Do Anti-bacterial Soap really matter?

The introduction of soap to the medical world is among the greatest single technological advances in the history of humanity. If you ever wonder at the attitude displayed in some old-world histories and period pieces, the distrust and hostility shown to surgeons and physicians just a few hundred years ago, consider the odds: in the worst cases, studies have shown that fully 50% of historical surgical patients died from infection. That’s in addition to those who died from more mundane complications, or from the ailment which necessitated the surgery in the first place. Though they were not even yet completely sure of the reasons for their actions, doctors noticed the effect of soap immediately. A surgeon with clean hands was a surgeon with living patients.

Pic: Global Hand washing Day

Now, we know the reasons for the dramatic increase in survival: bacteria. Soap emulsifies oils, breaks them up with a chemical efficiency that you cannot achieve with water — this means that it can both help sweep bacteria off the hand with a stream of water or kill them by breaking the fatty exterior membranes. By carrying less bacteria into an open wound, the doctors were no longer the single greatest danger to their patients. Eventually, this practice evolved in the almost neurotic sterility we find in modern operating rooms; in the pursuit of bacteria we will boil our instruments and throw out ton after ton of disposable medical supplies.

And so, when you are in your supermarket isle, why would you not turn for the anti-bacterial option? Why not provide your family with the same protections afforded a patient in a hospital? Well, two reasons. One: You are, we hope, not putting your hands inside any open wounds. And two: Well, that’s really it. Most anti-bacterial soaps add just a single killer molecule to the mix, something that gets at the bacteria in a more directed way than fat-solubility. The most common agents is Triclosan, which stops the cells from producing new fatty acids, and EDTA, a ubiquitous food product that can starve the bacteria of necessary minerals like calcium and iron.

Washing your hands after using the bathroom, especially before eating, is a necessity. However, the reason for this is not the small percentage of bacteria killed by anti-bacterial soaps that are missed by regular ones. Our bodies are naturally anti-bacterial, and need little outside help in fighting them off — it’s nice if you sterilize your hands before shoving them into the stomach, for example, but overkill before rubbing your eyes. In those cases, a simple cleaning will do, and research from private and government groups has found no reliable health benefit to everyday use of antibacterial soaps. They do not kill viruses (“deactivate” viruses, technically, since they were never really alive,) any more effectively than normal soaps, nor are they any better at clearing away harmful, non-living substances and chemicals.

However, there has been some evidence of downsides. Bacteria are extremely good at evolving resistances to simple molecular challenges, and many have suggested that we are ill-advised to breed super-bacteria in our very homes. The evidence that we are, in fact, doing any such thing is slim, however. It seems that anti-bacterial hand soap is safe for the very same reason it is not helpful: it just really doesn’t matter that much. The basic efficacy of soap is high enough that the extra juice provided by a killer additive is, sadly, largely a non-issue.

As with so many everyday health claims, there is a grain of truth here: if your immune system is depressed, or if you have wounds or other vulnerable areas, anti-bacterial soap can be a literal life-saver. For the rest of us, it’s probably just an extra dollar we could have saved.

The common question that may arise in your mind now. Is your hand clean even after washing your hands with soap solution?

-Saumyadip Sarkar (Science Communicator)