By Dr. Mercola
Using antiperspirant and deodorant has become second nature to most people. Advertisers have been making arguments against your natural balanced scent to convince you to purchase their fragrant antiperspirants and deodorants, promising everything from matchmaking to self-confidence to result from their use.
No personal care product can follow through on these promises. We are only beginning to tap into the power of your relationship with bacteria living on and in your body. While not all of those relationships are healthy, science is still determining all the ways your body uses the bacteria living on your skin.
Although the U.S. Food and Drug Administration (FDA) and advertisers want you to believe your deodorants and antiperspirants are completely safe, you only have to look at the Material Safety Data Sheet (MSDS) for the ingredients listed in each product to understand this likely is not the case.
Why Do You Smell?
Your body has two different types of sweat glands. Eccrine glands are located over most of your body area. They secrete fluid onto the surface of your skin as your body temperature rises. As this fluid evaporates, it helps to lower your core temperature and cool your body.
It is the fluid from your second set of sweat glands that causes body odor. These are the apocrine glands, located mostly where there are dense areas of hair, such as your armpits and groin. These glands empty fluid into your hair follicles just under your skin.
While the eccrine glands produce clear, salty fluid, the apocrine glands produce a milky substance in response to stressors. The fluid itself is odorless but quickly develops an odor when combined with the bacteria living under your armpits.
Your armpits offer a dark, warm and moist environment for bacteria to live and flourish. As bacteria break down the fluid from the apocrine glands, they produce a product called thioalcohols. These pungent thioalcohols evaporate from under your armpits and produce the odor.
In an effort to understand which of the bacteria normally living under your arms produces the most thioalcohols, scientists from the University of York measured the concentrations produced by different bacteria.1
They found Staphylococcus hominis was one of the bacteria producing the most thioalcohols and one of the worst offenders.
Factors That Play Into Development of Body Odor
Anxiety releases cortisol in your body, the fight-or-flight hormone. This triggers the release of sweat from your apocrine glands. When combined with bacteria under your arms, your sweat starts to smell.
Some medications may increase the amount of sweat you produce, increasing the potential for body odor.6
Medications with this side effect include nonsteroidal anti-inflammatory medications, Lupron (cancer treatments), Topamax (seizures and epilepsy), and several of the antidepressant medications, such as Paxil and Wellbutrin.
Foods like onion, garlic and curry may change your body odor, especially the ones containing sulfur.7 Meat may change the scent from your armpits and metabolites from alcohol will be released from your respiratory system (your breath) and your sweat glands.
✓ Refined Sugar
Foods high in refined sugar or net carbohydrates may affect your body odor. This is because the sugars are a food source for the bacteria, while whole food alternatives act more like natural body deodorizers.
Your deodorant may be the cause of your stinky underarm odor. You may think that daily use will cut bacterial growth and reduce odor, when in fact you may be encouraging a rebound growth effect of smell-producing bacteria.
✓ Hair Growth
You may have noticed that when you don’t shave your underarms, the smell increases.
The increase in scent is imperceptibly different between seven days of growth and six to 10 weeks of growth.10 However, study participants were able to distinguish scent differences between a freshly shaved underarm and a one-week growth.
✓ Medical Conditions
There are several health conditions that may cause you to sweat more than usual, including: diabetes, pregnancy, thyroid problems, hypoglycemia, endocarditis, heart attack, leukemia, menopause, obesity and alcoholism.
Deodorant, Armpit Bacteria and Your Skin
Antiperspirants and deodorants are not the same. The primary function of deodorants is to kill the bacteria living on your skin, thereby reducing your body odor. Antiperspirants often have a dual purpose. They both kill the bacteria to reduce odor and plug your pores with aluminum to reduce sweating.
In a recent study, researchers found participants who used antiperspirants had strikingly altered bacterial communities compared to those who use deodorants.11 There were also significant differences between those who used either of these products and those who used none.
Individuals who routinely use deodorant or antiperspirants support colonies of Staphylococcaceae bacteria, and those who don’t routinely use these products have higher numbers of Corynebacterium which, like Staphylococcus hominis, contribute to the production of armpit odor.
Participants who used antiperspirants had underarms more highly colonized with specific species of bacteria. The researchers presumed that because antiperspirants have only been used in the last century, the bacteria do not represent those which were historically common in human underarms.
Antiperspirants May Worsen Underarm Odor
Interestingly, research12,13 published in 2014 found that using deodorant and/or antiperspirants can actually worsen your armpit odor. Here, they found that those who used antiperspirants had higher levels of Actinobacteria, yet another bacterium responsible for foul-smelling armpit odor.
Essentially, the researchers found that the aluminum in antiperspirants killed off less odor-causing bacteria, allowing bacteria that produce more pungent odors to thrive instead.
In some participants, abstaining from antiperspirant caused the population of Actinobacteria to dwindle into virtual nonexistence. The take-home message: using an antiperspirant can make the stink from your armpits more pronounced, while quitting antiperspirants may eventually mellow the smell.
Why Ingredients in Deodorants and Antiperspirants Pose Risks to Health
Unfortunately, altering the microbiome in your armpit isn't the worst thing that can happen when you regularly use antiperspirants or deodorants. The ingredients in these products are the real cause for alarm. While deodorants are designed to work outside the body, they contain chemicals that can pass through the skin barrier. Your skin may appear to be impermeable, but it is not.
Drug companies commonly use transdermal patches to deliver medications through your skin.14 For just this reason, smearing chemicals on your skin may be more dangerous than swallowing them. Associate professor of biology at North Carolina State University, Heather Patisaul, Ph.D., is quoted in Time Magazine, saying:15
“When you eat something, it’s broken down by your liver and digestive system. But when you put something on your skin, there are times when it can enter your bloodstream without being metabolized.”
5 Hazardous Deodorant and Antiperspirant Ingredients
Rubbing chemicals on your skin doesn’t mean they will make it to your bloodstream. However, blood testing shows many of the chemicals used in deodorants are able to permeate your skin and are found in your blood.16 Here are five common antiperspirant/deodorant ingredients that may pose a health risk.
This product is used in antiperspirants to block your sweat glands and reduce the amount of sweat you secrete. It doesn’t reduce the amount your body produces, only the amount that is secreted through your follicles. As mentioned, aluminum will also kill off some bacteria under your arms that don’t produce strong body odor, allowing those bacteria that do produce a pungent odor to proliferate.17
Aluminum is a metal that may increase gene instability in breast tissue.18 This instability may be related to changes promoting the growth of tumors. Although this is not proof that aluminum is a causative factor, those who use products containing aluminum tend to have higher rates of breast cancer.19
Parabens are preservatives used in many different types of personal care products, including moisturizers, deodorants, sunscreens, shaving creams and gels, hair products and make up. Parabens are associated with changes to the production and regulation of estrogen and other hormones in your body as they penetrate your skin and act like a weak estrogen.20
Although the American Cancer Society (ACS) and National Cancer Institute (NCI)21,22 deny conclusive evidence of an increased risk to your health, laboratory data from the University of Reading demonstrates mixing different types of parabens, as you would by using different personal care products, may increase the estrogenic effect in your body.23
These compounds help your personal care products stick to your skin or hair. This means anything you use with fragrance that lingers has phthalates to improve the stability of the scent. Hair shampoo, lotions, perfumes, deodorants, body sprays, antiperspirants, body wash and soap all contain phthalates that continue to build up in your body over time.
The compound appears to disrupt the androgen functions in your body. You may think of androgen and testosterone as strictly male hormones, but the female body uses this hormone as well to build and maintain muscle, and it plays a role in energy maintenance.
This chemical is so commonly used in products that 75 percent of Americans have detectable triclosan levels in their bloodstream.27 Although a common ingredient in antibacterial soaps, cosmetic manufacturers use it to kill bacteria on the skin in products such as anti-acne creams, deodorants and antiperspirants.28
Animal studies have linked triclosan with unusual hormonal activity,29 and through transdermal absorption it can disrupt the bacterial growth in your gut.30 According to Patisaul:31 “There’s evidence from amphibians and fish … that triclosan impairs thyroid function, which is crucial for brain development. To my knowledge, there aren’t any clear benefits associated with it when used in underarm products.”
The chemical ingredients in scents are concealed and protected by trade law. You may experience allergic reactions or skin irritation from fragrances contained in deodorants and antiperspirants.
Giving Up Deodorant and Antiperspirant
Giving up your chemical wash every morning is not as difficult as you might think. There are several natural options you may experiment with to find the combination that works for your unique bacterial colonization.32
When you don’t add an antiperspirant or deodorant to your morning routine, your odor may increase for a week or two until the bacterial growth under your arms stabilizes. Just like reducing or eliminating daily showers may help balance the natural oils on your skin, eliminating all deodorants may help your body to balance your natural odor.
✓ Lemon or Lime
The citric acid in lemons and limes kill odor-producing bacteria. Simply cut a lemon or lime in half and rub it under your arms. You can seal the fruit in a glass container, refrigerate it and reuse it. Just be sure you label it so it’s not used in your next meal!
✓ White or Apple Cider Vinegar
Both white and apple cider vinegar will also kill bacteria. Neither product requires refrigeration. Fill a spray bottle with white or apple cider vinegar and keep it in the bathroom.
✓ Baking Soda and Water
Just like in your refrigerator, baking soda neutralizes odors on your body. Keep the container in the kitchen so it isn’t affected by the higher humidity in the bathroom. Sprinkle a little in the palm of your hand and dip a couple of wet fingers in the powder. Spread it under your arm.
✓ Hydrogen Peroxide
Hydrogen peroxide works by breaking the membranes of bacteria and reacting with catalase inside the cell. This causes the foaming you see. Mix a teaspoon of 3 percent solution with 8 ounces of water. You can increase the amount of hydrogen peroxide if needed. Dab on with a cloth or use a spray bottle.
✓ Tea Tree and Coconut Oils
Both oils are naturally antibacterial. Tea tree oil can be diluted — two to three drops in an ounce of water. Coconut oil may be used as a moisturizer under your arms, especially directly after shaving. You could also add a drop of tea tree oil to a small amount of coconut oil, and spread that under your arms.