Pros and Cons of using four nootropics–caffeine, creatine, L‑theanine, Ashwaghanda–as cognitive enhancers

Humans have long been search­ing for a “mag­ic elixir” to make us smarter, and improve our focus and mem­o­ry. This includes tra­di­tion­al Chi­nese med­i­cine used thou­sands of years ago to improve cog­ni­tive function.

Now we have nootrop­ics, also known as smart drugs, brain boost­ers or cog­ni­tive enhancers.

You can buy these gum­mies, chew­ing gums, pills and skin patch­es online, or from super­mar­kets, phar­ma­cies or petrol sta­tions. You don’t need a pre­scrip­tion or to con­sult a health professional.

But do nootrop­ics actu­al­ly boost your brain? Here’s what the sci­ence says.

What are nootropics and how do they work?

Roman­ian psy­chol­o­gist and chemist Cor­nelius E. Giurgea coined the term nootrop­ics in the ear­ly 1970s to describe com­pounds that may boost mem­o­ry and learn­ing. The term comes from the Greek words noos (think­ing) and tropein (guide).

Nootrop­ics may work in the brain by improv­ing trans­mis­sion of sig­nals between nerve cells, main­tain­ing the health of nerve cells, and help­ing in ener­gy pro­duc­tion. Some nootrop­ics have antiox­i­dant prop­er­ties and may reduce dam­age to nerve cells in the brain caused by the accu­mu­la­tion of free radicals.

But how safe and effec­tive are they? Let’s look at four of the most wide­ly used nootropics.

1. Caffeine

You might be sur­prised to know caf­feine is a nootrop­ic. No won­der so many of us start our day with a cof­fee. It stim­u­lates our ner­vous system.

Caf­feine is rapid­ly absorbed into the blood and dis­trib­uted in near­ly all human tis­sues. This includes the brain where it increas­es our alert­ness, reac­tion time and mood, and we feel as if we have more energy.

For caf­feine to have these effects, you need to con­sume 32–300 mil­ligrams in a sin­gle dose. That’s equiv­a­lent to around two espres­sos (for the 300mg dose). So, why the wide range? Genet­ic vari­a­tions in a par­tic­u­lar gene (the CYP1A2 gene) can affect how fast you metabolise caf­feine. So this can explain why some peo­ple need more caf­feine than oth­ers to recog­nise any neu­rostim­u­lant effect.

Unfor­tu­nate­ly too much caf­feine can lead to anx­i­ety-like symp­toms and pan­ic attacks, sleep dis­tur­bances, hal­lu­ci­na­tions, gut dis­tur­bances and heart problems.

So it’s rec­om­mend­ed adults drink no more than 400mg caf­feine a day, the equiv­a­lent of up to three espressos.

2. L‑theanine

L‑theanine comes as a sup­ple­ment, chew­ing gum or in a bev­er­age. It’s also the most com­mon amino acid in green tea.

Con­sum­ing L‑theanine as a sup­ple­ment may increase pro­duc­tion of alpha waves in the brain. These are asso­ci­at­ed with increased alert­ness and per­cep­tion of calmness.

How­ev­er, it’s effect on cog­ni­tive func­tion­ing is still unclear. Var­i­ous stud­ies includ­ing those com­par­ing a sin­gle dose with a dai­ly dose for sev­er­al weeks, and in dif­fer­ent pop­u­la­tions, show dif­fer­ent outcomes.

But tak­ing L‑theanine with caf­feine as a sup­ple­ment improved cog­ni­tive per­for­mance and alert­ness in one study. Young adults who con­sumed L‑theanine (97mg) plus caf­feine (40mg) could more accu­rate­ly switch between tasks after a sin­gle dose, and said they were more alert.

Anoth­er study of peo­ple who took L‑theanine with caf­feine at sim­i­lar dos­es to the study above found improve­ments in sev­er­al cog­ni­tive out­comes, includ­ing being less sus­cep­ti­ble to distraction.

Although pure L‑theanine is well tol­er­at­ed, there are still rel­a­tive­ly few human tri­als to show it works or is safe over a pro­longed peri­od of time. Larg­er and longer stud­ies exam­in­ing the opti­mal dose are also needed.

3. Ashwaghanda

Ash­waghan­da is a plant extract com­mon­ly used in Indi­an Ayurvedic med­i­cine for improv­ing mem­o­ry and cog­ni­tive function.

In one study, 225–400mg dai­ly for 30 days improved cog­ni­tive per­for­mance in healthy males. There were sig­nif­i­cant improve­ments in cog­ni­tive flex­i­bil­i­ty (the abil­i­ty to switch tasks), visu­al mem­o­ry (recall­ing an image), reac­tion time (response to a stim­u­lus) and exec­u­tive func­tion­ing (recog­nis­ing rules and cat­e­gories, and man­ag­ing rapid deci­sion making).

There are sim­i­lar effects in old­er adults with mild cog­ni­tive impairment.

But we should be cau­tious about results from stud­ies using Ash­waghan­da sup­ple­ments; the stud­ies are rel­a­tive­ly small and only treat­ed par­tic­i­pants for a short time.

4. Creatine

Cre­a­tine is an organ­ic com­pound involved in how the body gen­er­ates ener­gy and is used as a sports sup­ple­ment. But it also has cog­ni­tive effects.

In a review of avail­able evi­dence, healthy adults aged 66–76 who took cre­a­tine sup­ple­ments had improved short-term memory.

Long-term sup­ple­men­ta­tion may also have ben­e­fits. In anoth­er study, peo­ple with fatigue after COVID took 4g a day of cre­a­tine for six months and report­ed they were bet­ter able to con­cen­trate, and were less fatigued. Cre­a­tine may reduce brain inflam­ma­tion and oxida­tive stress, to improve cog­ni­tive per­for­mance and reduce fatigue.

Side effects of cre­a­tine sup­ple­ments in stud­ies are rarely report­ed. But they include weight gain, gas­troin­testi­nal upset and changes in the liv­er and kidneys.

Where to now?

There is good evi­dence for brain boost­ing effects of caf­feine and cre­a­tine. But the jury is still out on the effi­ca­cy, opti­mal dose and safe­ty of most oth­er nootropics.

So until we have more evi­dence, con­sult your health pro­fes­sion­al before tak­ing a nootropic.

But drink­ing your dai­ly cof­fee isn’t like­ly to do much harm. Thank good­ness, because for some of us, it is a mag­ic elixir.

– Nenad Nau­movs­ki is a Pro­fes­sor in Food Sci­ence and Human Nutri­tion; Aman­da Bul­man is a PhD can­di­date study­ing the effects of nutri­ents on sleep, Uni­ver­si­ty of Can­ber­ra; and Andrew McK­une is a Pro­fes­sor of Exer­cise Sci­ence, all at the Uni­ver­si­ty of Can­ber­ra. This arti­cle was orig­i­nal­ly pub­lished on The Con­ver­sa­tion.

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SHARPBRAINS is an independent think-tank and consulting firm providing services at the frontier of applied neuroscience, health, leadership and innovation.
SHARPBRAINS es un think-tank y consultoría independiente proporcionando servicios para la neurociencia aplicada, salud, liderazgo e innovación.

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