Women, worldwide, appear to be drinking alcohol more in 2005 than in they did in 1985 and even in 1995, and drinking alcohol in a similar amount and pattern to men. In the USA in 1970s, the age-specific rate of initiation of alcohol use (measured in person years) in 10- to 14-year-olds showed a male female ratio of approximately 2:1, which had equalized to 1:1 by the 1990s and has remained equal (Substance Abuse and Mental Health Services Administration 1997, 1999). This trend has potentially significant clinical and public health implications as there are gender differences in vulnerability to the harmful effects of alcohol. For example, harm occurs for women after a shorter period of drinking smaller amounts of alcohol than for men (Brady and Randall 1999) such as alcohol-associated cognitive impairment (Crawford and Ryder 1986), alcohol-related liver disease (Morgan and Sherlock 1977, Becker et al. 1996), hypertension, malnutrition and intestinal haemorrhage (Ashley et al. 1977). Indeed, alcohol-related liver disease occurs in women after approximately 13.6 years of drinking alcohol at a hazardous level compared with 20.4 years in men. Hazardous consumption has been defined by the National Health and Medical Research Council of Australia as greater than two to four units of absolute alcohol per day (1987, 1992). In Australia, one unit, which is also referred to as a standard drink, represents 10 g of absolute alcohol or ethanol.
Hence the basic or general guideline for alcohol drinking in Australia to minimise both longer-term and short-term risks, and to gain longer-term benefits effects, is that men should not exceed 4 units or 40 g of absolute alcohol per day on a regular basis, or 28 units per week, and that women should not exceed 2 units of 20 g of absolute alcohol per day on a regular basis, or 14 units per week. For a 12% v/v alcohol wine, one standard drink is approximately 100 mL, and for a 1722% v/v alcohol fortified wine, such as a port or liqueur, one standard drink is approximately 60 mL.
The different guidelines for men and women, whereby men are considered to be able to safely consume twice as much wine per day as can women, are directly related to blood alcohol concentration (BAC), and there are several metabolic and physiological differences between men and women which contribute to women recording a significantly higher maximum BAC than men when they consume a comparable amount of alcohol (Jones and Jones 1976). First, the physiology or body composition of men is different to that of women. Men have a larger proportion of body water than women into which the alcohol rapidly distributes from the blood, that is, the absorbed alcohol is diluted more in the body fluids of men than it is in that of women (Marshall et al. 1983, Van Thiel et al. 1988). In addition, women have a larger proportion of fat, 33% compared with 12% that increases with age, into which the alcohol distributes slowly from their blood. Second, men are able to deal with a greater metabolic load of alcohol than women, because they generally have more of the alcohol-degrading liver enzymes, alcohol dehydrogenase and aldehyde dehydrogenase, than do women. These alcohol-degrading enzymes are also more active in men than in women. Unmetabolised alcohol continues to circulate in the blood to the body organs and tissues, passing through the liver, until it is completely broken down by the liver. Thus, it follows that women consuming comparable amounts of alcohol to men have a higher circulating BAC at any one time, where their organs and tissues are also exposed to a higher BAC and hence more damaging or toxic effects of alcohol for a longer period of time.
Another gender difference in alcohol metabolism is that although alcohol metabolism occurs mainly in the liver, it begins in the stomach, called first pass metabolism. When more alcohol is metabolised in the stomach, less is absorbed directly from the stomach into the blood stream and less is also presented to the liver for metabolism. Women also have less alcohol-degrading stomach enzymes and therefore less first pass metabolism of alcohol than men (Frezza et al. 1990, Pozzato et al. 1995, Baraona et al. 2001).
In addition, the organs and tissues of women appear inherently more vulnerable to the toxic effects of alcohol. It has been suggested that this inherent vulnerability is related to gender differences in estrogen concentration (Day et al 1998). Estrogen may increase the permeability of the gastrointestinal tract to bacterial cell wall products or endotoxins, which may activate or upregulate receptors for endotoxins on liver Kupffer cells, that produce oxidative free radicals, enhancing the production of tumor necrosis factor (Enomoto et al. 1999).
Furthermore, recent research suggests that pattern of alcohol drinking may independently influence the gender difference in vulnerability to alcohol-associated liver disease (Stranges et al. 2004), such that drinking alcohol while eating food is potentially less harmful for women than drinking without eating food; this was not observed for men. There were no beverage specific differences observed. Binge drinking by both men and women, however, was more potentially harmful and daily drinking by men was also more potentially harmful.
Thus, if the current trend of alcohol drinking by women continues without sufficient advertisement and advice about the gender differences in alcohol-related harm, alcohol-related harms in woman will begin to occur at an earlier stage of life and have a greater social and public health impact.
Creina Stockley is Health and Regulatory Manager at The Australian Wine Research Institute, and a valued member of the AIM Council.
Ashley MJ, Olin JS, le Riche WH, Kornaczewski A, Schmidt W, Rankin JG. Morbidity in alcoholics. Evidence for accelerated development of physical disease in women. Arch Intern Med. 1977 Jul;137(7):883-7.
Baraona E, Abittan CS, Dohmen K, Moretti M, Pozzato G, Chayes ZW, Schaefer C, Lieber CS. Gender differences in pharmacokinetics of alcohol. Alcohol Clin Exp Res. 2001 Apr;25(4):502-7.
Becker U, Deis A, Sorensen TI, Gronbaek M, Borch-Johnsen K, Muller CF, Schnohr P, Jensen G. Prediction of risk of liver disease by alcohol intake, sex, and age: a prospective population study. Hepatology. 1996 May;23(5):1025-9.
Brady KT, Randall CL. Gender differences in substance use disorders. Psychiatr Clin North Am. 1999 Jun;22(2):241-52.
Crawford S, Ryder D. A study of sex differences in cognitive impairment in alcoholics using traditional and computer-based tests. Drug Alcohol Depend. 1986 Dec;18(4):369-75.
Day CP. Who gets alcoholic liver disease: nature or nurture? J R Coll Physicians Lond. 2000 Nov-Dec;34(6):557-62.
Enomoto N, Yamashina S, Schemmer P, Rivera CA, Bradford BU, Enomoto A,
Brenner DA, Thurman RG. Estriol sensitizes rat Kupffer cells via gut-derived endotoxin. Am J Physiol. 1999 Sep;277(3 Pt 1):G671-7.
Frezza M, di Padova C, Pozzato G, Terpin M, Baraona E, Lieber CS. High blood alcohol levels in women. The role of decreased gastric alcohol dehydrogenase activity and first-pass metabolism. N Engl J Med. 1990 Jan 11;322(2):95-9.
Fuchs CS, Stampfer MJ, Colditz GA, Giovannucci EL, Manson JE, Kawachi I, Hunter DJ, Hankinson SE, Hennekens CH, Rosner B. Alcohol consumption and mortality among women. N Engl J Med. 1995 May 11;332(19):1245-50.
Jones BM, Jones MK. Alcohol effects in women during the menstrual cycle. Ann N Y Acad Sci. 1976;273:576-87.
Marshall AW, Kingstone D, Boss M, Morgan MY. Ethanol elimination in males and females: relationship to menstrual cycle and body composition. Hepatology. 1983 Sep-Oct;3(5):701-6.
Morgan MY, Sherlock S. Sex-related differences among 100 patients with alcoholic liver disease. Br Med J. 1977 Apr 9;1(6066):939-41.
National Health and Medical Research Council of Australia. Is there a safe level of consumption of alcohol for men and for women? Pirie Printers Pty Limited, ACT, Australia, 1987; 1992.
National Health and Medical Research Council of Australia, Australian Drinking Guidelines: health risks and health benefits. Commonwealth of Australia; 2001.
Pozzato G, Moretti M, Franzin F, Croce LS, Lacchin T, Benedetti G, Sablich R, Stebel M, Campanacci L. Ethanol metabolism and aging: the role of "first pass metabolism" and gastric alcohol dehydrogenase activity. J Gerontol A Biol Sci Med Sci. 1995 May;50(3):B135-41.
Stranges S, Freudenheim JL, Muti P, Farinaro E, Russell M, Nochajski TH, Trevisan M. Differential effects of alcohol drinking pattern on liver enzymes in men and women. Alcohol Clin Exp Res. 2004 Jun;28(6):949-56.
Substance abuse and Mental Health Services Administration. Substance use among women in the United States. Rockville, Maryland: US Department of Health and Human Services; 1997.
Substance abuse and Mental Health Services Administration. Summary of findings from the 1999 National Household Survey on Drug Abuse. Rockville, Maryland: US Department of Health and Human Services; 2000.
Van Thiel DH, Tarter RE, Rosenblum E, Gavaler JS. Ethanol, its metabolism and gonadal effects: does sex make a difference? Adv Alcohol Subst Abuse. 1988;7(3-4):131-69.