Changing my senses to take the bitterness in stride

I've been upping my consumption of tea and coffee lately - mostly due to the weather changes (it's starting to look like fall here in Orange County!), but also due to looming deadlines that keep on piling up.

Photo courtesy of Onpuichunsen

I used to have to drink my coffee with loads of cream and sugar, and I'd normally take my tea with a generous helping of honey (trust me, green tea and honey > airborne in warding off a cold). Now, I can get away with coffee with some sugar, and even some black tea without honey (though honey's always welcome).

Your body has a great way of adapting to bitter tastes if necessary. Take bittermelon, or even chinese brocolli (Gai Lan) - I used to hate eating these as a kid, but my mom would make me eat a bowl of these veggies in soup form before leaving the dining table. Now, when I see these items at the farmer's market, I try to have these vegetables circulate my kitchen a couple times a month. I mean, who could resist stuffed bittermelon soup?! Most people have had gai lan while out eating dimsum - it's normally generously lathered/masked in this sumptuous oyster sauce and tastes so sweet. Gai lan in its natural form is actually the complete opposite - in the same family as brocolli, this leafy green is packed with a bitter punch. I actually prefer to steam my gai lan, or use it in a very simple shrimp soup broth over rice.

Gai lan as most people enjoy it (photo courtesy of Stu)

While it's been long established that we adapt to eating certain things for the sake of reaping the nutrients of the food, the actual "sciency" rationale behind how our brain allows us to overcome this is something more of a black box of mystery.

Recently, researchers published a cool study in Science that looked at how animals may be adapting to bitter tastes over time using.... FLIES! Okay, don't stop reading from here. Flies are pretty awesome. If you look at early developmental work, there's a ton of crazy stuff that has been discovered using flies as the animal model (such as the discovery of hox genes - these genes are important for determining how to organize body segmentation).

Despite the prevalence of a majority of neuroscience work in mice and rats, flies haven't dropped off just yet (haha, get it?). With regards to sensing food, flies are great to use for taste research since they have multiple receptors on their body that can sense different flavors - they have a ton of tiny hairlike fibers called gustatory sensilla that have different food receptors. In this study, researchers looked at the flys' ability to adapt to consuming camphor, a bitter compound that tastes like a cross between a menthol cough drop and spoonful of cinnamon (yum). What they found was that over time, flies adapted to eating camphor, but it was a result of having less of a receptor that detected that bitter compound, in this case TRPL. So did the receptor disappear forever, go on a temporary hiatus, or what? As it turns out, the amount of receptor present was being controlled - depending on consumption of the bitter compound, there would either be more or less of the receptor present. So depending on your diet, the particular receptors can be ever changing helping you blunt or heighten your responses to detecting a particular taste. This study was only done with camphor, and they found that other bitter compounds had no effect on the receptor levels, suggesting that the actual regulation of flavor detection varies considerably on what receptor you have in the sensing environment.*

This study is fairly new, and not much has been done on the human forefront, but it would be interesting to see if regulation of your tasting environment is as dynamic as the fly's. Whether it's a mind over matter type situation for humans, or if there's actually chemical regulation to control how much bitter, sweet, or salty we can handle, it's still something to keep in mind. MOH can serve as a great example to this - when we first met, he declared a few things that he'd never stand for:

1. Swimming (he'd taken tons of lessons and could never float)
2. Doing high intensity cardiovascular activity
and
3. Eating bittermelon / durian in any form, whether it's soup-ified or in ice cream form

It's been a long journey with him and there's considerable progress on his end - he will eat bittermelon if it's sauteed with some onions and eggs, and enjoys spinning to loud EDM music. I can't say much about the exercise, but I think the gradual acceptance of bittermelon has something potentially to do with a rewiring or remodeling of the chemical environment in his mouth. No status on the durian - he still thinks it smells too much like feet to enjoy.

So much hate for durians - even they need love!

Until next time, happy eating all!


***The actual molecular mechanism behind regulation of the TRPL channel is through a Ube3a mediated ubiquitination and degradation of TRPL.

References:

Zhang YZ et al., 2013. Food experience - induced taste desensitization modulated by the Drosophila TRPL channel. Nature Neuroscience. 1468-1476