Refined and whole grain cereals and the risk of oral, oesophageal and laryngeal cancer

[Update: Epidemiology and Prevention of Oropharyngeal Cancer]

Due to the association with the causal HPV-16 infection, the oropharyngeal carcinoma spreads into two separate entities depending on HPV-16 positivity. More recent data show a diversified picture of the importance and prevalence of the surrogate parameter p16 (discordance) for a definitive HPV-16 association, which varies worldwide. In the context of prevention options, vaccination is of major and HPV screening of healthy people only of little importance.

Potential impact of time trend of whole grain intake on burden of major cancers in China

Numerous studies have revealed associations between high intake of whole grains and reduced risk of various cancers. Yet, in recent decades, the traditional Chinese diets have been challenged by reduction in whole grains and increase in refined grains. To assess the impact of this dietary transition on cancer prevention, we analyzed the time trend of whole grain intake using nationally representative sampling data of over 15 thousand individuals from the China Health and Nutrition Survey. We applied the comparative risk assessment method to estimate the population attributable fraction of cancers due to insufficient whole grain intake from 1997 to 2011 and projected the trend of whole grain intake and the associated burden of cancers to 2035. We found a significant decrease of approximately 59% of whole grain intake in the Chinese population from 1997 to 2011. Compared with 1997, insufficient intake of whole grains was responsible for 9940 more cases of breast cancer, 12,903 more cases of colorectal cancer and 434 more cases of pancreatic cancer in 2011. Our projections suggest that if every Chinese would consume 125 g whole grain per day as recommended by the latest Chinese Dietary Guidelines, 0.63% bladder cancer, 8.98% breast cancer, 15.85% colorectal cancer, 3.86% esophageal cancer, 2.52% liver cancer and 2.22% pancreatic cancer (totaling 186,659 incident cases) could theoretically be averted by 2035. Even if everyone maintained the 2011 whole grain intake level, an estimated 8.38% of cancer events could still be prevented by 2035.

Dietary Risk Factors in Upper Aero-Digestive Tract Cancers

The Upper AeroDigestive Tract (UADT) cancers are most common, invasive and have high morbidity. The two leading risk factors, smoking and alcohol, are well known but there is a long list of other risk factors which are not that well talked about. The aim of this study was to ascertain the dietary factors which could be important in their prevention.The PubMed and Google Scholar databases were searched for relevant studies from January 2001 to November 2021. Refined grains were found directly related to the risk of UADT cancer while the whole grain cereals were found protective. Significant inverse associations were observed for the highest compared to the lowest tertile of whole grains and yellow/orange vegetables. Stricter adherence to the Mediterranean diet was seen associated with a substantial and significant decrease in UADT cancer risk. A significant inverse association was also found between yoghurt intake and UADT cancer risk. Consumption of three or more cups of coffee per day was found to have a significant inverse association with UADT cancer. Carcinogenicity of cannabis consumption was observed for regular cannabis smokers (> 1 per day for years). The current study concludes that the protective dietary factors have substantial activity in the prevention of UADT cancer. Nevertheless, basic research is required in investigating the role of these dietary factors and valid biomarkers will be important for chemoprevention studies. The basic research on risk factors on the basis of current knowledge would ultimately lead to the better prevention of UADT cancer.

Overview of the Composition of Whole Grains’ Phenolic Acids and Dietary Fibre and Their Effect on Chronic Non-Communicable Diseases

Chronic non-communicable diseases are the major cause of death globally. Whole grains are recommended in dietary guidelines worldwide due to increasing evidence that their consumption can improve health beyond just providing energy and nutrients. Epidemiological studies have suggested that the incorporation of whole grains, as part of a healthy diet, plays a key role in reducing one’s risk for cardiovascular diseases (CVDs), obesity, type 2 diabetes (T2D) and cancer. Phenolic acids and dietary fibre are important components found in whole grains that are largely responsible for these health advantages. Both phenolic acids and dietary fibre, which are predominantly present in the bran layer, are abundant in whole-grain cereals and pseudo-cereals. Several studies indicate that whole grain dietary fibre and phenolic acids are linked to health regulation. The main focus of this study is two-fold. First, we provide an overview of phenolic acids and dietary fibres found in whole grains (wheat, barley, oats, rice and buckwheat). Second, we review existing literature on the linkages between the consumption of whole grains and the development of the following chronic non-communicable diseases: CVDs, obesity, T2D and cancer. Altogether, scientific evidence that the intake of whole grains reduces the risk of certain chronic non-communicable disease is encouraging but not convincing. Based on previous studies, the current review encourages further research to cover the gap between the emerging science of whole grains and human health.

PROTOCOL: The association between whole-grain dietary intake and noncommunicable diseases: A systematic review and meta-analysis

Our primary research questions are: (1) What is the association between whole grains (WG) intake and the prevalence of NCDs (i.e., type 2 diabetes, cardiovascular disease, obesity, cancer, mortality) and their biomarkers? (2) Which biomarker(s) has/have the greatest association with WG intake when combining multiple biomarkers together in the same analysis? Our secondary research question is: (3) Are there dose-response relationships between WG intake and biomarkers and prevalence of NCDs which could help inform a universal recommendation for WG intake?

Association between Oral Cancer and Diet: An Update

Oral cancer, included within head and neck cancer, is the sixth most common malignant neoplasm in the world. The main etiological factors are tobacco and alcohol, although currently, diet is considered an important determinant for its development. Several dietary nutrients have specific mechanisms of action, contributing to both protection against cancer and increasing the risk for development, growth, and spread. Foods such as fruits, vegetables, curcumin, and green tea can reduce the risk of oral cancer, while the so-called pro-inflammatory diet, rich in red meat and fried foods, can enhance the risk of occurrence. Dietary factors with a protective effect show different mechanisms that complement and overlap with antioxidant, anti-inflammatory, anti-angiogenic, and anti-proliferative effects. The main limitation of in vivo studies is the complexity of isolating the effects related to each one of the nutrients and the relationship with other possible etiological mechanisms. On the contrary, in vitro studies allow determining the specific mechanisms of action of some of the dietary compounds. In conclusion, and despite research limitations, the beneficial effects of a diet rich in vegetables and fruits are attributed to different micronutrients that are also found in fish and animal products. These compounds show antioxidant, anti-inflammatory, anti-angiogenic, and anti-proliferative properties that have a preventive role in the development of oral and other types of cancer.

The relationship between rice consumption and glioma: a case-control study in adults

Previous studies have shown the effect of refined grains on various cancers; however, data on the link between rice consumption and brain cancer are scarce. We aimed to investigate the relationship between rice consumption and glioma in Iranian adults. Current hospital-based case–control study was done in Tehran between 2009 and 2011. Cases were individuals with pathologically confirmed glioma in a maximally 1 month of the disease diagnosis (n = 128). Controls were individuals, aged between 20 and 75 years, who were hospitalized or were outpatients referred to other wards of the same hospital (n = 256). Cases and controls were frequently matched in terms of age and gender. Usual dietary intakes of participants, including rice consumption, during the preceding year were examined using a Block-format validated semi-quantitative 126-item food frequency questionnaire. Compared with participants in the lowest tertile of rice consumption (< 181 g/day), those in the highest tertile (≥ 279 g/day) had 2.47 times greater chance for having glioma (OR: 2.47, 95% CI 1.44–4.23). This relationship was also seen when potential confounders including demographic variables, energy and dietary intakes as well as body mass index were taking into account; such that individuals in the top tertile of rice consumption had 2.46 times greater odds of glioma compared with those in the bottom tertile (OR: 2.46, 95% CI 1.01–5.97). We found that rice consumption was positively associated with risk of glioma in adults. Further prospective studies are required to confirm this finding.

The Impact of Whole Grain Intake on Gastrointestinal Tumors: A Focus on Colorectal, Gastric, and Esophageal Cancers

Cereals are one of staple foods in human diet, mainly consumed as refined grains. Nonetheless, epidemiological data indicate that whole grain (WG) intake is inversely related to risk of type 2 diabetes, cardiovascular disease, and several cancer types, as well as to all-cause mortality. Particularly responsive to WG positive action is the gastrointestinal tract, daily exposed to bioactive food components. Herein, we shall provide an up-to-date overview on relationship between WG intake and prevention of gastrointestinal tumors, with a particular focus on colorectal, stomach, and esophagus cancers. Unlike refined counterparts, WG consumption is inversely associated with risk of these gastrointestinal cancers, most consistently with the risk of colorectal tumor. Some WG effects may be mediated by beneficial constituents (such as fiber and polyphenols) that are reduced/lost during milling process. Beside health-promoting action, WGs are still under-consumed in most countries; therefore, World Health Organization and other public/private stakeholders should cooperate to implement WG consumption in the whole population, in order to reach nutritionally effective intakes.

Whole Grains, Refined Grains, and Cancer Risk: A Systematic Review of Meta-Analyses of Observational Studies

PubMed, Web of Science, and the Cochrane Database of Systematic Reviews were searched for meta-analyses that provided risk estimates (±95% confidence intervals) for associations between intakes of whole and refined grains and risk of total and site-specific cancer. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Only meta-analyses that included whole grains and refined grains as separate food groups, and not as part of dietary patterns, were included. A total of 17 publications were identified that met inclusion criteria. Within these, results from a total of 54 distinct meta-analyses were reported for whole grains and 5 meta-analyses for refined grains. For total cancer mortality, 7 meta-analyses of cohort studies indicated that whole grain intake was associated with 6% to 12% lower risk in comparison of highest vs. lowest intake groups, and 3% to 20% lower risk for doses ranging from 15 to 90 g/day. For site-specific cancers, meta-analyses indicated that whole grain intake was consistently associated with lower risks of colorectal, colon, gastric, pancreatic, and esophageal cancers. Limited data were available for refined grains, with only 4 publications providing risk estimates, and only 1 of the meta-analyses included more than 3 studies. High intake of refined grains was associated with increased risk of colon and gastric cancer. By contrast, in the only dose-response meta-analysis, each 90 g/day consumption of refined grains was associated with a 6% lower risk of total cancer. In addition to the limited number of published meta-analyses on refined grains, results were also weakened due to the fact that refined grains were frequently defined to include both staple grain foods and indulgent grain foods, and the majority of studies included in the meta-analyses provided no specific definition of refined grains. Overall, meta-analyses of cohort and case-control studies consistently demonstrate that whole grain intake is associated with lower risk of total and site-specific cancer, and support current dietary recommendations to increase whole grain consumption. By contrast, the relationship between refined grain intake and cancer risk is inconclusive.

Association of whole grains intake and the risk of digestive tract cancer: a systematic review and meta-analysis

BACKGROUND

Several epidemiological studies have investigated the association between whole grains intake and digestive tract cancer risk; however, the results are still controversial. The purpose of this meta-analysis was to assess the association.

METHODS

Studies published before March 2020 were searched in database and other sources. The risk ratio (RR) with the 95% confidence interval (CI) were pooled using fix or random-effects models.

RESULTS

This meta-analysis included 34 articles reporting 35 studies, 18 studies of colorectal cancer, 11 studies of gastric cancer and 6 studies of esophagus cancer, involving 2,663,278 participants and 28,921 cases. Comparing the highest-intake participants with the lowest-intake participants for whole grains, we found that the intake of whole grains were inversely related to colorectal cancer (RR = 0.89, 95% CI: 0.84-0.93, P < 0.001), gastric cancer (RR = 0.64, 95% CI: 0.53-0.79, P < 0.001), esophagus cancer (RR = 0.54, 95% CI: 0.44-0.67, P < 0.001), respectively. However, subgroup analysis of colorectal cancer found no significant association in the case-control studies and studies of sample size < 500, and subgroup analysis of gastric cancer found no significant association in the cohort studies and studies of American population. No study significantly affected the findings in the sensitivity analysis. No publication bias was found in the studies for colorectal cancer and esophagus cancer except in the studies for gastric cancer.

CONCLUSION

This meta-analysis provides further evidence that whole grains intake was associated with a reduced risk of digestive tract cancer. Our result supports the dietary guidelines that increase whole grains intake to reduce the risk of digestive tract cancer.

Association of whole grain, refined grain, and cereal consumption with gastric cancer risk: A meta-analysis of observational studies

Many studies have analyzed the relationship between cereal, whole, or refined grain and the risk of gastric cancer (GC) and have yielded mixed results. Therefore, we performed a meta-analysis of observational studies to summarize the available evidence on this topic. Databases such as PubMed, EMBASE, Web of Science, MEDLINE, and the Cochrane Library were searched for studies focusing on these associations from inception to October 2017. Summary odd ratios (OR) and 95% confidence intervals (CI) were calculated by using either a random- or fixed-effect model according to the between-studies heterogeneity. Subgroup analysis was also performed. In total, eleven studies that included 530,176 participants were identified. In a pooled analysis of all studies, cereal exposure was not associated with GC risk (OR, 1.11, 95%CI, 0.85-1.36). Specific analyses indicated that whole grain consumption was associated with decreased GC risk (OR, 0.61, 95%CI, 0.40-0.83) and that refined grain consumption was associated with increased GC risk (OR, 1.65, 95%CI, 1.36-1.94). Higher whole grain and lower refined grain intake but not cereal consumption reduces GC risk. This study has been registered at ClinicalTrials.gov (ID: NCT03419663).

Effects of Starch on Oral Health: Systematic Review to Inform WHO Guideline

A systematic review was conducted to update evidence on the effect of total dietary starch and of replacing rapidly digestible starches (RDSs) with slowly digestible starches (SDSs) on oral health outcomes to inform updating of World Health Organization guidance on carbohydrate intake. Data sources included MEDLINE, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, LILACS, and Wanfang. Eligible studies were comparative and reported any intervention with a different starch content of diets or foods and data on oral health outcomes relating to dental caries, periodontal disease, or oral cancer. Studies that reported total dietary starch intake or change in starch intake were included or where comparisons or exposure included diets and foods that compared RDSs and/or SDSs. The review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) statement, and evidence was assessed with the GRADE Working Group guidelines. From 6,080 papers identified, 33 (28 studies) were included in the RDS versus SDS comparison: 15 (14 studies) assessed the relationship between SDS and/or RDS and dental caries; 16 (12 studies) considered oral cancer; and 2 studied periodontal disease. For total starch, 23 papers (22 studies) were included: 22 assessed the effects on dental caries, and 1 considered oral cancer. GRADE assessment indicated low-quality evidence, suggesting no association between total starch intake and caries risk but that RDS intake may significantly increase caries risk. Very low-quality evidence suggested no association between total starch and oral cancer risk, and low-quality evidence suggested that SDS decreases oral cancer risk. Data on RDS and oral cancer risk were inconclusive. Very low-quality data relating to periodontitis suggested a protective effect of whole grain starches (SDS). The best available evidence suggests that only RDS adversely affects oral health.

Diet and esophageal cancer risk in the Eastern Cape Province of South Africa

A multicenter hospital-based case-control study comprising 670 incident cases of esophageal cancer (EC) and 1188 controls, frequency-matched for age and sex, was conducted to evaluate the role of diet on EC development in the Eastern Cape Province, South Africa. A locally relevant lifestyle and dietary questionnaire was used. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were computed using unconditional multivariable logistic regression. Individually, maize or sorghum consumption vs. never or rare consumption were not associated with EC (P > 0.1). Males and females consuming green leafy vegetables 5-7 days/wk had 38% (P = 0.04) and 50% (P = 0.007) reduced odds of developing EC, respectively, compared with consumption ≤1 day/wk. A similar reduction in odds was observed with fruit consumption. Principal component factor analysis revealed 3 distinct dietary patterns. In females, high vs. low consumption of Pattern 1 (sorghum, green leafy vegetables, green legumes, fruits, meat) was inversely associated with EC development (OR = 0.54; 95% CI: 0.34-0.89), whereas for Pattern 2 (maize, wild greens-imifino, dry beans) the odds were elevated (OR = 1.67; 95% CI: 1.04-2.67). Compared with low adherence, high adherence to Pattern 3 (wheat-based products) reduced the odds by 35% for both sexes. This study provides further evidence on the role of diet in minimizing EC risk in this population.

Dietary acrylamide and human cancer: a systematic review of literature

Cancer remains the second leading cause of death in the United States, and the number of cases is expected to continue to rise worldwide. Cancer prevention strategies are crucial for reducing the cancer burden. The carcinogenic potential of dietary acrylamide exposure from cooked foods is unknown. Acrylamide is a by-product of the common Maillard reaction where reducing sugars (i.e., fructose and glucose) react with the amino acid, asparagine. Based on the evidence of acrylamide carcinogenicity in animals, the International Agency for Research on Cancer has classified acrylamide as a group 2A carcinogen for humans. Since the discovery of acrylamide in foods in 2002, a number of studies have explored its potential as a human carcinogen. This article outlines a systematic review of dietary acrylamide and human cancer, acrylamide exposure and internal dose, exposure assessment methods in the epidemiologic studies, existing data gaps, and future directions. A majority of the studies reported no statistically significant association between dietary acrylamide intake and various cancers, and few studies reported increased risk for renal, endometrial, and ovarian cancers; however, the exposure assessment has been inadequate leading to potential misclassification or underestimation of exposure. Future studies with improved dietary acrylamide exposure assessment are encouraged.

Adherence to Mediterranean-style dietary pattern and risk of esophageal squamous cell carcinoma: a case-control study in Iran

OBJECTIVE

The benefit of adherence to a Mediterranean-style dietary pattern in relation to the risk of esophageal squamous cell carcinoma (ESCC) has not been investigated among non-Mediterranean high-risk populations. The objective of the present study was to examine the association of compliance with the Mediterranean dietary pattern as measured by Mediterranean-Style Dietary Pattern Score (MSDPS) and the risk of ESCC in Iranian population.

METHODS

This case-control study was conducted on 47 ESCC cases and 96 hospital controls aged 40-75 years. Participants were interviewed using validated questionnaires, and dietary patterns were characterized using the MSDPS.

RESULTS

Generally, the mean MSDPS in this population was low (30.84 ± 8.58). MSDPS showed content validity through having expected positive associations with several lifestyle characteristics and dietary intakes. Being in the highest quartile category of MSDPS, compared to the lowest, was independently associated with 37% reduction in risk of ESCC. Two-unit and 3-unit increases in the MSDPS resulted in 41% and 47% reduction in risk of ESCC, respectively. Higher intakes of olive oil (odds ratio [OR] = 0.15, 95% CI: 0.01-0.49), fish and other seafood (OR = 0.48, 95% CI: 0.23-0.98), whole grain (OR = 0.57, 95% CI: 0.28-0.76), and fruits (OR = 0.77, 95% CI: 0.38-0.86) were significantly associated with reduced ESCC risk. In contrast, higher sweet (OR = 1.86, 95% CI: 1.04-2.12) and meat intakes (OR = 1.61, 95% CI: 1.25-2.49) were associated with higher ESCC risk.

CONCLUSION

Consuming a diet in concordance with the principles of the Mediterranean dietary pattern may protect against ESCC. Preventive strategies to reduce ESCC risk in high-risk countries should focus on overall dietary pattern and dietary habits to be effective.

Diet impacts mortality from cancer: results from the multiethnic cohort study

PURPOSE

Cancer is the second leading cause of death in the United States and mortality varies by ethnicity. The objective of this study was to examine the association between cancer mortality and dietary intake among a large multiethnic population.

METHODS

A prospective cohort design was used to examine cancer mortality among 146,389 participants. Multiethnic cohort study participants represent five ethnic groups: African American, Native Hawaiian, Japanese American, Latino, and Caucasian. Hazard ratios for cancer mortality by intake levels of five food groups and discretionary fat were calculated using Cox proportional hazards models stratified by sex and ethnicity.

RESULTS

There were a total of 2,028 male and 1,464 female fatal cancer cases at the end of follow-up. Among Japanese American men only, there was a significant protective effect seen in those reporting a high grain intake (HR = 0.49, 95 % CI 0.35-0.69); there was no effect of grain consumption in any other ethnic-sex group. There was no evidence that ethnicity modified associations between fruit, vegetable, meat, dairy, or discretionary fat intake and cancer mortality among men. Associations between food group consumption and risk for cancer mortality among women were similar across ethnic groups.

CONCLUSIONS

The considerable reduction in cancer risk associated with high grain consumption among a specific ethnic-sex group, Japanese American men, warrants further investigation. Additional research is needed to validate this observation and determine whether this was a chance finding, or possibly due to differential intake of specific grain subtypes, and/or related to a sex-specific cancer type.

Intake of grains and dietary fiber and prostate cancer aggressiveness by race

Purpose. To examine the associations among intake of refined grains, whole grains and dietary fiber and aggressiveness of prostate cancer in African Americans (AA, n = 930) and European Americans (EA, n = 993) in a population-based, case-only study (The North Carolina-Louisiana Prostate Cancer Project, PCaP). Methods. Prostate cancer aggressiveness was categorized as high, intermediate or low based on Gleason grade, PSA level and clinical stage. Dietary intake was assessed utilizing the NCI Diet History Questionnaire. Logistic regression (comparing high to intermediate/low aggressive cancers) and polytomous regression with adjustment for potential confounders were used to determine odds of high prostate cancer aggressiveness with intake of refined grains, whole grains and dietary fiber from all sources. Results. An inverse association with aggressive prostate cancer was observed in the 2nd and 3rd tertiles of total fiber intake (OR = 0.70; 95% CI, 0.50–0.97 and OR = 0.61; 95% CI, 0.40–0.93, resp.) as compared to the lowest tertile of intake. In the race-stratified analyses, inverse associations were observed in the 3rd tertile of total fiber intake for EA (OR = 0.44; 95% CI, 0.23–0.87) and the 2nd tertile of intake for AA (OR = 0.57; 95% CI, 0.35–0.95). Conclusions. Dietary fiber intake was inversely associated with aggressive prostate cancer among both AA and EA men.

Dietary pattern and oral cancer risk--a factor analysis study

OBJECTIVES

The role of diet in cancer risk has mainly been investigated based on intake of individual food items. However, food consumption is made up of a combination of various food items. This study aims to determine the association of dietary patterns with oral cancer risk.

METHODS

A total of 306 matched cases and controls were recruited in this study. Data on dietary intake were obtained using food frequency questionnaire (FFQ). Factor analysis (FA) was performed to identify dietary patterns based on the intake of nine major food groups, resulting in four factors/components being retained. The odds ratio (OR) was computed for each component using conditional logistic regression.

RESULTS

The first pattern labelled as 'modern' was loaded with processed foods and snacks, whereas the second pattern termed as 'prudent' was characterized by intake of fruits and vegetables. The third pattern labelled as 'traditional' consisted of beverages and starches, while the fourth pattern termed as 'combination' was loaded with intakes of dairy, fermented/salted and meat/by-products. A significant reduced risk was found for 'prudent' (OR 0.53, 95% CI = 0.28-0.98), whereas an increased risk was found for both 'combination' (OR 2.43, 95% CI = 1.33-4.45) and 'traditional' (OR 2.32, 95% CI = 1.23-4.25) patterns. However, after adjusting for risk habits of tobacco smoking, alcohol consumption and betel quid chewing, only 'combination' (aOR 2.99, 95% CI = 1.55-5.75) and 'traditional' (aOR 2.08, 95% CI = 1.09-3.97) patterns remained significant.

CONCLUSION

Consumption in the highest tertile of 'traditional' and 'combination' patterns may induce twice and thrice the risk of oral cancer, respectively.

Externalities from grain consumption: a survey

The US Department of Agriculture (USDA) publishes their MyPyramid plan as a recommended eating model for all Americans. As part of this model, grain consumption is emphasized. This grain consumption has the potential to generate positive externalities, such as reduced rates of obesity, diabetes and other chronic diseases. Such positive externalities can potentially produce tangible economic benefits in terms of public health. In contrast, newer nutritional research shows that grain consumption may have negative effects on health for certain population groups. Celiac disease is four times as common as it was 50 years ago and is often under-diagnosed. Other population groups exhibit gluten sensitivity which can impact the development of asthma, allergies and neurological difficulties. This survey intends to provide a comprehensive description of both the positive and negative externalities associated with grain consumption and the resulting impact on human health.

Antioxidant activity of alkylresorcinols from rye bran and their protective effects on cell viability of PC-12 AC cells

Alkylresorcinols (ARs) are phenolic lipids that are present in high amounts in the bran layer of different cereals. Rye samples, cultivar Hazlet, and a white rye genotype, RT202, were analyzed for their antioxidant properties and AR content and composition, based on six fractions of the bran, where 1 was the outermost fraction and 6 was the bran fraction closest to the endosperm. Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that the most commonly found AR homologue in Hazlet rye is C19:0 and that the total amount of ARs decreases from the outermost to innermost fractions. The antioxidant activity using oxygen radical absorbance capacity (ORAC) for both white rye genotype RT202 and Hazlet brans was determined to decrease from the outermost fraction (136.05 μmol TE/g for Hazlet fraction 1 and 186.57 μmol TE/g for white rye genotype RT202 fraction 1) to the innermost fraction (9.84 μmol TE/g for Hazlet fraction 6 and 78.75 μmol TE/g for white rye genotype RT202 fraction 2). A positive relationship was seen with GC-MS results. Treatment of PC-12 AC cells with Hazlet fraction 1 increased mitochondrial biogenesis as determined using mitochondrial fluorescent dyes. In the presence of a prooxidant (AAPH), PC-12 AC cells were better protected from free radical attack when treated with Hazlet fraction 1 than with all other bran fractions. The results suggest that higher AR content in bran fractions confers antioxidant protection against free radical damage.

Dietary fiber and grain consumption in relation to head and neck cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Dietary fiber and grain consumption may reduce the risk of head and neck cancer; however, the epidemiological evidence is limited. We investigated this relationship in the National Institutes of Health (NIH)-AARP Diet and Health Study.

METHODS

Cox proportional hazards models were used to calculate multivariable hazard ratios (HR) and 95% confidence intervals (CI) to investigate dietary fiber and grain intake in relation to head and neck cancer.

RESULTS

During approximately 11 years of follow-up, 1,867 (401 women/1,466 men) cases of head and neck cancer were diagnosed. Our data indicated that the relationship between fiber and grain intake and head and neck cancer is modified by sex (p-interactions < 0.001 and 0.001, respectively). Women with higher intake of total fiber and total grains had a lower risk of head and neck cancer (HR (10 g/day) = 0.77, 95% CI = 0.64-0.93; HR (serving/1,000 kcal) = 0.89, 95% CI = 0.80-0.99, respectively); this inverse relation was consistent across subtypes of fiber and grains. Conversely in men, the inverse associations were weaker and nonsignificant.

CONCLUSIONS

In the largest prospective cohort study to investigate this relation to date, intake of total fiber and grain foods was inversely associated with head and neck cancer incidence among women, but not among men.

New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

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.

Intake of whole grains, refined grains, and cereal fiber measured with 7-d diet records and associations with risk factors for chronic disease

BACKGROUND

Research studies examining foods are important, because they account for biological interactions that might otherwise be lost in the analysis of individual nutrients. Single-nutrient studies are also needed to explore the mechanisms by which foods may be protective.

OBJECTIVE

Our objective was to examine associations between whole grains, refined grains, and cereal fiber and chronic disease risk factors.

DESIGN

In a cross-sectional analysis of participants in the Baltimore Longitudinal Study of Aging, associations between dietary intakes and risk factors were examined with multivariate linear regression analysis. Dietary intakes were assessed with 7-d dietary records and quantified in g/d.

RESULTS

Compared with subjects in the lowest quintile (Q1) of whole-grain intake, subjects in the highest quintile (Q5) had lower body mass index (BMI; in kg/m(2); Q1: 25.5; Q5: 24.8; P for trend <0.0001) and weight (Q1: 75.0 kg; Q5: 72.4 kg; P for trend = 0.004) and smaller waist circumference (Q1: 87.4 cm; Q5: 85.0 cm; P for trend = 0.002). Whole grains were also inversely associated with total cholesterol (P for trend = 0.02), LDL cholesterol (P for trend = 0.04), and 2-h glucose (P for trend = 0.0006). Associations between cereal fiber and anthropometrics and plasma lipids were similar. In subgroup analyses, refined grains were positively associated with fasting insulin among women (P for trend = 0.002).

CONCLUSIONS

Similar associations of whole grains and cereal fiber with weight, BMI, waist circumference, plasma cholesterol, and 2-h glucose were observed, suggesting that cereal fiber and its constituents may in part mediate these relations. Refined grains were associated with fasting insulin among women but not men. Additional research should explore potential interaction effects with BMI, sex, age, and genes.

Antioxidant properties of Fusarium head blight-resistant and -susceptible soft red winter wheat grains grown in Virginia

Fusarium head blight (FHB) has emerged as a major threat to wheat crops around the world, and it has been hypothesized that wheat antioxidants may play a role against Fusarium infections. The current study aimed to determine antioxidant properties of FHB-resistant wheat grains as compared to susceptible wheat. The wheat samples were collected from a single growing location (Warsaw, VA) and the same growing season. The results showed that both FHB-resistant and -susceptible wheat grains exerted strong radical scavenging activities against DPPH* radical [0.91-1.53 micromol of Trolox equivalents (TE)/g], peroxyl radical (15.5-24.5 micromol of TE/g), and hydroxyl radical (15.7-35.8 micromol of TE/g). Their total phenolic contents ranged from 888 to 1117 microg of gallic acid equivalents (GAE)/g. Five phenolic acids including ferulic, syringic, vanillic, caffeic, and p-coumaric acids were determined in soluble and insoluble fractions of wheat grains, altogether with a range of 219-389 microg/g. On average, the FHB-resistant wheat group showed significantly higher average values in DPPH* and hydroxyl radicals scavenging activities (30 and 41% higher, respectively) than the FHB-susceptible wheat group.

NMR-based metabonomic studies reveal changes in the biochemical profile of plasma and urine from pigs fed high-fibre rye bread

This study presents an NMR-based metabonomic approach to elucidate the overall endogenous biochemical effects of a wholegrain diet. Two diets with similar levels of dietary fibre and macronutrients, but with contrasting levels of wholegrain ingredients, were prepared from wholegrain rye (wholegrain diet (WGD)) and non-wholegrain wheat (non-wholegrain diet (NWD)) and fed to four pigs in a crossover design. Plasma samples were collected after 7 d on each diet, and 1H NMR spectra were acquired on these. Partial least squares regression discriminant analysis (PLSDA) on spectra obtained for plasma samples revealed that the spectral region at 3·25 parts per million dominates the differentiation between the two diets, as the WGD is associated with higher spectral intensity in this region. Spiking experiments and LC–MS analyses of the plasma verified that this spectral difference could be ascribed to a significantly higher content of betaine in WGD plasma samples compared with NWD samples. In an identical study with the same diets, urine samples were collected, and1H NMR spectra were acquired on these. PLS-DA on spectra obtained for urine samples revealed changes in the intensities of spectral regions, which could be ascribed to differences in the content of betaine and creatine/creatinine between the two diets, and LC–MS analyses verified a significantly lower content of creatinine in WGD urine samples compared with NWD urine samples. In conclusion, using an explorative approach, the present studies disclosed biochemical effects of a wholegrain diet on plasma betaine content and excretion of betaine and creatinine.

Behavioural, attitudinal and dietary responses to the consumption of wholegrain foods

Whole grains are important dietary constituents as they provide a plethora of nutrients and protective chemicals that may have synergistic actions in promoting health. Regular consumption of wholegrain foods has been associated with a reduced risk of several chronic diseases such as CHD and certain cancers, although their exact role in disease prevention is not yet fully elucidated. Studies reporting levels of whole grain consumption reveal that those subjects who include higher levels of whole grain foods in their diets also have many other favourable dietary and lifestyle practices. While the actions of these practices and whole grains may not be mutually exclusive, these variables do not appear to explain the reduction in risk of disease observed for high-whole grain consumers. Actual whole grain consumption levels are extremely low and many practical barriers exist to consumer uptake of these foods. Effective communication of the whole grain health message is an important strategy to increase awareness of the importance of whole grains in the diet. Increasing the variety and availability of acceptable wholegrain foods is also important. Whole grain consumption at breakfast can have an important impact on total daily nutrient intakes. This simple dietary modification is potentially relatively easy to achieve and could greatly contribute to increased whole grain intake for many individuals.

Who consumes whole grains, and how much?

Regular consumption of whole grain foods has been associated with a reduction in the incidence of cardiovascular disease and diabetes, reductions in cancer mortality at certain sites and an overall reduction in premature death. Although benefits are observed at relatively low levels of intake (between two and three servings per d), the consumption of whole grain foods in some Western countries is less than one serving per d. The main sources of whole grain are wholemeal and rye breads and whole grain breakfast cereals. Typical consumers of whole-grain foods tend to be older, from a high socio-economic group, are less likely to smoke and are more likely to exercise than non-consumers. Some of these attributes may contribute to the observed health benefits. However whole grain foods are an important source of a range of nutrients as part of a healthy eating plan. There is considerable scope for strategies to promote increased consumption of whole grain foods to reduce the risk of a variety of chronic diseases

Onion and garlic use and human cancer

BACKGROUND

Interest in the potential benefits of allium vegetables, in particular, onion (Allium cepa) and garlic (Allium sativum), has its origin in antiquity, but the details of these benefits are still open to discussion.

OBJECTIVE

We investigated the role of allium vegetables in the etiology of various neoplasms. Previous data are scanty and are based mainly on Chinese studies.

DESIGN

Using data from an integrated network of Italian and Swiss case-control studies, we analyzed the relation between frequency of onion and garlic use and cancer at several sites. We calculated odds ratios (ORs) by using multivariate logistic regression models that were adjusted for energy intake and other major covariates.

RESULTS

Consumption of onions varied between 0-14 and 0-22 portions/wk among cases and controls, respectively. The multivariate ORs for the highest category of onion and garlic intake were, respectively, 0.16 and 0.61 for cancer of the oral cavity and pharynx, 0.12 and 0.43 for esophageal cancer, 0.44 and 0.74 for colorectal cancer, 0.17 and 0.56 for laryngeal cancer, 0.75 and 0.90 for breast cancer, 0.27 and 0.78 for ovarian cancer, 0.29 and 0.81 for prostate cancer, and 0.62 and 0.69 for renal cell cancer.

CONCLUSIONS

This uniquely large data set from southern European populations shows an inverse association between the frequency of use of allium vegetables and the risk of several common cancers. Allium vegetables are a favorable correlate of cancer risk in Europe.

Kinetics of the appearance of cereal alkylresorcinols in pig plasma

Alkylresorcinols (AR) are phenolic lipids found in high amounts in wholegrain wheat and rye. They may be important as bioactive components and/or biomarkers of wholegrain wheat and rye intake. AR absorption was studied with pigs during a habitual diet and after a single meal of AR-rich diet. In study 1, four pigs were fed wholegrain rye (RD) and white wheat bread (WD) for 1 week in a cross-over design. Arterial and venous AR concentrations were determined over 540 min after feeding on days 5 and 7. In study 2, four pigs were fed a synthetic, starch-based diet for 5 d, and arterial and venous AR concentrations were determined over 960 min after feeding a single meal of RD. In study 1, plasma AR concentrations after consuming RD peaked at 120 min, remained elevated between 120 and 420 min, and were re-elevated on refeeding at 480 min. In study 2, AR appeared in the plasma after 60 min, peaked at 180-240 min, and remained elevated after 960 min. The apparent elimination half-life was 3.93 h, and the maximum plasma concentration was 666 (sem 35) nmol/l. Arterial and venous plasma AR concentrations were similar, suggesting that AR are absorbed via the lymphatic system. AR concentrations in pig plasma increase rapidly after a meal containing AR, and persist in plasma for at least 5 d, indicating that AR may be a useful biomarker of wholegrain wheat and rye intake.

Dietary acrylamide and human cancer

Low levels of acrylamide have been found in several foods cooked at high temperatures. While there is sufficient evidence for the carcinogenicity of acrylamide in experimental animals, the few epidemiologic studies conducted to date on occupational and dietary exposure to acrylamide have found no consistent evidence of association with human cancer risk. Using data from an integrated network of Italian and Swiss hospital-based case-control studies, we analyzed the relation between dietary acrylamide intake and cancers of the oral cavity and pharynx (749 cases, 1,772 controls), esophagus (395 cases, 1,066 controls), large bowel (1,394 cases of colon, 886 cases of rectal cancer, 4,765 controls), larynx (527 cases, 1,297 controls), breast (2,900 cases, 3,122 controls), ovary (1,031 cases, 2,411 controls) and prostate (1,294 cases, 1,451 controls). All the studies included incident, histologically confirmed cancer cases and controls admitted to the same network of hospitals for acute nonneoplastic conditions. We calculated odds ratios (ORs) using multivariate logistic regression models, adjusted for energy intake and other major covariates of interest. The ORs for the highest versus the lowest quintile of acrylamide intake were 1.12 (95% CI = 0.76-1.66) for cancer of the oral cavity/pharynx, 1.10 (95% CI = 0.65-1.86) for esophageal, 0.97 (95% CI = 0.80-1.18) for colorectal, 1.23 (95% CI = 0.80-1.90) for laryngeal, 1.06 (95% CI = 0.88-1.28) for breast, 0.97 (95% CI = 0.73-1.31) for ovarian and 0.92 (95% CI = 0.69-1.23) for prostate cancer. None of the trend in risk was significant. This uniquely large and comprehensive data set does not show any consistent association between intake of acrylamide and the risk of breast and several other common cancers.

Role of fried foods and oral/pharyngeal and oesophageal cancers

We investigated the role of fried foods on oral-pharyngeal and oesophageal cancers, using data from two case–control studies conducted in Italy and Switzerland between 1992 and 1999, one with a total of 749 (634 men) cases of oral/pharyngeal cancer and 1772 (1252 men) controls, the other with 395 (351 men) cases of oesophageal cancer and 1066 (875 men) controls. Controls were admitted for acute, non-neoplastic conditions, unrelated to alcohol and smoking consumption. After allowance for sex, age, centre, education, body mass index, tobacco smoking, alcohol drinking and nonalcohol energy intake, the multivariate odds ratios (ORs) for an increment of one portion per week of total fried foods were 1.11 (95% confidence interval (CI): 1.05–1.17) for oral-pharyngeal and 1.16 (95% CI: 1.08–1.26) for oesophageal cancer. The ORs were consistent across strata of gender (OR in men only were 1.10 and 1.16, respectively), age, alcohol, tobacco consumption and body mass index.

Chromatographic analysis of alkylresorcinols and their metabolites

Alkylresorcinols (AR) are phenolic lipids present in high amounts in the bran fraction of wheat and rye. AR are of scientific interest as bioactive compounds, as markers for the presence of wholegrain or bran fractions of wheat and rye in food products, and as possible biomarkers of intake for wholegrain wheat and rye. This review discusses their extraction from cereal grains, food and biological fluids, and the various chromatographic methods used in their analysis.

Cereal alkylresorcinols elevate gamma-tocopherol levels in rats and inhibit gamma-tocopherol metabolism in vitro

Alkylresorcinols (AR) are a class of amphiphilic phenolic lipids present in high amounts in wheat and rye bran. They have been reported to be both growth retarding and innocuous when fed to rats, and to have a broad range of bioactivities in vitro, suggested to be related to their ability to bind to proteins and modify membranes. This study was designed to test the effects of AR (purified from rye bran) on growth, tocopherol levels, and cholesterol levels in rats. Rats were fed 1 of 4 different levels of AR for 4 wk: 0 (control), 1, 2, and 4 g/kg diet. AR did not affect final body, liver, or lung weights. The AR diets increased the levels of gamma-tocopherol in liver and lungs (P < 0.05). To investigate whether AR could have increased gamma-tocopherol levels via inhibition of tocopherol-omega-hydroxylase, HepG2 cells were incubated with AR and the metabolism of gamma-tocopherol measured. AR significantly inhibited the conversion of gamma-tocopherol to its water-soluble hydroxychroman metabolite in vitro, indicating that AR may increase gamma-tocopherol levels via inhibition of tocopherol metabolism in vivo. The 4 g AR/kg diet decreased liver cholesterol (P < 0.001), but did not affect plasma lipids. AR were detected in the perirenal adipose tissue samples of rats fed AR, indicating that they can accumulate in the fatty tissues of rats. High levels of dietary AR moderately affect gamma-tocopherol, possibly via inhibition of tocopherol metabolism, and decrease liver cholesterol in rats.

Cereal alkylresorcinols are absorbed by humans

Currently there is no biomarker to link consumption of whole grain cereals and their observed health benefits. A candidate for a biomarker of whole grain wheat and rye intake is a class of phenolic lipids, the alkylresorcinols (AR). Studies to determine the uptake of AR in humans were carried out with a low fiber diet based on white wheat bread (AR free) and a high fiber diet based on rye bran-enriched bread (AR rich). For each diet, two meal frequencies were used: nibbling (7 small meals/d) and ordinary (3 large meals/d). Ten human ileostomy-operated subjects started with the AR-free diet for 2 wk, wk 1 on either nibbling or ordinary and wk 2 on the other meal frequency in a crossover design, followed by a 1-wk washout period, before the AR-rich diet performed as the AR-free diet. Food and ileostomy samples were analyzed for AR. Approximately 40% of AR were recovered in effluent from the small intestine, indicating that 60% of AR are taken up from or converted in the small intestine (ileal digestibility) with no difference between nibbling and ordinary meal frequencies. AR absorbed by humans may be of importance as bioactive compounds, or as a biomarker of whole grain wheat and rye intake.

Fried potatoes and human cancer

A considerable public concern about cancer risk from acrylamide-rich foods followed the announcement that high concentrations of acrylamide are found in fried potatoes and potato chips and, more generally, in starch-containing foods cooked at high temperatures. From a series of hospital-based case-control studies conducted in Italy and Switzerland between 1991 and 2000, we have analyzed the relation between intake of fried/baked potatoes and cancer risk. The cancer sites considered were oral cavity and pharynx (749 cases, 1772 controls), esophagus (395 cases, 1066 controls), larynx (527 cases, 1297 controls), large bowel (1225 colon and 728 rectum cases, 4154 controls), breast (2569 cases, 2588 controls) and ovary (1031 cases, 2411 controls). All cancer cases were incident and histologically confirmed. Controls were subjects admitted to the same network of hospitals of cases for acute, non-neoplastic conditions. All the odds ratios (OR) for the highest vs. the lowest tertile of intake ranged between 0.8-1.1. We found no evidence of interaction with age, gender, alcohol and tobacco use. Our data provide reassuring evidence for the lack of an important association between consumption of fried/baked potatoes and cancer risk.

Epidemiological research on cancer with a focus on Europe

Cancer has been a growing public health problem throughout the last century. Cancer mortality rates in both sexes combined in the European Union (EU) reached a peak in 1988. Thereafter, they declined by 9.4% in 1998. Likewise, lung cancer rates in the EU for both sexes combined increased by 58% between 1960 and 1988, but declined by 14% in 1998. Over a third of the decline was accounted for by lung cancer alone and approximately half by the combination of tobacco-related neoplasms. About half of the decline in total cancer mortality not attributable to tobacco derived from the steady fall in mortality from gastric cancer. The remaining half, including favourable trends in colorectal, breast, testis and lymphoid neoplasms, can be at least in part attributed to advancements in cancer diagnosis and treatment. The major causes of cancer and hence the most important priorities for research will be reviewed, with a specific focus on European priorities for research.

Cigarette tar yield and risk of upper digestive tract cancers: case-control studies from Italy and Switzerland

BACKGROUND

Tobacco smoking is one of the main risk factors for oral, pharyngeal and oesophageal cancers in developed countries. Information on the role of the tar yield of cigarettes in upper digestive tract carcinogenesis is sparse and needs to be updated because the tar yield of cigarettes has steadily decreased over the last few decades.

PATIENTS AND METHODS

We analysed two case-control studies, from Italy and Switzerland, conducted between 1992 and 1999, involving 749 cases of oral and pharyngeal cancer and 1770 controls, and 395 cases of squamous-cell oesophageal carcinoma and 1066 matched controls. Odds ratios (ORs) were estimated by unconditional multiple logistic regression models, including terms for age, sex, study centre, education and alcohol consumption.

RESULTS

Based on the brand of cigarettes smoked for the longest time, the multivariate ORs for current smokers compared with never smokers were 6.1 for <20 mg and 9.8 for >or=20 mg tar for oral and pharyngeal neoplasms, and 4.8 and 5.4 for oesophageal cancer, respectively. For the cigarette brand smoked in the previous six months, the ORs for >or=10 mg compared with <10 mg were 1.9 for cancer of the oral cavity and pharynx and 1.8 for oesophageal cancer, after allowance for number of cigarettes and duration of smoking.

CONCLUSIONS

The present study confirms the direct relationship between the tar yield of cigarettes and upper digestive tract neoplasms, and provides innovative information on lower tar cigarettes, which imply reduced risks compared with higher tar ones. However, significant excess risks were observed even in the lower tar category, thus giving unequivocal indications for stopping smoking as a priority for prevention of upper digestive tract neoplasms.

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.

Fibre intake and laryngeal cancer risk

BACKGROUND

Consumption of vegetables, fruit and whole grain cereals has been inversely related to laryngeal cancer risk. Among the potential protective agents found in these foods, information on dietary fibres and laryngeal cancer risk are scanty.

PATIENTS AND METHODS

A multi-centric, hospital-based case-control study was conducted on 527 patients with squamous-cell carcinoma of the larynx and 1,297 non-neoplastic controls. Cases and controls, frequency matched by age, sex and study centre, were interviewed using a validated food frequency questionnaire.

RESULTS

Compared with the lowest quintile of fibre intake, the odds ratios (ORs) for the highest quintile were 0.3 [95% confidence interval (CI) 0.2-0.4] for total fibre, 0.3 (95% CI 0.2-0.5) for soluble non-cellulose polysaccharides (NCP) and for total insoluble fibre, including cellulose (OR = 0.3, 95% CI 0.2-0.4) and insoluble NCP (OR = 0.4, 95% CI 0.3-0.7). The ORs were 0.2 (95% CI 0.1-0.4) for fibre from vegetables, 0.5 (95% CI 0.3-0.7) from fruit and 1.1 (95% CI 0.6-1.9) from grains. The inverse association observed was similar among different subsites of laryngeal cancer, and consistent across strata of various covariates.

CONCLUSIONS

This study found a strong inverse association between fibre intake and laryngeal cancer risk, which points to fibre as one of the beneficial components of vegetables and fruit.

Natural and human-made mutagens and carcinogens in the human diet

With the exception of tobacco consumption, diet is probably the most important factor in the etiology of human cancer, responsible for around one third of all cases. Despite strenuous attempts in identification, no single causal factor stands out. However, high red meat consumption appears as a potential risk in a number of studies and may be important in New Zealand. Mutagens and carcinogens may be introduced to meat through preservation methods (N-nitroso compounds) and high temperature cooking (heterocyclic amines and polycyclic aromatic hydrocarbons). Mutagenic mycotoxins may be introduced to various dietary items through disease of livestock (sporidesmin) or of agricultural items leading to widespread environmental distribution (e.g. dothistromin). Debates on genetic engineering have raised the spectre of dangerous new genetic variants, but there is no proof that these have ever occurred. Many carcinogens may be endogenously generated. Lifestyle factors such as high alcohol and/or high calorie consumption may be important for some members of the population. The consumption of high fruits, vegetables and whole grain cereals are likely to be beneficial, but the relative roles of dietary fibre, micronutrients and non-nutrients as compared with whole foods is under debate. The effects of many of these dietary factors are also modulated by genotype. The increasing use of molecular genetic techniques, microarrays, proteomics, and the development of human biomonitoring methods yield the promise of gaining accurate perspectives on the relative roles of different dietary factors and genetic factors in human cancers.

Cancer of the oesophagus in Africans in sub-Saharan Africa: any hopes for its control?

Oesophageal cancer, a highly lethal tumour, occurs to a variable extent in Africans in sub-Saharan African countries. In many, its incidence remains low, as in the Ivory Coast, Mali and the Gambia. However, in other African countries, the incidence rate has risen considerably, especially in city populations, as in Durban, South Africa, in Kyadondo, Uganda, and in Harare, Zimbabwe, rising to levels far higher than those reported in white populations. As to risk factors, in some African settings, smoking is a factor, and in others, alcohol consumption. Nutritionally, one enquiry, made in Durban, indicated the use of less-refined cereal products, with higher consumptions of vegetables and fruit, to be protective. In developed populations, protective factors are considered to be those characteristic of a "prudent" lifestyle. However, known risk factors largely fail to explain the high variability in the disease's occurrence. In seeking to combat the disease, it is thought unlikely that most Africans, especially urban dwellers, are willing to alter their lifestyle appropriately, even with the understanding that the changes would confer other protective benefits. This suggests that further rises, especially in the contexts of high incidence rates, are inevitable.

Whole-grain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular disease in the Framingham Offspring Study

BACKGROUND

The influence of whole grains on cardiovascular disease risk may be mediated through multiple pathways, eg, a reduction in blood lipids and blood pressure, an enhancement of insulin sensitivity, and an improvement in blood glucose control.

OBJECTIVE

The objective was to examine the association between diets rich in whole- or refined-grain foods and several metabolic markers of disease risk in the Framingham Offspring Study cohort.

DESIGN

Whole-grain intake and metabolic risk markers were assessed in a cross-sectional study of 2941 subjects.

RESULTS

After adjustment for potential confounding factors, whole-grain intake was inversely associated with body mass index (: 26.9 in the lowest and 26.4 in the highest quintile of intake; P for trend = 0.06), waist-to-hip ratio (0.92 and 0.91, respectively; P for trend = 0.005), total cholesterol (5.20 and 5.09 mmol/L, respectively; P for trend = 0.06), LDL cholesterol (3.16 and 3.04 mmol/L, respectively; P for trend = 0.02), and fasting insulin (205 and 199 pmol/L, respectively; P for trend = 0.03). There were no significant trends in metabolic risk factor concentrations across quintile categories of refined-grain intake. The inverse association between whole-grain intake and fasting insulin was most striking among overweight participants. The association between whole-grain intake and fasting insulin was attenuated after adjustment for dietary fiber and magnesium.

CONCLUSION

Increased intakes of whole grains may reduce disease risk by means of favorable effects on metabolic risk factors.