Carcinogenicity of alcoholic beverages

Association between quality of cheap and unrecorded alcohol products and public health consequences in Poland

BACKGROUND

The research aimed to study the quality of cheap alcohol products in Poland. These included unrecorded alcohols (i.e., home-produced or illegally imported), estimated to constitute more than 25% of total consumption and fruit wines.

METHODS

A sample of alcohol products (n = 52) was collected from local markets and chemical analyses were conducted. The parameters studied were alcoholic strength, volatiles (methanol, acetaldehyde, and higher alcohols), ethyl carbamate, inorganic elements, and food additives including preservatives, colors, and sweeteners. The compositions of the beverages were then toxicologically evaluated using international standards.

RESULTS

With the exception of 1 fortified wine, the unrecorded alcohols were home-produced fruit-derived spirits (moonshine) and spirits imported from other countries. We did not detect any nonbeverage surrogate alcohol. The unrecorded spirits contained, on average, 45% vol of alcohol. However, some products with considerably higher alcoholic strengths were found (up to 85% vol) with no labeling of the content on the bottles. These products may cause more pronounced detrimental health effects (e.g., liver cirrhosis, injuries, some forms of malignant neoplasms, alcohol use disorders, and cardiovascular disease) than will commercial beverages, especially as the consumer may be unaware of the alcohol content consumed. Fruit wines containing between 9.5 and 12.2% vol alcohol showed problems in terms of their additive content and their labeling (e.g., sulfites, sorbic acid, saccharin, and artificial colors) and should be subjected to stricter control. Regarding the other components investigated, the suspected human carcinogens, acetaldehyde and ethyl carbamate, were found at levels relevant to public health concerns. While acetaldehyde is a typical constituent of fermented beverages, ethyl carbamate was found only in home-produced unrecorded alcohols derived from stone fruits with levels significantly above international guidelines.

CONCLUSIONS

The contamination of unrecorded alcohols with ethyl carbamate should be analyzed in a larger sample that also should include legal alcoholic beverages. Furthermore, the impacts of unrecorded alcohol on the health of people with lower socioeconomic status should be studied in detail. Overall, given the extent of the alcohol-attributable disease burden in Poland, the highest priority should be given to the problem of ethanol and its very high content in unrecorded alcohol products.

Global burden of disease and injury and economic cost attributable to alcohol use and alcohol-use disorders

Alcohol consumption has been identified as an important risk factor for chronic disease and injury. In the first paper in this Series, we quantify the burden of mortality and disease attributable to alcohol, both globally and for ten large countries. We assess alcohol exposure and prevalence of alcohol-use disorders on the basis of reviews of published work. After identification of other major disease categories causally linked to alcohol, we estimate attributable fractions by sex, age, and WHO region. Additionally, we compare social costs of alcohol in selected countries. The net effect of alcohol consumption on health is detrimental, with an estimated 3.8% of all global deaths and 4.6% of global disability-adjusted life-years attributable to alcohol. Disease burden is closely related to average volume of alcohol consumption, and, for every unit of exposure, is strongest in poor people and in those who are marginalised from society. The costs associated with alcohol amount to more than 1% of the gross national product in high-income and middle-income countries, with the costs of social harm constituting a major proportion in addition to health costs. Overall, we conclude that alcohol consumption is one of the major avoidable risk factors, and actions to reduce burden and costs associated with alcohol should be urgently increased.

Alcohol in Mayan Guatemala: consumption, distribution, production and composition of cuxa

AIMS

To describe the consumption, distribution, production and chemical composition of alcohol, including cuxa (pronounced 'coo sha'), in Nahualá, a highland Mayan municipality in Guatemala. Cuxa is a sugarcane-derived spirit, in part produced clandestinely, that has been distributed in the community for several decades.

METHODS

Key informant interviews with alcohol distributors and consumers, cuxa producers and health professionals, as well as analyses of questionnaires from a sample of 47 spouses who came to the local health centre for problems related to their husband's drinking. Sampling and chemical analysis of cuxa from 12 of 13 identified sales points in the head-town of Nahualá and its nearby settlements (10 km radius). Fieldwork was conducted between November 2007 and March 2008.

RESULTS

Alcohol consumption was found to be integrated culturally in this community. The overall drinking culture was marked by irregular heavy drinking occasions, especially around market days, with substantial inebriation and health problems, especially among street inhabiting drinkers. Cuxa contributed to these problems, and cuxa drinking was socially stigmatized. Cuxa was produced both clandestinely and industrially, and sold legally by taverns and illegally by clandestine distributors. The alcoholic strength of the samples was typically between 17 and 19% vol.; clandestinely produced cuxa samples showed acetaldehyde contamination.

CONCLUSIONS

Measures should be taken to reduce the harm associated with alcohol in this community, including efforts to reduce acetaldehyde levels in cuxa.

Ethanol Does Not Promote MeIQx-initiated Rat Colon Carcinogenesis Based on Evidence from Analysis of a Colon Cancer Surrogate Marker

Epidemiological studies suggest that alcohol consumption increases the risk of developing colorectal cancer. However, the data are confounded by numerous cosegregating variables. To cast further light on the relationships between alcohol intake and colon cancer development, 21-day-old male F344/DuCrj rats were fed 200 ppm 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in their diet for 8 weeks and doses of 0, 0.1, 0.3, 1, 3, 10 and 20% of ethanol in their drinking water ad libitum for 16 weeks thereafter. The rats were sacrificed after 24 weeks of experiment, and aberrant crypt foci (ACF), surrogate lesions for colon cancer, were examined under a light microscope at low magnification. Ethanol was found not to affect the ACF formation at any dose compared with the initiated-controls. Furthermore, ethanol did not alter colon epithelial cell proliferation. These data, obtained by analysis of a colon cancer surrogate marker lesion, indicate that ethanol lacks promotion activity for MeIQx-initiated rat colon carcinogenesis.

Acetaldehyde stimulates FANCD2 monoubiquitination, H2AX phosphorylation, and BRCA1 phosphorylation in human cells in vitro: implications for alcohol-related carcinogenesis

According to a recent IARC Working Group report, alcohol consumption is causally related to an increased risk of cancer of the upper aerodigestive tract, liver, colorectum, and female breast [R. Baan, K. Straif, Y. Grosse, B. Secretan, F. El Ghissassi, V. Bouvard, A. Altieri, V. Cogliano, Carcinogenicity of alcoholic beverages, Lancet Oncol. 8 (2007) 292-293]. Several lines of evidence indicate that acetaldehyde (AA), the first product of alcohol metabolism, plays a very important role in alcohol-related carcinogenesis, particularly in the esophagus. We previously proposed a model for alcohol-related carcinogenesis in which AA, generated from alcohol metabolism, reacts in cells to generate DNA lesions that form interstrand crosslinks (ICLs) [J.A. Theruvathu, P. Jaruga, R.G. Nath, M. Dizdaroglu, P.J. Brooks, Polyamines stimulate the formation of mutagenic 1,N2-propanodeoxyguanosine adducts from acetaldehyde, Nucleic Acids Res. 33 (2005) 3513-3520]. Since the Fanconi anemia-breast cancer associated (FANC-BRCA) DNA damage response network plays a crucial role in protecting cells against ICLs, in the present work we tested this hypothesis by exposing cells to AA and monitoring activation of this network. We found that AA exposure results in a concentration-dependent increase in FANCD2 monoubiquitination, which is dependent upon the FANC core complex. AA also stimulated BRCA1 phosphorylation at Ser1524 and increased the level of gammaH2AX, with both modifications occurring in a dose-dependent manner. However, AA did not detectably increase the levels of hyperphosphorylated RPA34, a marker of single-stranded DNA exposure at replication forks. These results provide the initial description of the AA-DNA damage response, which is qualitatively similar to the cellular response to mitomycin C, a known DNA crosslinking agent. We discuss the mechanistic implications of these results, as well as their possible relationship to alcohol-related carcinogenesis in different human tissues.

Carcinogenicity of acetaldehyde in alcoholic beverages: risk assessment outside ethanol metabolism

AIMS

In addition to being produced in ethanol metabolism, acetaldehyde occurs naturally in alcoholic beverages. Limited epidemiological evidence points to acetaldehyde as an independent risk factor for cancer during alcohol consumption, in addition to the effects of ethanol. This study aims to estimate human exposure to acetaldehyde from alcoholic beverages and provide a quantitative risk assessment.

METHODS

The human dietary intake of acetaldehyde via alcoholic beverages was estimated based on World Health Organization (WHO) consumption data and literature on the acetaldehyde contents of different beverage groups (beer, wine, spirits and unrecorded alcohol). The risk assessment was conducted using the European Food Safety Authority's margin of exposure (MOE) approach with benchmark doses obtained from dose-response modelling of animal experiments. Life-time cancer risk was calculated using the T25 dose descriptor.

RESULTS

The average exposure to acetaldehyde from alcoholic beverages was estimated at 0.112 mg/kg body weight/day. The MOE was calculated to be 498, and the life-time cancer risk at 7.6 in 10,000. Higher risk may exist for people exposed to high acetaldehyde contaminations, as we have found in certain unrecorded alcohol beverages in Guatemala and Russia, for which we have demonstrated possible exposure scenarios, with risks in the range of 1 in 1000.

CONCLUSIONS

The life-time cancer risks for acetaldehyde from alcoholic beverages greatly exceed the usual limits for cancer risks from the environment set between 1 : 10,000 and 1 : 1,000,000. Alcohol consumption has thus been identified as a direct source of acetaldehyde exposure, which in conjunction with other sources (food flavourings, tobacco) results in a magnitude of risk requiring intervention. An initial public health measure could be to reduce the acetaldehyde content in alcoholic beverages as low as technologically possible, and to restrict its use as a food flavour additive.

Lifestyle risk factors for oral cancer

The "style of life is the unique way in which individuals try to realize their fictional final goal and meet or avoid the three main tasks of life: work, community, love" (Alfred Adler, founder of the Individual Psychology). Lifestyle refers to the way individuals live their lives and how they handle problems and interpersonal relations. The lifestyle behaviours associated to oral cancer with convincing evidence are tobacco use, betel quid chewing, alcohol drinking, low fruit and vegetable consumption (the detrimental lifestyle is high fat and/or sugar intake, resulting in low fruit and/or vegetable intake). Worldwide, 25% of oral cancers are attributable to tobacco usage (smoking and/or chewing), 7-19% to alcohol drinking, 10-15% to micronutrient deficiency, more than 50% to betel quid chewing in areas of high chewing prevalence. Carcinogenicity is dose-dependent and magnified by multiple exposures. Conversely, low and single exposures do not significantly increase oral cancer risk. These behaviours have common characteristics: (i) they are widespread: one billion men, 250 million women smoke cigarettes, 600-1200 million people chew betel quid, two billion consume alcohol, unbalanced diet is common amongst developed and developing countries; (ii) they were already used by animals and human forerunners millions of years ago because they were essential to overcome conditions such as cold, hunger, famine; their use was seasonal and limited by low availability, in contrast with the pattern of consumption of the modern era, characterized by routine, heavy usage, for recreational activities and with multiple exposures; (iii) their consumption in small doses is not recognized as detrimental by the human body and activates the dopaminergic reward system of the brain, thus giving instant pleasure, "liking" (overconsumption) and "wanting" (craving). For these reasons, effective Public Health measures aimed at preventing oral cancer and other lifestyle-related conditions fail to realize their final goal to eradicate these lifestyles. Following Adler's theory and the principles of the "Ottawa Charter for Health Promotion", conditions such as education, sustainable resources, social justice, and equity must be satisfied before the implementation of physical health promotion campaigns.

The alcohol flushing response: an unrecognized risk factor for esophageal cancer from alcohol consumption

Philip Brooks and colleagues discuss evidence linking the alcohol flushing response (predominantly due to ALDH2 deficiency) with a much higher risk of esophageal cancer from alcohol consumption.

Is habitual alcohol drinking associated with reduced electrophoretic DNA migration in peripheral blood leukocytes from ALDH2-deficient male Japanese?

Alcohol drinking-derived acetaldehyde is believed to cross-link DNA and induce sister chromatid exchanges in peripheral blood lymphocytes. However, little population data are available to illustrate effects of alcohol-derived acetaldehyde on DNA migration as assayed by the comet assay in peripheral lymphocytes. In the present study, we investigated lifestyle behaviours, including alcohol consumption, in 150 Japanese males by questionnaire, determined their aldehyde dehydrogenase 2 (ALDH2) family genotypes by polymerase chain reaction and measured the DNA migration in peripheral blood leukocytes by the alkaline comet assay. The results showed that habitual alcohol drinking is significantly negatively associated with DNA migration in peripheral blood leukocytes (r = -0.321, P = 0.005) of ALDH2-deficient, but not of ALDH2-proficient genotypes (r = 0.048, P = 0.683). The amount of pure alcohol consumed per time by the subjects showed a similar phenomenon (r = -0.257, P = 0.025 for the ALDH2-deficient, but r = -0.061, P = 0.606 for the ALDH2-proficient genotype). Further stepwise multiple regression analysis showed that alcohol drinking frequency was a significant predictor of DNA migration for subjects with ALDH2-deficient genotype, but not for subjects with ALDH2-proficient genotype. In summary, the present result suggests that frequent alcohol drinking is significantly associated with a reduced electrophoretic DNA migration in peripheral blood leukocytes from ALDH2-deficient male Japanese subjects.

Chronic atrophic gastritis and metachronous gastric cancer in Japanese alcoholic men with esophageal squamous cell carcinoma

BACKGROUND

The risk of metachronous gastric cancer is high in Japanese with esophageal squamous cell carcinoma (SCC), especially in alcoholic men, suggesting a common background underlying the gastric and esophageal cancers.

METHODS

Endoscopic follow-up ranging from 7 to 160 months (median, 47 months) after the initial diagnosis was performed in 99 Japanese gastric-cancer-free alcoholic men (56.8 +/- 6.4 years) with esophageal SCC detected by an endoscopic screening examination. Chronic atrophic gastritis (CAG) assessed by the serum pepsinogen test and Helicobacter pylori status was compared between 90 of the 99 esophageal SCC cases and 180 age-matched Japanese gastric- and esophageal-cancer-free alcoholic men.

RESULTS

The serum pepsinogen test showed a higher seroprevalence of severe CAG among the cases than among the age-matched controls (35.4% vs. 14.2% for H. pylori-seropositive, 71.4% vs. 7.7% for H. pylori-indeterminate, and 17.1% vs. 9.8% for H. pylori-negative, respectively; H. pylori status-adjusted p = 0.0008), whereas their H. pylori status was similar. The accelerated progression of severe CAG observed in the Japanese alcoholic men with esophageal SCC suggests the existence of common mechanisms by which both esophageal SCC and H. pylori-related severe CAG develop in this population. Metachronous gastric adenocarcinoma was diagnosed in 11 of the 99 gastric-cancer-free patients, and the cumulative rate of metachronous gastric cancer within 5 years was estimated to be 15% according to the Kaplan-Meier method. The age-adjusted hazard ratios were 7.87 (95% confidence interval: 1.43 to 43.46) and 4.84 (1.16 to 20.21), respectively, in the patients with severe CAG in comparison with those without CAG and those without severe CAG. Inactive heterozygous aldehyde dehydrogenase-2, a very strong risk factor for esophageal SCC in the alcoholics, was not associated with an increased risk of metachronous gastric cancer.

CONCLUSIONS

Accelerated development of severe CAG at least partially explained the very high frequency of development of metachronous gastric cancer in this population.

Alcohol and genetic polymorphisms: effect on risk of alcohol-related cancer

Public health guidelines aim to limit the consumption of alcoholic beverages worldwide and the subsequent health burden. In particular, alcohol consumption is an avoidable risk factor for cancer. In human beings, ethanol in alcoholic drinks is mainly oxidised in the liver by alcohol dehydrogenases to acetaldehyde, and is further detoxified to acetate by aldehyde dehydrogenases. Functional variants in genes involved in alcohol metabolism result in differences between individuals in exposure to carcinogenic acetaldehyde, suggesting a possible interaction of genetic susceptibility and alcohol exposure in cancer. We reviewed available studies of the combined effects of alcohol drinking and genetic polymorphisms on alcohol-related cancer risk. Most available data were for polymorphisms in alcohol and folate metabolism. We give an overview of published studies on the combined effects of alcohol drinking and polymorphisms in genes for alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), cytochrome P450 2E1, and methylene-tetrahydrofolate reductase on the risk of alcohol-related cancer. Current data lend support to a role of polymorphisms ADH1B and ALDH2 combined with alcohol consumption in cancer. Other available data are insufficient or inconclusive, highlighting the need for additional studies.

An assessment of potential cancer risk following occupational exposure to ethanol

Recognition of the carcinogenic properties of ethanol has resulted from comprehensive evidence regarding the effect of consumption of alcohol; indeed, ethanol in alcoholic beverages is now considered a Group 1 carcinogen by the International Agency for Research on Cancer. However, there is little information on the effects of ethanol following exposure via the occupationally relevant routes of inhalation and dermal exposure. This review therefore focuses on these exposure routes, to assess potential carcinogenic risk associated with occupational exposure to ethanol. Inhalatory exposure at the current occupational exposure limit (OEL) for the United Kingdom (1000 ppm ethanol over an 8-h shift) was estimated to be equivalent to ingestion of 10 g ethanol (approximately 1 glass of alcohol) per day. However, in the occupational setting the dose-rate delivery of this amount of ethanol is low, allowing for its rapid and effective elimination, for the majority of individuals. Similarly, while dermal absorption in an occupational setting could potentially add to overall body ethanol burden, additional carcinogenic risk of such exposure is considered negligible. Thus, on balance, there appears little cause to suppose occupational exposure at or below the current OEL associates with any appreciable increase in risk of cancer. However, available occupational exposure data to confirm this view are currently limited. It is also suggested that adoption of a more flexible classification regime, considering risk in the context of hazard and exposure (such as that adopted by the German MAK commission), would represent an improvement over traditional occupational risk assessment practices.

Moderate alcohol intake and cancer incidence in women

BACKGROUND

With the exception of breast cancer, little is known about the effect of moderate intakes of alcohol, or of particular types of alcohol, on cancer risk in women.

METHODS

A total of 1,280,296 middle-aged women in the United Kingdom enrolled in the Million Women Study were routinely followed for incident cancer. Cox regression models were used to calculate adjusted relative risks and 95% confidence intervals (CIs) for 21 site-specific cancers according to amount and type of alcoholic beverage consumed. All statistical tests were two-sided.

RESULTS

A quarter of the cohort reported drinking no alcohol; 98% of drinkers consumed fewer than 21 drinks per week, with drinkers consuming an average of 10 g alcohol (1 drink) per day. During an average 7.2 years of follow-up per woman 68,775 invasive cancers occurred. Increasing alcohol consumption was associated with increased risks of cancers of the oral cavity and pharynx (increase per 10 g/d = 29%, 95% CI = 14% to 45%, Ptrend < .001), esophagus (22%, 95% CI = 8% to 38%, Ptrend = .002), larynx (44%, 95% CI = 10% to 88%, Ptrend = .008), rectum (10%, 95% CI = 2% to 18%, Ptrend = .02), liver (24%, 95% CI = 2% to 51%, Ptrend = .03), breast (12%, 95% CI = 9% to 14%, Ptrend < .001), and total cancer (6%, 95% CI = 4% to 7%, Ptrend < .001). The trends were similar in women who drank wine exclusively and other consumers of alcohol. For cancers of the upper aerodigestive tract, the alcohol-associated risk was confined to current smokers, with little or no effect of alcohol among never and past smokers (P(heterogeneity) < .001). Increasing levels of alcohol consumption were associated with a decreased risk of thyroid cancer (Ptrend = .005), non-Hodgkin lymphoma (Ptrend = .001), and renal cell carcinoma (Ptrend = .03).

CONCLUSIONS

Low to moderate alcohol consumption in women increases the risk of certain cancers. For every additional drink regularly consumed per day, the increase in incidence up to age 75 years per 1000 for women in developed countries is estimated to be about 11 for breast cancer, 1 for cancers of the oral cavity and pharynx, 1 for cancer of the rectum, and 0.7 each for cancers of the esophagus, larynx and liver, giving a total excess of about 15 cancers per 1000 women up to age 75.

Increased formation of gastric N(2)-ethylidene-2'-deoxyguanosine DNA adducts in aldehyde dehydrogenase-2 knockout mice treated with ethanol

We analyzed an acetaldehyde-derived DNA adduct, N(2)-ethylidene-2'-deoxyguanosine (N(2)-Eti-dG) in stomach DNA of aldehyde dehydrogenase (Aldh)-2-knockout mice that were fed with alcohol to determine effects of alcohol consumption and Aldh2 genotype on the level of DNA damage in stomach. Aldh2-active(+/+), heterozygote(+/-) and knockout(-/-) mice were fed 20% ethanol for 5 weeks, then the level of N(2)-Eti-dG in stomach was determined by liquid chromatography tandem mass spectrometry. The average N(2)-Eti-dG level in DNA from untreated mice was not significantly different among Aldh2 genotypes (2.0-3.1 adducts/10(7) bases), however, the average N(2)-Eti-dG level in DNA from ethanol-treated mice was 4.8+/-2.6 adducts/10(7) bases in Aldh2+/+ mice, 7.9+/-1.1 adducts/10(7) bases in Aldh2+/- mice, and 48.6+/-12.0 adducts/10(7) bases in Aldh2-/- mice, respectively. Our data clearly showed that alcohol drinking caused DNA damage in stomach, which was Aldh2 genotype-dependent in this experimental animal model. This result suggests that heavy-alcohol drinking and Aldh2 deficiency might be risk factors of stomach cancer.

Coffee and alcohol consumption and bladder cancer

Epidemiological studies on coffee, alcohol and bladder cancer risk published up to 2007 were reviewed. Coffee drinkers have a moderately higher relative risk of bladder cancer compared to non-drinkers. The association may partly be due to residual confounding by smoking or dietary factors, but the interpretation remains open to discussion, although the absence of dose and duration-risk relations weighs against the presence of a causal association. Most studies of alcohol and bladder cancer found no association, with some studies finding a direct and other an inverse one. This again may be due to differential confounding effect of tobacco smoking--the major risk factor for bladder cancer--in various populations. Thus, epidemiological findings on the relation between alcohol drinking and bladder cancer exclude any meaningful association.

Health risk appraisal models for mass screening for esophageal and pharyngeal cancer: an endoscopic follow-up study of cancer-free Japanese men

PURPOSE

To assess the performance of our health risk appraisal (HRA) models for screening individuals at high risk of esophageal/pharyngeal squamous cell carcinoma (EPSCC).

METHODS

Based on the results of our previous case-control study, we invented HRA models that enable screening for EPSCC cases in Japanese men with high sensitivity and specificity based on either their aldehyde dehydrogenase-2 genotype (HRA-G model) or alcohol flushing (HRA-F model) and drinking, smoking, and dietary habits. Follow-up endoscopy combined with esophageal iodine staining (median follow-up period: 5.0 years) was done on 404 Japanese men (50-78 years) who were registered as cancer-free controls in the previous study.

RESULTS

The follow-up endoscopy resulted in a diagnosis of 6 esophageal SCC (T(is) in 5 and T(1) in 1), 1 hypopharyngeal SCC (T(2)), and 1 oropharyngeal SCC (T(2)). Seven and 6 of the 8 EPSCC cases were in the top 10% risk group at baseline according to the HRA-G and HRA-F models, respectively. The EPSCC detection rates per 100 person-years in the top 10% risk groups by the HRA-G and HRA-F models were 4.38 (95% confidence interval, 1.76-9.01) and 3.48 (95% confidence interval, 1.28-7.58), respectively. Their age-adjusted relative risk was 95.1- and 26.3-fold, respectively (P < 0.0001), higher than in the bottom 90% risk groups.

CONCLUSIONS

The high detection rates for EPSCC in the top 10% risk group of this preliminary follow-up study were in good agreement with those predicted by the HRA models and thus encouraged the screening based on our HRA models in larger populations of Japanese men.

Contribution of alcohol and tobacco use in gastrointestinal cancer development

Tobacco smoke and alcohol are major risk factors for a variety of cancer sites, including those of the gastrointestinal tract. Tobacco smoke contains a great number of mutagenic and carcinogenic compounds, including polycyclic carbohydrates, nitrosamines, and nicotine, while ethanol per se has only weak carcinogenic potential, but its first metabolite, acetaldehyde, is a mutagen and carcinogen, since it forms stable adducts with DNA. The possibility of proto-oncogene mutation in gastrointestinal mucosa cells may be associated with tobacco smoking-induced cancers through the formation of unfavorable DNA adducts. Individuals with defective DNA repair mechanisms and unfavorable genetic make-up for carcinogen metabolism may be at increased risk for gastrointestinal cancers. Individuals with a high production rate of acetaldehyde from ethanol also have an increased cancer risk when they drink chronically. These include individuals with a genetically determined increased acetaldehyde production due to alcohol dehydrogenase polymorphism and those with a decreased detoxification of acetaldehyde due to acetaldehyde dehydrogenase mutation. In addition, oral bacterial overgrowth due to poor oral hygiene also increases salivary acetaldehyde. Dietary deficiencies such as a lack of folate, riboflavine, and zinc may also contribute to the increase cancer risk in the alcoholic patient. It is of considerable importance that smoking and drinking act synergistically. Smoking increases the acetaldehyde burden following alcohol consumption and drinking enhances the activation of various procarcinogens present in tobacco smoke due to increased metabolic activation by an induced cytochrome P450-2E1-dependent microsomal biotransformation system in the mucosa of the upper digestive tract and the liver.

Health risk appraisal models for mass screening of esophageal cancer in Japanese men

BACKGROUND

Because early squamous cell carcinoma (SCC) of the esophagus is detectable by endoscopic esophageal iodine staining with high accuracy and is easily treated by endoscopic mucosectomy, it is important to develop efficient methods for screening candidates for the endoscopic examination. Inactive aldehyde dehydrogenase-2 (ALDH2) is a very strong risk factor for esophageal SCC in alcohol drinkers and thus may be suitable as a screening tool.

PURPOSE

To assess the performance of health risk appraisal (HRA) models in screening for esophageal SCC in the Japanese male population.

METHODS

Two types of HRA models were developed based on our previous case-control study, which included assessment of ALDH2 activity and selected risk factors (HRA-G and HRA-F: activities of ALDH2 assessed by genotype and questionnaire for alcohol flushing, respectively). Each individual's risk of esophageal SCC was calculated quantitatively as a risk score. The sensitivity and specificity of the HRA models at various cutoff values of risk score was estimated by a leave-one-out cross-validation. The positive predictive value was estimated assuming the prevalence of esophageal SCC in the whole population to be 0.17% or 0.39% according to literatures.

RESULTS

When individuals ranked in the top 10% of the HRA-F risk score was screened, the sensitivity was 57.9% and positive predictive value was 0.93% or 2.12% according to the above assumptions, respectively. The sensitivity was slightly better by the HRA-G model than by the HRA-F model.

CONCLUSION

The HRA models may provide an important approach to early intervention strategies to control esophageal SCC in Japanese men.

Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity

Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, pharmaceutical preparations, and many household products). Contradictory evidence about the safety of such topical applications of the alcohol can be found in the scientific literature, yet an up-to-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking.The first and foremost concerns of topical ethanol applications for public health are its carcinogenic effects, as there is unambiguous evidence for the carcinogenicity of ethanol orally consumed in the form of alcoholic beverages. So far there is a lack of evidence to associate topical ethanol use with an increased risk of skin cancer. Limited and conflicting epidemiological evidence is available on the link between the use of ethanol in the oral cavity in the form of mouthwashes or mouthrinses and oral cancer. Some studies pointed to an increased risk of oral cancer due to locally produced acetaldehyde, operating via a similar mechanism to that found after alcoholic beverage ingestion.In addition, topically applied ethanol acts as a skin penetration enhancer and may facilitate the transdermal absorption of xenobiotics (e.g. carcinogenic contaminants in cosmetic formulations). Ethanol use is associated with skin irritation or contact dermatitis, especially in humans with an aldehyde dehydrogenase (ALDH) deficiency.After regular application of ethanol on the skin (e.g. in the form of hand disinfectants) relatively low but measurable blood concentrations of ethanol and its metabolite acetaldehyde may occur, which are, however, below acute toxic levels. Only in children, especially through lacerated skin, can percutaneous toxicity occur.As there might be industry bias in many studies about the safety of topical ethanol applications, as well as a general lack of scientific research on the long-term effects, there is a requirement for independent studies on this topic. The research focus should be set on the chronic toxic effects of ethanol and acetaldehyde at the point of impact, with special regard to children and individuals with genetic deficiencies in ethanol metabolism.

Lesion bypass of N2-ethylguanine by human DNA polymerase iota

Nucleotide incorporation and extension opposite N2-ethyl-Gua by DNA polymerase iota was measured and structures of the DNA polymerase iota-N2-ethyl-Gua complex with incoming nucleotides were solved. Efficiency and fidelity of DNA polymerase iota opposite N2-ethyl-Gua was determined by steady state kinetic analysis with Mg2+ or Mn2+ as the activating metal. DNA polymerase iota incorporates dCMP opposite N2-ethyl-Gua and unadducted Gua with similar efficiencies in the presence of Mg2+ and with greater efficiencies in the presence of Mn2+. However, the fidelity of nucleotide incorporation by DNA polymerase iota opposite N2-ethyl-Gua and Gua using Mn2+ is lower relative to that using Mg2+ indicating a metal-dependent effect. DNA polymerase iota extends from the N2-ethyl-Gua:Cyt 3' terminus more efficiently than from the Gua:Cyt base pair. Together these kinetic data indicate that the DNA polymerase iota catalyzed reaction is well suited for N(2)-ethyl-Gua bypass. The structure of DNA polymerase iota with N2-ethyl-Gua at the active site reveals the adducted base in the syn configuration when the correct incoming nucleotide is present. Positioning of the ethyl adduct into the major groove removes potential steric overlap between the adducted template base and the incoming dCTP. Comparing structures of DNA polymerase iota complexed with N2-ethyl-Gua and Gua at the active site suggests movements in the DNA polymerase iota polymerase-associated domain to accommodate the adduct providing direct evidence that DNA polymerase iota efficiently replicates past a minor groove DNA adduct by positioning the adducted base in the syn configuration.

Polymorphisms of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 and colorectal cancer risk in Chinese males

AIM: To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males.

METHODS: A case-control study was conducted in 190 cases and 223 population-based controls. ADH2 Arg47His (G-A) and ALDH2 Glu487Lys (G-A) genotypes were identified by PCR and denaturing high-performance liquid chromatography (DHPLC). Information on smoking and drinking was collected and odds ratio (OR) was estimated.

RESULTS: The ADH2 A/A and ALDH2 G/G genotypes showed moderately increased CRC risk. The age- and smoking-adjusted OR for ADH2 A/A relative to G/A and G/G was 1.60 (95% CI=1.08-2.36), and the adjusted OR for ALDH2 G/G relative to G/A and A/A was 1.79 (95% CI=1.19-2.69). Significant interactions between ADH2, ALDH2 and drinking were observed. As compared to the subjects with ADH2 G and ALDH2 A alleles, those with ADH2 A/A and ALDH2 G/G genotypes had a significantly increased OR (3.05, 95% CI= 1.67-5.57). The OR for CRC among drinkers with the ADH2 A/A genotype was increased to 3.44 (95% CI= 1.84-6.42) compared with non-drinkers with the ADH2 G allele. The OR for CRC among drinkers with the ALDH2 G/G genotype was also increased to 2.70 (95% CI= 1.57-4.66) compared with non-drinkers with the ALDH2 A allele.

CONCLUSION: Polymorphisms of the ADH2 and ALDH2 genes are significantly associated with CRC risk. There are also significant gene-gene and gene-environment interactions between drinking and ADH2 and ALDH2 polymorphisms regarding CRC risk in Chinese males.

Alcohol and tobacco use, and cancer risk for upper aerodigestive tract and liver

This study reviews the association between alcohol, tobacco, and the risk of cancers of the upper digestive and respiratory tract (i.e. oral cavity and pharynx, larynx, and esophagus) and liver. Alcohol drinking and tobacco smoking are the major risk factors for upper aerodigestive tract cancers, accounting for a large proportion (i.e. about three-quarters) of cases in developed countries. Consumption amount is the strongest alcohol-related determinant of risk, whereas the pattern of alcohol-related risk with duration is inconsistent. Both dose and duration of smoking have important effects on the risk of upper aerodigestive tract cancers. The combined exposure to alcohol and tobacco has a multiplicative effect on carcinogenesis of this tract. Alcohol and tobacco consumption are also causally related to liver cancer, although the associations are moderate and a lower fraction of neoplasms is attributable to these factors as compared with cancers of the upper aerodigestive tract. An interaction between alcohol drinking and tobacco smoking has been reported, but the issue is not adequately assessed.

Dietary risk factors for hypopharyngeal cancer in India

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Differential blocking effects of the acetaldehyde-derived DNA lesion N2-ethyl-2'-deoxyguanosine on transcription by multisubunit and single subunit RNA polymerases

Acetaldehyde, the first metabolite of ethanol, reacts with DNA to form adducts, including N(2)-ethyl-2'-deoxyguanosine (N(2)-Et-dG). Although the effects of N(2)-Et-dG on DNA polymerases have been well studied, nothing is known about possible effects of this lesion on transcription by RNA polymerases (RNAPs). Using primer extension assays in vitro, we found that a single N(2)-Et-dG lesion is a strong block to both mammalian RNAPII and two other multisubunit RNAPs, (yeast RNAPII and Escherichia coli RNAP), as well as to T7 RNAP. However, the mechanism of transcription blockage appears to differ between the multisubunit RNAPs and T7 RNAP. Specifically, all three of the multisubunit RNAPs can incorporate a single rNTP residue opposite the lesion, whereas T7 RNAP is essentially unable to do so. Using the mammalian RNAPII, we found that CMP is exclusively incorporated opposite the N(2)-Et-dG lesion. In addition, we also show that the accessory transcription factor TFIIS does not act as a lesion bypass factor, as it does for other nonbulky DNA lesions; instead, it stimulates the polymerase to remove the CMP incorporated opposite the lesion by mammalian RNAPII. We also include models of the N(2)-Et-dG within the active site of yeast RNAPII, which are compatible with our observations.

Salivary acetaldehyde concentration according to alcoholic beverage consumed and aldehyde dehydrogenase-2 genotype

BACKGROUND

Acetaldehyde is suspected of playing a critical role in cancer development in the upper aerodigestive tract (UADT). The high salivary acetaldehyde levels after alcohol drinking are partly due to acetaldehyde production by oral bacteria. Some alcoholic beverages, especially Calvados and shochu, contain very high levels of acetaldehyde. Inactive heterozygous aldehyde dehydrogenase-2 (ALDH2) increases the risk of UADT cancer in drinkers.

METHODS

In a randomized cross-over design study, 19 healthy Japanese volunteers ingested 0.6 g ethanol/kg body weight in the form of 13% ethanol Calvados, 13% ethanol shochu, 13% ethanol red wine, and 5% ethanol beer under the fasting conditions at 3-week intervals. We monitored blood and salivary acetaldehyde concentrations immediately after drinking, and 30, 60, 90, 120, and 180 minutes after completion of drinking.

RESULTS

The acetaldehyde concentration of each beverage was: Calvados 0.60 mM (1.86 mM in 40% undiluted solution), shochu 0.60 mM (1.16 mM in 25% undiluted solution), red wine 0.25 mM, and beer 0.14 mM. The salivary acetaldehyde concentration immediately after drinking wine was significantly lower than the other beverages, and it was significantly lower immediately after drinking beer than Calvados. The acetaldehyde concentrations 30 to 180 minutes after drinking were unrelated to the beverage type. Throughout the observation period the salivary acetaldehyde concentrations were much higher than the blood acetaldehyde concentrations in all 12 active ALDH2 homozygotes (24 to 53 microM in saliva vs. 2 to 5 microM in blood) and in all 7 inactive ALDH2 heterozygotes (37 to 76 microM in saliva vs. 12 to 25 microM in blood), and they were 13 to 25 microM higher in the ALDH2 heterozygotes than in the ALDH2 homozygotes after adjusting for age, body weight, sex, smoking and drinking habits, and time since the last toothbrushing. The values after subtracting the blood acetaldehyde concentration from the salivary acetaldehyde concentration were also higher in the ALDH2 heterozygotes than in the ALDH2 homozygotes.

CONCLUSIONS

There are differences in exposure of the UADT to high salivary acetaldehyde concentrations according to the type of alcoholic beverage and ALDH2 genotype, and the differences partly explain the differences in the cancer susceptibility of the UADT according to alcoholic beverage and ALDH2 genotype.

The role of acetaldehyde outside ethanol metabolism in the carcinogenicity of alcoholic beverages: evidence from a large chemical survey

Acetaldehyde is a volatile compound naturally found in alcoholic beverages, and it is regarded as possibly being carcinogenic to humans (IARC Group 2B). Acetaldehyde formed during ethanol metabolism is generally considered as a source of carcinogenicity in alcoholic beverages. However, no systematic data is available about its occurrence in alcoholic beverages and the carcinogenic potential of human exposure to this directly ingested form of acetaldehyde outside ethanol metabolism. In this study, we have analysed and evaluated a large sample collective of different alcoholic beverages (n=1,555). Beer (9+/-7 mg/l, range 0-63 mg/l) had significantly lower acetaldehyde contents than wine (34+/-34 mg/l, range 0-211 mg/l), or spirits (66+/-101 mg/l, range 0-1,159 mg/l). The highest acetaldehyde concentrations were generally found in fortified wines (118+/-120 mg/l, range 12-800 mg/l). Assuming an equal distribution between the beverage and saliva, the residual acetaldehyde concentrations in the saliva after swallowing could be on average 195 microM for beer, 734 microM for wine, 1,387 microM for spirits, or 2,417 microM for fortified wine, which are above levels previously regarded as potentially carcinogenic. Further research is needed to confirm the carcinogenic potential of directly ingested acetaldehyde. Until then, some possible preliminary interventions include the reduction of acetaldehyde in the beverages by improvement in production technology or the use of acetaldehyde binding additives. A re-evaluation of the 'generally recognized as safe' status of acetaldehyde is also required, which does not appear to be in agreement with its toxicity and carcinogenicity.

Risk of metachronous squamous cell carcinoma in the upper aerodigestive tract of Japanese alcoholic men with esophageal squamous cell carcinoma: a long-term endoscopic follow-up study

East Asian case-control studies have shown a strong relationship between alcohol consumption combined with inactive heterozygous aldehyde dehydrogenase-2 (ALDH2*1/*2) and the development of squamous cell carcinoma (SCC), especially multiple SCC, of the upper aerodigestive tract (UADT). This study aimed to identify determinants of the development of metachronous SCC in the UADT in alcoholics with esophageal SCC. Follow-up endoscopic examinations were carried out 4-160 months (median, 41 months) after initial diagnosis in 110 Japanese alcoholic men with esophageal SCC diagnosed by screening using endoscopy combined with oropharyngolaryngeal inspection and esophageal iodine staining. ALDH2*1/*2 was significantly associated with the presence of multiple primary intraesophageal SCC at the time of initial diagnosis. Metachronous primary SCC of the esophagus was diagnosed in 29 of the 81 patients whose initial esophageal SCC was treated by endoscopic mucosal resection alone, and metachronous primary SCC of the oropharyngolarynx was diagnosed in 23 of the 99 patients without synchronous primary SCC of the oropharyngolarynx at the time of initial diagnosis. The risks of metachronous esophageal SCC and oropharyngolaryngeal SCC were significantly higher in ALDH2*1/*2 heterozygotes than in ALDH2*1/*1 homozygotes (age-adjusted and alcohol-adjusted hazard ratio = 3.38 [95% confidence interval: 1.45-7.85] and 4.27 [1.42-12.89], respectively), and in patients with multiple intraesophageal SCC at the time of initial diagnosis than in patients with a solitary intraesophageal SCC (3.09 [1.41-6.78] and 3.25 [1.41-7.47], respectively). ALDH2*1/*2 and multiple synchronous intraesophageal SCC were found to be predictors of metachronous SCC in the UADT in this population.

Alcohol consumption and the risk for prostate cancer in the European Prospective Investigation into Cancer and Nutrition

Alcohol is a risk factor for several types of cancer. However, the results for prostate cancer have been inconsistent, with most studies showing no association. Within the European Prospective Investigation into Cancer and Nutrition, detailed information were collected from 142,607 male participants on the intake of alcoholic beverages at recruitment (for 100% of the cohort) and over lifetime (for 76% of the cohort) between 1992 and 2000. During a median follow-up of 8.7 years, 2,655 prostate cancer cases were observed. Multivariate Cox proportional hazard models were used to examine the association of alcohol consumption at recruitment and average lifetime alcohol consumption with prostate cancer adjusted for age, center, smoking, height, weight, physical activity, and nonalcohol energy intake. Overall, neither alcohol consumption at baseline nor average lifetime alcohol consumption was associated with the risk for prostate cancer in this cohort of men. Men who consumed >or=60 g alcohol per day had a relative risk of 0.88 [95% confidence interval (95% CI) 0.72-1.08] compared with men with an intake of 0.1-4.9 g/d; the respective relative risk for average lifetime intake was 1.09 (95% CI, 0.86-1.39). For advanced prostate cancer (n = 537), the relative risks for >or=60 and 0.1-4.9 g alcohol per day at baseline were 0.98 (95% CI, 0.66-1.44) and 1.28 (95% CI, 0.79-2-07), respectively, for average lifetime intake. No statistically significant association was observed for alcohol intake from specific alcoholic beverages. Our results indicate no association between the consumption of alcohol and prostate cancer in this cohort of European men.

Opium, tobacco, and alcohol use in relation to oesophageal squamous cell carcinoma in a high-risk area of Iran

The very high incidence of oesophageal squamous cell carcinoma (ESCC) in Golestan Province in northeastern Iran was suggested by studies in the 1970s as partly due to opium use, which is not uncommon in this area, but based on limited numbers. From December 2003 to June 2007, we administered a validated structured questionnaire to 300 ESCC cases and 571 controls, matched on neighbourhood of residence, age (±2 years), and sex. We used conditional logistic regression models to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) adjusted for potential confounders. Compared with those who used neither tobacco nor opium, risk of ESCC was increased in those who used tobacco only (OR, 95% CI: 1.70, 1.05–2.73), in those who used opium only (2.12, 1.21–3.74), and in those who used both tobacco and opium (2.35, 1.50–3.67). All forms of tobacco use (cigarettes, hookah, and nass) were associated with higher ESCC risk. Similarly, use of both crude opium and other forms of opium were associated with higher risk. Alcohol consumption was seen in only 2% of the cases and 2% of the controls, and was not associated with ESCC risk.

Carcinogenetic impact of ADH1B and ALDH2 genes on squamous cell carcinoma risk of the esophagus with regard to the consumption of alcohol, tobacco and betel quid

The consumption of alcohol, tobacco and betel quid has been found to be an important contributor to esophageal squamous cell carcinoma (ESCC) in Taiwan. The genotoxic effect of the ADH1B and ALDH2 genes modulating an individual's alcohol-metabolizing capacity on ESCC may be linked to drinking behavior, intake pattern and other exogenous factors. To investigate the interplay of these genetic and environmental factors in determining the risk of ESCC, a multicenter case-control study was conducted. Here, 406 patients with pathology-proven ESCC, as well as 656 gender, age and study hospital matched controls were recruited. Genetic polymorphisms of ADH1B and ALDH2 appeared to correlate with the abstinence of alcohol, though not with tobacco and betel quid. Within the same levels of alcohol consumption, carcinoma risks increased along with an increase in the numbers of ADH1B*1 and ALDH2*2 alleles. The inactive ALDH2*1/*2 genotype was found to multiplicatively interact with a low-to-moderate (0.1-30 g/day) and a heavy (>30 g/day) ethanol intake to increase the ESCC risk (the joint aOR = 14.5 and 102.6, respectively). Among low-to-moderate drinkers, a smoking-dependent carcinogenetic effect for the ADH1B*1/*1 and ALDH2*1/*2+*2/*2 genotypes was recognized, with significant risks found in smokers, but not in nonsmokers. Further, a supra-multiplicative combined risk of ESCC for alcohol and tobacco use was identified among carriers of the ADH1B*1/*1 genotype (p for interaction = 0.042). In conclusion, the interplay of the ADH1B and ALDH2 genotypes, in conjunction with a behaved drinking habit and a practiced drinking pattern, along with continued tobacco consumption, plays an important pathogenic role in modulating ESCC risk.

Public alcohol policy: current directions and new opportunities

Alcohol policy has been shown to have an impact on the incidence and prevalence of alcohol "addiction," or alcohol use disorders (AUDs), as currently defined by the International Classification of Diseases, volume 10, or by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. We will mainly use the term "addiction" to depict a state involving loss of control over intense urges to consume alcohol, even at the expense of adverse consequences. This definition goes beyond pure "physiological dependence." We will use the term AUD when referring to statistics based on the above-described definitions. In this overview we identify the pathways in the relationship between alcohol policy and addiction, present the empirical evidence, and draw conclusions. Special emphasis will be put on treatment policy.

Tobacco smoking and cancer: a meta-analysis

We conducted a systematic meta-analysis of observational studies on cigarette smoking and cancer from 1961 to 2003. The aim was to quantify the risk for 13 cancer sites, recognized to be related to tobacco smoking by the International Agency for Research on Cancer (IARC), and to analyze the risk variation for each site in a systematic manner. We extracted data from 254 reports published between 1961 and 2003 (177 case-control studies, 75 cohorts and 2 nested case-control studies) included in the 2004 IARC Monograph on Tobacco Smoke and Involuntary Smoking. The analyses were carried out on 216 studies with reported estimates for 'current' and/or 'former' smokers. We performed sensitivity analysis, and looked for publication and other types of bias. Lung (RR = 8.96; 95% CI: 6.73-12.11), laryngeal (RR = 6.98; 95% CI: 3.14-15.52) and pharyngeal (RR = 6.76; 95% CI: 2.86-15.98) cancers presented the highest relative risks (RRs) for current smokers, followed by upper digestive tract (RR = 3.57; 95% CI: 2.63-4.84) and oral (RR = 3.43; 95% CI: 2.37-4.94) cancers. As expected, pooled RRs for respiratory cancers were greater than the pooled estimates for other sites. The analysis of heterogeneity showed that study type, gender and adjustment for confounding factors significantly influence the RRs estimates and the reliability of the studies.

PPARalpha and PPARbeta are differentially affected by ethanol and the ethanol metabolite acetaldehyde in the MCF-7 breast cancer cell line

The activity and/or the level of the peroxisome proliferator-activated receptors (PPARs) in liver and oligodendrocytes are regulated by ethanol. Despite the association between ethanol consumption and breast cancer risk, and the increasing evidence for an involvement of PPARs in some cancers, there have been no studies on the effect of ethanol or its metabolite acetaldehyde on PPARs in breast cancer. Using the MCF-7 breast cancer cell line, we examined the relationship between ethanol and its metabolite acetaldehyde on PPARalpha and PPARbeta transactivation. Ethanol (20 mM) reduced the potency of the PPARbeta ligand GW0742, evident by a rightward shift in the GW0742 dose-response curve, whereas for PPARalpha activation by GW7647, ethanol mediated its effects primarily through reducing efficacy as evidenced by a reduction in maximal response. Using the enzyme inhibitors 4-methylpyrazole and cyanamide and the metabolite acetaldehyde, we showed that PPARalpha and PPARbeta are differentially modulated by ethanol and acetaldehyde. While acetaldehyde is responsible for the inhibition of PPARalpha ligand inhibition with a concentration that inhibits 50% of activity (IC50) of 111 nM, acetaldehyde has no effect on PPARbeta or its ligand activation. Instead, inhibition of PPARbeta transactivation is mediated directly by ethanol. The differential effect of ethanol and acetaldehyde on PPARalpha and PPARbeta further underscores the differences between these receptors and may indicate the relevance of PPARs in the effects of ethanol in the human breast.