One argument for showering less centres around the skin microbiome: the trillions of micro-organisms that live on the skin's surface, made up of about 1000 species of bacteria and up to 80 species of fungi. Some microbes feed off the oils in our skin, which is stripped away when we use soap. More brands are beginning to recognise the importance of these bacteria and even market themselves as "microbiome-friendly".
"In terms of research, we are probably 10 years behind the gut when it comes to the skin microbiome," says Prof Matthew Hardman, an expert in wound healing at Hull York Medical School. "All of the concepts that apply to the gut, you can also apply to the skin – there are good bacteria and bad bacteria. One of the differences is that the skin is actually more difficult for bacteria to colonise, as it is a much harsher environment.
"From a scientific perspective, the challenge has always been being able to identify those bacteria, understand exactly what's there and why."
The skin microbiome plays an important role, supporting our immune system, preventing pathogens from entering the body, reducing inflammation and lessening the chances of skin conditions such as eczema and psoriasis. Hardman led a 2014 study which found that skin microbes could help to heal chronic wounds, common in the elderly.
There are constant environmental factors that disrupt our skin's microbiome – taking regular showers being one of them. "If you shower regularly, you can deplete the amount of bacteria and oil on your skin, and increase its dryness," says Hardman.
"However, your skin is very resilient and it is easy to replace the oils because it is producing them all the time. When a product says it kills 99.9 per cent of bacteria, it only takes away a chunk; it could grow back within hours."
So should we be washing any differently? It is likely that everyone will have a different answer. As Hamblin sees it, the process isn't about sacrificing showers entirely: during the pandemic a morning shower helped to start his day and he acknowledges that many people enjoy them. Instead, he says, it is about having "the option of doing less".
"We don't always need to repeat, or add a product, or replace one with another; there is another way that isn't talked about very often." He says that people who suffer with skin conditions may benefit from stripping back their shower routines, under the guidance of a physician. "They may want to cut back on a product and take shorter or fewer hot showers to see if that helps."
Cases of psoriasis, eczema and dermatitis have all risen in recent years. Studies point to environmental factors, such as irritants and allergens that trigger the immune system, as contributing to the rise in people with eczema. In children, some experts put this down to the "hygiene hypothesis": the idea that early exposure to germs helps a child's immune system develop resistance to infections. In our excessively clean Western lifestyles, this exposure is limited.
"We know that washing with soaps is harmful to the skin barrier, especially with conditions such as eczema. This could potentially be down to changes in the microbiome, but the research is still too early to tell," says Dr Helen Alexander, of the St John's Institute of Dermatology at King's College London. She adds that there is no evidence that washing your hands is bad for the skin microbiome.
According to Fortune Business Insights, the global soap market is projected to reach US$55.3 billion by 2027. But we weren't always so addicted to scrubbing ourselves with soap. "Regular washing took off in different places at different times, but it mainly happened over the second half of the 20th century," says Hamblin.
"Before the invention of indoor plumbing or mass-produced soaps, it wasn't even an option. Throughout history soap was a luxury good or something that you made yourself – not something that you used every day." By the '80s the trend for showers as we know them – with jets, lights and different heads – had truly taken off, neatly coinciding with a burgeoning wellness industry.
Others advocate washing in cold water. Hardman explains that showering with hot water removes more of the protective oils and lipids from the surface of the skin. Cold showers have become popular in recent years, with celebrities such as Gwyneth Paltrow and Lady Gaga endorsing the health benefits of ice bathing. Also popular is the method devised by Dutch athlete Wim Hof, which uses a combination of meditation, breathing exercises and cold exposure to regulate stress levels.
The method states that showering or bathing in cold water can speed up metabolism, reduce inflammation and activate a better immune response. One study undertaken by Radboud University closely monitored followers of the Wim Hof method and non-followers after exposing them to a pathogen. The participants who practised the method showed an increased immune response and fewer symptoms of diseases.
At a time when we are more conscious of our hand hygiene than ever, it seems that the pandemic has pushed us back towards a more primitive way of washing. Although we don't know for certain whether it is healthier, it couldn't hurt to save money on the water bill.
