Don't buy into the hype of whole body deodorants

Big brands are jumping on the bandwagon of the odour-control market, selling whole-body deodorants and antiperspirants to spritz everything from your feet to your chest to your nether regions.

According to Tauranga-based dermatologist Dr AJ Seine, who is also the Dermatology Society’s spokesperson, it’s all part of the growing "skinification" trend — treating your whole body with the same level of care (and product overload) as your face.

While it may sound luxurious, he says these products play on misunderstandings around sweating and the associated shame.

Humans can sweat just about everywhere but it's only the apocrine glands, which are found in skinfolds such as the armpits and groin, that really smell, Seine explains.

These glands release a lipid-rich fluid that your skin's natural bacteria break down — causing that familiar odour.

"It's a normal part of what the bacteria's meant to do, it's actually a sign that the bacteria is functioning perfectly normally," he says.

On the other hand, eccrine glands – found nearly everywhere else - don't produce much of a smell because they're mostly water.

So, if odour mainly comes from your armpits and groin, why are brands pushing products for your whole body?

"They're sort of just trying to get on a trend rather than actually just going, well, really the only place where that smell's being produced is in the skin folds. It's not over the rest of the body."

As University of Bristol's professor of anatomy Michelle Spear puts it: "The notion that you need expensive products to achieve basic hygiene is a fallacy rooted in marketing, not science".

Deodorants just cover up the smell with fragrance. Antiperspirants, on the other hand, try to block the sweat altogether using aluminium salts – some also contain deodorant fragrances.

But Seine warns adding fragranced products or ones that mess with your natural pH levels to your daily routine could lead to skin irritation.

"We're seeing a rise in what we call allergic contact dermatitis, so an eczema-type of rash in response to fragrances."

In addition, professor Sally Gaw, an environmental scientist at the University of Canterbury, says certain synthetic and natural compounds as well as fragrances can be “endocrine disrupting chemicals”.

“That means that they can act like hormones.

“So, we've got two problems here. One, when it ends up in the environment through wastewater - you have your shower and wash it off or you’re spraying it.

“Or it might be whether these compounds can be absorbed across your skin, in which case then you might be changing your hormonal signal.”

Some brands might play up antibacterial compounds, like triclosan, but Seine warns these can destroy the healthy microbiome which fights off nastier bacteria, such as Staphylococcus aureus - the main culprit behind infected eczema and school sores.

“More and more evidence is coming out around how important our skin microbiome is, just like our gut microbiome, and the interplay between the two through our immune system. So it's something that we really need to look after.”

Disrupting the natural pH level downstairs can lead to issues like dermatitis or bacterial vaginosis, which ironically causes more odour, Seine says.

“You end up in a cycle where people start over-washing themselves, and then they start getting dermatitis. It just becomes a vicious cycle.”

Our genitals are largely designed to clean themselves.

“So, a soap-free cleanser is generally all that you need in those areas… Less is more around the genitals, is the key message.”

Seine understands sweat can be a challenge, even if people are reassured it’s a healthy and normal function. Here are some tips.