Alcohol's possible benefits for the brain

There seems to be quite a lot of evidence now, that a moderate amount of alcohol consumption (around 1-2 drinks a day) can help protect against Alzheimer’s — though not, a review concluded, vascular dementia or age-related cognitive decline (but the jury’s still out on that one, I think). Moderate alcohol consumption is significantly associated with other factors that help protect against dementia, such as better education, not living alone, and absence of depression, but seems to have an effect on its own account as well.

It must be emphasized that this positive effect is restricted to the ‘right’ level of alcohol consumption. The damage alcohol can do to the brain is only too well established.

The effect doesn’t appear to be restricted to a particular type of alcohol. Having said that, there are components in wine, especially red wine, that have also been associated with lower dementia risk. These components include polyphenols such as epicatechin, catechin and resveratrol.

Benefits may not apply to everyone however. One study found that carriers of the Alzheimer’s gene, APOe4, were more likely to develop dementia if they drank any alcohol — it was only non-carriers that showed a benefit of moderate drinking. Another large study found that the benefits of moderate drinking only applied to those who had no cognitive impairment. For those with mild cognitive impairment, drinking speeded up the rate of decline. Another, large long-running, study found that, although non-smokers who consumed moderate amounts of alcohol were less likely to have a stroke than non-drinkers, this didn’t apply to smokers.

These individual variations may explain the inconsistency in previous studies regarding the relationship between light to moderate drinking and age-related cognitive impairment.

The story of alcohol and the brain is clearly a complex one, not easily disentangled. One large, long-running study, for example, found an association between alcohol and brain atrophy even at moderate levels of consumption.

Data from 196,383 older adults (60+; mean age 64) in the UK Biobank found that a healthy lifestyle was associated with lower dementia risk regardless of genes.

Both an unhealthy lifestyle and high genetic risk were associated with higher dementia risk.

Lifestyle factors included smoking, physical activity, diet, and alcohol consumption. Bearing in mind that lifestyle factors were self-reported, 68.1% followed a healthy lifestyle, 23.6% were intermediate, and 8.2% followed an unhealthy lifestyle. Regarding genes, 20% were at high risk, 60% were intermediate, and 20% were at low risk.

Of those at high genetic risk, 1.23% developed dementia in the 8-year period (remember that these are people who are still relatively — the average age at study end would still only be 72), compared with 0.63% of those at low genetic risk. Of those at high genetic risk plus an unhealthy lifestyle, 1.78% developed dementia compared to 0.56% of those at low risk with a healthy lifestyle. Among those who had a high genetic risk but a healthy lifestyle, 1.13% developed dementia in the period.

I trust that these people will continue to be followed — it will be very interesting to see the statistics in another 10 years.

There were 1,769 new cases of dementia during the 8-year study period.

Large study shows level of beneficial alcohol consumption much lower than thought

A UK study using data from 13,342 middle-aged and older adults (40-73) has found that having up to one standard unit of alcohol a day improved reaction time, but more than that amount harmed cognitive performance. The effect was more pronounced in older adults.

While several studies have suggested a U-shaped relationship between alcohol and cognition, with light to moderate consumption being beneficial to older adults, this has been quite controversial, with little consensus on how much is too much.

This study uses data from the over half a million people who participated in the UK Biobank prospective cohort study. Of these, 20,346 undertook a repeat assessment 5 years after the initial assessment. The study excluded any who disclosed a history of neurological disorder, and then included only those who consumed alcohol at least once a week. Weekly drinkers had lower levels of socioeconomic deprivation, were more likely to hold a university degree, and to be male.

Cognitive performance was assessed very simply, using a 'stop-go' reaction time task. RT decreased as alcohol consumption increased up to 10g/day, and then increased after that point. This harmful effect became stronger as people got older.

This level of 10 g/day is markedly lower than that suggested by other studies, which have variously argued for: up to 40g for women and 80g for men; up to 34g for middle-aged adults; no more than 16g.

The study omitted people who didn't drink at all, because of the 'sick quitter' effect — it's been argued that the apparent connection between moderate alcohol consumption and better health and cognition is due to bias in the control group, with many people abstaining or quitting due to health issues, and this has been supported by some recent studies. For example, a 2016 review and meta-analysis found no significant difference in mortality for low-volume drinkers once abstainer biases were adjusted for.

The main takeaway from this study — which seems quite robust given the scale of the study — is that the level of 'positive' alcohol consumption is much lower than previously claimed.

The study is open access, and can be read in its entirety at

Study shows no benefits from alcohol consumption once abstainer bias accounted for

Another longitudinal study, using a subset of participants in the Swedish Twin Registry, found no evidence for any cognitive benefits at any level of alcohol consumption.

Participants were those 486 individuals who had been surveyed on their alcohol intake in their midlife (in 1967), and also taken part in cognitive assessments 25 years later. Cognitive tests occurred at 2-year intervals for the next 10 years.

The study found a significant negative dose-response association between alcohol intake in midlife and performance on the MMSE and tests of episodic memory. There was no significant association with semantic memory and spatial ability.

As with the other study, in order to remove abstainer bias, non-drinkers were excluded from the analysis. There were 181 non-drinkers, and this group were more likely to be women, to have less education, lower socioeconomic status, higher BMI, and were more likely to have diabetes and hypertension. They did indeed perform worse on all cognitive tests, but as you can see, most of the characteristics of this group do lend themselves to such a result.

Midlife alcohol consumption was used because it was assumed that this would give a better reflection of lifetime habits than that reported in old age. As it happened, there were no heavy drinkers in the cohort — the highest consumption was 15 units/week. In this study, 1 unit corresponded to 12g.

The study is open access, and can be read in its entirety at

Giovanni Piumatti, Simon C Moore, Damon M Berridge, Chinmoy Sarkar, John Gallacher, The relationship between alcohol use and long-term cognitive decline in middle and late life: a longitudinal analysis using UK Biobank, Journal of Public Health, Volume 40, Issue 2, June 2018, Pages 304–311,

Hassing, L. B. (2018). Light Alcohol Consumption Does Not Protect Cognitive Function: A Longitudinal Prospective Study. Frontiers in Aging Neuroscience, 10.


How alcohol increases Alzheimer's risk

A cell-culture study using rodent microglia found that some of the genes affected by alcohol and inflammation are also implicated in processes that clear amyloid beta, suggesting that alcohol may impede the clearance of amyloid beta in the brain.

In the study, rat microglial cells were exposed either to alcohol, pro-inflammatory chemicals called cytokines, or alcohol and cytokines, for 24 hours. Gene expression was altered for 312 genes under the alcohol condition; for 3,082 for the pro-inflammatory condition, and 3,552 for the alcohol and pro-inflammatory condition. Changes in gene expression ranged from a 50% decrease to a 72% increase. Many of the genes were involved in phagocytosis; just a handful of genes were involved in both phagocytosis and inflammation.

Chronic heavy drinking trebles dementia risk

Data from the French National Hospital Discharge database, involving over a million people diagnosed with dementia between 2008 and 2013, found that 38% of the 57,000 cases of early-onset dementia were directly alcohol-related and 18% had an additional diagnosis of alcohol use disorders.

Overall, alcohol use disorders were associated with a three times greater risk of all types of dementia.

The study only looked at people admitted to hospital due to chronic heavy drinking, so it will understate the link between alcohol use and dementia risk.

Moreover, heavy drinkers who had given up alcohol for a time did not reduce their dementia risk (although they were less likely to die early).

A pilot study involving 106 participants of the Rush Memory and Aging Project who had experienced a stroke followed participants for an average of 5.9 years, testing their cognitive function and monitoring their eating habits using food journals. It was found that those whose diets scored highest on the MIND (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay) diet score had substantially slower rates of cognitive decline than those who scored lowest. The estimated effect of the diet remained strong even after taking into account participants' level of education and participation in cognitive and physical activities. Those who instead scored high on the Mediterranean or DASH diets did not show the same slower decline.

Both the Mediterranean and DASH diets have been shown to be protective against coronary artery disease and stroke, but this finding suggests the MIND diet is better for overall brain health.

The MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. It has 15 components: 10 “brain-healthy food groups” and five unhealthy groups (red meat, butter, cheese, pastries and sweets, and fried or fast food).

To adhere to the MIND diet, you need to

  • eat at least three daily servings of whole grains
  • eat a green leafy vegetable and one other vegetable every day
  • drink a regular glass of wine
  • snack most days on nuts
  • have beans every other day or so
  • eat poultry and berries at least twice a week
  • eat fish at least once a week
  • limit butter to less than 1 1/2 teaspoons a day
  • eat less than 5 servings a week of sweets and pastries
  • eat less than one serving per week of whole fat cheese, and fried or fast food.

The researchers stress that this is a preliminary study, observational only. They are currently seeking participants for a wider, intervention study.

Laurel J. Cherian & Martha Clare Morris: Presentation at the American Stroke Association's International Stroke Conference 2018 in Los Angeles, January 25.

A new discovery helps explain why the “Alzheimer’s gene” ApoE4 is such a risk factor. It appears that ApoE4 causes a dramatic reduction in SirT1, an "anti-aging protein" that is targeted by resveratrol (present in red wine). This reduction in SirT1 was associated with a change in the way the amyloid precursor protein (APP) was processed. Moreover, there was evidence that ‘bad’ tau and amyloid-beta could be prevented by increasing SirT1.

[3611] Theendakara, V., Patent A., Libeu C P. A., Philpot B., Flores S., Descamps O., et al.
(2013).  Neuroprotective Sirtuin ratio reversed by ApoE4.
Proceedings of the National Academy of Sciences. 110(45), 18303 - 18308.

Because sleep is so important for memory and learning (and gathering evidence suggests sleep problems may play a significant role in age-related cognitive impairment), I thought I’d make quick note of a recent review bringing together all research on the immediate effects of alcohol on the sleep of healthy individuals.

The review found that alcohol in any amount reduces the time it takes to fall asleep, while greater amounts produce increasing amounts of deep sleep in the first half of the night. However, sleep is more disrupted in the second half. While increased deep sleep is generally good, there are two down sides here: first, it’s paired with sleep disruption in the second half of the night; second, those predisposed to problems such as sleepwalking or sleep apnea may be more vulnerable to them. (A comment from the researchers that makes me wonder if the relationship between deep sleep and slow-wave activity is more complicated than I realized.)

Additionally, at high doses of alcohol, REM sleep is significantly reduced in the first half, and overall. This may impair attention, memory, and motor skills. Moreover, at all doses, the first REM period is significantly delayed, producing less restful sleep.

The researchers conclude that, while alcohol may give the illusion of improving sleep, it is not in fact doing so.

[3269] Ebrahim, I. O., Shapiro C. M., Williams A. J., & Fenwick P. B.
(2013).  Alcohol and Sleep I: Effects on Normal Sleep.
Alcoholism: Clinical and Experimental Research. n/a - n/a.

It’s always difficult in human studies to disentangle the effects of lifestyle factors. Alcohol is a case in point, and in particular the vexed question of whether any alcohol is safe during pregnancy. A new study, however, has avoided the complication of co-occurring lifestyle and environment factors by looking directly at genetic variants.

This study, believed to be the first substantial one of its kind, used genetic variation to investigate the effects of moderate (<6 units of alcohol per week) drinking during pregnancy among a large group of women and their children. Since the individual variations that people have in their DNA are not connected to lifestyle and social factors, the approach removes that potential complication.

The study, involving 4,167 children, found that four genetic variants in alcohol-metabolizing genes were strongly related to lower IQ at age eight. But this effect was only seen among the children of women who were moderate drinkers (heavy drinkers were not included in the study), pointing to the effect requiring exposure to alcohol in the womb.

Ten SNPs from four genes previously implicated in alcohol metabolism, intake, or dependency, were analyzed. Four SNPs (particular variants) were related to children’s scores on the cognitive test (WISC), of which three are rare and one quite common. There was an additive effect, with carriers of multiple ‘bad’ alleles being more affected.

There was some evidence that only drinking one or two drinks a week was not harmful to the fetus, but because the numbers of women were relatively small, and individual variability was high, this can’t be assessed with any great certainty.

The critical factor appears to be metabolism of alcohol, with mothers who are ‘fast' metabolizers being safer for their fetus than mothers who metabolize alcohol more slowly.

Mothers' alcohol intake was based on questionnaires completed when they were 18 weeks and 32 weeks pregnant. ‘Moderate’ was defined as between one and six drinks a week. All participants were of white-European origin.

In the last five years, three studies have linked lower neighborhood socioeconomic status to lower cognitive function in older adults. Neighborhood has also been linked to self-rated health, cardiovascular disease, and mortality. Such links between health and neighborhood may come about through exposure to pollutants or other environmental stressors, access to alcohol and cigarettes, barriers to physical activity, reduced social support, and reduced access to good health and social services.

Data from the large Women’s Health Initiative Memory Study has now been analyzed to assess whether the relationship between neighborhood socioeconomic status can be explained by various risk and protective factors for poor cognitive function.

Results confirmed that higher neighborhood socioeconomic status was associated with higher cognitive function, even after individual factors such as age, ethnicity, income, education, and marital status have been taken into account. A good deal of this was explained by vascular factors (coronary heart disease, diabetes, stroke, hypertension), health behaviors (amount of alcohol consumed, smoking, physical activity), and psychosocial factors (depression, social support). Nevertheless, the association was still (barely) significant after these factors were taken account of, suggesting some other factors may also be involved. Potential factors include cognitive activity, diet, and access to health services.

In contradiction of earlier research, the association appeared to be stronger among younger women. Consistent with other research, the association was stronger for non-White women.

Data from 7,479 older women (65-81) was included in the analysis. Cognitive function was assessed by the Modified MMSE (3MSE). Neighborhood socioeconomic status was assessed on the basis of: percentage of adults over 25 with less than a high school education, percentage of male unemployment, percentage of households below the poverty line, percentage of households receiving public assistance, percentage of female-headed households with children, and median household income. Around 87% of participants were White, 7% Black, 3% Hispanic, and 3% other. Some 92% had graduated high school, and around 70% had at least some college.

[2523] Shih, R. A., Ghosh-Dastidar B., Margolis K. L., Slaughter M. E., Jewell A., Bird C. E., et al.
(2011).  Neighborhood Socioeconomic Status and Cognitive Function in Women.
Am J Public Health. 101(9), 1721 - 1728.


Lang IA, Llewellyn DJ, Langa KM, Wallace RB, Huppert FA, Melzer D. 2008. Neighborhood deprivation, individual socioeconomic status, and cognitive function in older people: analyses from the English Longitudinal Study of Ageing. J Am Geriatr Soc., 56(2), 191-198.

Sheffield KM, Peek MK. 2009. Neighborhood context and cognitive decline in older Mexican Americans: results from the Hispanic Established Populations for Epidemiologic Studies of the Elderly. Am J Epidemiol., 169(9), 1092-1101.

Wight RG, Aneshensel CS, Miller-Martinez D, et al. 2006. Urban neighborhood context, educational attainment, and cognitive function among older adults. Am J Epidemiol., 163(12), 1071-1078.

A review of 23 longitudinal studies of older adults (65+) has found that small amounts of alcohol were associated with lower incidence rates of overall dementia and Alzheimer dementia, but not of vascular dementia or age-related cognitive decline. A three-year German study involving 3,327 adults aged 75+ extends the evidence to the older-old.

The study found alcohol consumption was significantly associated with 3 other factors that helped protect against dementia: better education, not living alone, and absence of depression. Nevertheless, the lower risk remained after accounting for these factors.

The ‘magic’ amount of alcohol was between 20-29g, roughly 2-3 drinks a day. As in other studies, a U-shaped effect was found, with higher risk found among both those who consumed less than this amount of alcohol, and those who consumed more.

A study in which nearly 50 participants consumed either alcohol (.4 or .8 g/kg, around 2 or 4 glasses of wine) or a placebo drink, performed a memory task, then were shown a video of serious road traffic accidents, has found that those given the smaller amount of alcohol experienced more flashbacks during the next week than those given the larger amount of alcohol, and those given no alcohol. Although that may seem to suggest drinking a large amount of alcohol might result in less involuntary re-experiencing of the event, excessive alcohol produced an overall reduction in memory which may be even more distressing if they then imagine a 'worse case scenario.' The findings support the view that flashbacks reflect the reactivation of image-based egocentric representations (based on sensory features) in the absence of a corresponding allocentric representing (incorporating the spatiotemporal context). Alcohol appears to impair allocentric (contextual) memory first.

It’s well established that we are better at recognizing faces of our own racial group, but a new study shows that this ability disappears when we’re mildly intoxicated. The study tested about 140 university students of Western European and east-Asian descent and found that recognition of different-race faces was unaffected by alcohol, yet both groups showed impaired recognition of own-race faces, bringing it down to about the same level of accuracy as for different-race faces. Those given a placebo drink were unaffected.

Older news items (pre-2010) brought over from the old website

Regular moderate alcohol intake has cognitive benefits in older adults

A six-year study involving over 3,000 seniors (75+) has found that for those who had no cognitive impairment at the start of the study, moderate drinking (1-2 drinks a day) was associated with a 37% reduction in risk of developing dementia compared to individuals who did not drink at all. The type of alcohol didn’t matter. However, for those who started the study with mild cognitive impairment, any consumption of alcohol was associated with faster rates of cognitive decline. Moreover, heavy drinkers were almost twice as likely to develop dementia during the study. The results are consistent with previous studies of middle-aged adults that suggest mild to moderate alcohol intake may reduce the risk of dementia, except in the case of individuals who already have mild to moderate cognitive impairment.

Sink, K.M. et al. 2009. Moderate alcohol intake is associated with lower dementia incidence: results from the Ginkgo Evaluation of Memory Study (GEMS). Presented at the Alzheimer's Association International Conference on Alzheimer's Disease July 11-16 in Vienna.

Moderate drinking can reduce risks of Alzheimer's dementia and cognitive decline

A review of 44 studies has concluded that moderate drinkers often have lower risks of Alzheimer's disease and other cognitive loss. Moderate alcohol consumption generally is defined as 1 drink or less per day for women and 1-2 drinks or less per day for men.

[2374] Collins, M. A., Neafsey E. J., Mukamal K. J., Gray M. O., Parks D. A., Das D. K., et al.
(2009).  Alcohol in Moderation, Cardioprotection, and Neuroprotection: Epidemiological Considerations and Mechanistic Studies.
Alcoholism: Clinical and Experimental Research. 33(2), 206 - 219.

Chocolate, wine and tea improve brain performance

A study of over 2000 older Norwegians (aged 70-74) has found that those who consumed chocolate, wine, or tea had significantly better cognitive performance and lower risk of poor cognitive performance than those who did not. Those who consumed all 3 studied items had the best performance and the lowest risks for poor test performance. The associations between intake of these foodstuffs and cognition were dose dependent, with maximum effect at intakes of around 10 grams a day for chocolate and around 75–100 ml a day for wine, but approximately linear for tea. The effect was most pronounced for wine and modestly weaker for chocolate intake. The finding is consistent with research indicating that those who consume lots of flavonoids have a lower incidence of dementia.

[623] Nurk, E., Refsum H., Drevon C. A., Tell G. S., Nygaard H. A., Engedal K., et al.
(2009).  Intake of flavonoid-rich wine, tea, and chocolate by elderly men and women is associated with better cognitive test performance.
The Journal of Nutrition. 139(1), 120 - 127.

Red grape seeds may help prevent Alzheimer's disease

Research into the nearly 5000 compounds contained in red wine to reveal the source of the health benefits seen from red wine has revealed that polyphenols derived from red grape seeds may be useful agents to prevent or treat Alzheimer's disease. Red grape seeds currently being developed with the name of Meganatural AZ were found to significantly reduce cognitive deterioration in genetically engineered mice, by preventing the formation of amyloid beta. The mice were given the extract before the age at which they normally develop signs of disease, suggesting the extract may help prevent or postpone the development of Alzheimer’s. The major polyphenol components in the grape seed extract product are catechin and epicatechin, which are also abundant in tea and cocoa. Unlike the polyphenol resveratrol, which has been shown to have similar effects, but requires extremely high doses, the catechins appear to be effective at much lower doses. Further research will of course be needed before human recommendations can be made.

[2377] Wang, J., Ho L., Zhao W., Ono K., Rosensweig C., Chen L., et al.
(2008).  Grape-Derived Polyphenolics Prevent Aβ Oligomerization and Attenuate Cognitive Deterioration in a Mouse Model of Alzheimer's Disease.
The Journal of Neuroscience. 28(25), 6388 - 6392.

Why moderate drinking may boost memory

Another study has come out suggesting moderate amounts of alcohol are good for the brain, and explaining why. The rat study found that low levels of alcohol increased the expression of a particular receptor, NR1, on the surface of neurons in the hippocampus. Increasing the number of NR1 receptors in a different group of rats resulted in a memory boost similar to that seen in the rats given low doses of alcohol. There were no toxic effects of low-level alcohol consumption (1—2 drinks a day) on the brain, but a higher dose of alcohol did damage neurons.

The findings were presented at the Society for Neuroscience's annual meeting on October 14-18 in Atlanta, Georgia.

Cabernet sauvignon red wine reduces the risk of Alzheimer's disease

A mouse study has found moderate consumption of the red wine Cabernet Sauvignon significantly reduced Alzheimer’s-type deterioration of spatial memory function. The Cabernet Sauvignon used contained a very low content of resveratrol, 10-fold lower than the minimal effective concentration shown to promote Aß clearance in vitro. It is suggested that, instead, the benefit occurred through promoting non-amyloidogenic processing of amyloid precursor protein. The finding supports epidemiological evidence indicating that moderate wine consumption (one drink per day for women and two for men) may help reduce the relative risk for Alzheimer’s.

[2378] Wang, J., Ho L., Zhao Z., Seror I., Humala N., Dickstein D. L., et al.
(2006).  Moderate consumption of Cabernet Sauvignon attenuates Aß neuropathology in a mouse model of Alzheimer’s disease.
The FASEB Journal. 20(13), 2313 - 2320.

Moderate alcohol intake associated with better mental function in older women

A study of over 7,000 older women (65-80) found that those who drink a moderate amount of alcohol have slightly higher levels of mental function than non-drinkers, particularly in verbal abilities. The researcher warned that "Until we better understand the reasons why alcohol consumption is associated with better cognitive functioning, these results on their own are not a reason for people who don't drink to start or for those who drink to increase their intake."

[455] Espeland, M. A., Coker L. H., Wallace R., Rapp S. R., Resnick S. M., Limacher M., et al.
(2006).  Association between alcohol intake and domain-specific cognitive function in older women.
Neuroepidemiology. 27(1), 1 - 12.

More support for benefits of some alcohol

A longitudinal study of an elderly community sample found that, over an average of 7 years, mild-to-moderate drinking was associated with less average decline in cognitive function compared to not drinking.

[1203] Ganguli, M., Bilt V. J., Saxton J. A., Shen C., & Dodge H. H.
(2005).  Alcohol consumption and cognitive function in late life: A longitudinal community study.
Neurology. 65(8), 1210 - 1217.

Moderate alcohol intake may reduce cognitive decline in older women

Two recent large-scale epidemiological studies have come out recently with similar findings. Data from the Women's Health Initiative Memory Study (involving 4,461 women aged 65 to 79 years) has revealed that women who reported having one or more alcohol drinks daily had a 40% lower risk of significant declines in cognitive function over time, compared to women who reported no alcohol intake. It is possible that moderate alcohol intake may reduce the risk for narrowed vessels in the brain. In addition, alcohol may decrease the formation of plaque that is associated with Alzheimer's disease.
Data from the Nurses' Health Study, begun in 1976 and involving 12,480 women, now aged between 70 and 81 years old, has found that women who had the equivalent of one drink a day had a 23% lower risk of becoming mentally impaired during a two-year period, compared with non-drinkers. It made no significant difference whether they drank beer or wine.

[1108] Espeland, M. A., Gu L., Masaki K. H., Langer R. D., Coker L. H., Stefanick M. L., et al.
(2005).  Association between Reported Alcohol Intake and Cognition: Results from the Women's Health Initiative Memory Study.
Am. J. Epidemiol.. 161(3), 228 - 238.

[1115] Stampfer, M. J., Kang J H., Chen J., Cherry R., & Grodstein F.
(2005).  Effects of Moderate Alcohol Consumption on Cognitive Function in Women.
N Engl J Med. 352(3), 245 - 253. (1st study) (2nd study)

Drinking too much alcohol, and not enough, increases risk of cognitive impairment

In Finland, researchers re-examined 1018 participants from a study of 1464 men and women aged 65-79 studied in 1972 or 1977. They found that participants who drank no alcohol in midlife as well as those who drank alcohol frequently were twice as likely to have mild cognitive impairment in old age compared to those who drank alcohol infrequently. The effect of alcohol was however modified by the presence of the apolipoprotein e4 allele (implicated in dementia risk). People who were carriers of the apolipoprotein e4 allele had an increased risk of dementia with increasing alcohol consumption, with carriers of the gene significantly reducing their risk by never drinking.

[731] Kivipelto, M., Anttila T., Helkala E-L., Viitanen M., Kareholt I., Fratiglioni L., et al.
(2004).  Alcohol drinking in middle age and subsequent risk of mild cognitive impairment and dementia in old age: a prospective population based study.
BMJ. 329(7465), 539 - 539.

Possible benefits of alcohol in reducing cognitive decline

Another report from the Whitehall Study database. This one adds to the, still controversial, research linking moderate wine consumption with health and longevity. Of those who reported drinking alcohol in the past year, those who consumed at least one drink in the past week were significantly less likely to have poor cognitive function than those who did not. These benefits appeared even at levels of alcohol consumption that most sensible observers would consider excessive, and emphasizes once again that correlation is not causation. It seems likely that this association at least partly reflects other factors, and indeed, the correlation was reduced when social position was taken account of. It may also reflect the possible effect of alcohol in reducing risk of cardiovascular disease.

Alcohol's benefits for cognition may be overstated

Some studies (that receive a lot of media attention) have suggested that moderate alcohol drinking may have beneficial effects on the heart or the brain. Other studies have found no effect, or a negative one. Now a new study may provide an answer to the conflicting results. Using data from the Wisconsin Longitudinal Study, which has followed more than 10,000 men and women who graduated from Wisconsin high schools in 1957, researchers in 1992 asked the participants about their drinking habits. It was found that men who consumed low levels of alcohol in 1992 had higher scores on the abstract reasoning test than those who drank either more or less. However, when earlier cognitive ability (measured in high school) was taken into account, the difference between non-drinkers and those who had one drink a day disappeared. With the women, both non-drinkers and heavy drinkers had lower scores at age 53 than moderate drinkers. But when adolescent cognitive ability was taken into account, these differences disappeared. Participants will be re-examined next year, when they’re about 65.

[2375] Krahn, D., Freese J., Hauser R., Barry K., & Goodman B.
(2003).  Alcohol Use and Cognition at Mid‐Life: The Importance of Adjusting for Baseline Cognitive Ability and Educational Attainment.
Alcoholism: Clinical and Experimental Research. 27(7), 1162 - 1166.

Drinking wine may lower risk of dementia

Researchers in Copenhagen have followed up an analysis of drinking patterns for wine, beer and liquor of 1,709 people in the 1970s with an assessment of dementia in the 1990s, when participants were age 65 or older. 83 of the participants had developed dementia. Their alcohol intake was compared to that of those who did not develop dementia. It was found that those who drank wine occasionally had a lower risk of developing dementia, including Alzheimer's disease. Those who drank wine every day were no more or less likely to develop dementia than those who drank it less often. The study also found that occasional beer drinking was associated with an increased risk of developing dementia. It is important to note that eating habits were not investigated, and research suggests that wine drinkers may have better dietary habits than beer and liquor drinkers.

[2376] Truelsen, T., Thudium D., & Grønbæk M.
(2002).  Amount and type of alcohol and risk of dementia.
Neurology. 59(9), 1313 - 1319.

Moderate alcohol consumption may help prevent dementia

Recent research has suggested that moderate alcohol consumption may have positive health benefits for cardiovascular and cerebrovascular functioning. Given the connection between dementia in old age and cerebrovascular disease, a recent Italian study analyzed data from 15,807 patients (65 years of age or older) to assess whether there is any link between alcohol consumption and cognitive function. Signs of cognitive derangement were found in 19% of the participants who reported regular alcohol consumption, and in 29% of those who abstained from alcohol. The quantity of daily alcohol consumption was an important factor. The risk of cognitive impairment was reduced among women whose daily alcohol consumption was less than 40 grams and among men who drank less than 80 grams. Higher levels of alcohol consumption showed an increased risk of cognitive impairment when compared with both abstainers and moderate drinkers.

[954] Zuccalà, G., Onder G., Pedone C., Cesari M., Landi F., Bernabei R., et al.
(2001).  Dose-Related Impact of Alcohol Consumption on Cognitive Function in Advanced Age: Results of a Multicenter Survey.
Alcoholism: Clinical and Experimental Research. 25(12), 1743 - 1748.

A Dutch study suggests that light-to-moderate alcohol consumption could reduce the risk of dementia among older people. Light-to-moderate alcohol consumption (1 to 3 drinks per day) was associated with a 42% risk reduction of all dementia, and around a 70% reduction in risk of vascular dementia.

[794] Ruitenberg, A., van Swieten J. C., Witteman J CM., Mehta K. M., van Duijn C. M., Hofman A., et al.
(2002).  Alcohol consumption and risk of dementia: the Rotterdam Study.
The Lancet. 359(9303), 281 - 286.