Does Coffee Boost Brain/ Cognitive Functions Over Time?

A few eter­nal questions:
— Is caf­feine good for the brain?
— Does it boost cog­ni­tive functions?
— Does it pro­tect against dementia?

There is lit­tle doubt that drink­ing that morn­ing cup of cof­fee will like­ly increase alert­ness, but the main ques­tions that research is try­ing to answer go beyond that. Basi­cal­ly: is there a sus­tained, life­time, ben­e­fit or harm from drink­ing cof­fee regularly?

The answer, so far, con­tains good news and bad news. The good news for cof­fee drinkers is that most of the long-term results are direc­tion­al­ly more pos­i­tive than neg­a­tive, so no clear harm seems to occur. The bad news is that it is not clear so far whether caf­feine has ben­e­fi­cial effects on gen­er­al brain func­tions, either short-term or long-term (aged-relat­ed decline or risks of dementia).

It is impor­tant to note that many of the stud­ies show­ing an effect of cof­fee con­sump­tion on brain func­tions or risks of demen­tia report a cor­re­la­tion or asso­ci­a­tion (they are not ran­dom­ized clin­i­cal tri­als). As you know, cor­re­la­tion doesn’t prove cau­sa­tion: cof­fee drinkers may seem to do well in a num­ber in these long-term stud­ies, but there may be oth­er rea­sons why cof­fee drinkers do better.

Q: How does caf­feine affect my brain?
A: Caf­feine is a stimulant.

It belongs to a chem­i­cal group called xan­thine. Adeno­sine is a nat­u­ral­ly occur­ring xan­thine in the brain that slows down the activ­i­ty of brain cells (neu­rons). To a neu­ron, caf­feine looks like adeno­sine. It is there­fore used by some neu­rons in place of adeno­sine. The result is that these neu­rons speed up instead of slow­ing down.

This increased neu­ronal activ­i­ty trig­gers the release of the adren­a­line hor­mone, which will affect your body in sev­er­al ways: your heart­beat increas­es, your blood pres­sure ris­es, your breath­ing tubes open up, sug­ar is released in the blood­stream for extra energy.

In mod­er­ate dos­es (a few cups a day) caf­feine can increase alert­ness but also reduce fine motor coor­di­na­tion, cause insom­nia, cause headaches and nervousness.

Q: Does caf­feine boost brain functions?

A: To date 3 stud­ies sug­gest that the answer is “maybe”.

In one study of over 7000 peo­ple, results showed a cor­re­la­tion between cur­rent caf­feine intake and bet­ter per­for­mance on 4 tests. This was more pro­nounced in old­er indi­vid­u­als than in younger ones (Mar­tin, 1993).

Anoth­er study showed that in 1500 peo­ple over 65, life-time con­sump­tion of cof­fee was asso­ci­at­ed with increased per­for­mance in 6 out 12 tests. Cur­rent intake was relat­ed to bet­ter per­for­mance in only 2 out 12 tests (John­son-Kozlow, et al., 2002).

The third study showed for a group of 1875 adults aged 24 to 81, cur­rent intake of cof­fee was asso­ci­at­ed with bet­ter per­for­mance in 2 tests but not in 4 oth­ers. (Hameleers et al., 2000)

Thus, caf­feine con­sump­tion may be asso­ci­at­ed with bet­ter per­for­mance but 1) there are only very few stud­ies so far, 2) this effect seems lim­it­ed to some tasks only.

Q: Does caf­feine pro­tect against age-relat­ed cog­ni­tive decline?

A: Two stud­ies say “yes” and 3 stud­ies say “no”.

Van Gelder et al. (2007) fol­lowed 676 elder­ly men over 10 years and found that those who drank more cof­fee showed less decline in the Mini-Men­tal Test. The least decline was observed with 3 cups a day.

Ritchie et al. (2007) showed that over 4 years, women over 65 (but not men) who drank more than 3 cups a day showed less decline than women who drank one cup or less. This was observed only in a task of ver­bal memory.

Van Box­tel et al. (2003) fol­lowed 1376 indi­vid­u­als aged 24 to 81 for 6 years and found that caf­feine intake had a very small impact on a motor task but no effect on ver­bal mem­o­ry tasks.

Hameleers et al. (2000) found no evi­dence that caf­feine intake coun­ter­acts cog­ni­tive age-relat­ed decline in a group of 1875 peo­ple aged 24 to 81.

The most recent study of 2606 peo­ple showed that over 28 years cof­fee drink­ing was not relat­ed to bet­ter per­for­mance (Laita­la et al., 2009).

As you can see results are mixed. The evi­dence show­ing that caf­feine reduces age-relat­ed cog­ni­tive decline is lim­it­ed: very few stud­ies and very few tasks.

Q: Does caf­feine pro­tect against dementia?

A: Three stud­ies say “yes” and 2 stud­ies say “no”.

Maia et al. (2002) stud­ied 54 Alzheimer’s patients and their non-affect­ed rel­a­tives (Con­trols): High­er dai­ly caf­feine intake dur­ing the 20 years pri­or diag­no­sis was found to be asso­ci­at­ed with low­er risk of Alzheimer’s Dis­ease, sug­gest­ing that cof­fee may be protective.

Eske­li­nen et al. (2009) fol­lowed 1409 indi­vid­u­als aged 65 to 79 for 21 years and found that those who drank cof­fee had less risk of devel­op­ing demen­tia than those who didn’t. The low­est risk was in peo­ple drink­ing 3–5 cups a day.

Lind­say et al (2002) stud­ied 4615 indi­vid­u­als over 5 years and found that cof­fee con­sump­tion was asso­ci­at­ed with a reduced risk of Alzheimer’s Disease.

Ritchie et al. (2007) stud­ied 7017 indi­vid­u­als aged 65 and over and showed that, over 4 years, caf­feine con­sump­tion did not reduce demen­tia risk.

The most recent study to date showed that over 28 years, cof­fee drink­ing did not affect the risk of mild cog­ni­tive impair­ment or demen­tia (Laita­la et al., 2009).

Here again the evi­dence is mixed. Based on the few stud­ies, it is not pos­si­ble at this time to say that cof­fee con­sump­tion indeed decreas­es the risks of dementia.

– Pas­cale Mich­e­lon, Ph. D., is Sharp­Brains’ Research Man­ag­er for Edu­ca­tion­al Projects. Dr. Mich­e­lon has a Ph.D. in Cog­ni­tive Psy­chol­o­gy and has worked as a Research Sci­en­tist at Wash­ing­ton Uni­ver­si­ty in Saint Louis, in the Psy­chol­o­gy Depart­ment. She con­duct­ed sev­er­al research projects to under­stand how the brain makes use of visu­al infor­ma­tion and mem­o­rizes facts. She is now an Adjunct Fac­ul­ty at Wash­ing­ton University.

To learn more:

• The Sharp­Brains Guide to Brain Performance