From a cheese smell to a hint of onion: some people have a skin odor that stands out. Why do some people stink? And can you influence this?
The composition of bacteria on your skin is unique; your own skin microbiome is unique to you, and its appearance is partly genetically determined. Of all those billions of bacteria on your skin, there are a few that convert the fats, derived from sebaceous glands on the skin, into smelly variants of octanoic acid and butyric acid.
In the last twenty years, many substances have been found that contribute to a smelly body odor, such as volatile sulfur compounds, explains dermatologist and chemist Folkert Blok. “Some bacteria grow at the exit of apocrine sweat glands and convert the body’s own substances into smelly molecules that emit a foul odor when they leave the body through the sweat glands.”
There are two types of sweat glands that cause sweating. The eccrine sweat glands regulate your temperature, and the apocrine sweat glands secrete odor. The eccrine sweat glands do not emit odor. “So the eccrine sweat glands cause wet armpits and the apocrine sweat glands smelly armpits.”
It’s a pretty complex chemical story, but what it comes down to is that those stinky bacteria, such as Corynebacterium striatum, Staphylococcus hominis and Staphylococcus epidermis, are always present on your skin to a greater or lesser extent.
Because every skin is unique, you may, for example, have a few large colonies of bacteria on your skin that cause stench, and your neighbor does not. If you both live equally hygienically and sweat about the same amount, the hard reality is that you stink and your neighbor doesn’t.
Cumin, onion or rotting meat
Typical smelly body odors caused by skin bacteria are described by scientists as the smell of cheese, goat, cumin, rotting meat or onions. There are also pathogenic bacteria that secrete a smell of fish, boiled cabbage, old beer or baked bread.
If your skin mainly lives on bacteria that make you smell like cheese, goat or onion, there is not much you can do about it. If you sweat, that smell will be smelled. So it is important to prevent a lot of sweating. This can be done by clogging those sweat glands with natural salts, such as alum or aluminum salts. These aluminum salts are found in deodorant sprays or creams. This inhibits sweat production a bit.
Transplanting bacteria helps
Another interesting but certainly not low-threshold method is transplantation of skin microbiome, Blok explains. “Doctors then apply the healthy, non-stinky armpit microbiome from someone else to a clean armpit of someone with a stinky microbiome.”
The research is still in its infancy, says Blok. One of the stinky bacteria, the corynebacterium, can be tackled locally by antibiotics, but that is not a permanent, sustainable solution. The wrong bacteria quickly grow back.
You can’t change much about how the bacteria on your skin are composed. But you can influence what you eat and drink. Garlic and onions are well-known examples: the sulfur compounds in these bulbous crops are small molecules that are not broken down in the intestine, but are excreted by the sweat glands. That causes a strong odor.
Cruciferous vegetables, such as broccoli and cabbage, also contain sulfur-containing substances that can contribute to a strong odor when broken down.
Can you also naturally smell extra delicious?
There are odor compounds emitted by the body – terpenes – that we like to smell. Terpenes occur naturally in many herbs, fruits, vegetables and spices and form the basis of many perfumes. These scents are fresh and soft. If you eat a lot of citrus fruits, rosemary, basil or hops, terpenes such as limonene, linalool and myrcene can be released through the skin and breath, which can influence your body odor. Young children naturally smell good: they sweat little and have a sweet, pleasant scent that is reminiscent of licorice, says Blok.
Meat and alcohol cause strong odor
In 2006, scientists Jan Havlicek and Pavlina Lenochova investigated whether eating meat affects your body odor. They discovered that people who followed a vegetarian diet had a less intense body odor compared to meat eaters. The idea is that the extra fats and proteins you get from meat have to be broken down and emit a stronger odor.
Leaving alcohol also ensures that you smell better. Up to 10 percent of the alcohol you drink is excreted through sweat, breath and urine, this research shows. After drinking, alcohol is mainly broken down in the liver into acetic acid and diacetate, among other things, which are excreted through sweat.
The more alcohol you drink, the more these odors can be released through the skin. Because alcohol dilates the blood vessels, you sweat more and smell even stronger. If you often drink a lot, you will permanently give off a strong odor.
And wash more often? No, says Blok. “That only helps temporarily. You will continue to sweat anyway.”