Covid 19 coronavirus: does too much hand washing weaken my immune system?

People have been obsessed with cleanliness during the Covid-19 pandemic.

Supermarkets were forced to impose limitations on sales of hand sanitizers, and in some cases they sold out completely, meanwhile Trade Me even restricted prices.

Earlier in the year, officials told us to wash our hands well and that it was often one of the best protections we had against it.

But can we be too clean and is using too much hand cleaning or sanitizer bad for my immunity?

Hygiene hypothesis theory suggests that lack of exposure to microbes from excessively clean environments can lead to allergies and certain autoimmune disorders.

Experts in New Zealand say there is no evidence to suggest this is the case, but they also told the Herald that a little dirt was not a bad thing.

“There is no evidence that regular hand washing is harmful,” says University of Otago epidemiologist Professor Michael Baker.

“The bacteria that people have are very adaptable to be able to pass from one person to another, so washing your hands is key to interrupting that process.”

University of Otago biochemistry department professor Kurt Krause and Massey University professor David Hayman agreed.

Krause recommended that people use soap and water when possible, opting for a hand sanitizer when the traditional method of hand cleaning was not available.

Consistent use of hand sanitizer can lead to cracks in the skin, and cracking is more susceptible to bacteria, so it’s important to check your hands, he said.

“That’s one of the reasons I prefer soap and water. Good soap and water for 20 seconds will kill the virus and will not make your hands rough,” Krause said.

However, there is a fine line between exposing people between good bacteria and bad bacteria, which is difficult to portray, Hayman says.

“It’s one of those things, we want to prevent us from getting some infections, but on the other hand we want to expose ourselves to good bacteria,” he said.

“It’s like your probiotic yogurt, you want to have good natural intestinal flora because we are not sterile, but you don’t want the campylobacter to get through you and you’re vomiting.”

Krause says that people should not strive to be bacteria free, but to have clean surfaces and hands.

He thought getting dirty was not a bad thing, especially as a child, but people should make sure to clean properly afterwards.

Both Krause and Hayman reiterated Baker’s comments that a lack of evidence for keeping clean weakens his immunity.

Hayman also had a strong message for Kiwis: keep doing what you’re doing when it comes to personal hygiene and hand washing.

It comes after all Covid-19 patients in the community have recovered, and Auckland will go to alert level 1 tonight. There are three new cases in managed isolation today.