A lot of people use hand sanitizers constantly at this time of year, instead of washing up with water, thinking it will protect them against winter’s worst colds and the flu.
But Japanese researchers recently pitted hand sanitizers against plain water to see which one worked better against the flu. Of course, the results didn’t come as a surprise to me (or to my daughter). But they may be hard for some hand-sanitizer devotees to accept.
I’ll tell you all about that interesting study in just a moment. But first, let’s back up and talk about how the flu spreads…
Flu spreads mainly by direct contact
We’ve known for a long time that you typically catch a cold or flu virus by touching contaminated surfaces and then touching your face, eyes, nose, or mouth.
With a few exceptions, these microbes don’t just fly through the air and land on you. They’re transmitted from person to person.
And they’re designed to live and reproduce inside the body. So, they can only survive outside of the human body for a very short period of time.
Therefore, here are some good guidelines to follow for avoiding contact with the flu:
- Avoid contact with contaminated surfaces—such as doorknobs, countertops, pens, and credit card touch screens.
- Carry your own pen to use on touch screens and for signing receipts.
- Avoid crowded areas where the flu virus is easily transmitted.
Now, let’s talk about handwashing. As always, I recommend regularly washing your hands (and face) with plain old soap and water.
You can even use just plain water…without soap! It actually works quite well, as I learned 20 years ago when I helped my daughter on an interesting project about germs for her middle school science fair.
We found that just using plain water without soap does a pretty darn good job of killing germs. In fact, we found that water, all by itself, removed more than 90 percent of the germs. And regular soap and water removed about 99 percent of the germs.
Granted, you don’t always have access to soap and water. So, in these cases, I’ve always suggested using alcohol-based hand sanitizers—in place of doing nothing. But it turns out that you do need to rub it in for much longer than you might think…
Water sanitizes much more quickly than alcohol
In the new study I mentioned at the beginning of this Dispatch, Japanese scientists collected mucus fluids that contained influenza A. (Remember, humans expel mucus droplets through coughing, sneezing, and sometimes even just breathing.)
Next, they applied the mucus to human fingers. Then, they applied an alcohol-based hand sanitizer to the participants’ fingers.
It turns out, the alcohol had a hard time cutting through the mucus. In fact, even after two minutes of rubbing with the sanitizer, the virus remained active on the subjects’ fingers. And it only became deactivated after four full minutes!
On the other hand…
When the participants rubbed their contaminated fingers with plain saline (saltwater), which is similar to plain water, it killed the virus much faster. In fact, the saline broke through the mucus barrier, reached the virus, and deactivated it in just 30 seconds! (Of course, when you sweat, saltwater accumulates on your skin too.)
Now, I should note, when the mucus was allowed to fully dry out on the fingers first, the hand sanitizer did rapidly deactivate the virus. But that’s rather beside the point, don’t you think? Because by the time you let contaminated mucus dry, in many cases, you’ve probably already spread the virus onto your face!
CDC gets it all wrong, all over again
Interestingly, when researching this topic, I came across a pamphlet made by the Centers for Disease Control (CDC) called, “When and How to Wash Your Hands.” It recommends you use hand sanitizer for 20 seconds when you don’t have access to soap and water.
But clearly, as this study shows, 20 seconds isn’t nearly enough time to get rid of the flu virus. You need to use the sanitizer for 10 to 20 times longer!
So, based on these new findings, here are my updated guidelines for handwashing:
- Handwashing with regular soap and water is the ideal method, as always.
- When you don’t have access to soap, use plain water.
- When you don’t have access to soap and water, why not use some saline solution? You can purchase travel-sized bottles at your local grocery or convenience stores—making them just as easy to carry around as hand sanitizers!
Of course, boosting your immune system is another important strategy for avoiding the flu and any other virus this winter. In fact, as I reported in the December 2017 issue of my Insiders’ Cures newsletter (“The single vitamin secret to cutting your risk of colds, flu, and pneumonia in HALF”), it’s imperative that you take a certain vitamin that cut can your risk of contracting the flu in HALF. So if you’re not yet a newsletter subscriber, now’s the perfect time to become one!
“Situations Leading to Reduced Effectiveness of Current Hand Hygiene against Infectious Mucus from Influenza Virus-Infected Patients.” mSphere Sep 2019, 4 (5) e00474-19. doi.org/10.1128/mSphere.00474-19