Intakes of red meat, processed meat, and meat mutagens increase lung cancer risk

Causal association of dietary factors with five common cancers: univariate and multivariate Mendelian randomization studies

Background

Daily dietary habits are closely related to human health, and long-term unhealthy dietary intake, such as excessive consumption of alcohol and pickled foods, may promote the development of cancers. However, comprehensive research on the causal relationship between dietary habits and cancer is lacking. Therefore, this study aimed to reveal the potential causal link between dietary risk factors and the prognosis of cancer-related to genetic susceptibility.

Methods

GWAS (Genome-Wide Association Studies) summary data on dietary habits and five common types of cancer and their pathological subtypes were obtained from the UK Biobank and various cancer association consortia. A univariable two-sample Mendelian randomization (UVMR) and FDR correction analysis was conducted to explore the causal relationships between 45 dietary habits and five common types of cancer and their histopathological subtypes. In addition, multivariable Mendelian randomization analysis (MVMR) was performed to adjust for traditional risk factors for dietary habits, and the direct or indirect effects of diet on cancer were evaluated. Finally, the prognostic impact of selected instrumental variables on cancer was analyzed using an online data platform.

Results

In the UVMR analysis, four dietary habits were identified as risk factors for cancer, while five dietary habits were identified as protective factors. Among the latter, one dietary habit showed a significant association with cancer even after FDR correction, indicating a potential causal relationship. The MVMR analysis revealed that weekly beer and cider intake, may act as an independent risk factor for cancer development. Other causal associations between dietary habits and cancer risk may be mediated by intermediate factors. In the prognostic analysis, the SNPs (Single Nucleotide Polymorphisms) of average weekly beer and cider intake were set as independent risk factors and were found to significantly impact overall survival (OS) and cancer-specific survival (CSS) in lung cancer.

Conclusion

This causal relationship study supports the notion that adjusting daily dietary habits and specific dietary interventions may decrease the risk of cancer.

Perilipin1 Expression as a Prognostic Factor in Patients with Squamous Cell Carcinoma of the Lung

Perilipin (PLIN) is a major structural protein located on the surface of lipid droplets. PLIN plays an important role in human metabolism and is associated with metabolic diseases, such as obesity, diabetes, hypertension, and endocrine disorders. The dysregulation of lipid metabolism is one of the most prominent metabolic changes observed in cancers. Therefore, the PLIN protein family has recently attracted attention owing to its role in lipid metabolism and cancer. To date, no studies have addressed the association between the prognosis of lung cancer and PLIN1 expression. For the first time, we found that high PLIN1 expression was significantly correlated with worse disease-free survival (DFS) in lung squamous cell carcinoma (SCC). We examined PLIN1 expression by the immunohistochemical analysis of surgical lung SCC specimens obtained from 94 patients. We analyzed the correlation between PLIN1 expression, clinicopathological data, and patient survival, using a chi-squared test, Kaplan-Meier analysis with log-rank tests, and the multivariate Cox proportional hazards regression test. High PLIN1 expression was significantly correlated with lower DFS in the Kaplan-Meier analysis and the multivariate Cox proportional hazards regression model. High PLIN1 expression was significantly correlated with worse prognosis in lung SCC.

Low-fat dairy consumption and the risk of lung cancer: A large prospective cohort study

BACKGROUND

Despite the possible contribution of dairy products to the development or prevention of cancers, there is a lack of epidemiological evidence linking low-fat dairy consumption to the risk of developing lung cancer. This research was conducted to fill this knowledge gap.

METHODS

The data for this research were collected from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. The Cox proportional risk model was employed to evaluate the link between low-fat dairy consumption and the risk of developing lung cancer. Hazard ratios (HRs) and 95% confidence intervals (CIs) were measured in both unadjusted and adjusted models. A series of predefined subgroup analyses were performed to identify potential effect modifiers, and several sensitivity analyses were conducted to assess the stability of the findings.

RESULTS

The study included data from 98,459 individuals. During a total of 869,807.9 follow-up person-years, 1642 cases of lung cancer were observed, with an incidence of 0.189 cases for every 100 person-years. In the fully adjusted model, participants in the highest quartile of low-fat dairy consumption had a significantly decreased risk of lung cancer compared to the ones in the lowest quartile (HRquartile 4 vs. 1 : 0.769, 95% CI: 0.664, 0.891, ptrend  = 0.005). The restricted cubic spline plot revealed an inverse nonlinear dose-response relationship between low-fat dairy consumption and lung cancer risk (pnonlinearity  = 0.008). Subgroup analyses demonstrated that the inverse association was stronger among participants with higher daily caloric intake (pinteraction  = 0.031). Various sensitivity analyses produced consistent results.

CONCLUSION

Consuming more low-fat dairy products is significantly linked to a reduced risk of developing lung cancer, indicating that an appropriate increase in the use of low-fat dairy products may help prevent lung cancer.

Heme: The Lord of the Iron Ring

Heme is an iron-protoporphyrin complex with an essential physiologic function for all cells, especially for those in which heme is a key prosthetic group of proteins such as hemoglobin, myoglobin, and cytochromes of the mitochondria. However, it is also known that heme can participate in pro-oxidant and pro-inflammatory responses, leading to cytotoxicity in various tissues and organs such as the kidney, brain, heart, liver, and in immune cells. Indeed, heme, released as a result of tissue damage, can stimulate local and remote inflammatory reactions. These can initiate innate immune responses that, if left uncontrolled, can compound primary injuries and promote organ failure. In contrast, a cadre of heme receptors are arrayed on the plasma membrane that is designed either for heme import into the cell, or for the purpose of activating specific signaling pathways. Thus, free heme can serve either as a deleterious molecule, or one that can traffic and initiate highly specific cellular responses that are teleologically important for survival. Herein, we review heme metabolism and signaling pathways, including heme synthesis, degradation, and scavenging. We will focus on trauma and inflammatory diseases, including traumatic brain injury, trauma-related sepsis, cancer, and cardiovascular diseases where current work suggests that heme may be most important.

The Consumption of Animal and Plant Foods in Areas of High Prevalence of Stroke and Colorectal Cancer

Diets of red and processed meat have been reported as important risk factors for developing colorectal cancer. Given the racial and ethnic differences in the incidence of colorectal cancer, patterns of food consumption, and areas of residence, particularly in the South, more data is needed on the relationship between residing in a high stroke area, colorectal cancer incidence levels, and red meat and processed meat consumption. We created online surveys to ascertain meat, red meat, and healthy food consumption levels. We used OLS regression to evaluate the association between residence in Stroke Belt states and colorectal cancer incidence quartiles with food consumption. We further used path analysis using structural equation modeling to evaluate if age, sex, race/ethnicity, income, and comorbidity index mediated the association between residence in the eight-state Stroke Belt, colorectal cancer incidence groups, and meat consumption. Our sample included 923 participants, with 167 (18.1%) residing in the Stroke Belt and 13.9% being in the highest colorectal cancer incidence group. The findings show that residing in a Stroke Belt state is predictive of the consumption of overall meat 0.93 more days per week or red meat 0.55 more days per week compared to those not residing in a Stroke Belt state. These data can be used to develop future diet interventions in these high-risk areas to reduce rates of colorectal cancer and other negative health outcomes.

Dietary factors and the risk of lung cancer by epidermal growth factor receptor mutation status and histological subtypes

Background

Previous studies have reported differential associations of certain dietary factors such as soy consumption by epidermal growth factor receptor mutant (EGFR +) subtype of non-small cell lung cancer (NSCLC). However, whether the other dietary factors including meat, fruits, and vegetables have differential risks on different histological and molecular subtypes of lung cancer remains unclear. Therefore, we conducted a case-control study to evaluate these associations.

Methods

A total of 3,170 cases and 4,238 controls from three different studies (Genes and Environment in Lung Cancer Study, Lung Cancer Consortium Singapore Study, and Multi-ethnic Cohort Study) were included. Information on demographics, lifestyle, and dietary consumption was obtained using questionnaires. Diet was assessed by using the number of standard servings of each item consumed per week. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between meat, vegetables, and fruits consumption with lung cancer risk after adjusting for potential confounders.

Results

We identified a significant inverse association between higher consumption of fruits and the risk of lung cancer (2nd tertile: OR = 0.54, 95%CI = 0.46-0.65; 3rd tertile: OR = 0.77, 95%CI = 0.65-0.91), compared with the lower (1st tertile) consumption of fruits. Higher vegetable consumption was significantly associated with a lower risk of EGFR + lung cancer (OR = 0.69, 95% CI = 0.54-0.88), however, this association was not significant among EGFR wild-type (-) lung cancer. Conversely, higher consumption of total meat (OR = 2.10, 95%CI = 1.58-2.79) was significantly associated with higher lung cancer risk, as compared with the lower consumption group.

Conclusions

Differential associations between vegetable consumption with EGFR mutation status in NSCLC were found. Further prospective studies are warranted to assess this association and elucidate the biological mechanisms.

Dietary meat mutagens intake and cancer risk: A systematic review and meta-analysis

Background

Clinical and preclinical studies suggested that certain mutagens occurring as a reaction of creatine, amino acids, and sugar during the high temperature of cooking meat are involved in the pathogenesis of human cancer. Here we conducted a systematic review and meta-analysis to examine whether meat mutagens [PhIP, MeIQx, DiMeIQx, total HCA, and B(a)P] present a risk factor for human cancer.

Methods

We searched the following databases for relevant articles published from inception to 10 Oct 2021 with no language restrictions: Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Baidu Academic, Zhejiang Digital Library. Two independent researchers screened all titles and obtained eligible texts for further screening. Independent data extraction was conducted, and meta-analysis was carried out using random-effects models to calculate the risk ratio of the meat mutagens exposure.

Results

A total of 1,786,410 participants and 70,653 cancer cases were identified. Among these, there were 12 different types of cancer at various sites, i.e., breast, bladder, colorectal, colon, rectum, prostate, lung, Non-Hodgkin lymphoma, kidney, gastric, esophagus, pancreatic, hepatocellular carcinoma. Cancer risk was significantly increased by intake of PhIP (OR = 1.13;95% CI 1.07–1.21; p < 0.001), MeIQx (OR = 1.14; 95% CI: 1.07–1.21; p < 0.001), DiMeIQx (OR = 1.07; 95% CI: 1.01–1.13; p = 0.013), total HCA (OR = 1.20; 95% CI: 1.03–1.38; p = 0.016), and cancer risk was not significantly increased by intake of B(a)P (OR = 1.04; 95% CI: 0.98–1.10; p = 0.206).

Conclusion

Meat mutagens of PhIP, MeIQx, DiMeIQx, and total HCA have a positive association with the risk of cancer.

Systematic review registration

[www.crd.york.ac.uk/prospero], identifier [CRD42022148856].

Traditional Chinese medicine (TCM) as a source of new anticancer drugs

Covering: up to July 2020Drugs derived from traditional Chinese medicine (TCM) include both single chemical entities and multi-component preparations. Drugs of both types play a significant role in the healthcare system in China, but are not well-known outside China. The research and development process, the molecular mechanisms of action, and the clinical evaluation associated with some exemplificative anticancer drugs based on TCM are discussed, along with their potential of integration in western medicine.

The Multifaceted Role of Heme in Cancer

Heme, an iron-containing porphyrin, is of vital importance for cells due to its involvement in several biological processes, including oxygen transport, energy production and drug metabolism. Besides these vital functions, heme also bears toxic properties and, therefore, the amount of heme inside the cells must be tightly regulated. Similarly, heme intake from dietary sources is strictly controlled to meet body requirements. The multifaceted nature of heme renders it a best candidate molecule exploited/controlled by tumor cells in order to modulate their energetic metabolism, to interact with the microenvironment and to sustain proliferation and survival. The present review summarizes the literature on heme and cancer, emphasizing the importance to consider heme as a prominent player in different aspects of tumor onset and progression.

The relation of healthy and Western dietary patterns to the risk of endometrial and ovarian cancers: a systematic review and meta-analysis

Dietary patterns have been used to explore the association between dietary factors and risk of endometrial (EC) and ovarian cancer (OC); however, the results are inconclusive. This meta-analysis aimed to analyze these associations. Methods: Pertinent studies published prior to March 2016 were systematically searched. The common dietary patterns were selected and adjusted risk estimates were derived by comparing the highest with the lowest categories of dietary pattern scores. Results: A total of 8 studies, 5 for endometrial cancer (1 cohort and 4 case-control studies including 2617 cases and 78082 participants/controls) and 3 for ovarian cancer (1 cohort and 2 case-control studies with 2025 cases and 101482 participants/controls) were included in this meta-analysis. A lower risk of EC was shown for the highest compared with the lowest category of the healthy dietary pattern (OR = 0.84, 95% CI: 0.72-0.98; P for heterogeneity = 0.10), whereas the Western dietary pattern was related to the higher risk of EC (OR = 1.19, 95% CI: 1.01-1.41; P for heterogeneity = 0.35). No significant relationship was found between the healthy dietary pattern (OR = 1.03, 95% CI: 0.69-1.53; P for heterogeneity = 0.01) and OC, while, adherence to the western pattern was associated with a 73% higher risk of OC (OR = 1.73, 95% CI: 1.08-2.37; P for heterogeneity = 0.06). Conclusion: A Western dietary pattern might be associated with a higher risk of endometrial and ovarian cancer.

Outdoor particulate matter (PM10) exposure and lung cancer risk in the EAGLE study

Objective

Cohort studies in Europe, but not in North-America, showed an association between exposure to outdoor particulate matter with aerodynamic diameter ≤10 μm (PM₁₀) and lung cancer risk. Only a case-control study on lung cancer and PM₁₀ in South Korea has so far been performed. For the first time in Europe we analyzed quantitatively this association using a case-control study design in highly polluted areas in Italy.

Methods

The Environment And Genetics in Lung cancer Etiology (EAGLE) study, a population-based case-control study performed in the period 2002–2005 in the Lombardy Region, north-west Italy, enrolled 2099 cases and 2120 controls frequency-matched for area of residence, gender, and age. For this study we selected subjects with complete active and passive smoking history living in the same municipality since 1980 until study enrollment. Fine resolution annual PM₁₀ estimates obtained by applying land use regression modeling to satellite data calibrated with fixed site monitor measurements were used. We assigned each subject the PM₁₀ average estimates for year 2000 based on enrollment address. We used logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI) adjusted for matching variables, education, smoking, and dietary and occupational variables.

Results

We included 3473 subjects, 1665 cases (1318 men, 347 women) and 1808 controls (1368 men, 440 women), with PM₁₀ individual levels ranging from 2.3 to 53.8 μg/m³ (mean: 46.3). We found increasing lung cancer risk with increasing PM₁₀ category (P-value for trend: 0.04). The OR per 10 μg/m³ was 1.28 (95% CI: 0.95–1.72). The association appeared stronger for squamous cell carcinoma (OR 1.44, 95% CI: 0.90–2.29).

Conclusion

In a population living in highly polluted areas in Italy, our study added suggestive evidence of a positive association between PM₁₀ exposure and lung cancer risk. This study emphasizes the need to strengthen policies to reduce airborne pollution.

Distribution of serum levels of persistent organic pollutants, heterocyclic aromatic amine theoretical intake and nutritional cofactors in a semi-rural island population

Persistent organic pollutant (POP) exposure is strongly associated with negative health effects in humans. Heterocyclic aromatic amines (HAAs) are formed during high temperature cooking of foods (i.e. meat and fish). Human exposure to HAA is through food consumption and from similar food groups to POPs. A study of serum samples for POPs in a non-occupational exposed population (n = 149, age range 18-80 years, recruited in 2012) and comparison with estimated HAA daily intake calculations based on food diaries were undertaken. Three different age groups (group 1, 18-29 years; group 2, 30-44 years; and group 3, 45-80 years) were used to explore possible relationships between POP levels present in blood, HAA intake and nutritional cofactors. Significant differences (p < 0.05) between groups (1 and 3) for POP levels were found for p,p'-DDE, polychlorinated biphenyl (PCB) 153, PCB 138 and the sum of PCBs. A similar trend was found between groups 2 and 3 for PCB 153 and sum of PCBs. Significant differences were found between groups 1 and 3 and groups 2 and 3 for HAA intake., i.e. HAA intake was lowest in those of middle age, which may well reflect a different pathway of human exposure between HAA and POPs through the diet preferences.

Cured meat intake is associated with worsening asthma symptoms

BACKGROUND

Cured meat intake-a recent carcinogenic factor-may increase the risk of COPD, but its association with asthma remains unknown. Though body mass index (BMI) is a likely risk factor for asthma, its role in the diet-asthma association as a mediator has never been studied. We investigated the association between cured meat intake and worsening asthma symptoms in adults, and the role of BMI as a potential mediator.

METHODS

Using data from the French prospective EGEA study (baseline: 2003-2007; follow-up: 2011-2013), we applied a mediation analysis in the counterfactual framework, a marginal structural model (MSM), to estimate the direct effect of baseline cured meat intake (<1, 1-3.9, ≥4 servings/week) on change in asthma symptom score (worsening or not), and the indirect effect mediated by BMI.

RESULTS

Among the 971 participants (mean age 43 years; 49% men; 42% with asthma), 20% reported worsening asthma symptoms during the mean follow-up time of 7 years. Using the MSM, we reported a positive direct effect of cured meat intake on worsening asthma symptoms (multivariable OR=1.76, 95% CI 1.01 to 3.06 for ≥4 vs <1 serving/week). We also reported an indirect effect mediated by BMI (OR=1.07; 95% CI 1.01 to 1.14), accounting for 14% of the total effect.

CONCLUSIONS

Higher cured meat intake was associated with worsening asthma symptoms over time, through a direct effect and to a lesser extent an effect mediated by BMI. This research extends the effect of diet on asthma in adults.

Nut Consumption and Lung Cancer Risk: Results from Two Large Observational Studies

Background: Epidemiologic evidence on the association between nut consumption and lung cancer risk is limited.Methods: We investigated this relationship in the Environment and Genetics in Lung Cancer Etiology (EAGLE) study, a population-based case-control study, and the National Institutes of Health (NIH) American Association of Retired Persons (AARP) Diet and Health Study, a prospective cohort. We identified 2,098 lung cases for EAGLE and 18,533 incident cases in AARP. Diet was assessed by food frequency questionnaire for both studies. Multivariable ORs and HRs and respective 95% confidence intervals (CI) were calculated using unconditional logistic regression and Cox proportional hazards regression for EAGLE and AARP, respectively.Results: Higher frequency of intake of nut consumption was inversely associated with overall lung cancer risk (highest vs. lowest quintile, OR_EAGLE = 0.74; 95% CI, 0.57-0.95; HR_AARP = 0.86; 95% CI, 0.81-0.91), regardless of smoking status. Results from the prospective cohort showed similar associations across histologic subtypes and a more pronounced benefits from nut consumption for those who smoked 1 to 20 cigarettes/day (OR_EAGLE = 0.61; 95% CI, 0.39-0.95; HR_AARP = 0.83; 95% CI, 0.74-0.94).Conclusions: Nut consumption was inversely associated with lung cancer in two large population-based studies, and associations were independent of cigarette smoking and other known risk factors.Impact: To our knowledge, this is the first study that examined the association between nut consumption and lung cancer risk by histologic subtypes and smoking intensity. Cancer Epidemiol Biomarkers Prev; 26(6); 826-36. ©2017 AACR.

Heterocyclic Aromatic Amines in Cooked Meat Products: Causes, Formation, Occurrence, and Risk Assessment

Meat products are sources of protein with high biological value and an essential source of other nutrients, such as vitamins and minerals. Heating processes cause food to become more appetizing with changes in texture, appearance, flavor, and chemical properties by the altering of protein structure and other ingredients. During heat treatment, heterocyclic aromatic amines (HAAs), potent mutagens/carcinogens, are formed due to the Maillard reaction. The HAAs are classified in at least 2 groups: thermic HAAs (100 to 300 °C) and pyrolytic HAAs (>300 °C). This review focuses on the parameters and precursors which affect the formation of HAAs: preparation, such as the marinating of meat, and cooking methods, including temperature, duration, and heat transfer, as well as levels of precursors. Additionally, factors are described subject to pH, and the type of meat and ingredients, such as added antioxidants, types of carbohydrates and amino acids, ions, fat, and other substances inhibiting or enhancing the formation of HAAs. An overview of the different analytical methods available is shown to determine the HAAs, including their preparation to clean up the sample prior to extraction. Epidemiological results and human daily intake of HAAs obtained from questionnaires show a relationship between the preference for very well-done meat products with increased HAA levels and an enhanced risk of the incidence of cancer, besides other carcinogens in the diet. The metabolic pathway of HAAs is governed by the activity of several enzymes leading to the formation of DNA adducts or HAA excretion and genetic sensitivity of individuals to the impact of HAAs on human cancer risk.

Dietary habits of lung cancer patients from the Lower Silesia region of Poland

AIM OF THE STUDY

Assessment of lung cancer patients' dietary habits before treatment enable medical staff to provide more individual, precise and complex care to patients, taking into consideration their nutritional status. The aim of this study was, therefore, to evaluate dietary habits related to lung cancer risk of lung cancer patients in comparison with controls from the Lower Silesia region of Poland.

MATERIAL AND METHODS

Assessments of dietary habits, based on a validated questionnaire related to lung cancer risk were performed on 92 lung cancer patients and compared with the results obtained in 157 controls. Dietary patterns were evaluated concerning on eating frequency of high- and low- glycemic index products, vegetables and fruits, vegetable and fruit juices, green tea, liquid dairy products, meat and fried products over the previous year. Alcohol consumption was assessed on a dichotomous scale (yes or no).

RESULTS

Majority of patients had inappropriate dietary habits, such as low consumption of low GI cereal products, vegetables, fruit and green tea, and a high consumption frequency of fried products.

CONCLUSIONS

Reported dietary mistakes indicate the need for dietary education among people at lung cancer risk and with newly diagnosed disease, to enhance their nutritional status.

Processed meat consumption and squamous cell carcinoma of the oesophagus in a large case-control study in Uruguay

BACKGROUND

The role of processed meat in the aetiology of squamous cell oesophageal cancer has been explored in detail.

METHODS

In the time period 1990-2005, a case-control study was conducted in Montevideo, Uruguay including 2,368 participants (876 cases of oesophageal cancer and 1,492 controls). Relative risks, approximated by the odds ratios, were estimated by multiple unconditional logistic regression.

RESULTS

Processed meat was positively associated with oesophageal cancer (upper quartile vs lower quartile OR 2.30, 95%CI 1.72-3.07), whereas salted meat intake was positively associated with squamous cell oesophageal cancer (OR 3.82, 95%CI 2.74-5.33). Finally other cured meats were positively associated with oesophageal cancer (OR 1.65, 95%CI 1.22- 2.22).

CONCLUSIONS

It could be concluded that processed meat consumption could be an important risk factor for the aetiology of squamous cell oesophageal cancer in Uruguay.

Low-carbohydrate diets and cardiovascular and total mortality in Japanese: a 29-year follow-up of NIPPON DATA80

Long-term safety of consuming low-carbohydrate diets (LCD) in Asian populations, whose carbohydrate intake is relatively high, is not known. In the present study, the association of LCD with CVD and total mortality was assessed using data obtained in the NIPPON DATA80 (National Integrated Project for Prospective Observation of Non-communicable Disease and Its Trends in the Aged 1980) during 29 years of follow-up. At baseline in 1980, data were collected from study participants aged ≥ 30 years from randomly selected areas in Japan. LCD scores were calculated based on the percentage of energy as carbohydrate, fat and protein, estimated by 3 d weighed food records. A total of 9200 participants (56% women, mean age 51 years) were followed up. During the follow-up, 1171 CVD deaths (52% in women) and 3443 total deaths (48% in women) occurred. The multivariable-adjusted hazard ratio (HR) for CVD mortality using the Cox model comparing the highest v. lowest deciles of LCD score was 0·60 (95% CI 0·38, 0·94; P(trend) = 0·021) for women and 0·78 (95% CI 0·58, 1·05; P(trend) = 0·079) for women and men combined; the HR for total mortality was 0·74 (95% CI 0·57, 0·95; P(trend) = 0·029) for women and 0·87 (95% CI 0·74, 1·02; P(trend) = 0·090) for women and men combined. None of the associations was statistically significant in men. No differential effects of animal-based and plant-fish-based LCD were observed. In conclusions, moderate diets lower in carbohydrate and higher in protein and fat are significantly inversely associated with CVD and total mortality in women.

Comparing indices of diet quality with chronic disease mortality risk in postmenopausal women in the Women's Health Initiative Observational Study: evidence to inform national dietary guidance

Poor diet quality is thought to be a leading risk factor for years of life lost. We examined how scores on 4 commonly used diet quality indices-the Healthy Eating Index 2010 (HEI), the Alternative Healthy Eating Index 2010 (AHEI), the Alternate Mediterranean Diet (aMED), and the Dietary Approaches to Stop Hypertension (DASH)-are related to the risks of death from all causes, cardiovascular disease (CVD), and cancer among postmenopausal women. Our prospective cohort study included 63,805 participants in the Women's Health Initiative Observational Study (from 1993-2010) who completed a food frequency questionnaire at enrollment. Cox proportional hazards models were fit using person-years as the underlying time metric. We estimated multivariate hazard ratios and 95% confidence intervals for death associated with increasing quintiles of diet quality index scores. During 12.9 years of follow-up, 5,692 deaths occurred, including 1,483 from CVD and 2,384 from cancer. Across indices and after adjustment for multiple covariates, having better diet quality (as assessed by HEI, AHEI, aMED, and DASH scores) was associated with statistically significant 18%-26% lower all-cause and CVD mortality risk. Higher HEI, aMED, and DASH (but not AHEI) scores were associated with a statistically significant 20%-23% lower risk of cancer death. These results suggest that postmenopausal women consuming a diet in line with a priori diet quality indices have a lower risk of death from chronic disease.

Heme-related gene expression signatures of meat intakes in lung cancer tissues

Lung cancer causes more deaths worldwide than any other cancer. In addition to cigarette smoking, dietary factors may contribute to lung carcinogenesis. Epidemiologic studies, including the environment and genetics in lung cancer etiology (EAGLE), have reported increased consumption of red/processed meats to be associated with higher risk of lung cancer. Heme-iron toxicity may link meat intake with cancer. We investigated this hypothesis in meat-related lung carcinogenesis using whole genome expression. We measured genome-wide expression (HG-U133A) in 49 tumor and 42 non-involved fresh frozen lung tissues of 64 adenocarcinoma EAGLE patients. We studied gene expression profiles by high-versus-low meat consumption, with and without adjustment by sex, age, and smoking. Threshold for significance was a false discovery rate (FDR) ≤ 0.15. We studied whether the identified genes played a role in heme-iron related processes by means of manually curated literature search and gene ontology-based pathway analysis. We found that gene expression of 232 annotated genes in tumor tissue significantly distinguished lung adenocarcinoma cases who consumed above/below the median intake of fresh red meats (FDR = 0.12). Sixty-three (∼ 28%) of the 232 identified genes (12 expected by chance, P-value < 0.001) were involved in heme binding, absorption, transport, and Wnt signaling pathway (e.g., CYPs, TPO, HPX, HFE, SLCs, and WNTs). We also identified several genes involved in lipid metabolism (e.g., NCR1, TNF, and UCP3) and oxidative stress (e.g., TPO, SGK2, and MTHFR) that may be indirectly related to heme-toxicity. The study's results provide preliminary evidence that heme-iron toxicity might be one underlying mechanism linking fresh red meat intake and lung cancer.

Red and processed meat consumption and the risk of lung cancer: a dose-response meta-analysis of 33 published studies

This meta-analysis was to summarize the published studies about the association between red/processed meat consumption and the risk of lung cancer. 5 databases were systematically reviewed, and random-effect model was used to pool the study results and to assess dose-response relationships. Results shown that six cohort studies and twenty eight case-control studies were included in this meat-analysis. The pooled Risk Radios (RR) for total red meat and processed meat were 1.44 (95% CI, 1.29-1.61) and 1.23 (95% CI, 1.10-1.37), respectively. Dose-response analysis revealed that for every increment of 120 grams red meat per day the risk of lung cancer increases 35% and for every increment of 50 grams red meat per day the risk of lung cancer increases 20%. The present dose-response meta-analysis suggested that both red and processed meat consumption showed a positive effect on lung cancer risk.

Inverse hormesis of cancer growth mediated by narrow ranges of tumor-directed antibodies

Compelling evidence for naturally occurring immunosurveillance against malignancies informs and justifies some current approaches toward cancer immunotherapy. However, some types of immune reactions have also been shown to facilitate tumor progression. For example, our previous studies showed that although experimental tumor growth is enhanced by low levels of circulating antibodies directed against the nonhuman sialic acid N-glycolyl-neuraminic acid (Neu5Gc), which accumulates in human tumors, growth could be inhibited by anti-Neu5Gc antibodies from a different source, in a different model. However, it remains generally unclear whether the immune responses that mediate cancer immunosurveillance vs. those responsible for inflammatory facilitation are qualitatively and/or quantitatively distinct. Here, we address this question using multiple murine tumor growth models in which polyclonal antibodies against tumor antigens, such as Neu5Gc, can alter tumor progression. We found that although growth was stimulated at low antibody doses, it was inhibited by high doses, over a linear and remarkably narrow range, defining an immune response curve (IRC; i.e., inverse hormesis). Moreover, modulation of immune responses against the tumor by altering antibody avidity or by enhancing innate immunity shifted the IRC in the appropriate direction. Thus, the dualistic role of immunosurveillance vs. inflammation in modulating tumor progression can be quantitatively distinguished in multiple model systems, and can occur over a remarkably narrow range. Similar findings were made in a human tumor xenograft model using a narrow range of doses of a monoclonal antibody currently in clinical use. These findings may have implications for the etiology, prevention, and treatment of cancer.

Fried meat intake is a risk factor for lung adenocarcinoma in a prospective cohort of Chinese men and women in Singapore

Probable human carcinogens are generated during Chinese-style high-temperature cooking of meat and have been detected in the ambient air and on the meat surface. Although the inhalation of these compounds is an established risk factor for lung cancer, exposure via fried meat consumption has not yet been prospectively evaluated as a risk factor. The relationship between fried meat intake and lung cancer risk was investigated using data from a prospective cohort study among Chinese in Singapore. Lung cancer cases (n = 1130) were identified from 61 321 men and women, 70% of whom were lifetime never smokers. Proportional hazards regression methods were used to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Overall, there was no association between fried meat intake and risk of all lung cancers combined. For lung adenocarcinoma, fried meat intake had a statistically significant association with increased risk. The association between fried meat intake and risk of lung adenocarcinoma became stronger when analyses were restricted to lifetime never smokers. Compared with the lowest tertile of fried meat intake, the HRs (95% CIs) for the second and third tertiles were 1.43 (0.98, 2.08) and 1.51 (1.03, 2.22), respectively (P for trend = 0.04). The positive association was present among both men and women. There was no association between fried meat intake and risk of non-adenocarcinomas of the lung. Our prospective results for fried meat intake support consumption as an important route of exposure to compounds from Chinese-style high-temperature cooking for the development of lung adenocarcinoma.

Meat consumption and risk of lung cancer: evidence from observational studies

BACKGROUND

A number of epidemiological studies have reported inconsistent findings on the association between meat consumption and lung cancer.

DESIGN

We therefore conducted a systematic review and meta-analysis to investigate the relationship between meat consumption and lung cancer risk in epidemiological studies.

RESULTS

Twenty-three case-control and 11 cohort studies were included. All studies adjusted for smoking or conducted in never smokers. The summary relative risks (RRs) of lung cancer for the highest versus lowest intake categories were 1.35 (95% confidence interval (CI) 1.08-1.69) for total meat, 1.34 (95% CI 1.18-1.52) for red meat, and 1.06 (95% CI 0.90-1.25) for processed meat. An inverse association was found between poultry intake and lung cancer (RR = 0.91, 95% CI 0.85-0.97), but not for total white meat (RR = 1.06, 95% CI 0.82-1.37) or fish (RR = 1.01, 95% CI 0.96-1.07).

CONCLUSIONS

The relationship between meat intake and lung cancer risk appears to depend on the types of meat consumed. A high intake of red meat may increase the risk of lung cancer by about 35%, while a high intake of poultry decreases the risk by about 10%. More well-designed cohort studies on meat mutagens or heme iron, meat cooking preferences, and doneness level are needed to fully characterize this meat-lung cancer association.

Processed meat consumption and risk of cancer: a multisite case-control study in Uruguay

BACKGROUND

The role of processed meat in the aetiology of several cancers was explored in detail.

METHODS

In the time period 1996-2004, a multisite case-control study was conducted in Montevideo, Uruguay. The study included 6 060 participants (3 528 cases and 2 532 controls) corresponding to cancers of the oral cavity, pharynx, oesophagus, stomach, colon, rectum, larynx, lung, female breast, prostate, urinary bladder, and kidney (renal cell carcinoma only).

RESULTS

The highest odds ratios (ORs) were positively associated with cancers of the colon, rectum, stomach, oesophagus, and lung. With the exception of renal cell carcinoma, the remaining cancer sites were significantly associated with elevated risks for processed meat consumption. Furthermore, mortadella, salami, hot dog, ham, and salted meat were strongly associated with risk of several cancer sites.

CONCLUSION

It could be concluded that processed meat intake could be a powerful multiorgan carcinogen.

Fresh Garlic Extract Induces Growth Arrest and Morphological Differentiation of MCF7 Breast Cancer Cells

Consumption of diets rich in fruits and vegetables is often associated with a reduced risk of developing cancer, particularly breast cancer. Considering that 1 in 8 women in the United States will develop breast cancer in the course of her lifetime, dietary manipulation could have a major impact on the incidence of breast cancer. We report here that fresh extracts of garlic (not boiled) arrested the growth and altered the morphology of MCF7 breast cancer cells. Deregulated levels of E-cadherin, cytokeratin8/18, and β-catenin correlated with the altered phenotype. We propose that early down-regulation of cyclin D1, reduced phosphorylation of ERK1, and increased phosphorylation of eIF2-α triggered the phenotypical changes. Reduced expression of hsp27 and sam68 and elevated levels of Rb and p21 further contributed to the sustained growth reduction. These findings provide a better understanding of the cellular responses to dietary supplements and provide potential options to treat breast cancer.

Influence of quercetin-rich food intake on microRNA expression in lung cancer tissues

BACKGROUND

Epidemiologic studies have reported that frequent consumption of quercetin-rich foods is inversely associated with lung cancer incidence. A quercetin-rich diet might modulate microRNA (miR) expression; however, this mechanism has not been fully examined.

METHODS

miR expression data were measured by a custom-made array in formalin-fixed paraffin-embedded tissue samples from 264 lung cancer cases (144 adenocarcinomas and 120 squamous cell carcinomas). Intake of quercetin-rich foods was derived from a food-frequency questionnaire. In individual-miR-based analyses, we compared the expression of miRs (n = 198) between lung cancer cases consuming high versus low quercetin-rich food intake using multivariate ANOVA tests. In family-miR-based analyses, we used Functional Class Scoring (FCS) to assess differential effect on biologically functional miR families. We accounted for multiple testing using 10,000 global permutations (significance at P(global) < 0.10). All multivariate analyses were conducted separately by histology and by smoking status (former and current smokers).

RESULTS

Family-based analyses showed that a quercetin-rich diet differentiated miR expression profiles of the tumor suppressor let-7 family among adenocarcinomas (P(FCS) < 0.001). Other significantly differentiated miR families included carcinogenesis-related miR-146, miR-26, and miR-17 (P (FCS) < 0.05). In individual-based analyses, we found that among former and current smokers with adenocarcinoma, 33 miRs were observed to be differentiated between highest and lowest quercetin-rich food consumers (23 expected by chance; P(global) = 0.047).

CONCLUSIONS

We observed differential expression of key biologically functional miRs between high versus low consumers of quercetin-rich foods in adenocarcinoma cases.

IMPACT

Our findings provide preliminary evidence on the mechanism underlying quercetin-related lung carcinogenesis.

Role of CYP1A2 polymorphisms on lung cancer risk in a prospective study

Cytochrome P4501A2 (CYP1A2) is a key enzyme for lung carcinogen activation and lung inflammation. We studied the interactions of the CYP1A2 functional variants -3860G/A(rs2069514),-2467T/delT(rs3569413),-163C/A(rs762551)] with occupational/environmental carcinogenic exposures in the development of lung cancer in a case-control study nested in the Danish prospective cohort "Diet, Cancer and Health." At enrollment (1993-1997), blood samples for genotype analyses and information on lifestyle were collected 5 (mean value) years before the onset of the disease. The study population included 425 lung cancer cases and 786 subcohort members, who were gender- and age-matched. We found that -163A carriers were at increased risk of lung cancer (P=0.035) in a multivariate COX regression model, which was adjusted for personal habits (i.e., cumulative smoking, passive smoke at home, alcohol intake, and fruit intake) and occupational exposure. Additionally, the interaction between -2467delT and smoking increases lung cancer risk in males, especially light smokers (<21.5 pack-years, P=0.004). The increased lung cancer risk found in -163C carriers, independent of smoking status, and in -2467delT male smokers, suggests that these variants could influence lung cancer development through different mechanisms (i.e. lung carcinogen activation and lung inflammation).

Intake of red meat and heterocyclic amines, metabolic pathway genes and bladder cancer risk

We analyzed the association between meat intake, heterocyclic amines (HCAs) and bladder cancer (BC) risk in a large case-control study comprised of 884 BC cases and 878 healthy controls, recruited from 1999 to 2009. Epidemiologic and dietary data were collected via an in-person interview. Compared to the lowest quartile of red meat intake, the odds ratios (ORs) for the second, third and fourth quartiles were 1.17 (95% CI: 0.87-1.58), 1.47 (95% CI: 1.09-1.99) and 1.95 (95% CI: 1.41-2.68), respectively, (p-for trend <0.001). In a subset of participants with intakes of HCAs available, compared with those with the lowest quartile of intake, the ORs for the second, third and fourth quartiles were 1.47 (95% CI: 0.60-3.64), 2.58 (95% CI: 1.09-6.11) and 3.32 (95% CI: 1.37-8.01), respectively, (p for trend <0.001). In cumulative analysis of SNPs in the pathway, compared with subjects carrying 0-4 unfavorable genotypes, subjects carrying 5 and 6 or more unfavorable genotypes were at 1.60-fold (95% CI: 1.20-2.12) and 2.37-fold (95% CI: 1.82-3.10) increased risk, respectively. Moreover, subjects carrying six or more unfavorable genotypes and whose red meat intake was in the highest quartile were at 5.09-fold increased risk (95% CI: 2.89-8.96; p < 0.001). These results strongly support that high red meat intake, high intake of HCAs and carrying high number of unfavorable genotypes in the HCA metabolic pathways are associated with increased risk of BC in the study population.

Red meat consumption and cancer: reasons to suspect involvement of bovine infectious factors in colorectal cancer

An increased risk for colorectal cancer has been consistently reported for long-time consumption of cooked and processed red meat. This has frequently been attributed to chemical carcinogens arising during the cooking process of meat. Long-time fish or poultry consumption apparently does not increase the risk, although similar or higher concentrations of chemical carcinogens were recorded in their preparation for consumption. The geographic epidemiology of colorectal cancer seems to correspond to regions with a high rate of beef consumption. Countries with a virtual absence of beef in the diet (India) or where preferably lamb or goat meat is consumed (several Arabic countries) reveal low rates of colorectal cancer. In China, pork consumption has a long tradition, with an intermediate colorectal cancer rate. In Japan and Korea, large scale beef and pork imports started after World War II or after the Korean War. A steep rise in colorectal cancer incidence was noted after 1970 in Japan and 1990 in Korea. The consumption of undercooked beef (e.g., shabu-shabu, Korean yukhoe and Japanese yukke) became very popular in both countries. The available data are compatible with the interpretation that a specific beef factor, suspected to be one or more thermoresistant potentially oncogenic bovine viruses (e.g., polyoma-, papilloma- or possibly single-stranded DNA viruses) may contaminate beef preparations and lead to latent infections in the colorectal tract. Preceding, concomitant or subsequent exposure to chemical carcinogens arising during cooking procedures should result in increased risk for colorectal cancer synergistic with these infections.

Diet and the risk of head and neck cancer: a pooled analysis in the INHANCE consortium

We investigated the association between diet and head and neck cancer (HNC) risk using data from the International Head and Neck Cancer Epidemiology (INHANCE) consortium. The INHANCE pooled data included 22 case-control studies with 14,520 cases and 22,737 controls. Center-specific quartiles among the controls were used for food groups, and frequencies per week were used for single food items. A dietary pattern score combining high fruit and vegetable intake and low red meat intake was created. Odds ratios (OR) and 95% confidence intervals (CI) for the dietary items on the risk of HNC were estimated with a two-stage random-effects logistic regression model. An inverse association was observed for higher-frequency intake of fruit (4th vs. 1st quartile OR = 0.52, 95% CI = 0.43-0.62, p (trend) < 0.01) and vegetables (OR = 0.66, 95% CI = 0.49-0.90, p (trend) = 0.01). Intake of red meat (OR = 1.40, 95% CI = 1.13-1.74, p (trend) = 0.13) and processed meat (OR = 1.37, 95% CI = 1.14-1.65, p (trend) < 0.01) was positively associated with HNC risk. Higher dietary pattern scores, reflecting high fruit/vegetable and low red meat intake, were associated with reduced HNC risk (per score increment OR = 0.90, 95% CI = 0.84-0.97).

Health Implications of a Vegetarian Diet

There is now a significant amount of research that demonstrates the health benefits of vegetarian and plant-based diets, which have been associated with a reduced risk of obesity, diabetes, heart disease, and some types of cancer as well as increased longevity. Vegetarian diets are typically lower in fat, particularly saturated fat, and higher in dietary fiber. They are also likely to include more whole grains, legumes, nuts, and soy protein, and together with the absence of red meat, this type of eating plan may provide many benefits for the prevention and treatment of obesity and chronic health problems, including diabetes and cardiovascular disease. Although a well-planned vegetarian or vegan diet can meet all the nutritional needs of an individual, it may be necessary to pay particular attention to some nutrients to ensure an adequate intake, particularly if the person is on a vegan diet. This article will review the evidence for the health benefits of a vegetarian diet and also discuss strategies for meeting the nutritional needs of those following a vegetarian or plant-based eating pattern.

Meat consumption, cooking practices, meat mutagens, and risk of prostate cancer

Consumption of red meat, particularly well-done meat, has been associated with increased prostate cancer risk. High-temperature cooking methods such as grilling and barbecuing may produce heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are known carcinogens. We assessed the association with meat consumption and estimated HCA and PAH exposure in a population-based case-control study of prostate cancer. Newly diagnosed cases aged 40-79 years (531 advanced cases, 195 localized cases) and 527 controls were asked about dietary intake, including usual meat cooking methods and doneness levels. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate logistic regression. For advanced prostate cancer, but not localized disease, increased risks were associated with higher consumption of hamburgers (OR = 1.79, CI = 1.10-2.92), processed meat (OR = 1.57, CI = 1.04-2.36), grilled red meat (OR = 1.63, CI = 0.99-2.68), and well-done red meat (OR = 1.52, CI = 0.93-2.46), and intermediate intake of 2-amino-1-methyl1-6-phenylimidazo[4,5-b]pyridine (PhIP) (Quartile 2 vs. 1: OR = 1.41, CI = 0.98-2.01; Quartile 3 vs. 1: OR = 1.42, CI = 0.98-2.04), but not for higher intake. White meat consumption was not associated with prostate cancer. These findings provide further evidence that consumption of processed meat and red meat cooked at high temperature is associated with increased risk of advanced, but not localized, prostate cancer.

Meat-cooking mutagens and risk of renal cell carcinoma

BACKGROUND

High-temperature cooked meat contains two families of carcinogens, heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). Given the kidneys' role in metabolism and urinary excretion of these compounds, we investigated meat-derived mutagens, as well as meat intake and cooking methods, in a population-based case-control study conducted in metropolitan Detroit and Chicago.

METHODS

Newly diagnosed, histologically confirmed adenocarcinoma of the renal parenchyma (renal cell carcinoma (RCC)) cases (n=1192) were frequency matched on age, sex, and race to controls (n=1175). The interviewer-administered Diet History Questionnaire (DHQ) included queries for meat-cooking methods and doneness with photographic aids. Levels of meat mutagens were estimated using the DHQ in conjunction with the CHARRED database.

RESULTS

The risk of RCC increased with intake of barbecued meat (P(trend)=0.04) and the PAH, benzo(a)pyrene (BaP) (multivariable-adjusted odds ratio and 95% confidence interval, highest vs lowest quartile: 1.50 (1.14, 1.95), P(trend)=0.001). With increasing BaP intake, the risk of RCC was more than twofold in African Americans and current smokers (P(interaction)<0.05). We found no association for HCAs or overall meat intake.

CONCLUSION

BaP intake, a PAH in barbecued meat, was positively associated with RCC. These biologically plausible findings advocate further epidemiological investigation into dietary intake of BaP and risk of RCC.

Meat consumption and risk of lung cancer among never-smoking women

The relationship between diet and lung cancer, apart from the protective effect of fruit and vegetables, is poorly understood. Reports on the role of dietary components such as meat are inconsistent, and few studies include sufficient numbers of nonsmokers. We examined the relationship between meat consumption and never-smoking lung cancer in a hospital-based case-control study of Singapore Chinese women, a population with low smoking prevalence. Three hundred and ninety-nine cases and 815 controls were recruited, of whom 258 cases and 712 controls were never smokers. A standardized questionnaire (which included a food frequency questionnaire module) was administered by trained interviewers. Among these never smokers, fruit and vegetable intake were inversely associated with lung cancer risk. Seventy-two percent of meat consumed was white meat (chicken or fish). Meat consumption overall was inversely associated with lung cancer [adjusted odds ratio (OR), 0.88, 0.59 for second, third tertiles, P (trend) = .012]. An inverse relationship between fish consumption and lung cancer (adjusted OR, 0.81, 0.47 for 2nd, 3rd tertiles, P (trend) < .001) was observed. No association was seen between consumption of processed meats and lung cancer, nor between dietary heterocyclic amines and lung cancer. Our data suggest that fish consumption may be protective against lung cancer in never smokers.

Dietary patterns affect lung cancer risk in never smokers

A number of studies suggest a role of dietary factors as risk predictors of lung cancer in never smokers. However, it is difficult to interpret the observed associations of lung cancer risk with any particular dietary item due to high correlation among different dietary items. In this study, we derived uncorrelated patterns of dietary items in the never smokers and evaluated the association of these patterns with lung cancer risk, using food frequency data from 299 never-smoker lung cancer patients and 317 controls enrolled in an ongoing case-control lung cancer study. We identified 2 major dietary patterns in never smokers: a "healthy eating" pattern including vegetables, fruits, and low-fat food items, and a "mixed dishes" pattern including most foods with positive loadings. Using multivariable regression analysis, we show that the healthy eating pattern is associated with a significant reduction of lung cancer risk among never smokers. The effect of the healthy eating pattern remained significant after adjustment for age, gender, education, caloric intake, secondhand smoke exposure, and family history of cancer. This finding, if confirmed in a prospective study, has a clear preventive significance, by promoting interventions encouraging healthier diets.

Comparison of standard methods for assessing dietary intake of benzo[a]pyrene

BACKGROUND

Inconsistent presence and strength of associations between dietary benzo[a]pyrene (BaP) exposure and cancers may be due to differences in exposure assessment methods. Thus, we determined correlations of usual meat and BaP intake among three methods: food frequency questionnaires (FFQ), diet diaries, and a biomarker.

METHODS

Thirty-six nonsmokers were recruited in Baltimore, MD during 2004-2005. Meat and BaP intake estimated from baseline and follow-up FFQs combined with a BaP residue database (FFQ-RD), mean meat and BaP intake estimated from three diet diaries coupled with the residue database (Diary-RD), and mean of three urinary 1-hydroxypyrene glucuronide (1-OHPG) measurements were compared using Spearman correlations. Collections spanned approximately nine months.

RESULTS

BaP intakes from meat from the baseline [median = 6.4, interquartile range (IQR) = 13.9 ng/d] and follow-up FFQ-RD (median = 7.3, IQR = 35.7 ng/d) were higher than the Diary-RD (median = 1.1, IQR = 7.4 ng/d). Mean 1-OHPG concentration was weakly correlated with mean meat intake (r = 0.33, P = 0.05) and BaP intake from meat (r = 0.27, P = 0.11) from the Diary-RD. Mean BaP intake estimated from the Diary-RD was positively correlated with the follow-up (r = 0.35, P = 0.04) but not baseline (r = 0.20, P = 0.24) FFQ; the converse was true for meat intake.

CONCLUSIONS

Diary-RD estimates were supported by biomarker measurements, but considerable unexplained variability remained. Limited correlation among the dietary BaP exposure assessment methods could be due to differences in timeframes covered by the assessments, interpersonal variability in metabolism, deficiencies in the residue database, or nondietary exposures to BaP.

IMPACT

Limited correlation in estimated BaP intake among standard methods may contribute to inconsistent epidemiology of BaP and cancer.

Does adherence to the Mediterranean diet have a protective effect against active and passive smoking?

OBJECTIVE

To investigate the existing evidence about whether adherence to the Mediterranean diet may have a role as an effect modifier of active and passive smoking on human health.

STUDY DESIGN

Review.

METHODS

An overview of emerging evidence and published studies that cover the interaction between the Mediterranean diet and smoking.

RESULTS

Both epidemiological and laboratory studies have shown that the Mediterranean diet has a protective effect against biochemical and molecular processes that lead to cancer, cardiovascular disease and respiratory illness. Based on the high daily intake of vitamins and antioxidants, the Mediterranean diet is comprised of a number of compounds that could alter certain outcomes related to smoking. Studies have indicated that certain diseases attributable to smoking, such as lung cancer, asthma and cardiovascular disease, are inversely associated with certain antioxidants and lipids.

CONCLUSIONS

The literature indicates that the existence of a partial interaction between adherence to the Mediterranean diet and the health effects of smoking is possible. Further research is needed to lead to a conclusive statement on this hypothesis.

Low-carbohydrate diets and all-cause and cause-specific mortality: two cohort studies

BACKGROUND

Data on the long-term association between low-carbohydrate diets and mortality are sparse.

OBJECTIVE

To examine the association of low-carbohydrate diets with mortality during 26 years of follow-up in women and 20 years in men.

DESIGN

Prospective cohort study of women and men who were followed from 1980 (women) or 1986 (men) until 2006. Low-carbohydrate diets, either animal-based (emphasizing animal sources of fat and protein) or vegetable-based (emphasizing vegetable sources of fat and protein), were computed from several validated food-frequency questionnaires assessed during follow-up.

SETTING

Nurses' Health Study and Health Professionals' Follow-up Study.

PARTICIPANTS

85 168 women (aged 34 to 59 years at baseline) and 44 548 men (aged 40 to 75 years at baseline) without heart disease, cancer, or diabetes.

MEASUREMENTS

Investigators documented 12 555 deaths (2458 cardiovascular-related and 5780 cancer-related) in women and 8678 deaths (2746 cardiovascular-related and 2960 cancer-related) in men.

RESULTS

The overall low-carbohydrate score was associated with a modest increase in overall mortality in a pooled analysis (hazard ratio [HR] comparing extreme deciles, 1.12 [95% CI, 1.01 to 1.24]; P for trend = 0.136). The animal low-carbohydrate score was associated with higher all-cause mortality (pooled HR comparing extreme deciles, 1.23 [CI, 1.11 to 1.37]; P for trend = 0.051), cardiovascular mortality (corresponding HR, 1.14 [CI, 1.01 to 1.29]; P for trend = 0.029), and cancer mortality (corresponding HR, 1.28 [CI, 1.02 to 1.60]; P for trend = 0.089). In contrast, a higher vegetable low-carbohydrate score was associated with lower all-cause mortality (HR, 0.80 [CI, 0.75 to 0.85]; P for trend

LIMITATIONS

Diet and lifestyle characteristics were assessed with some degree of error. Sensitivity analyses indicated that results were probably not substantively affected by residual confounding or an unmeasured confounder. Participants were not a representative sample of the U.S. population.

CONCLUSION

A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates.

PRIMARY FUNDING SOURCE

National Institutes of Health.

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Key Words

• diet
• nutrition
• mortality
• carbohydrate
• protein

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MESH Headings

• Adult
• Animals
• Cardiovascular Diseases/mortality
• Cause of Death
• Diet, Carbohydrate-Restricted
• Dietary Fats/administration & dosage
• Dietary Proteins/administration & dosage
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Neoplasms/mortality
• Plant Proteins, Dietary/administration & dosage
• Young Adult

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Grants

• R01 CA095589 NCI NIH HHS
• P30 DK040561 NIDDK NIH HHS
• P01 CA087969 NCI NIH HHS
• R01 CA095589-05A2 NCI NIH HHS
• HL60712 NHLBI NIH HHS
• CA95589 NCI NIH HHS
• R01 HL060712 NHLBI NIH HHS
• R01 HL060712-02 NHLBI NIH HHS
• CA87969 NCI NIH HHS
• P30 DK040561-15 NIDDK NIH HHS

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Affiliation(s)

Teresa T Fung Harvard School of Public Health, Boston, Massachusetts 02115, USA.
Rob M van Dam
Susan E Hankinson
Meir Stampfer
Walter C Willett
Frank B Hu

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Low-carbohydrate diets and all-cause and cause-specific mortality: two cohort studies

BACKGROUND

Data on the long-term association between low-carbohydrate diets and mortality are sparse.

OBJECTIVE

To examine the association of low-carbohydrate diets with mortality during 26 years of follow-up in women and 20 years in men.

DESIGN

Prospective cohort study of women and men who were followed from 1980 (women) or 1986 (men) until 2006. Low-carbohydrate diets, either animal-based (emphasizing animal sources of fat and protein) or vegetable-based (emphasizing vegetable sources of fat and protein), were computed from several validated food-frequency questionnaires assessed during follow-up.

SETTING

Nurses' Health Study and Health Professionals' Follow-up Study.

PARTICIPANTS

85 168 women (aged 34 to 59 years at baseline) and 44 548 men (aged 40 to 75 years at baseline) without heart disease, cancer, or diabetes.

MEASUREMENTS

Investigators documented 12 555 deaths (2458 cardiovascular-related and 5780 cancer-related) in women and 8678 deaths (2746 cardiovascular-related and 2960 cancer-related) in men.

RESULTS

The overall low-carbohydrate score was associated with a modest increase in overall mortality in a pooled analysis (hazard ratio [HR] comparing extreme deciles, 1.12 [95% CI, 1.01 to 1.24]; P for trend = 0.136). The animal low-carbohydrate score was associated with higher all-cause mortality (pooled HR comparing extreme deciles, 1.23 [CI, 1.11 to 1.37]; P for trend = 0.051), cardiovascular mortality (corresponding HR, 1.14 [CI, 1.01 to 1.29]; P for trend = 0.029), and cancer mortality (corresponding HR, 1.28 [CI, 1.02 to 1.60]; P for trend = 0.089). In contrast, a higher vegetable low-carbohydrate score was associated with lower all-cause mortality (HR, 0.80 [CI, 0.75 to 0.85]; P for trend

LIMITATIONS

Diet and lifestyle characteristics were assessed with some degree of error. Sensitivity analyses indicated that results were probably not substantively affected by residual confounding or an unmeasured confounder. Participants were not a representative sample of the U.S. population.

CONCLUSION

A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates.

PRIMARY FUNDING SOURCE

National Institutes of Health.

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Key Words

• diet
• nutrition
• mortality
• carbohydrate
• protein

Collapse

MESH Headings

• Adult
• Animals
• Cardiovascular Diseases/mortality
• Cause of Death
• Diet, Carbohydrate-Restricted
• Dietary Fats/administration & dosage
• Dietary Proteins/administration & dosage
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Neoplasms/mortality
• Plant Proteins, Dietary/administration & dosage
• Young Adult

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Grants

• R01 CA095589 NCI NIH HHS
• P30 DK040561 NIDDK NIH HHS
• P01 CA087969 NCI NIH HHS
• R01 CA095589-05A2 NCI NIH HHS
• HL60712 NHLBI NIH HHS
• CA95589 NCI NIH HHS
• R01 HL060712 NHLBI NIH HHS
• R01 HL060712-02 NHLBI NIH HHS
• CA87969 NCI NIH HHS
• P30 DK040561-15 NIDDK NIH HHS

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Affiliation(s)

Teresa T Fung Harvard School of Public Health, Boston, Massachusetts 02115, USA.
Rob M van Dam
Susan E Hankinson
Meir Stampfer
Walter C Willett
Frank B Hu

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Lung cancer and environmental chemical exposure: a review of our current state of knowledge with reference to the role of hormones and hormone receptors as an increased risk factor for developing lung cancer in man

Lung cancer is a dominant cause of cancer mortality. The etiology of lung cancer is mainly related to cigarette smoking, airborne genotoxic carcinogens, and arsenic, but its sex-specific incidence suggests that other mechanisms, such as hormones, may also be involved in the process of carcinogenesis. A number of agents commonly present in the living environment can have dual biological effects: not only are they genotoxic / carcinogenic, but they are also hormonally active as xenoestrogens. This dualism may explain sex-specific differences reported in both types and incidence of lung cancer. In a novel approach to investigate the complexity of lung cancer, etiology, including systems biology, will be used as a tool for a simultaneous interpretation of measurable environmental and biological parameters. Using this approach, the etiology of human lung cancer can be more thoroughly investigated using the available data from oncology and environmental health. The information gained could be applied in the introduction of preventive measures, in personalized medicine, and in more relevant legislation, which should be adjusted to reflect the current knowledge on the complex environmental interactions underlying this life-threatening disease.