The Science Behind Why We Stink

From B.O. to bad breath, Dr. Melissa Lem explains the science behind why we stink—and how to freshen up! Plug your nose, everyone!

the_science_behind_why_we_stink1.jpg Body Odour
Cause: Body odour is primarily caused by bacteria. Like people, bacteria need food, water and a comfortable place to live in order to grow and thrive. But the similarities don't end there: Bacteria also produce waste, and depending on the type of bacterium, what it eats and where it lives, it will produce different waste chemicals each with their own unique odour.

Culprit #1: Smelly feet. With more than 250,000 sweat glands, your feet are prone to perspiration. A lifetime spent stuck in shoes and socks only exacerbates the problem by allowing the sweat to collect. And guess what? Bacteria just love to congregate in dark, moist areas and feed off all that sweat, producing plenty of waste (i.e. stink). Fun fact: The two main types of bacteria that cause foot odour, Brevibacteria and Staphylococcus epidermis, are also used to ferment cheese!

Culprit #2: Stinky pits. Just like your feet, your armpits sweat a lot creating a welcoming environment for bacteria. However, armpits are unique in that they contain apocrine glands. These sweat glands secrete a milky liquid, which contains protein and fat—two things that make bacteria very happy.(They're also what cause those yellowish stains on your shirts!) Armpit hair doesn't help either; it's the perfect breeding ground for bacteria.

Cure: First and foremost, hygiene is key! Wash feet and pits frequently and be sure to exfoliate those tootsies as well as bacteria just love to feed on dead skin cells. Opt for footwear made of natural materials like cotton and leather, which breathe better than synthetics. Also, try not to wear the same shoes for two days in a row. If your feet are prone to excessive sweating, you can even try anti-perspirant! A little baking soda on the soles of your shoes may also help.

As for your pits, use anti-perspirant regularly and shave or trim your underarm hair (boys, too!). What you eat also contributes to body odour. Steer clear of red meat, fats, onions, garlic and spicy foods. In extreme cases, botox injections in the armpits are recommended to burb overactive sweat glands.

Bad Breath
Cause: The majority (80%) of bad breath (a.k.a. halitosis) originates in the mouth. (The other 20% actually comes from the stomach.) Bacteria accumulate between the teeth and at the back of the tongue, where they feed off of food particles and then release foul odours. Saliva works like a natural mouthwash to flush away bacteria, which is why people with dry mouth often have worse breath. Saliva production also decreases at night, hence the dreaded morning breath. Yuck!

But bad breath can be more than just a friendly faux pas; it might actually indicate something more serious is going on with your health, such as heartburn, a sinus or throat infection or even oral cancer. Both low-carb diets and diabetes can cause a fruity fragrance, while the smell of bleach on the breath can be a sign of liver or kidney disease. If you suspect that your bad breath is a cause for concern, consult your doctor.

Cure: Most bad breath can be treated with good hygiene. Brush and floss regularly and use a tongue scraper to scale the back of your tongue. Alcohol-based mouthwash can dry out the mouth, so try one with zinc chloride instead. Drink lots of water and chew sugarless gum to prevent dry mouth. Chewing mint or parsley can also help.

Cause: Flatulence comes from two sources: 1. the air that we swallow and 2. the by-products of digestion. Some CO2 is indeed produced in the stomach and small intestine, where proteins and fats are digested, but most gas originates in the large intestine. The large intestine contains 500 different kinds of bacteria that feast on undigested carbs and starches and produce waste. Because everyone's bacterial makeup is different, so is their gas. Diet also plays a role. Certain foods cause worse gas than others. The primary offenders are beans, dairy, starches, fruit, carbonated drinks and cruciferous veggies (e.g. cabbage). The average person passes gas 10 to 20 times per day. There's no getting around it: If you hold it in, it will just come out when you sleep!

Like bad breath, excessive gas can be an indication of something more serious. Certain enzyme deficiencies in the pancreas, gallbladder and intestinal lining may cause excessive gas, as can some parasites or bacteria. Medications and diseases like hypothyroidism, diverticulitis and cancer may also increase flatulence. Warning signs of a bigger issue include a change in bowel behaviour, abdominal pain, blood in the stool or a persistent foul smell. If you have any concerns, see your family doctor.

Cure: Changes to your diet, such as eating more slowly and steaming vegetables before you eat, can help. Probiotics found in foods like yogurt will aid in digestion. Some over-the-counter meds (e.g. Beano and Pepto-Bismol) can also be effective in treating gas. If you're self-conscious, look for carbon-fibre underwear, which absorbs odour. If your doctor finds an infection is at the root of your problem, they may prescribe antibiotics.