluten cereal grains, cow's milk and cow's milk products, fruits, vegetables, meat and poultry, and fish were analyzed in a survival analysis.

RESULTS

Adjusting for breast-feeding duration, age at first cereal introduction, ethnicity, HLA genotype, family history of T1DM, and total caloric intake, higher maternal intake of potatoes (hazard ratio for one standard deviation difference: 0.49, 95% confidence interval: 0.28-0.86) was associated with a delayed time to IA onset. No other food groups ingested during pregnancy were associated with IA in the child.

CONCLUSIONS

The composition of the maternal diet during pregnancy may play a role in the offspring's risk of development of IA and potentially T1DM.

Lycopene and other carotenoid intake in relation to risk of uterine leiomyomata

OBJECTIVE

Carotenoids have antioxidant properties and have been associated with reduced risks of some cancers. We hypothesized that carotenoid intake may reduce the risk of diagnosed uterine leiomyoma (UL).

STUDY DESIGN

We evaluated the associations between dietary carotenoids and risk of diagnosed UL in 82,512 premenopausal women aged 26-46 years in 1991 in the Nurses' Health Study II over 10 years of follow-up. Diet was assessed every 4 years with a validated food frequency questionnaire, and incidence of UL was assessed biennially by questionnaire.

RESULTS

Total lycopene intake was not associated with diagnosed UL risk. Intake of beta-carotene was associated with slightly increased risks of diagnosed UL; this association was restricted to current smokers (for highest vs lowest quintile, relative risk = 1.36, 95% confidence interval 1.05 to 1.76; P(trend) = .003).

CONCLUSION

Overall, our findings do not suggest that carotenoids reduce the risk of diagnosed UL. Among current smokers, high intake of beta-carotene may slightly increase risk of diagnosed UL.

Improving metabolic stability of cancer chemoprotective polyphenols

Dietary flavonoids and other polyphenols have the potential to be developed as effective food supplements as well as drugs for the prevention, as well as treatment of, cancer and other disease conditions. However, their very poor oral bioavailability, mainly due to extensive conjugation by glucuronidation and sulfation, is a severe limiting factor. First, this review shows the use of a simple, commercially available model system, the human hepatic S9 fraction, by which metabolic stability can be assessed effectively and accurately. Second, permethylation of the polyphenols effectively blocks the metabolic conjugation reactions, thereby dramatically increasing both metabolic stability and intestinal absorption, while maintaining or even increasing the biologic activities. Thus, permethylated polyphenols may have a future as chemoprotective agents.

Methoxylated flavones, a superior cancer chemopreventive flavonoid subclass?

Dietary flavonoids and other polyphenols show great potential as cancer chemopreventive agents in cell culture studies. This does not translate well into in vivo activity, because of extensive conjugative metabolism of these compounds in the intestine and liver. This paper presents a review of a flavonoid subclass in which all hydroxyl groups are capped by methylation. This results in dramatically increased metabolic stability and membrane transport in the intestine/liver, thus improving oral bioavailability. The methoxyflavones also show increased cancer chemopreventive properties. At the cancer initiation stage, bioactivation of polyaromatic hydrocarbon carcinogens and binding to DNA are markedly diminished through effects on CYP1A1/1B1 transcription but also through direct interactions with the proteins. At the cancer promotion stage, the proliferation of cancer cells, but not normal cells, is inhibited with greater potency than with the unmethylated flavones. Limited mechanistic experiments, such as of effects on cell cycle regulation, indicate that the mechanisms of methoxyflavone activities are unique, including aromatase inhibition. The cancer preventive effects and mechanisms of the polymethoxyflavones, such as tangeretin and nobiletin, are discussed in comparison. It is concluded that the methoxyflavones have properties that may make them particularly useful as cancer chemopreventive agents.

Prospective study of vitamins C, E, and A and carotenoids and risk of oral premalignant lesions in men

Case-control studies indicate that vitamins C, E, A and carotenoids decrease risk of oral premalignant lesions (OPLs) and oral cancer, but clinical trials have failed to find protective effects of beta-carotene and suggest that vitamin E may increase risk. The authors prospectively evaluated the association between intake of vitamins C, E, A and carotenoids and incidence of OPL. Participants were 42,340 men in the Health Professionals Follow-up Study who provided information on supplement use and diet every 2-4 years by food frequency questionnaire. The authors confirmed 207 clinically or histopathologically diagnosed OPL events occurring between 1986 and 2002 by medical record review. Multivariate-adjusted relative risks (RR) of OPL were calculated with proportional hazards models. Total intake of vitamin C, vitamin A or carotenoids was not significantly associated with OPL risk. Dietary vitamin C was significantly associated with reduced risk (quintile 5 vs. 1, RR = 0.52, 95% CI 0.31-0.85, p(trend) = 0.04), but no association with supplemental vitamin C was observed. Inverse associations were apparent for beta-cryptoxanthin and alpha-carotene intake. No clear relationship emerged with beta-carotene, lycopene or lutein/zeaxanthin. Vitamin E was associated with increased risk (quintile 5 vs. 1, RR = 1.86, 95% CI 1.06-3.19), particularly among current smokers and with supplemental intake (current-smokers, supplement dose tertile 3 vs. 1, RR = 3.07, 95% CI 1.28-7.34, p(trend) = 0.01). For current smokers, beta-carotene also increased risk. Vitamin C from dietary sources, but not supplements, was associated with a reduced risk of OPL. The observed increased risk for current smokers with high vitamin E or beta-carotene intake should be explored further.

Cancer chemopreventive properties of orally bioavailable flavonoids--methylated versus unmethylated flavones

Poor oral bioavailability has been a major limitation for the successful use of dietary flavonoids as cancer chemopreventive agents. In this study, we examined fully methylated flavones as promising improved agents. In the human oral SCC-9 cancer cells, 5,7-dimethoxyflavone and 5,7,4'-trimethoxyflavone were both 10 times more potent inhibitors of cell proliferation (IC(50) values 5-8 microM) than the corresponding unmethylated analogs chrysin and apigenin. Flow cytometry indicated that both methylated flavones arrested the SCC-9 cells in the G1 phase with a concomitant decrease in the S phase, dramatically different from the unmethylated analogs, which promoted G2/M phase arrest. Both methylated compounds inhibited the proliferation of two other cancer cell lines with very little effect on two immortalized normal cell lines. Examination of additional flavone structures indicated that methylated flavones in general have antiproliferative properties. Finally, we demonstrated that 5,7-dimethoxyflavone, in contrast to its unmethylated analog chrysin, was well absorbed and had high oral bioavailability as well as tissue accumulation in vivo in the rat. Thus, fully methylated flavones appear to have great potential as cancer chemopreventive/chemotherapeutic agents, in particular in oral cancer.