Brain Evolution and Why it is Meaningful Today to Improve Our Brain Health

Over the last months, thanks to the traf­fic growth of SharpBrains.com (over 100,000 unique vis­i­tors per month these days, THANK YOU for vis­it­ing today and please come back!), a num­ber of proac­tive book agents, pub­lish­ers and authors have con­tact­ed us to inform us of their lat­est brain-relat­ed books. We have tak­en a look at many books, wrote reviews of The Dana Guide to Brain Health book review‚ and Best of the Brain from Sci­en­tif­ic Amer­i­can, and inter­viewed sci­en­tists such as Judith Beck, Robert Emmons and James Zull.

Now we are launch­ing a new Author Speaks Series to pro­vide a plat­form for lead­ing sci­en­tists and experts writ­ing high-qual­i­ty brain-relat­ed books to reach a wide audi­ence. We are hon­ored to start the series with an arti­cle by Lar­ry McCleary, M.D, for­mer act­ing Chief of Pedi­atric Neu­ro­surgery at Den­ver Chil­dren’s Hos­pi­tal, and author of The Brain Trust Pro­gram: A Sci­en­tif­i­cal­ly Based Three-Part Plan to Improve Mem­o­ry, Ele­vate Mood, Enhance Atten­tion, Alle­vi­ate Migraine and Menopausal Symp­toms, and Boost Men­tal Ener­gy (Perigee Trade, 2007).

With­out fur­ther ado, let’s enjoy Dr. McCleary’s article:

Brain Evo­lu­tion and Why it is Mean­ing­ful Today to Improve Our Brain Health

You may feel over­whelmed by the stream of seem­ing­ly con­tra­dic­to­ry sug­ges­tions regard­ing the best way to main­tain men­tal clar­i­ty as you age. Based on an analy­sis of sem­i­nal fac­tors in the devel­op­ment of mod­ern brain anato­my, I believe it is pos­si­ble to make some very com­pelling rec­om­men­da­tions for grow­ing big brains, enhanc­ing their func­tion, and mak­ing them resis­tant to the aging process. These may be loose­ly cat­e­go­rized as fac­tors per­tain­ing to the men­tal or phys­i­cal attrib­ut­es of the brain. Although they are not tru­ly inde­pen­dent enti­ties, such a con­cep­tu­al­iza­tion pro­vides a basis for the gen­er­a­tion of brain healthy pre­scrip­tions. Diet, phys­i­cal exer­cise, and stress reduc­tion enhance neu­ronal resilience. Sleep and men­tal stim­u­la­tion are vital for cog­ni­tive abil­i­ty, learn­ing, and memory.

Diet: Fol­low a mod­ern shore-based/­ma­rine diet includ­ing seafood in its most gen­er­al sense, non-starchy veg­eta­bles of all col­ors, berries, and eggs. Oth­er sources of lean pro­tein con­tain­ing long-chain omega 3 fat­ty acids such as free range beef, chick­en, bison, or elk are nutri­tious alternatives.

Phys­i­cal exer­cise (Think fight or flight — activ­i­ty.): Include all types. Aer­o­bic activ­i­ties such as swim­ming, bicy­cling, walk­ing, or hik­ing for pro­mo­tion of vas­cu­lar health and weight con­trol; resis­tance train­ing for pro­mo­tion of neu­rotroph­ic fac­tors, nat­u­ral­ly occur­ring com­pounds that make brain cells more resis­tant to aging, such as IGF‑1 (Insulin-like growth factor‑1) and BDNF (Brain-derived neu­rotroph­ic fac­tor); and bal­ance, coor­di­na­tion, and agili­ty train­ing such as ping-pong, bal­ance beam, tram­po­line, and jump­ing rope to enhance cog­ni­tive speed and motor skills.

Stress Con­trol: From an evo­lu­tion­ary per­spec­tive, stres­sors (such as meet­ing a cave bear) and intense phys­i­cal activ­i­ty (run­ning or fight­ing) were brief in dura­tion and usu­al­ly occurred togeth­er. Mod­ern stres­sors (psy­cho­log­i­cal or emo­tion­al stress) tend to be unremit­ting and are gen­er­al­ly uncou­pled from the phys­i­cal (fight or flight) com­po­nent, mean­ing stress devel­ops with­out any asso­ci­at­ed phys­i­cal activ­i­ty. Such intense phys­i­cal pur­suits are now called exer­cise. Not sur­pris­ing­ly, exer­cise is a per­fect phys­i­o­log­ic anti­dote for stress due to its ben­e­fi­cial impact on cor­ti­sol (the stress hor­mone) and blood pres­sure and should be incor­po­rat­ed into any pro­gram of stress reduction.

Ade­quate sleep: The body needs rest, but the brain requires sleep. Acute or chron­ic sleep depri­va­tion caus­es dev­as­tat­ing short and long-term con­se­quences to brain anato­my (synap­tic loss) and func­tion (mem­o­ry and learn­ing dif­fi­cul­ties). Off-line infor­ma­tion pro­cess­ing and mem­o­ry con­sol­i­da­tion are addi­tion­al sleep-relat­ed benefits.

Men­tal stim­u­la­tion: Brain-train­ing, a cog­ni­tive­ly chal­leng­ing lifestyle, nov­el­ty, and social­iza­tion are vital for the pro­mo­tion of neu­ronal plas­tic­i­ty and neu­ro­ge­n­e­sis (the for­ma­tion of new nerve cells and neu­ronal con­nec­tions), the enhance­ment of spe­cif­ic brain func­tions such as mem­o­ry, and the devel­op­ment of cog­ni­tive reserve — addi­tion­al men­tal pro­cess­ing poten­tial that may be brought online when needed.

The com­bi­na­tion of these rec­om­men­da­tions, each of which was instru­men­tal in the trans­for­ma­tion from prim­i­tive to mod­ern ner­vous sys­tems, pro­vides a tem­plate for the most log­i­cal approach for enhanc­ing men­tal func­tion and resist­ing neu­rode­gen­er­a­tion as we trav­el through life.

The Evo­lu­tion­ary Rationale

The human brain clear­ly has the genet­ic poten­tial for dra­mat­ic expan­sion. This was illus­trat­ed about 1,500,000 years ago. Enlarge­ment from 900 grams to almost 1300 grams required less than a mil­lion years to com­plete ‚- a mere speck on the evo­lu­tion­ary time­line. Why and how it hap­pened are open ques­tions. What remains undis­put­ed are the mag­ni­tude of the change and the impact it had on human capa­bil­i­ties. The rapid vol­u­met­ric explo­sion pri­mar­i­ly involved the frontal lobe region, a por­tion of the brain that, until recent­ly, was referred to as the silent‚ brain because of its rel­a­tive lack of any dis­cern­able func­tion­al­i­ty. The frontal lobes are now viewed as the con­duc­tor of the orches­tra, because they have been rec­og­nized as being respon­si­ble for artic­u­lat­ing the big pic­ture and coor­di­nat­ing oth­er brain regions, as need­ed, to exe­cute the   game plan.   The Pre­frontal cor­tex (PFC), the most ante­ri­or por­tion of the frontal cor­tex, has dense con­nec­tions with all the oth­er regions it over­sees. It is gen­er­al­ly con­sid­ered the most plas­tic cor­ti­cal region because its synaps­es are con­tin­u­al­ly being torn down and recon­fig­ured in response to real-time expe­ri­ences. Plas­tic­i­ty allows the brain to think on its feet. Expan­sion of PFC enabled the cog­ni­tive pre­em­i­nence of mod­ern day humans over all non-human pri­mates. The plas­tic­i­ty of the PFC and its mas­sive con­nec­tiv­i­ty with oth­er brain regions rely entire­ly on the pro­duc­tion and main­te­nance of point-to-point nerve cell con­nec­tions, or synapses.

In addi­tion to being a think­ing machine, the brain is also a flesh and blood organ that must com­ply with the laws of metab­o­lism and phys­i­ol­o­gy. Insight into both its men­tal and phys­i­cal prop­er­ties is vital for com­pre­hend­ing key aspects of brain health and func­tion. Much has been writ­ten about the facil­i­ta­tion of brain growth by cog­ni­tive­ly demand­ing tasks such as tool use and hunt­ing. How­ev­er, there is a com­po­nent of cir­cu­lar rea­son­ing in this argu­ment. For it to par­tic­i­pate in such men­tal­ly demand­ing endeav­ors, the brain would have relied on the pri­or exis­tence of sophis­ti­cat­ed neu­ronal cir­cuit­ry. I sug­gest a nutri­tion­al basis for the dra­mat­ic cere­bral expan­sion, with enhanced func­tion­al­i­ty (such as devel­op­ment of tool use and hunt­ing strat­e­gy) being the nat­ur­al respons­es of a larg­er, more plas­tic organ to nov­el­ty and envi­ron­men­tal chal­lenges. The com­mon link between the evo­lu­tion­ary cere­bral expan­sion and mod­ern brain health/function resides in the mas­sive wiring demands inher­ent in both process­es. This marked ampli­fi­ca­tion in neu­ronal con­nec­tiv­i­ty is made pos­si­ble by the enhanced pro­duc­tion of synap­tic mem­branes (nerve cell mem­branes in the regions of points of nerve cell contact).

How was it pos­si­ble to fuel the pro­duc­tion of major increas­es in neu­ronal num­ber and synap­tic den­si­ty? This required the con­cor­dant expres­sion of genet­ic poten­tial (like­ly dri­ven, in part, by the pro­vi­sion of an unin­ter­rupt­ed ener­gy sup­ply) and prop­er nutri­tion­al con­tent — mean­ing high, sus­tained caloric and nutri­ent den­si­ty. Just as a cer­tain lev­el of fat mass is a pre­req­ui­site for expan­sion of the female body to sup­port a suc­cess­ful preg­nan­cy, a per­sis­tent sup­ply of nutri­ent dense calo­ries is essen­tial for brain expan­sion. In times of fre­quent star­va­tion, this was a sub­stan­tial nutri­tion­al demand. To ful­ly appre­ci­ate how ener­get­i­cal­ly expen­sive brains are, con­sid­er that mod­ern brains com­prise about 2.3% of the body mass, yet con­sume almost one quar­ter of the avail­able ener­gy. New­born brains uti­lize ful­ly 75% of the body energy!

What type of brain-build­ing diet might have been acces­si­ble 1.5 mil­lion years ago that did­n’t require the cog­ni­tive demands inher­ent in hunt­ing? One solu­tion would be a “shore-based” diet. This means for­ag­ing for life forms such as mol­lusks, crus­taceans, eggs, spawn­ing fish, frogs, and con­tigu­ous plant life read­i­ly avail­able along lake shores or riv­er banks. In a warm clime it would have pro­vid­ed a year-round, high qual­i­ty diet abun­dant in calo­ries, fat and pro­tein. It also sup­plied long-chain omega 3 fat­ty acids (includ­ing DHA), the build­ing blocks of elec­tri­cal­ly active mem­branes in neu­rons and pho­tore­cep­tor cells.

Big brains must also syn­the­size abun­dant cho­les­terol and oth­er com­po­nents of nerve cell mem­branes. This requires a water-sol­u­ble source of appro­pri­ate build­ing blocks. Ketone bod­ies (ace­toac­etate and hydrox­y­bu­tyrate) gen­er­at­ed nat­u­ral­ly from par­tial­ly burned fat were, and con­tin­ue to be, an ide­al ener­gy source for the brain while simul­ta­ne­ous­ly pro­vid­ing key pre­cur­sors for syn­the­sis of nerve cell mem­branes and synaps­es. These facil­i­tat­ed the anatom­ic expan­sion of the brain, which pro­vid­ed the addi­tion­al neu­ronal cir­cuit­ry that made the learn­ing of hunt­ing skills a possibility.

Hence, what was com­pul­so­ry for explo­sive brain expan­sion of the species is as vital today for opti­mal brain func­tion and plas­tic­i­ty. It is the ongo­ing abil­i­ty to pro­duce high lev­els of the most func­tion­al sites of nerve cells the synap­tic mem­branes. Appro­pri­ate assem­blies of nerve cells, as deter­mined by their con­nec­tions (synaps­es), pro­vide the basis for the func­tion­al attrib­ut­es we enjoy today. Stress reduc­tion, men­tal stim­u­la­tion and prop­er sleep enhance their resis­tance to the aging process.

—This arti­cle was writ­ten by Lar­ry McCleary, M.D, for SharpBrains.com’s Author Speaks Series. Dr. McCleary (blog) is a for­mer act­ing Chief of Pedi­atric Neu­ro­surgery at Den­ver Chil­dren’s Hos­pi­tal. He is trained and has prac­ticed as a pedi­atric neu­ro­sur­geon and has com­plet­ed post-grad­u­ate train­ing in the­o­ret­i­cal physics. His sci­en­tif­ic pub­li­ca­tions span the fields of meta­bol­ic med­i­cine, tumor immunol­o­gy, biotech­nol­o­gy and neu­ro­log­i­cal dis­ease. He is the author of The Brain Trust Pro­gram: A Sci­en­tif­i­cal­ly Based Three-Part Plan to Improve Mem­o­ry, Ele­vate Mood, Enhance Atten­tion, Alle­vi­ate Migraine and Menopausal Symp­toms, and Boost Men­tal Ener­gy (Perigee Trade, 2007).