Do epidemiological data on exercise and substance abuse support prescriptions for prevention?

June 7, 2011

A Twitt from the Foundation for Alcohol Research (@AlcoholResearch) today struck my attention. It sounded to me like the usual slippery slope of creating human health prescriptions from limited scientific findings.

Teen athletes may drink more, but smoke less & use fewer drugs. How do you lessen your teen’s risk? http://bit.ly/mysWna

ResearchBlogging.orgThe link is to their newsletter which overviews a paper by Terry-McElrath and O’Malley, currently in pre-print at Addiction. The overview is pretty straightforward, based closely on the paper and eschews the problem with the Twitt, which was the question as to whether you could “lessen your teen’s risk”. So I am mostly mollified.
The paper in question reports data from a survey of over 11,000 US high school seniors (classes of 1986-2001), captured as seniors and then followed longitudinally until age 26. These data were collected as part of the Monitoring the Future study which we discuss quite frequently on this blog.
The key focus of this paper is on the amount of physical activity the surveyed HS seniors reported at first contact. The Participation in Sports, Athletics or Exercising (PSAE) measure was derived:

…by asking, “How often do you actively participate in sports, athletics or exercising” (1=never, 2=a few times a year, 3=once or twice a month, 4=at least once a week, 5=almost every day).


The other questions of interest to this analysis were the ones relating to past-30-day use of various recreational drugs. This is a part of the MtF dataset that we have discussed now and again. I like it better than the past-12-month and Lifetime measures because it gets us away from the population who has just sampled a drug once or twice and biases it more for those who use the substance occasionally-to-often, for lack of a better concept.
The drug analysis used frequency of use for marijuana/cannabis, alcohol and tobacco smoking. Other illicit drugs other than marijuana were combined into a single dichotomous variable because they occur at a much lower frequency.
There is a lot of correlational statistical foofraw involved in something like this, I’ll omit the details for this purpose. At the end of the selected study window (with the sample aged 26 with 4 followup surveys attempted), the authors ended up with a sample of 40,424 individuals.
The key results were that
-alcohol use at 18 was positively associated with PSAE (see below for a clue as to why)
-rate of change in alcohol and PSAE from 18-22 did not co-vary, there was a positive relationship from 22-26 years of age.
-increasing PSAE values from 18 to 25 were associated with decreased cigarette use.
-increasing PSAE values from 18-22 were associated with decreased marijuana and illicit drugs other than marijuana but there was no relationship from 22 to 26.
Another paper from this group took a related focus and provides some additional valuable context. Terry-McElrath, O’Malley and Johnston examined PSAE and drug use just within the middle- to high-school population (8th, 10th, 12th grades). It doesn’t get at the question of lasting impact but it is perhaps more relevant to the question of acute intervention during the teen years and what can/cannot be accomplished. These analyses took into account participation in school-centered athletics separately from a more global estimation of exercise/physical activity and found that the frequency of exercise was related to decreased past-30-day and binge alcohol use in high school. In contrast, increasing athletic team participation was associated with increased alcohol use. A similar relationship held for smokeless tobacco use. The exercise and athletic team participation frequency measures were both negatively associated with tobacco and marijuana smoking.
This latter paper really brings to a fine point the prescriptive query in the motivating Twitt. If you push your teen onto a sports team, these data suggest that s/he will be more likely to drink alcohol and use smokeless tobacco products. If you push your kid into less team oriented endeavors, the more they work out, the less likely they are to use cigarettes, marijuana or alcohol.
That’s the best read. But of course we know, in the back of our minds, that these are just correlations in both of these papers. There are a whole host of factors which influence sports / team / exercise participation in high school and then additional ones as one grows into young adult hood. There are other factors which may influence how seriously a given teen takes their participation in team sports, which team sport they select and how much exercise it requires, etc. For all we know, there is nothing there in the nature of a direct neurobiological connection between increased activity and decreased drug use/liking whatsoever.
Perhaps the factors which cause your kid to work out also cause her to disdain drugs? [personal anecdote: two major factors kept me from ever trying marijuana in adolescence- one of which was my assumption that the smoking part would be detrimental to my performance in the aerobic sporting endeavors that was in to at the time.]
This brings me to two additional papers which have the benefit of removing the social and other extraneous factors. In a paper that was reviewed by Scicurious at Neurotic Physiology awhile ago, Cosgrove and colleagues gave rats access to a running wheel until they were “stable” (not specified). They next permitted the rats to self-administer cocaine. The key manipulation was when they presented the rats with the simultaneous opportunity to respond for drug or run on the wheel. The amount of cocaine taken dropped significantly (in females, similar but nonsignificant outcome in males). Almost there. Smith and colleagues nailed it down even better. They allowed female rats access to a running wheel for 6 weeks and then trained them to self-administer cocaine. This was a between-groups study (unlike Cosgrove et al) and they showed that the exercised rats took less cocaine (two different per-infusion doses under a Progressive Ratio schedule) than did the sedentary rats.
These, in combination with the epidemiological data, are the start of something. Together they start to get us closer to something like an ability to make a prescriptive decision that if we make our teens exercise more we may have an impact on their propensity to use recreational drugs.
__
Terry-McElrath YM, & O’Malley PM (2011). Substance Use and Exercise Participation Among Young Adults: Parallel Trajectories in a National Cohort-Sequential Study. Addiction (Abingdon, England) PMID: 21561496
also see
Terry-McElrath YM, O’Malley PM, & Johnston LD (2011). Exercise and substance use among American youth, 1991-2009. American journal of preventive medicine, 40 (5), 530-40 PMID: 21496752

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21 Responses to “Do epidemiological data on exercise and substance abuse support prescriptions for prevention?”


  1. This makes some sense, I think my participation in sports helped to limit my exposure to drugs. A big part of that was that athletes at our high school were drug tested and it would suck to get booted off a team if you pissed positive for weed.
    On the other hand, at least in the martial arts community, I’m seeing a lot of guys late 20-early 40s that are working out in gyms and do martial arts stoned. Some of the different disciplines you really can’t get away with being high, but others such as jiu jitsu it seems to have a calming effect as you try to defend a guy from choking you.

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  2. Carol Says:

    Genomic: “A big part of that was that athletes at our high school were drug tested and it would suck to get booted off a team if you pissed positive for weed.”
    Bingo! Unfortunately, that’s the real reason why many athletes are driven to drink, which is sad because alcohol is far more harmful than marijuana. Marijuana does not appear to be an impediment to great athletic ability for Michael Phelps, Tim Lincecum, Mark Stepnoski, Ricky Williams, Randy Moss, Michael Irvin, Kareem Abdul-Jabbar, all people who use marijuana and had or continue to have very successful athletic careers.

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  3. Neuro-conservative Says:

    @Carol #2 — If we are going to play the anecdata game, then it is only fair to include Todd Marinovich, JaMarcus Russell, Jennifer Capriati, and countless others whose names we don’t know, because they never achieved their full potential.

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  4. Joseph Says:

    Isn’t the solution here an encouragement trial where we randomize children to exercise encouragement or dietary encouragement (make it three arm, so it is team sports, solo exercise and nutritional counseling). Make the main point of the trail cardiovascular (this cannot hurt) but put in a sub-study to test for use of substances (like marijuana, tobacco and alcohol). I also think we could check for factors like social support (which may have perverse effects).
    That would not only help test the hypothesis, it would frame whether or not there is a potentially helpful intervention here.

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  5. harold Says:

    I suspect that multiple factors may be at play here.
    One factor may be that working out does decrease desire for some exogenous substances. That fits with the rat data and with my own experience. At risk of oversimplifying, this could be related to “endorphin high” type brain activity.
    Cultural factors could also partly explain the data; I suspect slightly different data might be obtained in a younger cohort. Back in the eighties there was still sort of a sharp demarcation between jock culture and the pan-drug use subcultures, and marijuana was far more associated with the latter. Today, marijuana is widely accepted as mainstream by most younger people. It’s possible that a survey of a younger cohort would show less impact of sports/exercise on marijuana; possibly there would be no impact or even the opposite impact. On the other hand, if exercise provides some similar positive psychological experiences, there might still be a negative correlation with marijuana use for that reason. It probably depends on whether thinking of marijuana as bad for performance/associated with less athletic subcultures, or whether simply not craving marijuana as much because exercise had a biological effect, is the main reason why the exercising students used less. If the former, that effect may be gone from current cohorts, if the latter, it may still hold.
    At the same time, there has been an increase in awareness of the harmful nature of things like cocaine and methamphetamine. Serious use of those drugs in high school might be associated with very high risk behavior and lack of adequate adult supervision. Although there are always talented athletes who will abuse themselves and succeed on the field anyway, at least during youth, I would suspect that simply having it together enough to work out or make it to practices would correlate negatively with the use of such drugs, whether or not there is also a biological effect.
    I would assume that the alcohol pattern is purely social. Teenagers can’t just buy their own drinks legally, so they tend to get alcohol at social gatherings, which are associated with binges. Being involved in a sport may increase opportunities to attend such gatherings.
    Finally, I would like to note a key point which is not discussed here. There are two overlapping but distinct exercising populations, and this is clearly true even at the high school level. There are people who are talented at major sports. These people are reinforced for participating in sports. Their primary concern is performance. Major sport athletes are not associated with especially health-conscious lifestyles. The desire to maximize performance will lead to some limitations, but pressure to “party” is also high. Other people work out for some combination of health and appearance. This latter group is strongly associated with dietary concerns, non-smoking, and the like, to a much greater degree than size-speed-and-talent selected spectator sport athletes. Lumping these groups together will cause confusion.

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  6. becca Says:

    As a parent, what I’d like to know is both the ‘school sports’ vs. ‘other sports’ and ‘team sports’ vs. ‘individual sports’ correlations. Although it’s kind of tough to classify an individual sport with a real social-support network team involved (e.g. collegiate gymnastics).
    Has anyone done the in-group comparison- socially housed animals vs. not-socially housed animals on self-administration of cocaine?

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  7. DrugMonkey Says:

    becca-
    Yes, there is a small lit on that. Looks mixed but evidence for more drug taking to no diff in social housed. Didn’t see anything w/ increased drug taking on a quick read on pubmed. That’s rats. Then the Nader group has some social dominance stuff with cocaine self-admin in monkeys that is probably pertinent to your question.

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  8. Carol Says:

    @ Neuro-conservative — Yes, lets talk about how many people who never realized their full potential because they are dead due to alcohol-related disease and violence (and not including DWI accidents) compared to marijuana. According to the CDC, hundreds of people die each year from binge drinking, and the number of people who die due to overuse of marijuana: Big Fat ZERO.
    Alcohol use is a major contributor to most family violence and other violence outside the home. However, politicians are paid to greatly favor the alcohol industry over the marijuana industry and receive millions of dollars each year for doing so.
    Alcohol industry donations to state and federal political candidates during years 2000 – 2010:
    Democratic candidates: $89,369,196
    Republican candidates: $104,751,212
    Source(s):
    FollowtheMoney:
    http://www.followthemoney.org/database/IndustryTotals.phtml?f=0&s=0&i%5B%5D=57
    Open Secrets:
    http://www.opensecrets.org/industries/totals.php?cycle=2010&ind=N02

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  9. Carol Says:

    Neuro-conservative: I will also add that those three people you noted are poor examples of anecdata: Todd Marinovich, JaMarcus Russell, and Jennifer Capriati had issues with hard drugs (cocaine, meth, overdosing on prescription drugs, etc.), not marijuana.

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  10. Isabel Says:

    “A big part of that was that athletes at our high school were drug tested and it would suck to get booted off a team if you pissed positive for weed.”
    Yes it really sucks that that happens to people. It is super creepy in fact. Mean, and rather pointless (which is part of what makes it so mean). Test for performance enhancing drugs if you have to, but pot? What the fuck business is it of theirs? Weren’t you enraged??
    What’s worse is when kids lose their chance to get student loans. I even had to take a drug test to pour wine in a fucking winery!
    “Alcohol industry donations to state and federal political candidates during years 2000 – 2010:
    Democratic candidates: $89,369,196
    Republican candidates: $104,751,212”
    Thanks for the stats, but *why* does one drug need to be favored? We can’t have both? I like both, as do lots of people I know. Is there evidence the money was meant to pressure politicians to keep cannabis illegal? It seems stupid.
    Why are sports always revered as if they are a total positive anyway?
    Here are some worrisome data about just one sport.
    “A 2000 University of North Carolina study found that in the period between 1977 and 1998, each year on average 13 athletes had suffered catastrophic injuries (primarily permanent paralysis) through direct result of participation in football; it also found that between 1977 and 1998 “200 football players received a permanent cervical cord injury, and 66 sustained a permanent cerebral injury…An estimated 40,000 concussions are suffered every year among high school players.”
    http://en.wikipedia.org/wiki/Health_issues_in_American_football

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  11. Isabel Says:

    Sorry about the swearing. I know some people dislike it, and I’ve been trying to quit. But this issue makes me so mad! And our acceptance of it drives me up the wall, as if it is somehow normal to inspect other peoples’ urine for evidence of cannabis use. There is absolutely no reason to do this, yet we turn over our urine, or allow our kids to do so, sheep-like.
    This could be a variable in the current discussion, as young people 18-26 are starting to get real jobs which may require drug testing.
    One advantage to you DM to legalization would be improvement in your ability to compare the two most popular drugs used in our society. For example, people could freely choose which they preferred. Who knows, maybe alcohol use *would* go down, which would be a positive for society, no doubt.

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  12. Carol Says:

    @Isabel: “Thanks for the stats, but *why* does one drug need to be favored? We can’t have both? I like both, as do lots of people I know.”
    You can enjoy both. However, when people use marijuana, they tend to moderate their drinking. However, when you drink more, you tend to be more impulsive and spend more. Ask the casinos in Las Vegas. Whereas, marijuana tends to inhibit people and they are less likely to take risks. If you’re in the hospitality industry, it makes perfect business sense to be against marijuana legalization, which is another reason why the marijuana legalization initiatives failed repeatedly in Nevada.
    “Is there evidence the money was meant to pressure politicians to keep cannabis illegal? It seems stupid.”
    Just Google search:
    California “prop 19” “alcohol industry”

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  13. Neuro-conservative Says:

    Carol — I don’t want to get into the tired alcohol vs marijuana debate, but suffice it to say that my comment in no way suggested that alcohol was preferable or not harmful.
    Your point @#9 is false, in two ways. First, both TM and JC were primarily known for their problems with marijuana. More importantly, it is a logical fallacy to exclude these individuals from consideration because they also used other drugs — many people who get into trouble with marijuana also get into trouble with other drugs. Since your “methodology” already excludes from consideration any people who failed to get famous due to their drug use, you are creating a circular argument — mj is OK because there are 6 athletes who appear to be unimpaired.

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  14. Carol Says:

    @Neuro-Conservative — Marijuana is far safer than alcohol. Alcohol is far more addictive and impairing, far more toxic to the human body, and of course fosters a huge amount of violence, whereas marijuana does not. A person as high as they could possibly be is far less a threat to themselves or to others than someone who just had a glass of martini. Therefore, using alcohol significantly decreases your chances of staying alive long enough to see any success. If we don’t want to send the dangerous message to people that alcohol is more acceptable than marijuana, then perhaps the law should treat both equally. Furthermore, if people get caught up with meth, heroin and cocaine while using marijuana, it is most likely because we allow meth, heroin and cocaine dealers to use marijuana as their calling card. Ultimately, the biggest problem associated with marijuana use for hundreds of thousands of people each year is marijuana prohibition itself.

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  15. Isabel Says:

    “Just Google search:
    California “prop 19” “alcohol industry” ”
    That’s just fucked up.

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  16. Pete Says:

    This makes a lot of sense. Anecdotally, I can think of several people for whom an exercise regimen helped them curb a drug or alcohol problem.

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  17. DrugMonkey Says:

    The evidence there seems mixed, Pete. Mostly smoking cessation trials and not very many of them in the lit but there are some positives and some failures to show benefit. Unclear if this has to do with the amount/type of exercise, whether some populations benefit and others do not, etc.
    I forgot to mention in the OP that NIDA put out an RFA a couple of years ago so I am hoping to see some new data soon. Both human studies and animal studies were funded so it should span quite a good range of topics.
    I notice that this RFA funded Smith to do more work and he has a new paper showing that 6 weeks of exercise training protects against cocaine self-administration escalation that is observed with extended daily sessions (23 hr or 6 hr sessions as opposed to the standard 2hr that he uses).
    Don’t you love it when the system works? Homeboy had one of the first papers on the topic, then the relevant NIH IC put out an RFA, dude gets his grant and then pumps out another paper on the issue right away. SLAC prof too, far as I can tell.

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  18. Jacob Says:

    Hello, Ashtanga yoga, mysore style self practice, for 90-100 mins 5 or 6 mornings a week.
    Keeps me off the alcohol nicely. I’ve quit other things (coffee etc) too but alcohol is the one I could not have done without the Ashtanga Yoga.
    What I have to do to keep doing the yoga? That is another story…
    I can give lots of information, I teach it myself and have helped a couple of addicts which was very rewarding and I hope to do it again when I can afford to work for nothing again.

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  19. Jacob Says:

    @Harold
    Endorphin high? That’s not the line any more, it’s an endocannabinoid high.
    That’s why cannabis users don’t need to move so vigorously, they bypass the need to generate one’s own cannabinoids. It’s late, I’ll find the DOI if I can.
    Could autism involve the endocannabinoid system somehow? The constant need to ‘stim’ goes away thanks to cannabis. Could there be an easy win for autism science here? Do you know, are there any good studies on CBR1 and CBR2 receptors in autistic persons, or maybe lower levels of anandamide or other endogenous cannabinoids?
    The most puzzling thing about cannabis therapy for autism is that it just works!.
    The patient reports that it works, the patient’s parents report that it works, the friends, partners, doctors, clients and employers all get on better with that person. It’s uncanny.
    I know of only 3 studies. Kurz, Hedrick and the Montana study. Only Kurtz has been published. Hedrick’s UCI study with 11 families is being written up right now, I don’t know if they are proposing a mechanism of action.
    Do you know anything please?

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  20. Jacob Says:

    Why does ORAC delete and ban anything to do with cannabis being anti-tumour? It’ll be common knowledge soon enough anyway.
    His commentariat even claim that they can’t find it:
    http://www.google.co.uk/search?aq=f&sourceid=chrome&ie=UTF-8&q=national+cancer+institute+cannabis
    lol

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  21. Jesse Says:

    One thing that seems a huge confounding factor: many people in major spots use steroids. That it seems to me would have an effect on the drug use — largely because of the other physical effects steroids have.
    @Neuro Conservative– I don’t think you can make much of a case these days as to the dangers of marijuana as opposed to alcohol or tobacco (the latter of which is undeniably one of the more addictive substances on the market today). Nor does the “gateway drug” argument hold much water, because a rather large number — a majority, IIRC — of people with drug problems started with alcohol. Whatever predisposes people to addiction seems to me to be substance-independent, though obviously some drugs, such as cocaine or heroin, are more addictive than something like marijuana or LSD, and the method of ingestion makes a difference as well, which is why crack or injectable cocaine is such a problem. (Doctors especially tend to have drug problems with the latter). But the relative dangers are kind of a whole separate issue.
    Getting back to athletics, I can think of a number of reasons why athletics might predispose to certain drugs and not others. Much of that is cultural. Athletes tend to be drinkers and use alcohol in their social gatherings. The physical part might just be a time issue, as the sheer number of hours you spend at practice or whatever eats into the job of finding good drugs. (It does take a good couple of hours to score the good stuff — unless your connection is prompt, and “on time” is not a trait dealers are known for).
    Also, it would be interesting to check the use of illegal drugs among professional athletes. Is it higher than the rate of the general population? Lower? They obviously use more steroids. And I am old enough to remember when baseball players were taking amphetamines like candy. (Remember “greenies?”) That would be interesting if someone could get hard numbers.

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