Saturday, August 15, 2015

Smelling farts is good for you

Immediately you feel obligated to read this, don’t you? It was a common interpretation of a published research study by the media last year, especially in the UK. It’s a headline that will get plenty of attention, and the story exists only because people easily misinterpret science, leap to conclusions or get just too lazy to ask the study authors for an explanation.

If you have already clicked on the link and read the abstract, you will immediately see that it has nothing, absolutely nothing at all, to do with farting and your health.
Hydrogen Sulfide
It is a study about hydrogen sulfide (H2S), that smelly gas that is produced by your intestinal bacteria after they have chomped through the fibre in your meals. So any study about H2S must also relate to breaking wind, right?

Actually, the H2S story has its own fascination. From a physiological perspective H2S is called a gasotransmitter and has a really interesting role. Just so you know, nitric oxide (NO) and carbon monoxide (CO) are also gasotransmitters that you may have heard about.

All three gasotransmitters are vasodilators, which just means that they help your arteries to widen with ease, which in turn means that blood flows through easier. So, if the heart requires less pressure to pump blood through your arteries, then your blood pressure is lower. It doesn’t stop there. H2S also reduces the level of inflammation linked to heart disease, and is critical for the health of your mitochondria, famous for delivering energy for muscle contraction. And, because they are smart molecules, H2S, NO and CO all “talk” to each other to make sure they are all cruising through your body at ideal levels.

Depending upon levels, H2S is either toxic or healthy
While we knew that atmospheric H2S was toxic to the body for many years (and I don’t mean from passive farting, we are talking industrial waste levels here) it has only been since 1996 that we began to appreciate its role when very small amounts are manufactured within the body. Problems with the natural production of H2S have been linked to hypertension and diabetes, and conditions of chronic inflammation such as rheumatoid arthritis. When your body produces normal levels of H2S, you get up with a smile on your face and a zip in your step.

What does it all mean?
We make the same mistake all the time, assuming that a compound has a similar effect inside and outside the body. The classic example was assuming that cholesterol in food became cholesterol in blood, so everyone stopped eating eggs, yet body weight, genetics and maybe too much saturated fat are the real culprits. Just because H2S is very useful when manufactured by body cells, doesn’t mean that snorting your own gas emissions will have the same positive effect. The same goes for CO. Inhale car emissions in a concentrated space and you will eventually collapse and die. Yet the tiny bit of CO produced by your body is good for you.

As you know:
1. Nothing is bad; it is the amount that determines whether it is bad.
2. Journalists don’t specialise in science or asking smart questions.
3. By the time you have reached your 17th birthday you will have ignited some H2S. Ok, maybe not all the ladies. Just most.

Oh, why spell it sulfide and not sulphide? Because the Royal Society of Chemistry and the International Union of Pure and Applied Chemistry both spell it sulfide and you just don’t mess with purity and royalty.

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