Most of us have ideas about the ways in which the food we eat influences our body odour.
Among the foods claimed to cause bad body odour are onions and garlic, certain dairy products such as blue cheese, fermented foods such as sauerkraut, vinegar and – most of all – curries.
Many alternative practices such as ayurveda suggest impurities and toxins in our body from improperly digested food can result in poor body odour. However, the causes of body odour are not fully understood yet, and there is very little scientific evidence linking diet with body odour.
“Body smells are caused by a number of factors working in combination,” says Dr Rosemary Lester, Victoria’s chief health officer. “These include chemicals in sweat, wastes excreted through the skin, the actions of bacteria that live on the skin, and unwashed clothes.”
It is those first two factors that could be influenced by what we eat, though not necessarily in the direct way some people imagine.
Humans have two types of sweat glands – eccrine glands and apocrine glands.
Eccrine glands control body temperature and are concentrated on our foreheads, underarms, soles and palms.
They release sweat with little odour, mostly composed of water, salt and other trace minerals such as calcium
Apocrine glands are found mostly around the armpits, lower abdomen and genitals.
Their purpose is to excrete wastes (mostly fats and proteins) from the body. Although this sweat also has little odour itself, bacteria on the skin feed on it and produce malodorous waste products such as androstenes and isovaleric acid.
The process takes about 20 minutes.
Studies show that women find fresh male sweat reasonably pleasant, but the chemical compounds that result from its breakdown highly unpleasant.
Busting BO myths
If bacteria are eating the fats and proteins in your sweat, it may follow that cutting down on foods that contain plenty of these (such as junk food) will reduce body odour.
On the other hand, the popular belief that a diet of milk makes babies smell good is improbable. If children smell better than adults, it is because apocrine glands don’t develop until puberty.
Mint, parsley, citrus fruits and chlorophyll, which is abundant in leafy greens such as kale and watercress, are also claimed to help produce sweeter-smelling sweat, but a lot more research is needed to confirm these claims.
One thing that might work is sage. Research has shown that sage can reduce sweating, so sage tea might well leave you smelling prettier.
Quantity not quality
It is the amount you perspire rather than what you perspire that is probably the chief cause of body odour. In other words, it isn’t that curries produce foul-smelling sweat; it is simply that curries raise our body temperature and make us sweat more profusely.
There are also many reasons beyond diet that influence body odour.
“An individual’s odour can change due to a variety of factors, such as menstrual cycle, emotional state, health and perhaps age,” says Dr Dustin Penn of the University of Vienna.
He adds that smoking, drug use and health issues such as diabetes and kidney failure are other factors that can influence body odour.
Penn studied the body odour of 200 people in an Austrian alpine village and concluded that, most of all, people simply have their own particular smells.
“Each individual may retain his or her own particular scent, analogous to a signature or fingerprint,” Penn says.
Other studies have shown that, like a fingerprint, body odour is at least partly determined by our genes.
BAD FOR BO
There is not much research yet, but here is what we do know:
+ Alcohol is mostly processed by the liver but about 10 per cent is excreted through sweat, breath and urine. Alcohol also promotes more profuse sweating.
+ Garlic is one of the few substances we know comes out in perspiration, naturopath Mim Beim says. “Perhaps that’s one reason curry has a bad reputation.”
+ A study in Prague found women assessed the sweat of male meat eaters as worse than that of vegetarians.
+ Foods high in methyl compounds, such as spinach, beetroot and soy products, release trimethylamine, which is excreted through sweat and has a fishy odour.