Science As We Know It

Dear reader, I am going to ask you for a moment of reflection: Have you ever had one situation where you were so stressed that you just wanted to scream or start crying, and suddenly someone or something makes you laugh?

While I hope this is not the case right now and you are not putting all your hopes on me to make you giggle, I want you to think about how you felt after that laugh. Probably better, like a sudden medicine to your pain had been administered.

Well, that is because laughing is a very good medicine and yesterday, 5^th May, was the International Day of Laugh, made to remember that sometimes the only thing we need to calm down our minds is not a 30-minute speech, nor a chocolate or buckets of ice cream, much less a pill, but surprisingly, just a good genuine laugh.

But why does this happen?

Although the reason for this relief can come in multiple ways, including at the psychological level, let’s go deep into what happens in our bodies and brain (despite the importance of psychology, I am still a biologist, so I will avoid a tough adventure in the lands of Sigmund Freud).

To answer this biological question, several studies have been done, mainly by showing the study participants videos with humor content followed by blood sampling or PET*. Yes, you can contribute to science while watching YouTube videos of mischievous cats and dramatic huskies.

These studies showed that at a biological level, laughter decreases the levels of DOPAC, which is a molecule present in the blood and that results from the destruction of dopamine (a very important molecule for our brains to feel pleasure and motivation). Therefore, the low levels of DOPAC indicate that dopamine is not being destroyed as before laughing, and we can store it in our brains, making us feel good.  

Additionally, cortisol was also reduced. This is a hormone released during physiological stress (including some diseases) and psychological burden, and has multiple effects on our bodies, including the way we process sugars and accumulate fat (unfortunately, I couldn’t find evidence that laughter makes us slimmer).

Lastly, laughter triggers a higher release of endogenous opioids (yes, our bodies can produce opioids, including the now famous endorphins released after practicing sports). These molecules are mainly produced in our brains, but have functions in our entire body, including slowing our respiratory rate and digestive system, explaining why we feel our bodies calming down after laughing.

Figure 1-Chemical mechanisms happening before and after laugh in the brain.

Though these biological changes can explain why laughing is sometimes indeed the best remedy, a lot of research is still needed to completely unveil the biological effects of laughing, which can be depended on the type of laugh (spontaneous laughter, conversational laughter, inducible laugh- the one you get after some beers and everything is funny etc…).

While more efforts are being made to understand whether laughter can be used as therapy not only for mental disorders but physiological diseases, one thing we know for sure: laughter is an excellent communication tool to integrate us within society and makes us more relaxed and happier.

So, my dear reader, whether you are a fellow scientist whose experiment has just failed, a parent of a stubborn child, a tutor of a pet that does not follow your rules, a broken-hearted soul, or if life is just not being easy, go ahead and surround yourself with people who will make you laugh. 

Happy International Laugh Day!

PET: Medical imaging technology that allows to detect and locate certain molecules, such as dopamine or others, in organs.

References:

1. Lee S. Berk et al. The American Journal of the Medical Sciences,1989
2. Sandra Manninen et al., The Journal of Neurosciences, 2017
3. Caroline Kaercher Kramer et al., Plos One, 2023

Cover art by Inês Caiado, inspired by an image generated using Microsoft Bing Image Creator, powered by DALL-E