bad news everyone
Scientists may have pinpointed a reason for your persistent bad breath — and it really stinks.
In a new study published in the journal Nature Genetics, researchers found that chronic halitosis that seems to have no obvious dietary cause may actually be the result of genetics. Specifically, a genetic mutation in a protein called "SELENBP1" may be hindering the bodies of these unlucky breathers from naturally breaking down odorous compounds in the blood.
Gizmodo's Ryan Mandelbaum explains that the researchers analyzed the breath of five individuals — kindly described in the scientific study as having "cabbage-like breath odor" — and found that the bad smells came from sulfuric compounds in their blood. All five individuals were found to have a mutation in their SELENBP1 gene, which prompted the researchers to investigate further.
Working with lab mice, the scientists removed the SELENBP1 gene from the animals to see what resulted. They ultimately found that after the gene was removed, the rodents had "way higher levels of these stinky sulfur compounds in their blood plasma," Mandelbaum explains. This led the researchers to hypothesize that SELENBP1, in its unmutated state, plays a role in breaking down fetid molecules in human breath, thus allowing people to better recognize malodors and avoid, say, rotting food that could cause health problems.
In short, your bad breath may just be an evolutionary defect that makes it harder for you tell when your cheese has gone bad. Read the full study at Nature Genetics.