The brain virtues of physical exercise

Dr. Adri­an Pre­da, our newest Expert Con­trib­u­tor, writes today the first in a series of thought-pro­vok­ing arti­cles, chal­leng­ing us to think about phys­i­cal exer­cise as the best and most unap­pre­ci­at­ed form of “brain exer­cise”. A superb article.

And one thing is clear, he points out: “the brain real­ly likes it when it’s asked to be “active”. Pas­sive audi­ences, which are spoon fed infor­ma­tion, score less well when test­ed on reten­tion and under­stand­ing of the pre­sent­ed mate­r­i­al than audi­ences that were kept engaged through the process.”

So, will you write a com­ment below and con­tribute to an engag­ing con­ver­sa­tion? Thoughts? reac­tions? questions?
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Don’t ignore plain old com­mon sense.

Brain Lessons Part 1

– By Adri­an Pre­da, M.D.

Let me start with a list of com­mon bias­es: expen­sive is bet­ter than cheap, free is of dubi­ous val­ue (why would then be free?), rare is like­ly to be valu­able, and while new is bet­ter than old, ancient is always best. Which explains a com­mon sce­nario that is reen­act­ed about twice a week in my office. It starts like this: a patient shows me a fan­cy look­ing bot­tle of the brain sup­ple­ment of the week: ancient roots with obscure names mixed togeth­er in anoth­er nov­el com­bi­na­tion which you can exclu­sive­ly find in that one and only store (rar­i­ty oblige!). And not to for­get: it ain’t cheap either! Of course, there it is, the per­fect the recipe for suc­cess: ancient yet new, rare and expen­sive. It got to be good! But is it, really?

The prob­lem with rec­om­mend­ing phys­i­cal exer­cise when it comes to brain fit­ness is that is doesn’t have any of the glam­our traits I have just men­tioned: it’s been around for a long time – so there is noth­ing new and excit­ing about it, there is no fan­cy name or exclu­sive label mar­ket­ing it and, worst of all, it is as cheap as cheap can be: not only free but also avail­able in unlim­it­ed supplies.

So when I tell my patients that the sin­gle most impor­tant thing they need to pay atten­tion to when it comes to keep­ing their brain in shape is exer­cise I invari­ably get a “really, and you need­ed to get an MD to tell me this?” look. Nowa­days every­body seems to know that phys­i­cal exer­cise is good for the brain. Big news they say. And they need­ed to study that? Duh?

For most it’s no big sur­prise to find out the peo­ple who have a phys­i­cal­ly active life style have a decreased risk of Alzheimer’s demen­tia or the num­ber of blocks one walks every­day appears to inverse­ly cor­re­late with the rate of cog­ni­tive decline lat­er in life. It sort of makes sense to assume that has to be the case. Here are a few well estab­lished facts.

First of all, reg­u­lar phys­i­cal exer­cise cor­re­lates with improved health – mean­ing less risk for high blood pres­sure, meta­bol­ic prob­lems (cho­les­terol, lipids and glu­cose dys­reg­u­la­tion) and weight gain, which is all good for the brain. A healthy brain needs a healthy envi­ron­ment, doesn’t it? Or to put it in a slight­ly dif­fer­ent way: an unhealthy envi­ron­ment would not be good for the brain, wouldn’t it? I think we would all agree on that one.

Now, would a healthy envi­ron­ment not only pro­tect but also improve the brain struc­ture and per­for­mance? Would it also pro­mote the growth (if pos­si­ble) of the brain? The answers to such ques­tions are less obvi­ous. For exam­ple we know that not all healthy peo­ple end up with “good brains”. Well, why is that? Specif­i­cal­ly, when it comes to phys­i­cal exer­cise then are there such things as a min­i­mal dose of exer­cise that can result in pos­i­tive brain effects? And is there a max­i­mal or “toxic” dose of phys­i­cal exer­cise which may in fact hurt the brain? Is all phys­i­cal exer­cise equal­ly good for the brain or do dif­fer­ent phys­i­cal exer­cise rou­tines dif­fer in terms of their brain effects? I put those ques­tions on the table and the chance is that I got the “duh” people’s attention.

First, let me say that to sci­en­tists the phys­i­cal exer­cise ques­tion is no dif­fer­ent that any oth­er sci­en­tif­ic ques­tion. Sci­en­tists tend to be a skep­ti­cal bunch and as such they like to always point out that cor­re­la­tion does not nec­es­sar­i­ly imply cau­sa­tion. Take the old active peo­ple who didn’t get Alzheimer’s exam­ple. One pos­si­bil­i­ty is that their con­sis­tent exer­cis­ing keeps them from get­ting Alzheimer’s. But what is it that got them to exer­cise more in the first place? Could it be that their brains were equipped with the sort of gear that gets one excit­ed about push­ing them­selves a bit, which would then result in these fel­lows being more prone towards doing phys­i­cal things to start with? Then they will be more active phys­i­cal­ly but that is because their brains were wired dif­fer­ent­ly from the gecko and that, in itself, might have decreased the risk of Alzheimer’s demen­tia. In a sit­u­a­tion like this phys­i­cal exer­cise is what sci­en­tists call a con­founder – i.e. a con­comi­tant but not nec­es­sar­i­ly casu­al event that can false­ly be seen as a cause result­ing in the final effect.

How can one fig­ure this one out? Over the next few columns we will look togeth­er at ways of answer­ing appar­ent­ly not so straight­for­ward ques­tions about phys­i­cal exer­cise and the brain.

Now, to begin I will like to make this col­umn, to what­ev­er extent pos­si­ble, an inter­ac­tive forum. And that is as it turns out that the brain real­ly likes it when it’s asked to be “active”. Pas­sive audi­ences, which are spoon fed infor­ma­tion, score less well when test­ed on reten­tion and under­stand­ing of the pre­sent­ed mate­r­i­al than audi­ences that were kept engaged through the process. So, in the spir­it of “engagement” I will start by ask­ing a few ques­tions about what is impor­tant when it comes to the effects of phys­i­cal exer­cise on the brain. Depend­ing on what your answers will be we will then take it to the next lev­el, i.e. crit­i­cal­ly exam­ine the research evi­dence about spe­cif­ic brain effects of dif­fer­ent types of phys­i­cal exercise.

So, con­sid­er which of the fol­low­ing pos­si­bil­i­ties will get you con­vinced that phys­i­cal exer­cise is good for the brain. Would you be con­vinced if exer­cise has been shown to:

1. Increase longevi­ty (as a bet­ter brain should make us live longer, shouldn’t it?)
2. Decrease the risk of Alzheimer and oth­er types of dementia
3. Decrease the risk of “normal” age relat­ed mem­o­ry loss or cog­ni­tive decline
4. Increase one’s abil­i­ty to prob­lem solve
5. Decrease one’s risk for depres­sion or anxiety.
6. Improve one’s mem­o­ry, con­cen­tra­tion and attention.
7. Improve one’s abil­i­ty to feel con­sis­tent­ly happy.
8. Increase the num­ber of nerve cells or nerve cells con­nec­tions in the brain?
9. Cor­re­late with high­er education
10. Cor­re­late with high­er social eco­nom­ic status?
11. Chem­i­cals released dur­ing exer­cise were shown to pro­mote nerve cell growth?
12. Exer­cise would “correct” chem­i­cal abnor­mal­i­ties report­ed in men­tal or brain illness?

I am look­ing for­ward to your answers. Please do not hes­i­tate to come up with oth­er ques­tions or hypothe­ses. We’ll make this into an exer­cise about how to think about phys­i­cal exer­cise. Anoth­er form of exer­cise that might be good for the brain.

– Adri­an Pre­da, M.D. is an Assis­tant Pro­fes­sor of Psy­chi­a­try and Human Behav­ior in the UC Irvine School of Med­i­cine’s Depart­ment of Psy­chi­a­try and Human Behav­ior. His exper­tise in human behav­ior, psy­chol­o­gy and spir­i­tu­al­i­ty is based on years of expe­ri­ence work­ing as a psy­chi­a­trist, psy­chother­a­pist, teacher and researcher in a vari­ety of aca­d­e­m­ic clin­i­cal and non-clin­i­cal set­tings. He also teach­es the UC Irvine Exten­sion class The Mind that Changes the Brain: Well­ness in the Sec­ond Millennium.