A Drink a Day May Keep Alzheimer's Away (Analysis of 143 studies shows risk decreased by 23%)

Medscape Medical News ^ | August 26, 2011 | Fran Lowry

[Stoat]

A Drink a Day May Keep Alzheimer's Away

Fran Lowry

 

August 26, 2011 — Light to moderate drinking seems to reduce the risk for dementia and cognitive decline, according to a new study published in the August issue of Neuropsychiatric Disease and Treatment.

A meta-analysis of 143 studies on the effects of alcohol on the brain showed that moderate drinking, defined as no more than 2 drinks a day for a man and no more than 1 drink a day for a woman, reduced the risk for Alzheimer's disease and other forms of dementia by 23%.

"It doesn't seem to matter if it's beer, wine, or spirits, as long as the drinking was moderate," Edward J. Neafsey, PhD, from the Department of Molecular Pharmacology and Therapeutics at Loyola University Medical Center, Maywood, Illinois, told Medscape Medical News.

Dr. Edward J. Neafsey

Dr. Neafsey and coauthor Michael A. Collins, PhD, became interested in seeing whether alcohol might be protective of human brains after their experiments showed that rat brains exposed to low doses of alcohol for a few days demonstrated resiliency when subsequently treated with a toxin.

"If the rat brain slices were treated for 5 or 6 days with low alcohol and then the toxin was administered, there was hardly any damage, whereas if they didn't get the pretreatment with alcohol, there was significant damage. This led us to ask if there was anything in the human literature that would fit with this protective effect of alcohol," Dr. Neafsey explained.

The researchers reviewed studies dating from 1977 up to the present. The studies fell into 2 categories: those that provided ratios of risk between drinkers and nondrinkers (n = 74) and those that rated cognition in drinkers as "better," "no different," or "worse" than cognition in nondrinkers (n = 69).

Heavy Drinking a Different Story

Light to moderate drinking conferred a similar benefit, but heavy drinking (more than 3 - 5 drinks/day) was associated with a nonsignificantly higher risk for dementia and cognitive impairment.

Most of the studies did not distinguish between the different types of alcohol, but in a few studies, wine appeared to be more beneficial than beer or spirits. "It really seemed to be that alcohol per se was protective, not the type, because the few studies that did make the distinction reported no difference among the effects of the different types of alcohol," Dr. Neafsey said.

The protective effect of moderate drinking held after adjusting for age, education, sex, and smoking.

A number of explanations for the protective effect of moderate alcohol have been proposed. Some dementias are related to cardiovascular system problems, such as atherosclerosis, and alcohol may be protective because it raises the level of high-density lipoprotein (the good) cholesterol and might improve blood flow in the brain.

One theory that Dr. Neafsey and Dr. Collins are working on now holds that alcohol acts as a mild stressor for brain cells and "preconditions" them, making them better able to ward off stress.

"Alcohol doesn't kill the brain cells, but it's a slight stress. When the cells are exposed they increase levels of various protective compounds, so...they are prepared when something more stressful that might kill or damage them comes along. The theory is called 'preconditioning,' where a mild stress given a few days before a severe stress causes a significant protection."

Understanding the mechanism of alcohol's protective effect could lead to a treatment to prevent cognitive impairment and dementias, Dr. Neafsey said.

"Whether it's treatment with a pill or a lifestyle change, if we could understand the mechanism, it would improve our ability to deal with these illnesses," he said.

Novel Approach

Medscape Medical News asked Anton P. Porsteinsson, MD, the William B. and Sheila Konar professor of psychiatry at the University of Rochester School of Medicine, New York, to comment on this study.

"This is a well-done meta analysis. The findings are consistent with other meta analyses that have been done. Am I tremendously surprised at the findings? No, because they are looking at the same pool of studies," Dr. Porsteinsson said.

"The fact that they approach it in slightly different ways and yet find similar outcomes makes me confident that this is what the data are actually signaling to us: that very modest alcohol consumption is protective," he said.

The next step is to figure out how moderate alcohol consumption exerts its protective effect.

"Is it some direct effect of the alcohol on the brain? Are people who consume moderate amounts of alcohol different in some way, in their diet, or their level of exercise? Are low concentrations of alcohol neuroprotective? Is it through some metabolic impact?" Dr. Porsteinsson said.

Also interesting was that alcohol appeared to protect against all types of dementia, he said.

"This makes it less likely to have a direct effect on beta amyloid or tau, but more of a global effect. It is an interesting review. They made it a pleasure to read."

The study was supported by the National Institutes of Health. Dr. Neafsey, Dr. Collins, and Dr. Porsteinsson have disclosed no relevant financial relationships.

Neuropsychiatric Dis Treat. 2011;7:465-484. Abstract

[Stoat]

Related article:

 

More Evidence Moderate Alcohol Reduces Cognitive Impairment

Pam Harrison

http://www.medscape.com/viewarticle/740233

April 5, 2011 (Toronto, Ontario) — Heavy alcohol consumption is associated with an increased risk for cognitive impairment, whereas light to moderate alcohol consumption reduces the risk, a new study shows.

Leung-Wing Chu, MD, from the University of Hong Kong, China, and colleagues found that the average weekly alcohol consumption in the cognitively impaired was significantly higher at a mean of 861.89 grams per week than that consumed by the normal cognition group at a mean of 241.21 grams per week (P < .001). Mini-Mental Status Examination (MMSE) scores were also higher for light to moderate drinkers compared with both nondrinkers and heavy drinkers.

In this analysis, more than 30 minutes a day of exercise was also independently associated with a 60% lower risk for cognitive impairment vs no exercise, with an adjusted odds ratio of 0.40 (P = .02). Those who reported doing fewer than 30 minutes of exercise a day still had a 48% lower risk for cognitive impairment at an adjusted odds ratio of 0.52 (P = .05).

The results were presented here at the Alzheimer's Disease International 26th International Conference.

Chinese in Hong Kong

For the study, the authors recruited a cross-sectional sample of 314 Southern Chinese older adults (mean age, 79.9 years) in Hong Kong. The MMSE along with participants' social demographic status, the presence of comorbid disease, and alcohol drinking habits were ascertained in a face-to-face interview. Heavy drinkers were defined as individuals who drank in excess of 400 grams of alcohol for men and more than 280 grams of alcohol for women. Light and moderate drinkers consumed less than 400 grams for men and less than 280 grams for women.

Brandy containing 45% alcohol would deliver about 21 grams of alcohol in 1 drink: wine at 12% with about 9.6 grams of alcohol per glass and beer at 4% with about 10.5 grams in a can. Based on logistic regression analyses, researchers found that light drinkers had an adjusted odds ratio of 0.28 for cognitive impairment (P = .004), whereas moderate drinkers had an adjusted odds ratio of 0.15 for cognitive impairment (P < .001).

In contrast, heavy drinkers had a 4.94 times greater adjusted odds ratio for cognitive impairment (P = .001).

"This is a cross-sectional study and we cannot say for sure that there is a link between cause and effect, but in this small study, we found that heavy alcohol consumption is associated with increased risk for cognitive impairment, whereas light to moderate consumption is associated with reduced risk in older Chinese people,” Dr. Chu concluded.

Confirmatory Study

Session chair, Amos Korczyn, MD, chairman, CONy World Congress on Controversies in Neurology, toldMedscape Medical News that this was another "confirmatory" study that once again demonstrated the harmful effects of heavy drinking on cognition.

"We have known for years that in western populations some drinking is good for you and a lot of drinking is very bad for you, so we recommend that everybody drink a glass of wine every day — maybe 2 and maybe even 3 — but beyond that, it is detrimental. Now this has been confirmed among the Chinese, which is also very interesting."

Alzheimer's Disease International (ADI) 26th International Conference: Abstract O051. Presented March 28, 2011

 

[Stoat]

[evets]

'Two drinks a day'? Works for me...

... that's one down the hatch.

[decimon]

Thanks, Stoat.

Cheers ping.

[Stoat]

An abstract as well as a link to a free PDF download of the complete 20 page original article as published in Neuropsychiatric Disease And Treatment Journal is available here

Moderate alcohol consumption and cognitive risk

[Stoat]

Thanks, Stoat.

 

You're quite welcome, and thank you very much for pinging your list :-)

 

[djf]

I actually have a Brandy snifter that big.

Seriesly!

I kinda sorta have a collection of old bottles, beer mugs, and interesting glass items.

[SkyDancer]

Okay - two drinks = 23% then four should = 46% and eight - waitaminnit~! WeHeR’s tH’ gLaSs?????

[fnord]

2 drinks a day ... I’m up to the year 2525 already

“Alzheimer’s Disease International (ADI) 26th International Conference: Abstract O051. Presented March 28, 2011”

Dammit, how did I forget to attend this conference?

[eggman]

I guess Cliff Clavin was right.

Cliff expounds his "Buffalo Theory" to Norm:

“Well, you see, Norm, it’s like this. A herd of buffalo can only move as fast as the slowest buffalo. And when the herd is hunted, it’s the slowest and weakest ones at the back that are killed first. This natural selection is good for the herd as a whole, because the general speed and health of the whole group keeps improving by the regular killing of the weakest members.

In much the same way, the human brain can only operate as fast as the slowest brain cells. Now, as we know, excessive intake of alcohol kills brain cells. But naturally, it attacks the slowest and weakest brain cells first. In this way, regular consumption of beer eliminates the weaker brain cells, making the brain a faster and more efficient machine.

And that, Norm, is why you always feel smarter after a few beers.”

[evets]

Ha ha, that's great... but do you have DAS BOOT!

[Stoat]

 

[Taffini]

rarely drink, so what is a good brandy and how can you fix it to make it taste better?

[count-your-change]

Not only keeping it away but chasing Alzheimer’s outta the state on a beer truck....errrrPP!

[Steve Van Doorn]

I am sorry but that is grams of liquid?
Thank you

[Stoat]

I am sorry but that is grams of liquid? 
 

 

Yes. You'll frequently find liquid measures expressed in grams instead of ounces in medical parlance.   Here's a convenient chart which may help in a conversion from grams to ounces:

 

Ounce To Gram Chart

Ounce	Gram		Ounce	Gram		Ounce	Gram		Ounce	Gram
1	28.3495231		26	737.0876006		51	1445.825678		76	2154.563756
2	56.6990462		27	765.4371237		52	1474.175201		77	2182.913279
3	85.0485693		28	793.7866468		53	1502.524724		78	2211.262802
4	113.3980924		29	822.1361699		54	1530.874247		79	2239.612325
5	141.7476155		30	850.485693		55	1559.223771		80	2267.961848
6	170.0971386		31	878.8352161		56	1587.573294		81	2296.311371
7	198.4466617		32	907.1847392		57	1615.922817		82	2324.660894
8	226.7961848		33	935.5342623		58	1644.27234		83	2353.010417
9	255.1457079		34	963.8837854		59	1672.621863		84	2381.35994
10	283.495231		35	992.2333085		60	1700.971386		85	2409.709464
11	311.8447541		36	1020.582832		61	1729.320909		86	2438.058987
12	340.1942772		37	1048.932355		62	1757.670432		87	2466.40851
13	368.5438003		38	1077.281878		63	1786.019955		88	2494.758033
14	396.8933234		39	1105.631401		64	1814.369478		89	2523.107556
15	425.2428465		40	1133.980924		65	1842.719002		90	2551.457079
16	453.5923696		41	1162.330447		66	1871.068525		100	2834.95231
17	481.9418927		42	1190.67997		67	1899.418048		125	3543.690388
18	510.2914158		43	1219.029493		68	1927.767571		150	4252.428465
19	538.6409389		44	1247.379016		69	1956.117094		175	4961.166543
20	566.990462		45	1275.72854		70	1984.466617		200	5669.90462
21	595.3399851		46	1304.078063		71	2012.81614		250	7087.380775
22	623.6895082		47	1332.427586		72	2041.165663		300	8504.85693
23	652.0390313		48	1360.777109		73	2069.515186		500	14174.76155
24	680.3885544		49	1389.126632		74	2097.864709		750	21262.14233
25	708.7380775		50	1417.476155		75	2126.214233		1000	28349.5231

 

Thank you

 

You're quite welcome, and I hope that this might be of some help :-)

[Ladysmith]

That does it... I’m heading out and get ma’ beer. I earned it today!

[ContraryMary]

That’s good to know...as I sit here with my glass of Chardonnay...

[meyer]

You'll frequently find liquid measures expressed in grams instead of ounces in medical parlance.

How does that reconcile with liquids of different densities?

[Stoat]

rarely drink, so what is a good brandy and how can you fix it to make it taste better?

 

I confess that I also rarely drink and so I should leave the recommendation of specific brands to people who are more in the league of spirit connoisseur  than I am.

Of course there are the famous, expensive brands like Hennesy which will delight most people but as far as the lesser-known and lesser-priced brandies I'm afraid I'd be hard pressed to recommend one over another merely because I haven't tried many of them.

As to mixing brandies in a cocktail there are a variety of web pages with many recipes available. Hopefully these links might serve to get you started.:

 

Brandy Cocktail Recipes - Index of Cocktails and Mixed Drinks with Brandy and Cognac

 

brandy cocktail recipes - Google Search