[Paleopsych] SW: Alcohol and Cognitive Function in Women
checker at panix.com
Mon May 23 19:46:49 UTC 2005
Medical Biology: Alcohol and Cognitive Function in Women
The following points are made by M.J. Stampfer et al (New Engl. J.
Med. 2005 352:245):
1) Habitual excess alcohol intake impairs the brain, but the effect
of moderate consumption is unclear. A cognitive benefit from moderate
alcohol intake is plausible, given the strong link between moderate
alcohol intake and the decreased risk of cardiovascular disease[2,3].
Cognitive impairment and cardiovascular disease share common risk
factors. In addition, Ruitenberg et al reported that moderate
alcohol consumption was related to a decreased risk of both vascular
and nonvascular dementia and proposed that moderate alcohol
consumption may increase the release of brain acetylcholine. Most
studies, but not all, have tended to show that moderate drinkers do
better on cognitive tests than nondrinkers. However, few studies have
had samples that were large enough to yield statistically significant
results or to assess long-term stable patterns of alcohol intake and
very early signs of cognitive decline. Also, many studies have been
limited by inadequate control for confounding, and none have examined
specific alcoholic beverages.
2) The Nurses' Health Study began in 1976, when 121,700 female
registered nurses, 30 to 55 years of age, completed a mailed
questionnaire about their lifestyle and health. Every two years, the
authors mailed follow-up questionnaires, and in 1980 they added a
food-frequency questionnaire. Starting in 1995, the authors identified
participants in the Nurses' Health Study who were 70 years of age or
older for a study of cognitive function. Eligible women were
community-dwelling participants without a diagnosis of stroke. Of the
21,202 women contacted, 93 percent completed the telephone cognitive
interview, with response rates varying by no more than 2 percent
across categories of alcohol intake. With the exclusion of the 3
percent of women who died after the baseline cognitive assessment, the
authors repeated the telephone assessments of cognitive function after
an average of 1.8 years (range, 1.3 to 5.5) in 93 percent of the
women; 7 percent declined or were lost to follow-up. All aspects of
the study were approved by the human research committee at Brigham and
Women's Hospital. For the questionnaire information, the return of the
completed questionnaire was considered to imply informed consent. For
the telephone interview, the authors obtained oral consent. For the
genetic substudy, the authors obtained written informed consent.
3) The authors report that older women who consumed up to one drink
per day had consistently better cognitive performance than
nondrinkers. Overall, as compared with nondrinkers, women who drank
1.0 to 14.9 g of alcohol per day had a decrease in the risk of
cognitive impairment of approximately 20 percent. Moreover, moderate
drinkers were less likely to have a substantial decline in cognitive
function over a two-year period. The authors found similar inverse
associations for all types of alcoholic beverages.
4) The authors point out their study had several limitations. They
could not assess the effect of high levels of alcohol intake, since
there were few heavy drinkers in their cohort. Also, cognitive decline
was assessed only over a two-year interval; thus, the association
between alcohol consumption and longer-term cognitive decline could
not be evaluated. Information on alcohol consumption was
self-reported, perhaps leading to some misclassification. However, the
assessment of alcohol intake was validated on the basis of dietary
records and levels of biochemical markers and has been used to predict
several disease outcomes in this cohort.
5) The authors conclude their data suggest that in women up to one
drink per day does not impair cognitive function and may actually
decrease the risk of cognitive decline.
1. Chick JD, Smith MA, Engleman HM, et al. Magnetic resonance imaging
of the brain in alcoholics: cerebral atrophy, lifetime alcohol
consumption, and cognitive deficits. Alcohol Clin Exp Res
2. Rimm EB, Stampfer MJ. Alcohol abstinence: a risk factor for
coronary heart disease. Heart Disease Updates 2000;2:1-9
3. Rimm EB, Williams P, Fosher K, Criqui M, Stampfer MJ. Moderate
alcohol intake and lower risk of coronary heart disease: meta-analysis
of effects on lipids and haemostatic factors. BMJ 1999;319:1523-1528
4. Breteler MM, van Swieten JC, Bots ML, et al. Cerebral white matter
lesions, vascular risk factors, and cognitive function in a
population-based study: the Rotterdam Study. Neurology
5. Ruitenberg A, van Swieten JC, Witteman JC, et al. Alcohol
consumption and risk of dementia: the Rotterdam Study. Lancet
New Engl. J. Med. http://www.nejm.org
ALCOHOL AND BREAST CANCER
The following points are made by K.W. Singletary and S.M. Gapstur (J.
Am. Med. Assoc. 2001 286:2143):
1) The association of alcohol consumption with increased risk for
breast cancer has been a consistent finding in a majority of
epidemiologic studies during the past two decades. The authors
summarize information on this association from human and animal
investigations, with particular reference to epidemiologic data
published since 1995.
2) Increased estrogen and androgen levels in women consuming alcohol
appear to be important mechanisms underlying the association. Other
plausible mechanisms include enhanced mammary gland susceptibility to
carcinogenesis, increased mammary carcinogen DNA damage, and greater
metastatic potential of breast cancer cells, processes for which the
magnitude likely depends on the amount of alcohol consumed.
3) Susceptibility to the breast cancer-enhancing effect of alcohol may
also be affected by other dietary factors (such as low folate intake),
life-style habits (such as use of hormone replacement therapy), or
biological characteristics (such as tumor hormone receptor status).
4) Additional progress in understanding the enhancing effect of
alcohol on breast cancer will depend on a better understanding of the
interactions between alcohol and other risk factors and on additional
insights into the multiple biological mechanisms involved. There is
apparently firm evidence that in general women who consume alcohol,
even at the level of 1 drink per day, have higher blood levels of
estrogen (estradiol) than women who do not drink. The authors
recommend that in general women who do not drink should not start, and
those who do drink should do so in moderation, which is generally
recognized to be approximately 1 drink per day.
J. Am. Med. Assoc. http://www.jama.com
ON ALCOHOL IN THE WESTERN WORLD
Notes by ScienceWeek:
The consumption of alcohol (ethanol) is recognized as a major and
potentially preventable health problem. In general, a linear
correlation exists between the intensity of alcohol abuse in terms of
duration and dose and the development of a wide spectrum of
pathologies, especially liver disease. As little as 200 ml wine or 60
ml whiskey in women, 1200 ml of 5% beer in men, when consumed on a
daily basis over years, can produce liver injury. The mechanisms by
which alcohol damages the liver are still unclear, but the damage is
undisputed. Given all of the above, however, it is a fact that alcohol
consumption has been an important aspect of Western civilization for
thousands of years, and has probably existed for at least 10,000 years
in various communities.
The following points are made by Bert L. Vallee (Scientific American
1) Ethanol (ethyl alcohol) is a multifaceted entity: it may be social
lubricant, sophisticated dining companion, cardiovascular health
benefactor, or agent of destruction.
2) For most of the past 10,000 years in the Western world, alcoholic
beverages may have been the most popular and common daily drinks,
indispensable sources of fluids and calories in a world of
contaminated and dangerous water supplies.
3) The experience of the East differed greatly. For at least the past
2000 years, the practice of boiling water, usually for tea, has
created a potable supply of non-alcoholic beverages. In addition,
genetics plays an important role in making Asia avoid alcohol:
approximately half of all Asian people metabolize alcohol differently
than non-Asians, making the experience of drinking alcohol quite
unpleasant [see background material below].
4) Beer and wine became staples in Western societies and remained
there until the end of the last century. Indeed, throughout Western
history, the normal state of mind may have been one of inebriation.
5) Although yeasts produce alcohol, they can tolerate concentrations
of only about 16 percent, so that fermented beverages had a natural
maximum proof. Distillation, introduced by the Arabs about 700 A.D.,
circumvented the fermentation limit by taking advantage of alcohol's
boiling point being lower than water (78 vs. 100 degrees centigrade)
to boil off and then condense the alcohol from fermented mixtures.
6) Presently, alcohol contributes to 100,000 deaths in the US each
year, making it the 3rd leading cause of preventable mortality.
7) Each year, approximately 12,000 children of drinking mothers are
born with the physical signs and intellectual deficits associated with
full-blown fetal alcohol syndrome, and thousands more suffer lesser
8) Alcoholism, in historical terms, has only just been understood and
accepted as a disease, and we are still coping with the historically
recent arrival of concentrated alcohol. The author concludes: "Alcohol
today is a substance primarily of relaxation, celebration and,
tragically, mass destruction. To consider it as having been a primary
agent for the development of an entire culture [Western civilization]
may be jolting, even offensive to some. Any good physician, however,
takes a history before attempting a cure."
Scientific American http://www.sciam.com
Notes by ScienceWeek:
Ethanol is readily absorbed from the gastrointestinal tract, and more
than 90 percent is metabolized by the liver through oxidative
mechanism involving mainly the enzyme alcohol dehydrogenase and
certain other enzymes. Alcohol cannot be stored and all of it is
metabolized. Alcohol dehydrogenase oxidizes alcohol to acetaldehyde.
Apparently, approximately 85 percent of the Japanese population has an
atypical alcohol dehydrogenase that operates about 5 times faster than
the same enzyme does in non-Japanese. Other Asian groups may exhibit
the same phenomenon. Consumption of alcohol by such persons leads to
the accumulation of acetaldehyde, resulting in extensive vasodilation,
facial flushing, and compensatory tachycardia (rapid heartbeat greater
than 100 per minute).
More information about the paleopsych