Nutrient-based dietary patterns and nasopharyngeal cancer: evidence from an exploratory factor analysis

Are Major a Posteriori Dietary Patterns Reproducible in the Italian Population? A Systematic Review and Quantitative Assessment

Although a posteriori dietary patterns (DPs) naturally reflect actual dietary behavior in a population, their specificity limits generalizability. Among other issues, the absence of a standardized approach to analysis have further hindered discovery of genuinely reproducible DPs across studies from the same/similar populations. A systematic review on a posteriori DPs from principal component analysis or exploratory factor analysis (EFA) across study populations from Italy provides the basis to explore assessment and drivers of DP reproducibility in a case study of epidemiological interest. First to our knowledge, we carried out a qualitative (i.e., similarity plots built on text descriptions) and quantitative (i.e., congruence coefficients, CCs) assessment of DP reproducibility. The 52 selected articles were published in 2001-2022 and represented dietary habits in 1965-2022 from 70% of the Italian regions; children/adolescents, pregnancy/breastfeeding women, and elderly were considered in 15 articles. The included studies mainly derived EFA-based DPs on food groups from food frequency questionnaires and were of "good quality" according to standard scales. Based on text descriptions, the 186 identified DPs were collapsed into 113 (69 food-based and 44 nutrient-based) apparently different DPs (39.3% reduction), later summarized along with the 3 "Mixed-Salad/Vegetable-based Patterns," "Pasta-and-Meat-oriented/Starchy Patterns," and "Dairy Products" and "Sweets/Animal-based Patterns" groups, by matching similar food-based and nutrient-based groups of collapsed DPs. Based on CCs (215 CCs, 68 DPs, 18 articles using the same input lists), all pairs of DPs showing the same/similar names were at least "fairly similar" and ∼81% were "equivalent." The 30 "equivalent" DPs ended up into 6 genuinely different DPs (80% reduction) that targeted fruits and (raw) vegetables, pasta and meat combined, and cheese and deli meats. Such reduction reflects the same study design, list of input variables, and DP identification method followed across articles from the same groups. This review was registered at PROSPERO as CRD42022341037.

Effects of a Diet Based on Foods from Symbiotic Agriculture on the Gut Microbiota of Subjects at Risk for Metabolic Syndrome

Diet is a major driver of gut microbiota variation and plays a role in metabolic disorders, including metabolic syndrome (MS). Mycorrhized foods from symbiotic agriculture (SA) exhibit improved nutritional properties, but potential benefits have never been investigated in humans. We conducted a pilot interventional study on 60 adults with ≥ 1 risk factors for MS, of whom 33 consumed SA-derived fresh foods and 27 received probiotics over 30 days, with a 15-day follow-up. Stool, urine and blood were collected over time to explore changes in gut microbiota, metabolome, and biochemical, inflammatory and immunologic parameters; previous dietary habits were investigated through a validated food-frequency questionnaire. The baseline microbiota showed alterations typical of metabolic disorders, mainly an increase in Coriobacteriaceae and a decrease in health-associated taxa, which were partly reversed after the SA-based diet. Improvements were observed in metabolome, MS presence (two out of six subjects no longer had MS) or components. Changes were more pronounced with less healthy baseline diets. Probiotics had a marginal, not entirely favorable, effect, although one out of three subjects no longer suffered from MS. These findings suggest that improved dietary patterns can modulate the host microbiota and metabolome, counteracting the risk of developing MS.

Dietary patterns and risk of nasopharyngeal carcinoma: a population-based case-control study in southern China

BACKGROUND

Dietary factors, such as consumption of preserved foods, fresh vegetables, and fruits, have been linked to the risk of nasopharyngeal carcinoma (NPC). However, little is known about associations between dietary patterns and the risk of NPC in NPC-endemic areas.

OBJECTIVES

We aimed to evaluate whether dietary patterns are associated with NPC risk.

METHODS

We studied 2554 newly diagnosed NPC patients aged 20-74 y living in 3 endemic regions of southern China, and 2648 population-based controls frequency-matched to case patients by age, sex, and region, between 2010 and 2014. Dietary components were derived from food frequency data in adulthood and adolescence using principal component analysis. Four dietary components were identified and highly similar in adulthood and adolescence. We used multivariable unconditional logistic regression to calculate ORs with 95% CIs for the association between dietary patterns and NPC risk.

RESULTS

Compared with the lowest quartile, individuals in the highest quartile of the "plant-based factor" in adulthood had a 52% (OR: 0.48; 95% CI: 0.38, 0.59) decreased risk of NPC, and those in the highest quartile of the "animal-based factor" had a >2-fold (OR: 2.26; 95% CI: 1.85, 2.77) increased risk, with a monotonic dose-response trend (P-trend < 0.0001). Similar but weaker associations were found in adolescence. High intakes of the "preserved-food factor" were associated with increased NPC risk in both periods, although stronger associations were found in adolescence. Results from joint analysis and sensitivity analyses indicated that dietary factors in adulthood might be more stable and robust predictors of NPC risk than those in adolescence.

CONCLUSIONS

Our results deliver compelling evidence that plant- and animal-based dietary factors are associated with NPC risk, and provide more insights on the associations of diets and cancer risk that may assist healthy diet recommendations.

The Evolving Epidemiology of Nasopharyngeal Carcinoma

BACKGROUND

The epidemiology of nasopharyngeal carcinoma (NPC) has long been a source of fascination due to the malignancy's striking geographic distribution, the involvement of the oncogenic Epstein-Barr virus (EBV), the unique association with intake of Chinese-style salt-preserved fish, and etiologic heterogeneity by histologic subtype.

METHODS

This review summarizes the current epidemiologic literature on NPC, highlighting recent results from our population-based case-control study in southern China.

RESULTS

Findings from our case-control study provide new insight into the epidemiology of NPC, including a diminished role of Chinese-style salt-preserved fish, a profound impact of EBV genetic sequence variation, modest positive associations with passive smoking and household air pollution, and possible effects of oral health and the oral microbiome. Recent findings from other studies include a protective association with infectious mononucleosis, suggesting a causal role of early EBV infection; familial risk conferred by shared genetic variation in the host antibody-mediated immune response to EBV infection; and an unclear association with occupational exposure to formaldehyde.

CONCLUSIONS

To shed further light on the interplay of environmental, genetic, and viral causes of NPC, large pooled studies must accumulate sufficient cases with detailed exposure data.

IMPACT

New epidemiologic findings have reshaped the causal model for NPC.

Understanding eating choices among university students: A study using data from cafeteria cashiers' transactions

OBJECTIVE

To illustrate the use of automatically collected data from cashier transactions to understand eating habits among university students using cafeteria and to identify individual characteristics associated with the diverse behaviors.

METHODS

The study was carried out at a large university located in Pisa, central Italy, using data about meals automatically recorded from cashier transaction meals during the academic year 2015-16 as well as data from the administrative archive of the university. A model-based clustering relying on multivariate beta distribution was used to cluster eating choices while multivariate multinomial logistic regressions were applied to identify variables associated to diverse clusters identified.

RESULTS

Considering 4643 students and about 200,000 meals consumed, results suggest that healthy eaters represented a minority (11.2 %) of the study population while the large part of students composed their meals combining grains with processed food or proteins (32.7 %) and limiting the choice of fruit (42.9 %). Male gender and younger age were associated with eating behavior not in line with recommendations for a healthy diet.

CONCLUSIONS

Eating choice resulted to be "compromised" in most of students and specific characteristics associated with unhealthy choice were also identified that can help inform and target specific policy. The use of routinely collected data gives the opportunity to both cafeterias and university to take an active role in policy development.

Decreased expression of folate transport proteins in oral cancer

OBJECTIVES

The purpose of this study was to assess the expression of the 3 major folate transporters-folate receptors (FRs), reduced folate carrier (RFC), and proton-coupled folate transporter (PCFT)-in oral squamous cell carcinoma (OSCC). We hypothesized that patterns of expression of folate transporters would be different in OSCC compared with normal oral epithelium.

STUDY DESIGN

We used immunohistochemistry to examine the expression of FR, RFC, and PCFT in 15 primary specimens collected from patients with OSCC, 2 human cadaveric samples of OSCC, and 12 normal human cadaveric oral tissues from a medical gross anatomy laboratory. Possible correlations between the expression of each folate transporter and patients' clinical data were determined.

RESULTS

All 3 folate transporters were highly expressed in normal oral epithelium. In contrast, OSCC samples generally demonstrated low expression of FR, RFC, and PCFT, with wide distribution in the invading cancer cells. There were no differences in folate transporter expression between OSCC samples collected from patients and from human cadavers. The lowest expression of FR and PCFT characterized less-differentiated tumors, and the lowest expression of RFC correlated with higher lymph node involvement.

CONCLUSIONS

Human oral cancer samples expressed decreased amounts of all 3 major folate transport proteins compared with controls from normal cadaveric oral tissues.

IL-17A promotes the proliferation of human nasopharyngeal carcinoma cells through p300-mediated Akt1 acetylation

Interleukin (IL)-17A is a T helper (Th)17 cell-secreted cytokine that is able to induce various inflammatory responses. There is emerging evidence that IL-17A is generated in the cancer microenvironment of human nasopharyngeal carcinoma (NPC). However, the role of IL-17A in NPC remains unclear. Thus, the present study aimed to examine the direct influence of IL-17A stimulation on the proliferation of human NPC cells and identify the underlying molecular mechanisms. Furthermore, E1A binding protein p300 (p300)-mediated AKT serine/threonine kinase 1 (Akt1) acetylation and its role in regulating the proliferation of NPC cells was investigated. The results of the current study demonstrated that IL-17A stimulation in vitro increased the proliferation of human NPC cells. Furthermore, Akt1 acetylation was identified to be enhanced in human NPC cells induced by IL-17A. Additionally, p300 induction was demonstrated to be required for Akt1 acetylation in human NPC cells following exposure to IL-17A. Functionally, p300-mediated Akt1 acetylation contributed to the proliferation of human NPC cells stimulated by IL-17A. In conclusion, the results of the present demonstrate a novel activity of IL-17A that promotes human NPC cell proliferation via p300-mediated Akt1 acetylation. This may provide a potential strategy for the treatment of patients with NPC through the inhibition of IL-17A or its receptors.

Adherence to the Mediterranean diet and nasopharyngeal cancer risk in Italy

PURPOSE

Few studies investigated the role of diet on nasopharyngeal cancer (NPC) risk in non-endemic areas. The aim of this study was to assess the association between adherence to the traditional Mediterranean diet and NPC risk in a southern European low-risk population.

METHODS

We conducted a hospital-based case-control study in Italy, including 198 histologically confirmed NPC cases and 594 matched controls. Dietary habits were collected by means of a validated food-frequency questionnaire, including 83 foods, food groups, or beverages. Adherence to the traditional Mediterranean diet was assessed through a Mediterranean Diet Score (MDS), based on nine dietary components characterizing this dietary profile, i.e., high intake of vegetables, fruits and nuts, cereals, legumes, and fish; low intake of dairy products and meat; high monounsaturated to saturated fatty acid ratio; and moderate alcohol intake. We estimated odds ratios (ORs) of NPC, and the corresponding 95% confidence intervals (CIs), for increasing MDS (i.e., increasing adherence) using multiple logistic regression models, adjusted for major confounding factors.

RESULTS

As compared to MDS ≤ 4, the ORs of NPC were 0.83 (95% CI: 0.54-1.25) for MDS of 5 and 0.66 (95% CI: 0.44-0.99) for MDS ≥ 6, with a significant trend of decreasing risk (p 0.043). The corresponding population attributable fraction was 22%, indicating that 22% of NPC cases in this population would be avoided by shifting all subjects to a score ≥6.

CONCLUSIONS

Our study supports a favorable role of the Mediterranean diet on NPC risk.

Increased Risk of Nasopharyngeal Carcinoma with Increasing Levels of Diet-Associated Inflammation in an Italian Case-Control Study

PURPOSE

Components of diet can modulate inflammation and therefore may have an important role in the development of nasopharyngeal carcinoma (NPC). Little is known about the inflammatory potential of diet in relation to nasopharyngeal carcinogenesis.

METHODS

Data from an Italian multicenter case-control study conducted between 1992 and 2008 and including 198 cases with incident, histologically confirmed NPC, and 594 controls hospitalized for acute nonneoplastic diseases were used to estimate the relation between a dietary inflammatory index (DII) and the risk of NPC. The DII was computed based on the intake of selected dietary factors assessed by a validated 78-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) adjusted for study center, place of living, sex, age, year of interview, education, tobacco smoking, alcohol drinking, and energy intake using the residual method.

RESULTS

Subjects with higher DII scores had an increased risk of NPC, with each DII point increasing risk by nearly 20% [OR: 1.19; 95% confidence interval (CI): 1.05-1.36]. Compared to subjects in the lowest DII tertile, those in the highest tertile had >60% higher risk of NPC (OR: 1.64; 95% CI: 1.06-2.55; Ptrend = 0.04).

CONCLUSION

These results indicate that inflammatory potential of diet plays a role in NPC.

Partial Least Square Discriminant Analysis Discovered a Dietary Pattern Inversely Associated with Nasopharyngeal Carcinoma Risk

Evidence on the association between dietary component, dietary pattern and nasopharyngeal carcinoma (NPC) is scarce. A major challenge is the high degree of correlation among dietary constituents. We aimed to identify dietary pattern associated with NPC and to illustrate the dose-response relationship between the identified dietary pattern scores and the risk of NPC. Taking advantage of a matched NPC case–control study, data from a total of 319 incident cases and 319 matched controls were analyzed. Dietary pattern was derived employing partial least square discriminant analysis (PLS-DA) performed on energy-adjusted food frequencies derived from a 66-item food-frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated with multiple conditional logistic regression models, linking pattern scores and NPC risk. A high score of the PLS-DA derived pattern was characterized by high intakes of fruits, milk, fresh fish, vegetables, tea, and eggs ordered by loading values. We observed that one unit increase in the scores was associated with a significantly lower risk of NPC (OR_adj = 0.73, 95% CI = 0.60–0.88) after controlling for potential confounders. Similar results were observed among Epstein-Barr virus seropositive subjects. An NPC protective diet is indicated with more phytonutrient-rich plant foods (fruits, vegetables), milk, other protein-rich foods (in particular fresh fish and eggs), and tea. This information may be used to design potential dietary regimen for NPC prevention.