Scientific Nutrition Update 37: The Nocebo Effect

Yesterday we got to discuss one of my favorite effects in health the placebo effect. It is a fascinating window into the effect that our psychology and our mindset has on our health.  Today we are looking at the opposite effect, which is called the nocebo effect.  The nocebo effect is when you actually get worse or develop side effects from a substance that should be inert and it is a really cool effect.


Script (Remember I ad-lib and occasionally change things while I’m recording, script is not accurate):

For today’s episode I am going to talk about the nocebo effect.  Now most people know what the placebo effect is, they realize that it is when you receive a beneficial effect from a treatment because you believe it will be beneficial, even if the treatment itself is otherwise worthless.  The nocebo effect is like that, but instead of getting positive effects you are instead getting negative side effects from compounds which again should be doing nothing. I highly recommend you listen to yesterday’s episode 36 about the placebo effect before you listen to this, but hey you make your own decisions.  


Placebos and nocebos are fascinating because if we were totally rational they should neither have an effect, but both can have very large effects.  The reason this is so important is because we need to realize what role our own psychology plays in so much of our health. This part is often ignored, discarded, and overlooked, and when I say our psychology I do not just mean mental illness, although that is not excluded, I mean our internal frameworks, ideas, beliefs, scripts, and desires.  All of these affect our health and need to considered as part of a complete health framework.


One of the most dangerous side effects of opioids is the respiratory depression they induce, and amazingly enough placebos/nocebos can actually induce this very same effect.  When given with the expectation that is an opioid patients suffer from similar respiratory depression and we see significant activation of the endogenous opioid system. The nocebo effect is big guys.


Similar effects have been in pain, where when given a nocebo where the patients were told that there was a chance it could make their pain worse, their pain worsened.  Purely because they expected it to.


It is also an important thing to understand this effect when we are looking at side effects.  Many medications have incredibly long lists of side effects, and often times these side effects do not appear to occur more frequently in the treatment group than the placebo group, but they still get listed.  So remember when you are reading or listening to that crazy long list, there is a chance many of those do not represent a real risk. Always consult with your physician. Although funny enough discussing side effects with your doctor may actually make things worse because now you’ll be expecting those effects.  Either way you should still do it.


There is another reason I wanted to make this very clear.  These effects are quite large. I also occasionally review supplements, compounds, and things based on their effect on me.  I always try to make it clear that it is just my experience, but it is important to realize that there is a significant chance that there is a placebo effect that is playing into those effects.


Never forget how important your psychology is when you are analyzing something in health, fitness or nutrition.  It is the dimension most often forgotten.

Bibliography (I may not directly address these studies in the episode but I looked at them and thought they might be valuable):

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