Body Odor Explained and What You Can Do Control It


I’m not an authority on sweat or body odor but the topic interests me. I have personally gone from being super stinky to virtually odorless since changing my diet years ago. And I’ve observed the same in others after they’ve made major diet changes. Yet I know some people who still smell like death despite having a great diet and I know others who don’t smell at all despite having an atrocious diet.

What gives?

After doing a little research on the subject, I learned that there may be a genetic component to body odor. Certain diseases can contribute to it. Medications can cause it. And various aspects of the diet can affect it.

The odor is not due to sweat itself – our sweat is virtually odorless. Certain chemicals that come out in the sweat can smell pretty foul, but mainly it is the scent of particular microbial activity that creates the body odor we are most familiar with. Bacteria multiply rapidly in the presence of sweat. As they break sweat down into acids we start to smell bad.

Where We Sweat

Apocrine glands – Most of the apocrine glands in the skin are located in the groin, armpits and around the nipples of the breast. The apocrine glands are mainly responsible for body odor because the sweat they produce is high in protein which bacteria can break down easily.

Eccrine glands – These glands are located all over the human body and produce sweat which is high in salt.

Bacteria That Thrive On Sweat

  • Propionibacteria turn sweat into propionic acid. A subspecies of this bacteria is responsible for the smell of Swiss cheese. This bacteria is also one of the causes of acne.
  • Staphylococcus epidermidis creates body odor by breaking sweat into isovaleric acid (3-methyl butanoic acid).
  • Bacillus subtilis creates strong foot odor.

The Acids That Smell

● Propionic acid (propanoic acid) – Propionibacteria break amino acids down into propionic acid. Propionic acid has a vinegar-like smell.

● Isovaleric acid (3-methyl butanoic acid) – Isovaleric acid is another source of body odor as a result of actions of the bacteria Staphylococcus epidermidis. Not everyone can smell this acid!

Causes of Excessive Sweating

Sweating alone isn’t going to make you stink. You’ve got to host the right kind of bacteria or the right toxins to make that happen. But add to that a little sweat and you’ve got the recipe for underarm odor. People who sweat excessively are more at risk of smelling more often. Conditions that cause excessive sweating include:
  • Thyroid problems
  • Diabetes
  • Overweight
  • Hypoglycemia
  • Pregnancy
  • Alcoholism
  • Sick with virus
  • Some medications
  • Anxiety

Why Some Of Us Smell Worse Than Others

Getting the causes of excess sweating under control will go a long way towards improving health in general but, as I said before, sweat, per se, is not the problem. The problems are microbes and certain chemicals.

Some pungent foods can lead to body odor if the other organs of detoxification, like the liver, don’t eliminate their byproducts.

If microbes are the problem, there is a chance you can change your skin flora. If the bacteria responsible for body odor can be tamed, then the gut probably plays a big role. Compromised gut health can be caused by:

  • Fermentation of carbs due to malabsorption
  • SIBO (small intestinal bacterial overgrowth)
  • Antibiotics
  • Drinking chlorinated water
  • Sugar
  • Food allergies
  • Diarrhea and constipation

Solutions for BO

Establishing a healthy colony of microbes and strengthening the immune system so that it can fight off pathogens will likely help to control body odor. Fermented foods and probiotics will help re-establish a healthy community of microbes. Avoiding chemicals, alcohol (in some people), and sugar are equally important for maintaining gut health.

According to the study linked to above, citral, citronellal, and geraniol are all “fragrant agents that inhibit the generation of isovaleric acid at low concentrations”. As you work to establish good health on the inside, these might help on the outside.

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  1. a Few months after I went primal and started doing green juice twice a day my overall odor has reduced significantly to the point of almost not being there at all. Hooray Diet!.

    • Jason, do you drink green juices in place of two meals, then have a primal dinner? Just curious – I like green juices and hadn’t thought to drink them while eating primally. I associate them more with raw food; it’s nice to see the raw food and primal way of eating combined.

      • Ingrid,
        I think a lot of people in the primal community do green juices. I still have my juicer and make green juice often. While I was pregnant I made it nearly every day!

        • Peggy, I know you have FODMAP issues – what do you put in your green juice? I know that a lot of traditional “juicing” veggies like kale are FODMAP no-no’s, so I’m wondering what’s left that you would juice? I just stick to eating a lot of lettuce salads myself, but I like the theory of juicing, I’m just trying to picture how to make it FODMAP-friendly.

          • Hi Laura,

            There are so many veggies that are suitable for FODMAPs. Spinach, celery, bok choy, all kinds. I like to eat lettuce salads too. :)

  2. I wanted to add some of us cannot break down ammonia properly(me) becuae of a CBS gene. My ammonia levels are crazy high and I think the plays a huge part for my BO. I never used to be this way so I think something turn this gene “on” maybe congested liver??

  3. I don’t remember where I read this, but apparently women especially can smell pheromones of sexually competitive women as something distinctly unpleasant. This is the only thing that ever made my mother’s obsession with my apparently BO make sense; even if I was right out of the shower, in freshly bleached clothes, she’s still convinced I stink. Ever since I hit puberty. *exasperated sigh*

    • Did anyone besides your mother think you smelled? It is true, though, that we are equipped to smell each other differently. Scents within a family can apparently be unappealing in order to prevent inbreeding.

    • Same here, my mom claims I stink even if I’ve just showered. My fiance assures me I don’t.

      My stinkiness has definitely come down a lot since changing my diet. It used to be a huge issue for me. Now I hardly ever have to wash my tops, unless it’s something super tight in the armpits.

      The deodorant I use is by Weleda, it’s really just a spray of alcohol with some essential oils, so I can spray more on if I do get stinky and it just kills the bacteria and the smell goes away. When I’ve gone places with less than ideal shower facilities I’ve not showered for a week, resprayed that stuff once or twice a day and never smelled at all.

  4. magnesium will stop body odor.. use it with patients

    • That is interesting. Can you point me towards any papers on this? I’ve taken magnesium at times in my life when I smelled bad. I never noticed a connection.

    • I have had crazy sweating and BO problems all of my post-pubescent life, and have tried all the natural deodorants possible. Magnesium oil (zechstein minerals brand) was the one I tried longest, for about 3 1/2 months. It neither helped my sweating or my odor in any way. Just wanted to put my input out there.

  5. I smell less since getting healthier. I think I didn’t smell at all when I avoided dairy for several weeks. I only need deodorant on days I don’t shower, so I guess that’s not too bad.

  6. Coffee seems to be the number one culprit for me. I believe it affects my adrenals/stress hormones. Coffee = B.O. (while I’m typically odor-free) and painful acne breakouts in and around my hair line. I haven’t experimented with caffeine-containing tea, yet… curious.

  7. Can anyone tell me that if once odor get off then it came again?

  8. I also have fructose malabsorption and had a longstanding confirmed candida overgrowth along with an h.pylori infection. Pungent armpit odor within an hour(!) of eating sugary carbs (cake, etc) helped me put it all together, switch my diet, and get diagnosed. Oregano oil helped short term, but diet has bed the long-term solution, including low sugar, low fodmap. The pungent smell and excess sweating are gone — I still sweat underemotional stress, but no foul smell anymore.

  9. I too have noticed a correlation with diet and body odor. I have some sort of bacterial overgrowth/dysbiosis, and when I stay away from sugar and most simple carbs, eat Paleo, my odor subsides. I’ve always been a sweaty, stinky, anxious kind of person. With Paleo and grain-free, I no longer deal with these and a host of other issues like brain fog, moodiness, joint pain and fatigue. I also think I am gluten intolerant, so this is part of the reason, but not all of it. I definitely know there is a link to this.

    • Vanessa, you appear to have the same symptoms and conditions I suffer. I am also gluten intolerant for sure. Even going GF, I eventually started feeling nauseous every morning no matter what I ate. So I started the specific card diet (a lot like paleo) 8 months ago and that has helped but still having problems. I have tried a naturopathic doctor and lots of supplements. I am open for any suggestions. I can’t find any pattern to my diet and sick feelings.

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