The next time you let rip in bed (be it a soft wafting or a comical trumpeting) and your partner threatens to pull the plug on your relationship, tell them to suck it up and be thankful.
The rotten-egg component of flatulence – hydrogen sulphide (H2S) – just might help you both live longer.
In fact, there’s a growing area of research that’s exploring the various ways hydrogen sulphide serves our well-being.
But isn’t it toxic and highly flammable?
OK, hydrogen sulphide may have wiped out 95 per cent of all life on earth about 251 million years ago. And, yes hydrogen sulphide was used as a weapon in World War I – and can kill people at a modest concentration of 200 parts per million.
Plus, it’s explosive! It will burn yellow or orange if you’re a lighter of farts with a higher concentration of hydrogen as your main flatulent fuel (methane burns blue).
How explosive? This footage of a tanker full of hydrogen sulphide going to God will give you some idea:
All of which seemingly gives weight to that old excuse for cutting the cheese in company: better out than in.
But the body actually makes this deadly stuff
Most of the gases in our farts (about one and a half litres worth of gas per person every day) are odourless: oxygen and nitrogen are swallowed when breathing; carbon dioxide, methane and hydrogen are a product of bacteria fermenting carbohydrates in our gut.
It’s high protein foods such as meat, poultry and eggs (along with onions and garlic) that produce hydrogen sulphide – and this explains why body builders gorging on protein powder are on the stinky side when passing gas.
(To offset the fallout of protein, simply eat more resistant starch, found in bananas and cold potatoes.)
In 2013, a study from Southern Methodist University demonstrated for the first time that hydrogen sulphide is generated by our body’s growing cells – confirming what scientists knew all along, that these potentially toxic gaseous molecules serve as key signalling agents in the body.
The researchers developed a chemical probe that reacts and lights up when live human cells generate hydrogen sulphide – a process that can be observed in real time under a microscope.
According to a statement from the university, hydrogen sulphide – along with nitric oxide, carbon monoxide and others in this emerging class of gaseous signalling molecules – assists the body’s large proteins.
Large proteins do much of the functional work in the body, such as digesting the food we eat and harnessing the energy in the oxygen we breathe. Their size, however, forces them to move slowly inside the cell.
“In contrast, H2S and other small gaseous molecules diffuse quickly and easily across cellular membranes, enabling them to travel much faster and rapidly deliver information that mediates critical functions, such as blood pressure regulation,” said Dr Alexander Lippert, an associate professor of chemistry who designed the experiment.
Better recovery from heart attack
In 2007, University of Alabama researchers found that administering hydrogen sulphide directly into the heart during a simulated heart attack significantly reduces the tissue and cell damage often seen in oxygen-starved organs.
The researchers found that hydrogen sulphide boosts post-heart-attack function – at least in mice – by helping to minimise reperfusion injury, a side effect of restoring blood flow swiftly to hearts suffering from low oxygen.
The injection of hydrogen sulphide led to a 72 per cent reduction in the amount of severe heart-tissue death after restoring normal oxygen and blood flow to mice hearts.
Also in 2007, these same researchers found that hydrogen sulphide is key to explaining the efficacy of an old folk remedy: garlic as a tool for lowering high blood pressure and protecting oneself from cardiovascular disease.
How so? The scientists found that garlic triggers red blood cells to release hydrogen sulphide which then leads to the relaxation of blood vessels – the first step toward lowering blood pressure.
And then there’s the question of ageing
In 2013, scientists from University of South China, in a systematic review, argued that hydrogen sulphide slows ageing by inhibiting free-radical reactions. It does this by activating an enzyme called SIRT1, believed to be a regulator of lifespan.
They also observed the gene, klotho – thought to extend lifespan via a number of different pathways – appears to be stimulated by hydrogen sulphide.
“Data available so far strongly suggest that H2S may become the next potent agent for preventing and ameliorating the symptoms of ageing and age-associated diseases,” concluded Dr Zhi-Sheng Jiang of the University of South China’s Institute of Cardiovascular Disease in an interview with Sci News.
In the future, he said people may take H2S via food, or as an anti-ageing supplement.
The research that set off a media stink bomb
In 2014, scientists from the University of Exeter developed a compound (AP39) as a means of delivering very small amounts of hydrogen sulphide to key components inside cells – as a mechanism for future therapies.
According to a statement from the university, the scientists had already found that the compound protects mitochondria – the “powerhouse” of cells, which drive energy production in blood vessel cells.
Preventing or reversing mitochondrial damage is a key strategy for treatments of a variety of conditions such as stroke, heart failure, diabetes and arthritis, dementia and ageing. Mitochondria determine whether cells live or die and they regulate inflammation. In the clinic, dysfunctional mitochondria are strongly linked to disease severity.
Professor Matt Whiteman, who led the research, said: “When cells become stressed by disease, they draw in enzymes to generate minute quantities of hydrogen sulphide. This keeps the mitochondria ticking over and allows cells to live. If this doesn’t happen, the cells die and lose the ability to regulate survival and control inflammation.
“We have exploited this natural process by making a compound, called AP39, which slowly delivers very small amounts of this gas specifically to the mitochondria. Our results indicate that if stressed cells are treated with AP39, mitochondria are protected and cells stay alive.”
This led to a stink bomb of media stories that wildly claimed the scientists had found a cure for cancer. The researchers responded with a disclaimer on the university press release:
“In light of misleading headlines on the above press release, the authors would like to stress that neither the papers (here, here, here, here and here) nor the accompanying press release above make any reference at all to cancer or to any health benefits from inhaling (sniffing) hydrogen sulphide. The research is an early stage drug development project and has not yet been trialled in humans.”