Are non-drinkers more likely to get dementia?

According to a major new study in the British Medical Journal, people who drink heavily ...

Posted: Aug 2, 2018 12:35 PM
Updated: Aug 2, 2018 12:35 PM

According to a major new study in the British Medical Journal, people who drink heavily are more likely to get dementia. That's not surprising -- we know that excessive alcohol use is linked to lots of diseases. But what might surprise you is that people who don't drink at all are also more likely to get dementia.

Considerably so, in fact. The study -- which took 9,000 British people between the ages of 35 and 55 in the mid-1980s and followed them for 30 years -- found that people who didn't drink at all for a period of 10 years or more were almost 50% more likely to develop dementia in later life than people who drank a moderate amount.

Aging and health

Dementia

Diseases and disorders

Geriatric medicine

Health and health care (by demographic group)

Health and medical

Medical fields and specialties

Neurological disorders and injuries

People who drank excessively -- more than the recommended 14 units a week -- were also at higher risk.

This finding is called a "J-shaped curve," because the risk dips at first, as you drink more, and then starts to climb again, in the shape of a J, or a tick.

Earlier studies have found the same thing, and it's actually been seen in other conditions. Heart disease, strokes and diabetes all show a similar pattern (if you don't drink, you're at higher risk; if you drink a bit, it drops, and then it climbs again). So does overall mortality, your risk of dying in a given period.

Related: Alcohol -- Do you drink too much?

What this doesn't mean, though, is that if you don't drink, you ought to start drinking for the sake of your future brain.

For one thing, while a 50% increased risk sounds bad, it's worth putting into context.

Only about 400 of the study's participants -- a bit less than 5% -- actually developed dementia. Of the 1,300 long-term abstainers, 98 people (7.5%) developed dementia. The risk is indeed 50% higher, but 150% of a small number is still fairly small.

Second, it's far from clear that abstaining from alcohol actually causes the dementia -- or, more accurately, it's not clear that alcohol has a protective effect. That's because, in British society at least, people who don't drink at all are quite unusual.

You can see that in the study. People in the "abstainers" group are more likely to be non-white, less likely to have higher educational certificates, more likely to live alone.

Those groups may be more prone to dementia naturally. The study tries to account for those differences with statistical methods, but that's tricky. "Although the model they use tries to take account of these differences," says Dr Suzi Gage, a psychologist and epidemiologist at the University of Liverpool. But you can never be sure "first that all the differences are included, and second that the measures you're using capture all those differences."

For instance, she says, the reason some people don't drink is because they have been told not to by their GP, for health reasons. "It's one of the first things doctors tell you," she says, if you've been diagnosed with heart problems.

If you've got lots of people who have underlying health conditions in the abstainers group, it wouldn't be surprising if they tended to get dementia (and stroke, and heart disease) more often. Some heavy drinkers become abstainers, too.

The study's authors are aware of all these limitations, and were careful not to say that alcohol protects against dementia, although they do think it might. It's not clear exactly how that might work, biologically -- the study suggests some possibilities, but, Dr Gage warns, "you can come up with plausible mechanisms for almost any finding". "It could be that a small amount of alcohol is protective," she says. "But I'm not convinced." Other scientists think there is a protective effect, but it is an ongoing debate, and it seems unlikely that it is as big as the 50% increase in risk that we talked about earlier.

At the moment, the advice for British people is to drink less than 14 units -- about seven pints of beer or glasses of wine -- a week, spread over several days. This study supports that advice. But, as it says itself, it shouldn't "motivate people who do not drink to start drinking, given the known detrimental effects of alcohol consumption."

Starting to drink for the benefit of your health is probably still a bad idea.

Minnesota Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 57779

Reported Deaths: 1670
CountyConfirmedDeaths
Hennepin18393825
Ramsey7130261
Dakota4112104
Anoka3456113
Stearns284720
Washington197843
Nobles17516
Olmsted164923
Scott143918
Mower10882
Rice10068
Blue Earth8655
Wright8275
Carver8052
Clay75840
Kandiyohi6811
Sherburne6677
St. Louis47519
Todd4212
Lyon4203
Freeborn3561
Steele3341
Nicollet32213
Benton3133
Watonwan3000
Winona25216
Crow Wing22114
Beltrami2070
Martin2045
Le Sueur2031
Chisago1841
Goodhue1838
Otter Tail1823
Cottonwood1730
Becker1481
McLeod1450
Pipestone1449
Polk1393
Douglas1360
Itasca13512
Waseca1330
Carlton1300
Pine1280
Dodge1250
Murray1221
Isanti1140
Unassigned10941
Chippewa1011
Brown852
Meeker852
Wabasha840
Faribault830
Morrison821
Sibley802
Rock750
Koochiching743
Pennington731
Jackson710
Mille Lacs693
Cass662
Fillmore610
Renville605
Lincoln540
Grant521
Swift521
Yellow Medicine500
Pope460
Roseau460
Houston400
Norman370
Redwood320
Wilkin313
Hubbard300
Kanabec301
Aitkin291
Marshall290
Mahnomen251
Wadena240
Big Stone220
Red Lake210
Lake180
Stevens160
Clearwater140
Traverse100
Lac qui Parle60
Kittson30
Cook20
Lake of the Woods10

Iowa Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 46704

Reported Deaths: 899
CountyConfirmedDeaths
Polk9874204
Woodbury367351
Black Hawk305462
Linn219887
Johnson200216
Dallas180735
Buena Vista179012
Scott163613
Dubuque159431
Marshall140725
Pottawattamie125724
Story112614
Wapello86633
Muscatine83948
Webster7637
Crawford7263
Sioux6072
Cerro Gordo58617
Tama54329
Warren5421
Jasper45825
Wright4511
Plymouth4488
Louisa37914
Dickinson3784
Clinton3383
Washington28810
Hamilton2431
Boone2342
Franklin2278
Bremer1967
Clarke1903
Emmet1852
Carroll1831
Shelby1761
Clay1741
Hardin1710
Marion1590
Allamakee1524
Poweshiek1518
Jackson1461
Benton1451
Des Moines1432
Mahaska13717
Floyd1322
Guthrie1285
Jones1262
Cedar1231
Buchanan1181
Butler1182
Hancock1172
Henry1143
Pocahontas1141
Lyon1080
Madison1072
Clayton1013
Cherokee991
Harrison990
Lee993
Delaware941
Humboldt941
Iowa941
Taylor940
Monona910
Winneshiek901
Mills850
Calhoun822
Kossuth820
Fayette810
Sac810
Palo Alto800
Mitchell780
Osceola780
Jefferson770
Page770
Grundy761
Winnebago760
Union741
Monroe707
Worth640
Lucas534
Chickasaw520
Davis511
Howard490
Cass481
Montgomery454
Appanoose433
Greene380
Fremont340
Van Buren341
Keokuk311
Ida290
Audubon281
Adair230
Decatur230
Ringgold211
Wayne191
Adams160
Unassigned40
Rochester
Broken Clouds
64° wxIcon
Hi: 76° Lo: 62°
Feels Like: 64°
Mason City
Overcast
62° wxIcon
Hi: 78° Lo: 62°
Feels Like: 62°
Albert Lea
Broken Clouds
63° wxIcon
Hi: 76° Lo: 63°
Feels Like: 63°
Austin
64° wxIcon
Hi: 77° Lo: 63°
Feels Like: 64°
Charles City
Overcast
63° wxIcon
Hi: 77° Lo: 62°
Feels Like: 63°
Warming temps and rain inbound
KIMT Radar
KIMT Eye in the sky

Community Events