We’re going to need a new explanation of why heroin works then


We’re always being told this, but again, there is no scientific evidence for it, Dr Mosely told Ruth Langsford.

‘The endorphin molecules are simply too big to cross the blood-brain barrier.

‘I personally find exercise doesn’t boost my mood at all.’

Maybe that’s true, although I very much doubt it. But if it is then we’re going to need a new explanation of why opiates feel good, aren’t we? Given that they mimic the behaviour of endorphins and all…..

16 thoughts on “We’re going to need a new explanation of why heroin works then”

  1. Exercise certainly makes me feel better. I have a longstanding back injury which responds well to the pain from stretching and lifting weights in certain ways, too. That is, increasing the pain temporarily seems to reduce it in the long term. Probably some sort of habituation effect.

    All pain is essentially in the head anyway. I’ve seen people go through horrendous injuries with a smile – it largely seems to depend on morale.

  2. I definitely get feelings of euphoria after a run, and so do my dogs.

    After sex as well, but there my dogs are not involved. Honest.

  3. I got feelings of euphoria from my first decent run and my first serious attempts at weight-lifting this year after a pretty inactive winter – it was bloody marvellous, I felt light on my feet and was bouncing up the stairs.

    On the second and to date all subsequent attempts, absolutely nothing except the anticipated muscle aches.

  4. Its tabloid tripe–yes its good for you/no-it isn’t–it being anything at all from vitamins to unsaturated dogshite.

    As so often in life people will have to decide for themselves on the merits or otherwise.

  5. I went to cardiology exercise classes a few years ago. I felt exhilarated. “Quite normal” the trainers told me.

    That’s apart from the day I overdid it and nearly collapsed of course.

  6. One of the generators of endorphins is the pituitary gland, which sits inside the brain.
    If these endorphins can’t cross the blood/brain barrier, how are they released into the blood stream?

    Does Dr Mosely have a new book to plug?

  7. @Jonathan ‘@ Interested, If you get pain while lifting you’re doing it wrong.’

    Yep, I’m familiar with the general principle and certainly wouldn’t ever dead lift or lift from the waist – that’s not the sort of pain I’m talking about. I mean pain caused by agitating the supporting muscles via stretching and some discrete lifting. Trust me, it works (for me).

  8. Exercise doesn’t realise ‘feel-good’ endorphins…there is no scientific evidence for it

    That’s false, the evidence is overwhelming.

    The endorphin molecules are simply too big to cross the blood-brain barrier.

    That’s true.

    But it’s absurd to suppose that we would have evolved opioid receptors in our brains if there were no mechanism for them to be triggered.

    The evidence is that endorphins are released into the bloodstream by the pituitary gland and into the cerebrospinal fluid by the hypothalmus.

    Morphine doesn’t easily get into the brain. But diamorphine is fat-soluble, so it does. Which is why you get a rush from heroine but not morphine.

  9. @Interested ” Trust me, it works (for me).”
    That’s good. I see too many guys in the gym who have no idea how to lift properly. Proper stretching is good too.

  10. Timmy, trust me on this. Heroin is great when you first try it. The second time round it’s really deeply boring.

    A bit like exercise, it seems, judging from comments above. (Each to his/her area of personal expertise.)

  11. PaulB’s suggestion makes sense. I’ve run in all weathers (sub zero to heatwaves, snow to monsoons) for decades. Doubt I’d have kept it up without strong positive feedback. I seem to recall a bloke in the Boston Marathon breaking one of his leg bones in fast start and going on to complete the course. Decent time, too.

  12. Bloke in Costa Rica

    PaulB: that’s what immediately struck me. The very name gives it away: endorphins. If they’re produced in cerebro-spinal fluid in the CNS and by the pituitary then the blood-brain barrier is a red herring. Of course I Am Not A Doctor.

  13. bloke (not) in spain

    Can’t help wondering how much of sport related ‘exercise highs’ is self delusion.
    There’s plenty of physical activities with work rates as high if not higher than marathon running, don’t produce pleasurable sensations.
    I suggest you try unloading a couple of truck’s worth of cement bags in a search for exhilaration.

  14. @ b(n)is
    Digging ditches doesn’t make many people feel better but lots of people feel better after a gentle (or not-so-gentle) run, especially on a summer’s evening. And it’s not self-delusion if you aren’t expecting it to happen.

  15. Paul B is right. The endorphins and enkephalins that act in the brain to cause euphoria are synthesised within the brain. Opiates are fat-soluble so can get into the brain and mimic the endorphins made there. Any endorphins measured in the blood have been made in other tissues and can’t get into the brain as they are peptides (not fat-soluble).

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