Vegetables and fruit and human cancer: update of an Italian study

Microglial activation in Alzheimer's disease: The role of flavonoids and microRNAs

Alzheimer's disease (AD) is the most common form of senile dementia and is characterized by progressive cognitive impairment and neuronal degeneration. Microglial activation is an important pathologic hallmark of AD. During disease progression, microglial cells switch from an alternative or anti-inflammatory and neuroprotective profile (M2) to a classic or proinflammatory and neurotoxic profile (M1). Phenotypically, M1 microglia is characterized by the activation of inflammatory signaling pathways that cause increased expression of proinflammatory genes, including those coding for cytokines and chemokines. This microglia-mediated neuroinflammation contributes to neuronal cell death. Recent studies in microglial cells have shown that a group of plant-derived compounds, known as flavonoids, possess anti-inflammatory properties and therefore exert a neuroprotective effect through regulating microglia activation. Here, we discuss how flavonoids can promote the switch from an inflammatory M1 phenotype to an anti-inflammatory M2 phenotype in microglia and how this represents a valuable opportunity for the development of novel therapeutic strategies to blunt neuroinflammation and boost neuronal recovery in AD. We also review how certain flavonoids can inhibit neuroinflammation through their action on the expression of microglia-specific microRNAs (miRNAs), which also constitute a key therapeutic approach in different neuropathologies involving an inflammatory component, including AD. Finally, we propose novel targets of microglia-specific miRNAs that may be considered for AD treatment.

Vegetable intake and the risk of bladder cancer in the BLadder Cancer Epidemiology and Nutritional Determinants (BLEND) international study

BACKGROUND

Although a potential inverse association between vegetable intake and bladder cancer risk has been reported, epidemiological evidence is inconsistent. This research aimed to elucidate the association between vegetable intake and bladder cancer risk by conducting a pooled analysis of data from prospective cohort studies.

METHODS

Vegetable intake in relation to bladder cancer risk was examined by pooling individual-level data from 13 cohort studies, comprising 3203 cases among a total of 555,685 participants. Pooled multivariate hazard ratios (HRs), with corresponding 95% confidence intervals (CIs), were estimated using Cox proportional hazards regression models stratified by cohort for intakes of total vegetable, vegetable subtypes (i.e. non-starchy, starchy, green leafy and cruciferous vegetables) and individual vegetable types. In addition, a diet diversity score was used to assess the association of the varied types of vegetable intake on bladder cancer risk.

RESULTS

The association between vegetable intake and bladder cancer risk differed by sex (P-interaction = 0.011) and smoking status (P-interaction = 0.038); therefore, analyses were stratified by sex and smoking status. With adjustment of age, sex, smoking, energy intake, ethnicity and other potential dietary factors, we found that higher intake of total and non-starchy vegetables were inversely associated with the risk of bladder cancer among women (comparing the highest with lowest intake tertile: HR = 0.79, 95% CI = 0.64-0.98, P = 0.037 for trend, HR per 1 SD increment = 0.89, 95% CI = 0.81-0.99; HR = 0.78, 95% CI = 0.63-0.97, P = 0.034 for trend, HR per 1 SD increment = 0.88, 95% CI = 0.79-0.98, respectively). However, no evidence of association was observed among men, and the intake of vegetable was not found to be associated with bladder cancer when stratified by smoking status. Moreover, we found no evidence of association for diet diversity with bladder cancer risk.

CONCLUSION

Higher intakes of total and non-starchy vegetable are associated with reduced risk of bladder cancer for women. Further studies are needed to clarify whether these results reflect causal processes and potential underlying mechanisms.

Dietary patterns and oral and pharyngeal cancer using latent class analysis

The methods traditionally used to identify a posteriori dietary patterns are principal components, factor and cluster analysis. The aim of our study is to assess the relationship between dietary patterns derived with latent class analysis (LCA) and oral/pharyngeal cancer risk (OPC), highlighting the strengths of this method compared to traditional ones. We analyzed data from an Italian multicentric case-control study on OPC including 946 cases and 2,492 hospital controls. Dietary patterns were derived using LCA on 25 food groups. A multiple logistic regression model was used to derive odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for OPC according to the dietary patterns identified. We identified four dietary patterns. The first one was characterized by a high intake of leafy and fruiting vegetable and fruits (Prudent pattern), the second one showed a high intake of red meat and low intake of selected fruits and vegetables (Western pattern). The last two patterns showed a combination-type of diet. We labeled "Lower consumers-combination pattern" the cluster that showed a low intake of the majority of foods, and "Higher consumers-combination pattern" the one characterized by a high intake of various foods. Compared to the "Prudent pattern", the "Western" and the "Lower consumers-combination" ones were positively related to the risk of OPC (OR = 2.56, 95% CI: 1.90-3.45 and OR = 2.23, 95% CI: 1.64-3.02). No difference in risk emerged for the "Higher consumers-combination pattern" (OR = 1.28, 95% CI: 0.92-1.77).

Adherence to the World Cancer Research Fund/American Institute for Cancer Research recommendations and head and neck cancers risk

OBJECTIVES

The World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) have proposed eight recommendations for cancer prevention, related to body fatness, diet, and physical activity. Our aim is to evaluate the role of adherence to these recommendations on head and neck cancers risk.

MATERIALS AND METHODS

We obtained an overall score including seven of the WCRF/AICR recommendations, and examined its relationship with head and neck cancers risk in two Italian case-control studies including 946 patients with oral cavity and pharyngeal (OCP) cancer and 2492 controls, and 689 patients with laryngeal cancer and 1605 controls.

RESULTS

Higher adherence to WCRF/AICR recommendations was associated to a reduced risk of OCP cancer (odds ratio, OR=0.45, 95% confidence interval, CI: 0.33-0.62 for a score of 4-<5, and OR=0.32, 95% CI: 0.22-0.49 for a score of ⩾5 as compared to <3). The ORs for laryngeal cancer were 0.68 (95% CI: 0.50-0.92) for a score of 3-<4, 0.39 (95% CI: 0.28-0.55) for a score of 4-<5, and 0.24 (95% CI: 0.15-0.38) for a score of ⩾5.

CONCLUSION

Our study indicates that high adherence to the WCRF/AICR recommendations for cancer prevention is associated with a substantially decreased risk of head and neck cancers.

Bioavailability, bioactivity and impact on health of dietary flavonoids and related compounds: an update

There is substantial interest in the role of plant secondary metabolites as protective dietary agents. In particular, the involvement of flavonoids and related compounds has become a major topic in human nutrition research. Evidence from epidemiological and human intervention studies is emerging regarding the protective effects of various (poly)phenol-rich foods against several chronic diseases, including neurodegeneration, cancer and cardiovascular diseases. In recent years, the use of HPLC-MS for the analysis of flavonoids and related compounds in foods and biological samples has significantly enhanced our understanding of (poly)phenol bioavailability. These advancements have also led to improvements in the available food composition and metabolomic databases, and consequently in the development of biomarkers of (poly)phenol intake to use in epidemiological studies. Efforts to create adequate standardised materials and well-matched controls to use in randomised controlled trials have also improved the quality of the available data. In vitro investigations using physiologically achievable concentrations of (poly)phenol metabolites and catabolites with appropriate model test systems have provided new and interesting insights on potential mechanisms of actions. This article will summarise recent findings on the bioavailability and biological activity of (poly)phenols, focusing on the epidemiological and clinical evidence of beneficial effects of flavonoids and related compounds on urinary tract infections, cognitive function and age-related cognitive decline, cancer and cardiovascular disease.

Dietary (poly)phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases

Human intervention trials have provided evidence for protective effects of various (poly)phenol-rich foods against chronic disease, including cardiovascular disease, neurodegeneration, and cancer. While there are considerable data suggesting benefits of (poly)phenol intake, conclusions regarding their preventive potential remain unresolved due to several limitations in existing studies. Bioactivity investigations using cell lines have made an extensive use of both (poly)phenolic aglycones and sugar conjugates, these being the typical forms that exist in planta, at concentrations in the low-μM-to-mM range. However, after ingestion, dietary (poly)phenolics appear in the circulatory system not as the parent compounds, but as phase II metabolites, and their presence in plasma after dietary intake rarely exceeds nM concentrations. Substantial quantities of both the parent compounds and their metabolites pass to the colon where they are degraded by the action of the local microbiota, giving rise principally to small phenolic acid and aromatic catabolites that are absorbed into the circulatory system. This comprehensive review describes the different groups of compounds that have been reported to be involved in human nutrition, their fate in the body as they pass through the gastrointestinal tract and are absorbed into the circulatory system, the evidence of their impact on human chronic diseases, and the possible mechanisms of action through which (poly)phenol metabolites and catabolites may exert these protective actions. It is concluded that better performed in vivo intervention and in vitro mechanistic studies are needed to fully understand how these molecules interact with human physiological and pathological processes.

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).

Polyphenols and human health: prevention of disease and mechanisms of action

Polyphenols are found ubiquitously in plants and their regular consumption has been associated with a reduced risk of a number of chronic diseases, including cancer, cardiovascular disease (CVD) and neurodegenerative disorders. Rather than exerting direct antioxidant effects, the mechanisms by which polyphenols express these beneficial properties appear to involve their interaction with cellular signaling pathways and related machinery that mediate cell function under both normal and pathological conditions. We illustrate that their interactions with two such pathways, the MAP kinase (ERK, JNK, p38) and PI3 kinase/Akt signaling cascades, allow them to impact upon normal and abnormal cell function, thus influencing the cellular processes involved in the initiation and progression of cancer, CVD and neurodegeneration. For example, their ability to activate ERK in neurons leads to a promotion of neuronal survival and cognitive enhancements, both of which influence the progression of Alzheimer’s disease, whilst ERK activation by polyphenols in vascular endothelial cells influences nitric oxide production, blood pressure and ultimately CVD risk. The main focus of this review is to provide an overview of the role that polyphenols play in the prevention of cancer, cardiovascular disease and neurodegeneration. We present epidemiological data, human intervention study findings, as well as animal and in vitro studies in support of these actions and in each case we consider how their actions at the cellular level may underpin their physiological effects.

Selected aspects of Mediterranean diet and cancer risk

European Mediterranean populations have a high life expectancy. Several aspects of their diet are considered favorable on health. We considered the role of various aspects of the Mediterranean diet on cancer risk in a series of Italian case-control studies including about 10,000 cases of cancer at 13 different sites and over 17,000 controls. For most epithelial cancers, the risk decreased with increasing vegetable consumption. Allium vegetables were also favorably related to cancer risk. Fruit intake was inversely associated with digestive tract and laryngeal cancers. For digestive tract cancers, the population attributable risks for low intake of vegetables and fruit ranged between 15% and 40%. Olive oil and unsaturated fats, which are typical aspects of the Mediterranean diet, were inversely related to the risk of several cancers, particularly of the upper aerodigestive tract. Whole grain food (and hence possibly fiber) intake was also related to reduced risk of various cancers. In contrast, refined grains and, consequently, glycemic load and index were associated to increased risks. Several micronutrients and food components (including folate, flavonoids, and carotenoids) showed inverse relations with cancer risk, but the main component(s) responsible for the favorable effect of a diet rich in vegetables and fruit remain undefined.

Citrus fruit and cancer risk in a network of case-control studies

BACKGROUND

Citrus fruit has shown a favorable effect against various cancers. To better understand their role in cancer risk, we analyzed data from a series of case-control studies conducted in Italy and Switzerland.

PATIENTS AND METHODS

The studies included 955 patients with oral and pharyngeal cancer, 395 with esophageal, 999 with stomach, 3,634 with large bowel, 527 with laryngeal, 2,900 with breast, 454 with endometrial, 1,031 with ovarian, 1,294 with prostate, and 767 with renal cell cancer. All cancers were incident and histologically confirmed. Controls were admitted to the same network of hospitals for acute, nonneoplastic conditions. Odds ratios (OR) were estimated by multiple logistic regression models, including terms for major identified confounding factors for each cancer site, and energy intake.

RESULTS

The ORs for the highest versus lowest category of citrus fruit consumption were 0.47 (95% confidence interval, CI, 0.36-0.61) for oral and pharyngeal, 0.42 (95% CI, 0.25-0.70) for esophageal, 0.69 (95% CI, 0.52-0.92) for stomach, 0.82 (95% CI, 0.72-0.93) for colorectal, and 0.55 (95% CI, 0.37-0.83) for laryngeal cancer. No consistent association was found with breast, endometrial, ovarian, prostate, and renal cell cancer.

CONCLUSIONS

Our findings indicate that citrus fruit has a protective role against cancers of the digestive and upper respiratory tract.

Association between Mediterranean dietary patterns and cancer risk

To evaluate the association between diet and cancer risk in Mediterranean countries, data presented from a series of case-control studies conducted in Italy were reviewed. The series comprised over 20,000 cases affecting 20 cancer sites and included 18,000 controls. For most epithelial cancers, risk decreased with increasing vegetable and fruit consumption. Fish and whole grains (but not refined grains) were also favorable diet indicators. Olive oil and other monounsaturated and unsaturated fats were inversely related to cancer risk at several sites. A Mediterranean diet pattern appears to be favorable for a reduced cancer risk, indicating the importance of dietary patterns.

Recent patterns in gastric cancer: a global overview

Until the mid-1990s, gastric cancer has been the first cause of cancer death worldwide, although rates had been declining for several decades and gastric cancer has become a relatively rare cancer in North America and in most Northern and Western Europe, but not in Eastern Europe, Russia and selected areas of Central and South America or East Asia. We analyzed gastric cancer mortality in Europe and other areas of the world from 1980 to 2005 using joinpoint regression analysis, and provided updated site-specific incidence rates from 51 selected registries. Over the last decade, the annual percent change (APC) in mortality rate was around -3, -4% for the major European countries. The APC were similar for the Republic of Korea (APC = -4.3%), Australia (-3.7%), the USA (-3.6%), Japan (-3.5%), Ukraine (-3%) and the Russian Federation (-2.8%). In Latin America, the decline was less marked, but constant with APC around -1.6% in Chile and Brazil, -2.3% in Argentina and Mexico and -2.6% in Colombia. Cancers in the fundus and pylorus are more common in high incidence and mortality areas and have been declining more than cardia gastric cancer. Steady downward trends persist in gastric cancer mortality worldwide even in middle aged population, and hence further appreciable declines are likely in the near future.

Flavonoids and laryngeal cancer risk in Italy

BACKGROUND

Flavonoids may play an important role in explaining the protective effect of vegetables and fruit against cancer.

PATIENTS AND METHODS

To investigate the relation between flavonoids and laryngeal cancer risk, we have applied data on the composition of foods and beverages in terms of six principal classes of flavonoids to a case-control study of laryngeal cancer conducted from 1992 to 2000 in Italy. Cases were 460 subjects with incident, histologically confirmed laryngeal cancer; controls were 1088 patients admitted for acute, non-neoplastic diseases. Odds ratios (OR) were estimated through multiple logistic regression models, including terms for sociodemographic and lifestyle factors, tobacco smoking, alcohol consumption and energy intake.

RESULTS

Significant inverse relations were found for the highest versus the lowest quintile of intake for flavan-3-ols (OR = 0.64), flavanones (OR = 0.60), flavonols (OR = 0.32) and total flavonoids (OR = 0.60), although the overall trends in risk were significant only for flavanones and flavonols. No consistent associations were observed for isoflavones, anthocyanidins and flavones. The estimates did not differ substantially across strata of alcohol drinking, tobacco smoking, body mass index and education, and tended to persist even after controlling for vegetable and fruit intake.

CONCLUSION

This study provides support for a beneficial effect of selected flavonoids on laryngeal cancer risk.

Mediterranean diet and cancer

Objective:

To analyse the role of various aspects of the Mediterranean diet in several common epithelial cancers, including digestive and selected non-digestive tract neoplasms.

Design:

Systematic analysis of data from a series of case-control studies.

Setting:

Northern Italy, between 1983 and 1998.

Subjects:

Over 12 000 cases of 20 cancer sites and 10 000 controls.

Results:

For most epithelial cancers, the risk decreased with increasing vegetable and fruit consumption, with relative risk (RR) between 0.3 and 0.7 for the highest versus the lowest tertile. For digestive tract cancers, population-attributable risks for low intake of vegetables and fruit ranged between 15 and 40%. A protective effect was observed also for breast, female genital tract, urinary tract and a few other epithelial neoplasms. A number of antioxidants and other micronutrients showed an inverse relationship with cancer risk, but the main components responsible for the favourable effect of a diet rich in vegetables and fruit remain undefined. Fish tended to be another favourable diet indicator. In contrast, subjects reporting frequent red meat intake showed RRs above unity for several common neoplasms. Intake of whole-grain foods was related to a reduced risk of several types of cancer, particularly of the upper digestive tract. This may be due to a favourable role of fibre, but the issue is still open to discussion. In contrast, refined grain intake and, consequently, glycaemic load and glycaemic index were associated with increased risk of different types of cancer including, among others, breast and colorectal.

Conclusions:

A low-risk diet for cancer in the Mediterranean would imply increasing the consumption of fruit and vegetables, as well as avoiding increasing the intakes of meat and refined carbohydrates. Further, olive oil and other unsaturated fats, which are also typical aspects of the Mediterranean diet, should be preferred to saturated ones.

Diet and cancer risk in Mediterranean countries: open issues

Objective

To analyse various aspects of the Mediterranean diet in relation to the risk of several common cancers in Italy.

Design

Data from a series of case-control studies conducted in northern Italy between 1983 and 2004 on over 20 000 cases of several major cancers and 18 000 controls.

Results

For most digestive tract cancers, the risk decreased with increasing vegetable and fruit consumption, with relative risks between 0.3 and 0.7 for the highest level of intake, and the population-attributable risks for low intake of vegetables and fruit ranged between 15 and 40%. Less strong inverse relations were observed for other (epithelial) cancers, too. A number of micronutrients contained in vegetables and fruit showed an inverse relation with cancer risk. In particular, flavones, flavonols and resveratrol were inversely related to breast cancer risk. Olive oil, which is a typical aspect of the Mediterranean diet, has also been inversely related to cancers of the colorectum and breast, and mainly of the upper digestive and respiratory tract. Consumption of pizza, one of the most typical Italian foods, was related to a reduced risk of digestive tract cancers, although pizza may simply be an aspecific indicator of the Italian diet.

Conclusions

Adherence to the Mediterranean diet is a favourable indicator of the risk of several common epithelial cancers in Italy. A score summarising the major characteristics of the Mediterranean diet was related to a priori defined reduced risks of several digestive tract neoplasms by over 50%.

Food groups and risk of non-Hodgkin lymphoma: a multicenter, case-control study in Italy

Incidence of non-Hodgkin lymphoma (NHL) has been rising worldwide, but the reasons are undefined. Dietary habits may play a role in the etiology of NHL by influencing the metabolic pathways of several cells of the immune system. This case-control study investigated the relation between food consumption and NHL risk. Between 1999 and 2002, we conducted a hospital-based case-control study on NHL in 2 areas of Italy. Cases were 190 patients (median age 58 years) with incident NHL admitted to specialized and general hospitals. Controls were 484 patients (median age 63 years) with acute non-neoplastic conditions admitted to the same hospitals network of cases. A validated food-frequency questionnaire was used to assess habitual diet 2 years before interview. Unconditional multiple logistic regression was used to estimate the odds ratios (OR) and the corresponding 95% confidence intervals (CI), with allowance for energy intake, according to the residual model. Consumption of highest versus lowest quartile of pasta/rice (OR = 1.87, 95% CI: 1.04-3.36) and cheese (OR = 1.66, 95% CI: 0.98-2.83) were associated with a significantly increased NHL risk. Inverse association was found for vegetables (OR = 0.49, 95% CI: 0.28-0.87), fruits (OR = 0.51, 95% CI: 0.30-0.85), and egg consumption (OR = 0.59, 95% CI: 0.36-0.97). The association of pasta/rice was also supported by an increased risk of high glycemic load levels (OR = 1.86, 95% CI: 1.04-3.32). In conclusion, our results suggested that diet could affect NHL risk.

Apples increase nitric oxide production by human saliva at the acidic pH of the stomach: a new biological function for polyphenols with a catechol group?

Dietary inorganic nitrate is secreted in saliva and reduced to nitrite by bacterial flora. At the acidic pH of the stomach nitrite is present as nitrous acid in equilibrium with nitric oxide (*NO), and other nitrogen oxides with nitrating and nitrosating activity. *NO in the stomach exerts several beneficial effects, but nitrosating/nitrating species have been implicated as a possible cause of epithelial neoplasia at the gastroesophageal junction. We investigated the effects of apple extracts on *NO release by human saliva at pH 2. A water extract obtained from apple homogenate increased *NO release caused by acidification of saliva. Data show that polyphenols were responsible for this activity, with chlorogenic acid and (+)-catechin the most active and concentrated species. However, ferulic acid, a hydroxycinnamic acid with only one aromatic hydroxyl group, did not increase *NO release. Fructose, the most representative sugar in apples, was also inactive. Interestingly, ascorbic acid in saliva induced a SCN(-)-enhanced burst of *NO but, unlike apple, the release was transient. The simultaneous addition of ascorbic acid and apple extract caused a burst of *NO followed by the increased steady-state level characteristic of saliva containing apple extract. Chlorogenic acid and (+)-catechin, but not ferulic acid, formed o-semiquinone radicals and nitrated polyphenols, suggesting the scavenging of *NO(2) by o-semiquinones. Our results propose that some apple polyphenols not only inhibit nitrosation/nitration but also promote *NO bio-availabilty at the gastric level, a previously unappreciated function.

Fruits and Vegetables and Ovarian Cancer Risk in a Pooled Analysis of 12 Cohort Studies

Because fruits and vegetables are rich in bioactive compounds with potential cancer-preventive actions, increased consumption may reduce the risk of ovarian cancer. Evidence on the association between fruit and vegetable intake and ovarian cancer risk has not been consistent. We analyzed and pooled the primary data from 12 prospective studies in North America and Europe. Fruit and vegetable intake was measured at baseline in each study using a validated food-frequency questionnaire. To summarize the association between fruit and vegetable intake and ovarian cancer, study-specific relative risks (RR) were estimated using the Cox proportional hazards model, and then combined using a random-effects model. Among 560,441 women, 2,130 cases of invasive epithelial ovarian cancer occurred during a maximum follow-up of 7 to 22 years across studies. Total fruit intake was not associated with ovarian cancer risk-the pooled multivariate RR for the highest versus the lowest quartile of intake was 1.06 [95% confidence interval (95% CI), 0.92-1.21; P value, test for trend = 0.73; P value, test for between-studies heterogeneity = 0.74]. Similarly, results for total vegetable intake indicated no significant association (pooled multivariate RR, 0.90; 95% CI, 0.78-1.04, for the highest versus the lowest quartile; P value, test for trend = 0.06; P value, test for between-studies heterogeneity = 0.31). Intakes of botanically defined fruit and vegetable groups and individual fruits and vegetables were also not associated with ovarian cancer risk. Associations for total fruits and vegetables were similar for different histologic types. These results suggest that fruit and vegetable consumption in adulthood has no important association with the risk of ovarian cancer.

Mediterranean diet and cancer risk

Various aspects of the Mediterranean diet are considered favourable with regard to cancer risk. These aspects were analysed using data from a series of case-control studies conducted in northern Italy between 1983 and 2001 on over 12,000 cases of 20 cancer sites and 10,000 controls. For most epithelial cancers, the risk decreased with increasing vegetable and fruit consumption, with odds ratios (OR) between 0.3 and 0.7 for the highest versus the lowest tertile. Subjects reporting frequent red meat intake showed ORs above unity for several common neoplasms. Conversely, fish (and consequently, n-3 fatty acids) tended to be another favourable dietary indicator. Wholegrain food intake was related to reduced risk of several types of cancer, particularly of the upper digestive tract, probably on account of its high fibre content. Fibres were in fact found to be protective with regard to colorectal and other selected cancers. In contrast to wholegrain, refined grain intake, and consequently glycaemic load, was associated with an increased risk of different types of cancer, including those of the upper digestive tract, colorectum, breast and endometrium. These results thus suggest that a low-risk diet for cancer entails increasing vegetables and fruit, reducing meat, but also refined carbohydrate consumption. Furthermore, olive oil and other unsaturated fats, which may be a unique common characteristic of the Mediterranean diet, should be preferred to animal and saturated fats. A score summarizing the major characteristics of the Mediterranean diet was inversely and consistently related to the risk of selected cancer sites. Regular consumption of pizza, one of the most typical Italian foods, showed a reduced risk of digestive tract cancers. Pizza could however simply be an indicator of a typical Italian diet.

Cancer mortality in Europe, 1995-1999, and an overview of trends since 1960

Mortality data, abstracted from the World Health Organization database, are presented in tabular form for 26 cancer sites or groups of sites, plus total cancer mortality, in 36 European countries during the period 1995-1999. Trends in mortality are also given in graphic form for 23 major countries plus the European Union as a whole over the period 1960-1999. In the European Union, total cancer mortality declined by 7% for both sexes over the last 5 years considered. The fall since the late 1980s was 10% in both sexes, corresponding to the avoidance of over 90000 deaths per year, as compared to the rates of the late 1980s. For the first time, over the last few years, some leveling of mortality was reported also in the Russian Federation, the Czech Republic, Poland, Hungary and other Eastern European countries, although cancer rates in those areas remain exceedingly high. The overall favorable pattern of cancer mortality over recent years is largely driven by the decline of tobacco-related cancer mortality in men. However, important components of the trends are also the persistence of substantial falls in gastric cancer, mainly in Russia and Eastern Europe, the recent decline in intestinal cancer in both sexes and of breast cancer in women, together with the long-term falls in uterine (cervical) cancer, leukemias, Hodgkin's disease and other neoplasms amenable to advancements in diagnosis and treatment. Female lung cancer mortality has been declining in the Russian Federation, but is still rising in other areas of the continent. Thus, urgent intervention is needed to bring under control the tobacco-related lung cancer epidemic in European women before it reaches the high level observed in North America. Supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html

Folate intake and risk of oral and pharyngeal cancer

BACKGROUND

Diet has been recognised as having a role in the aetiology of oral and pharyngeal cancer, and dietary factors may account for 10-15% of cases in Europe. Folate deficiency has been linked to risk of several cancers, but has not been studied adequately with respect to oral cancer.

PATIENTS AND METHODS

This case-control study, conducted in Italy and French-speaking Switzerland, included 749 patients with incident cancer of the oral cavity and pharynx, and 1772 hospital controls with acute, non-neoplastic conditions. The interviews used a validated food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using multiple logistic regression.

RESULTS

The ORs were 0.68 (95% CI 0.52-0.88) for the intermediate tertile and 0.53 (95% CI 0.40-0.69) for the highest tertile of dietary folate intake, compared with the lowest tertile. No heterogeneity was found in strata of gender, age, methionine intake or alcohol consumption. The combined OR for low-folate and high-alcohol intake versus high-folate and low-alcohol intake was 22.3 (95% CI 13.1-38).

CONCLUSIONS

Our study supports a protective role of folate against oral and pharyngeal carcinogenesis. Compared with low folate intake, a consistent reduction in risk was already observed from intermediate levels of intake, suggesting that cancer risk may be related to relative folate deficiency.

Diet and risk of seromucinous benign ovarian cysts

OBJECTIVE

To analyze the relation between selected dietary indicators and the risk of seromucinous benign ovarian cysts.

STUDY DESIGN

We used data from a case-control study on risk factors for benign ovarian cysts conducted in Italy between 1984 and 1994. Cases included 225 women with a histologically confirmed diagnosis of benign seromucinous ovarian neoplasm dating back no more than 2 years. Controls were 450 women below the age of 65 years admitted for acute non-gynecological, non-hormonal, non-neoplastic conditions.

RESULTS

Women with seromucinous cysts reported more frequent consumption of beef and other red meat and cheese and less frequent consumption of green vegetables. The multivariate odds ratios (ORs) in highest versus less frequent consumption levels were 2.7 (95% confidence interval (CI) 1.8-4.3) for beef and other red meat, 0.6 (95% CI 0.3-0.9) for green vegetables and 1.4 (95% CI 1.0-2.2) for cheese.

CONCLUSION

Seromucinous benign ovarian cysts are associated with beef and cheese consumption, whereas high intake of green vegetables seems to have a protective effect.

Epidemiologic evidence of the protective effect of fruit and vegetables on cancer risk

BACKGROUND

Diets rich in fruit and vegetables have been recommended for preventing cancer. The evidence supporting this recommendation is based on observational studies, although results of several prospective studies have cast some doubts on whether fruit and vegetables are associated with cancer risk reduction.

OBJECTIVE

We sought to summarize evidence from case-control and prospective studies on fruit and vegetable intake and cancer risk with a meta-analytic approach.

DESIGN

Published case-control and cohort studies that reported on total vegetable and fruit intake and risk of cancer of several sites were included. Relative risks were estimated by using linear logistic regression models.

RESULTS

Case-control studies overall support a significant reduction in the risks of cancers of the esophagus, lung, stomach, and colorectum associated with both fruit and vegetables; breast cancer is associated with vegetables but not with fruit; and bladder cancer is associated with fruit but not with vegetables. The overall relative risk estimates from cohort studies suggest a protective effect of both fruit and vegetables for most cancer sites considered, but the risk reduction is significant only for cancers of the lung and bladder and only for fruit.

CONCLUSIONS

Prospective studies provide weaker evidence than do case-control studies of the association of fruit and vegetable consumption with reduced cancer risk. The discrepancies may be related to recall and selection biases in case-control studies. In contrast, the association may have been underestimated in prospective studies because of the combined effects of imprecise dietary measurements and limited variability of dietary intakes within each cohort.

Session: whole cereal grains, fibre and human cancer wholegrain cereals and cancer in Italy

The relationship between frequency of consumption of whole-grain foods and cancer risk has been analysed using data from an updated series of case-control studies conducted in Northern Italy between 1983 and 1997. The overall dataset included the following incident histologically-confirmed neoplasms: oral cavity and pharynx 524, oesophagus 410, stomach 745, colon 955, rectum 625, liver 435, gallbladder 65, pancreas 402, larynx 388, soft tissue sarcomas 217, breast 3412, endometrium 750, ovary 971, prostate 127, bladder 431, kidney 190, thyroid 428, Hodgkin's disease 201, non-Hodgkin's lymphomas 529, multiple myelomas 185. Controls were 10 058 patients admitted to hospital for acute non-neoplastic conditions unrelated to long-term modifications in diet, tobacco or alcohol use. The multivariate odds ratios for the highest category of wholegrain cereal consumption were 0.3-0.5 for upper digestive tract and respiratory neoplasms and colon, 0.6 for rectum and liver, 0.4 for gallbladder, 0.8 for pancreas, 0.2 for soft tissue sarcomas, 0.9 for breast and endometrium, 0.7 for ovary, 0.7 for prostate, 0.4 for bladder and kidney, 1.1 for thyroid and about 0.5 for lymphomas and 0.6 for myelomas. In this population whole-grain food consumption is an indicator of reduced risk of several neoplasms.

Tomatoes, lycopene intake, and digestive tract and female hormone-related neoplasms

Tomato consumption showed a consistent inverse relation with the risk of digestive tract neoplasms in Italy in an integrated series of studies conducted in the 1980s. Another series of case-control studies was conducted between 1992 and 1999 in different areas of Italy. Cases were patients below age 80 with incident, histologically confirmed cancer of the oral cavity and pharynx (n = 754), esophagus (n = 304), colorectum (n = 1953), breast (n = 2529), and ovary (n = 1031). The comparison group involved, overall, over 5000 patients below age 80 with acute, non-neoplastic, nonhormone-related diseases, unrelated to long-term diet modifications and admitted to the same network of hospitals. Information was collected in hospital by trained interviewers using a validated food frequency questionnaire, including 78 foods or groups of foods, various alcoholic beverage, and fat-intake pattern. The multivariate relative risk (RR) of oral, pharyngeal, and esophageal cancer decreased across subsequent levels of lycopene intake to reach 0.7 (95% confidence interval [CI] 0.4-1.0) for oral and pharyngeal, and 0.7 (95% CI 0.4-1.1) for esophageal cancer in the highest quintile of intake. Both trends in risk were of borderline statistical significance. With reference to colorectal, breast, and ovarian cancer, although no consistent association was observed for lycopene (RR = 1.0 for colorectal, 1.2 for breast, and 1.1 for ovary in the highest quintile), tomato intake was inversely and significantly related with colorectal cancer (RR = 0.8). The inverse relation between lycopene and upper digestive tract neoplasms was not explained by alcohol or tobacco, sociodemographic factors, or total energy intake. The interpretation of such an inverse relation, however, remains open to discussion because it may be related to an effect of lycopene due to its antioxidant effect and/or a potential role of lycopene in decreasing insulin growth factor I, which is a promoter in the process of carcinogenesis.

Risk factors for focal nodular hyperplasia of the liver: an Italian case-control study

OBJECTIVES

Risk factors for focal nodular hyperplasia (FNH) of the liver are largely unknown, except for a possible role of female hormones. We evaluated the role of tobacco smoking and some lifestyle and dietary factors in its etiology.

METHODS

A hospital-based case-control study was conducted in Italy between January, 1999 and February, 2000 on 28 patients with histologically confirmed FNH of the liver and 115 controls in the hospital for acute, nonneoplastic, non-liver related diseases. Odds ratios (OR) and 95% confidence intervals (CI) were computed using multiple logistic regression equations.

RESULTS

Compared to those who never smoked the multivariate ORs were 1.9 (95% CI = 0.6-6.0) in ex-smokers and 3.5 (95% CI = 1.2-9.7) in current smokers, and the risk increased with number of cigarettes smoked to 8.0 (95% CI = 1.7-37.4) for > or = 20 cigarettes/day. Intake of whole-grain foods was inversely related to risk, with an OR of 0.3 (95% CI = 0.1-0.7) in consumers versus nonconsumers. No significant association was observed with education, alcohol drinking, and selected indicator foods.

CONCLUSIONS

This study indicates that cigarette smoking is an indicator of elevated risk for FNH of the liver, whereas whole grain and, possibly, vegetable intake seems to be a favorable indicator.

Dietary fibres and ovarian cancer risk

Data from an Italian multicentre case-control study on ovarian cancer were used to analyse the relationship between various types of fibres and ovarian cancer risk. The study, conducted between 1992 and 1999, included 1031 cases of incident, histologically-confirmed epithelial ovarian cancer. Controls were 2411 women admitted to the same network of hospitals for acute, non-malignant, non-hormonal-related diseases. Cases and controls were interviewed using a validated food frequency questionnaire (FFQ). Odds ratios (ORs), and the corresponding 95% confidence intervals (CI), were estimated using unconditional multiple logistic regression models. For total (Englyst) fibre, the OR for the highest versus the lowest quintile of intake was 0.68, and the continuous OR for the difference between the 80th and the 20th percentile of intake was 0.87. For most types of fibre, the continuous OR was significantly below 1. The OR was 0.83 for cellulose, 0.89 for soluble non-cellulose polysaccharides (NCPs), 0.86 for total insoluble fibre, 0.92 for insoluble NCP, and 0.95 (non-significant) for lignin. The inverse association was consistent across strata of age, family history and menopausal status, even if the association was apparently stronger in postmenopausal women. When fibre was classified according to the source, vegetable (but not grain) fibres, showed a significant protective effect, with an OR of 0.78.

Dietary fibre and the risk of colorectal cancer

The relationship between various types of fibre and colorectal cancer risk was investigated using data from a case-control study conducted in the Swiss Canton of Vaud between January 1992 and December 2000. The study included 286 cases of incident, histologically-confirmed colorectal cancers (149 colon and 137 rectal cancers) admitted to the University Hospital of Lausanne, and 550 controls whose admission diagnosis was of acute, non-neoplastic diseases. Dietary habits were investigated using a validated food frequency questionnaire (FFQ). Odds ratios (ORs) were computed after allowance for age, sex, education, physical activity and energy intake. Fibre was analysed both as a continuous variable and in tertiles. There was a significant inverse relationship of total fibre intake (determined by the Englyst method as non-starch polysaccharides) and of its components with the risk of colorectal cancer. ORs for a difference in intake of one standard deviation from the mean fibre intake of the control distribution was 0.57 for total fibres, 0.55 for soluble non-cellulose polysaccharides (NCPs), 0.58 for total insoluble fibres, 0.57 for cellulose, 0.62 for insoluble NCP and 0.62 for lignin. When fibre was classified according to its source, the OR was 0.60 for vegetables, 0.78 for fruit and 0.74 for grain fibre. The ORs were similar for colon and rectal cancer and consistent across the strata of the major covariates and of several types of fibres.

Diet and ovarian cancer risk: a case-control study in Italy

To assess the dietary correlates of cancer of the ovary, the consumption of a wide range of food groups has been investigated in a case-control study conducted between January 1992 and September 1999 in 4 Italian areas. Cases were 1,031 women with incident, histologically confirmed epithelial ovarian cancer; controls were 2,411 women admitted to the same network of hospitals as the cases for acute, non-malignant and non-gynecological conditions, unrelated to hormonal or digestive tract diseases or to long-term modifications of diet. The subjects' usual diet was investigated through a validated food frequency questionnaire including 78 foods and recipes, then grouped into 18 food groups. Odds ratios (OR), and the corresponding 95% confidence intervals (CI) were estimated using unconditional multiple logistic regression models including terms for age, study center, education, year at interview, parity, oral contraceptive use and energy intake. Significant trends of increasing risk emerged for red meat (OR = 1.53 for the highest compared with the lowest quintile of consumption), whereas inverse associations were observed for consumption of fish (OR = 0.51), raw (OR = 0.47) and cooked vegetables (OR = 0.65), and pulses (OR = 0.77).

Selected micronutrients and colorectal cancer. a case-control study from the canton of Vaud, Switzerland

The association between dietary intake of various micronutrients and colorectal cancer risk was analysed using data from a case-control study conducted between 1992 and 1997 in the Swiss Canton of Vaud. Cases were 223 subjects (142 (64%) males, 81 (36%) females; median age 63 years) with incident, histologically confirmed colon (n=119; 53%) or rectal (n=104; 47%) cancer, and controls were 491 subjects (211 (43%) males, 280 (57%) females; median age 58 years; range 27-74) admitted to the same university hospital for a wide spectrum of acute non-neoplastic conditions, unrelated to long-term modifications of diet. Dietary habits were investigated using a validated food frequency questionnaire (FFQ). Odds ratios (OR) were obtained after allowance for age, sex, education, smoking, alcohol, body mass index, physical activity, and total energy and fibre intake. No significant association was observed for calcium, retinol, folate, vitamin D or E. The risk of colorectal cancer was directly associated with measures of iron intake (OR=2.43 for the highest tertile, 95% confidence interval (CI): 1.2-5.1) and inversely associated with vitamin C (OR=0.45; 95% CI: 0.3-0.8), and non-significantly with total carotenoids (OR=0.66, 95% CI: 0.4-1.1). Among various individual carotenoids considered, inverse associations were observed for alpha-carotene, beta-carotene and lutein/zeaxanthin. These findings were consistent across the strata of gender and age, and support the hypothesis that selected micronutrients have a favourable effect on colorectal carcinogenesis.

Diet diversity and colorectal cancer

BACKGROUND

Food diversity has been recommended to achieve a healthy diet and prevent cancer. The relation between diet diversity and the risk of colorectal cancer was investigated using data from a multicenter case-control study carried out between 1992 and 1996 in Italy.

METHODS

The study included 1225 subjects with cancer of the colon (688 men and 537 women), 728 with cancer of the rectum (437 men and 291 women), and 4154 controls (2073 men and 2081 women) residing in the same geographical areas. Odds ratios (ORs) of colon and rectal cancer and the corresponding 95% confidence intervals (CI) according to food diversity were derived from unconditional multiple logistic regression equations.

RESULTS

For colon cancer, an inverse association for total diversity was found in males (adjusted OR of 0.65 for the highest vs the lowest quintile of total diversity; 95% CI: 0.46-0.93) and in females (OR = 0.85; 95% CI: 0.57-1.26). With respect to specific food groups, there was an inverse association only with diversity within vegetables (OR = 0.66; 95% CI: 0.54-0.81 in colon cancer and OR = 0.71; 95% CI: 0.55-0.91 in rectal cancer).

CONCLUSIONS

This study suggests that total diversity is moderately related to a decreased risk of colorectal cancer risk. A better understanding of the potential influence of dietary patterns on colorectal cancer is needed.

Cancer prevention: epidemiology and perspectives

Following increases up until the late 1980s, some decline in cancer mortality has been observed in North America and in Western Europe. Approximately half the decline can be attributed to the levelling off in lung and other tobacco-related cancer epidemics and the rest to several factors, including reduced exposure to occupational carcinogens, prevention and early diagnosis, and improved treatment. Between 25 and 30% of all cancer deaths in Europe are due to tobacco smoking. In this review the effect of tobacco smoking on cancer incidence and mortality is examined, together with other important aetiological factors including alcohol, diet and environmental and occupational carcinogens. The effect of new treatments and the potential for prevention of cancer are also discussed.

Cancer prevention: epidemiology and perspectives

Following increases up until the late 1980s, some decline in cancer mortality has been observed in North America and in Western Europe. Approximately half the decline can be attributed to the levelling off in lung and other tobacco-related cancer epidemics and the rest to several factors, including reduced exposure to occupational carcinogens, prevention and early diagnosis, and improved treatment. Between 25 and 30% of all cancer deaths in Europe are due to tobacco smoking. In this review the effect of tobacco smoking on cancer incidence and mortality is examined, together with other important aetiological factors including alcohol, diet and environmental and occupational carcinogens. The effect of new treatments and the potential for prevention of cancer are also discussed.