1/13
Why does cilantro taste and smell so delicious to some people but like soap (or worse) to others?

Personally, I love cilantro. 🌿

Some folks can't even be around it. 🧼

Why?

#tweetorial #medtwitter
2/
The disagreement about cilantro - whether it is delicious or disgusting - is nothing new.

Pliny, the 1st century Roman naturalist, referred to it as having "cooling and refreshing properties". 

bit.ly/3ebhtRC
3/
Conversely, John Gerard, a 16th century herbalist, called cilantro (aka coriander leaf) a "stinking herb with venomous quality".

His French contemporary, Olivier de Serres, said it "smells like stinkbugs". 

Are we even talking about the same plant?

online.ucpress.edu/gastronomica/a…
4/
The prevalence of distaste for cilantro varies by ethnocultural group.

💡This study found that 10-15% of people dislike its smell and taste.

💡Cultures whose diets feature cilantro more prominently are more likely to enjoy it.

rdcu.be/b9zRO
5/
So why do some of us love cilantro and others taste soap when eating it?

🔑 One clue may be a specific aldehyde that is found in the leaves of the herb: trans-2-decenal (shown in red below).

ai.stanford.edu/~chuongdo/pape…
6/
Aldehydes contribute to cilantro's unique taste.

In a genome-wide association study, those who taste and smell soap w/ cilantro had a specific polymorphism of the OR6A2 olfactory receptor.

💥OR6A2 is an aldehyde receptor that binds trans-2-decenal.

flavourjournal.biomedcentral.com/articles/10.11…
7/
This strongly suggests that variations in OR6A2, and the ability to bind trans-2-decenal, are the source of why some people hate cilantro.

The genetic testing company @23andme even offers OR6A2 variant testing for this purpose.

blog.23andme.com/health-traits/…
8/
Recall from tweet #3 that Olivier de Serres said cilantro "smells like stinkbugs".

He actually wasn't wrong. Stinkbugs, aka the insect Halyomorpha halys, release aldehydes to repel predators by scent.

Which aldehyde do they release? Trans-2-decenal.

pubmed.ncbi.nlm.nih.gov/27656692/
9/
There is hope, though, for those who don't like cilantro.

One way to mitigate its flavor is to dice or grind it up.

💡Dicing activates an aldehyde reductase enzyme in the leaf, which breaks down aldehydes like trans-2-decenal.

pubs.acs.org/doi/10.1021/jf…
10/
Let's conclude with one final question:

Why do those who hate cilantro often specifically smell and taste soap when encountering it?
11/
Saponification (ie soap production) = lipid hydrolysis via heat and sodium hydroxide, which produces fatty acid salts that comprise soap.

Aldehydes, including trans-2-decenal, are byproducts of this reaction and contribute to a given soap's aroma.

ncbi.nlm.nih.gov/pmc/articles/P…
12/
What does this imply?

🧼 When someone says that cilantro tastes like soap, they actually are indeed tasting soap.
13/
🌿Love-hate responses to cilantro arise from different sensitivity to trans-2-decenal
🌿This results from genetic variations in OR6A2 olfactory receptor
🌿Trans-2-decenal is also a byproduct of saponification, and those who taste soap w/ cilantro actually are tasting soap

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More from @AvrahamCooperMD

27 Oct
1/14
Why doesn't daptomycin treat pneumonia?

The answer also explains why dapto raises serum CK levels.

#medtwitter #tweetorial
2/
First let's establish that daptomycin (bactericidal against gram positives) lacks efficacy in treating lung infections.

⚡️ In this study with mouse lungs, daptomycin didn't reliably kill strep pneumo or MRSA, even at high doses of the drug.

pubmed.ncbi.nlm.nih.gov/15898002/
3/
What about lung infections in humans?

Compared to ceftriaxone,  daptomycin had lower cure rates for treatment of community acquired pneumonia (CAP).

pubmed.ncbi.nlm.nih.gov/18444848/
Read 14 tweets
3 Oct
1/
What is the mechanism of brain freeze?

Why do some people (myself included) get piercing headaches when eating cold food or drinks while others are totally unaffected?

#medtwitter #tweetorial
2/
Brain freeze, formally known as cold stimulus headache, actually has a diagnostic classification:

Transient frontal, temporal, or occipital headaches caused by passage of cold liquids or food over the palate and posterior oropharynx.

pubmed.ncbi.nlm.nih.gov/29368949/
3/
The first question that I had was how common is susceptibility to brain freeze?

I asked #medtwitter what percentage experience it and 82% said they do.

Read 19 tweets
12 Sep
1/
Ever wonder why eosinophils vanish from the blood after exposure to steroids?

I assumed that steroids somehow destroy them and that is why they disappear.

But there's a lot more going on.

#tweetorial #medtwitter
2/
First let's review eosinophil biology.

Eosinophils are granulocytic white blood cells that develop in the bone marrow and reside primarily in tissues.

They have a multitude of physiologic functions, from parasite defense to immuno-regulation.

pubmed.ncbi.nlm.nih.gov/31977298/
3/
In the 1970s the effects of steroids on blood eosinophil levels were first studied.

🔑 Prednisone led to marked declines in peripheral eosinophil counts within 4 hours.

(bonus: the senior author on this paper was Dr. Anthony Fauci!)

pubmed.ncbi.nlm.nih.gov/313411/
Read 14 tweets
28 Aug
1/
Why does albuterol induce a lactic acidosis when given in high doses?

This can occur even as patients with severe asthma exacerbations are improving in every other way.

#medtwitter #tweetorial
2/
The first observation that β₂ agonists could produce lactic acidosis came in the early 1980s.

Terbutaline (a β₂ agonist like albuterol) was given as a tocolytic to 6 women in preterm labor. Their serum lactate levels rose within a few hours.

pubmed.ncbi.nlm.nih.gov/7315890/
3/
By 1985, the first case report of lactic acidosis from inhaled β₂ agonist therapy for status asthmaticus was published.

The patient's acidemia persisted despite normalization of PCO₂, and a new anion gap emerged.

💥Her lactate level was 7.

pubmed.ncbi.nlm.nih.gov/4033719/
Read 13 tweets
8 Aug
1/
Why can furosemide improve dyspnea/pulmonary edema from acute congestive heart failure within minutes of administration?

The answer does not involve diuresis.

#medtwitter #tweetorial Image
2/
Furosemide (aka Lasix) was introduced as a loop diuretic in 1964.

It was soon observed that treatment of pulmonary edema w/ furosemide led to rapid improvement in dyspnea, sometimes before diuresis.

The mechanism of this effect was unknown.

ncbi.nlm.nih.gov/pmc/articles/P… Image
3/
The first clue as to why came in a subsequent study in 1973.

It was noted that left ventricular (LV) filling pressures ⬇️ within 5 minutes of administering furosemide to patients w/ heart failure.

pubmed.ncbi.nlm.nih.gov/4697939/ Image
Read 14 tweets
18 Jul
1/16
Ever wonder why Wilson disease causes Kayser-Fleischer rings to form in the cornea?

Let’s explore the history, mechanism, and implications of the infamous ring.

#medtwitter #tweetorial
2/
First, a quick rundown on Kayser-Fleischer (KF) rings:

🔹KF rings are characterized by dark circles at the periphery of the cornea.

🔹Though sometimes visible to the naked eye, they often require a slit lamp examination to be seen.

ncbi.nlm.nih.gov/books/NBK45918…
3/
Next, let's review the pathophysiology of Wilson disease.

🔑 Wilson = inherited dysfunction of the ATP7B hepatic copper (Cu) transporter.

🔑 Instead of excretion in bile, excess Cu builds up in the liver, damaging hepatocytes and ⬆️ serum Cu levels.

pubmed.ncbi.nlm.nih.gov/20955957/
Read 16 tweets

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