Tag: Body Odor

Does Sickness Smell?

(Dr. Mercola) Your olfactory sense, or the ability to smell, is integral to your health. Inside your nasal passages are two patches of cells designed to detect odors. They are made up of nearly 6 million olfactory receptor cells that allow you to detect and differentiate thousands of different scents. Although impressive, other animals have an even more acute sense of smell as often their survival is dependent on being able to smell enemies or their food.1

Your sense of smell is also intimately tied to your emotions, memories, ability to taste and even to sexual attraction. Research demonstrates that your ability to smell may peak at age 8. According to different studies, you may begin to lose sensitivity to scent between age 15 and your early 20s.2 However, that loss in sensitivity to scent is not consistent from person to person as some 80-year-olds have a sense of smell as keen as that of a young adult.

Some degradation of your sense of smell, and therefore your ability to taste food, may be related to air pollution.3 A combination of solvents, pesticides, disinfectants, pharmaceuticals, and perfumes may have a negative effect over the years on your ability to discern scent and on your sensitivity to smell.4 Loss of this ability may affect your capacity to pull up memories from the past.

Research shows odors are an effective reminder of experience,5 which may be tied to the way your brain processes odors and memories. Researchers have also found your sense of smell may predict your longevity, and you may be able to smell the scent of illness. In other words, the relationship between your sense of smell and your health is a two-way street.

Recommended: Candida, Gut Flora, Allergies, and Disease

Illness Has a Smell

From the early days of medical practice, doctors have used smell and taste to determine if their patients had a disease. Examples may be found from the late 1600s when English physician Thomas Willis observed the relationship between sweet-tasting urine and diabetes,6 to physicians today who may note a fruity scent on the breath of a diabetic whose blood sugar is too high.7 Over the years physicians have moved away from smell and taste to using more reliable methods of diagnosis.

However, a sensitive sense of smell may still give physicians a unique advantage. Some diseases have a particular scent. You may have even detected the scent of a sinus infection on the breath of a loved one. Researchers have described several scents related to diseases,8 including the smell of baked bread on someone with typhoid fever, boiled cabbage in someone unable to metabolize methionine, and the scent of a butcher’s shop on someone who suffers from yellow fever.

It appears that animals use this ability to maintain the health of the group.9 For instance, mice can determine through scent if another is sick, thus avoiding them. After testing this behavior, researchers concluded an inflammatory process in the body of a mouse had a profound impact on social behavior of the individual, reducing the motivation to engage in social interaction. At the same time, illness-related odor cues from a sick mouse inhibited social investigation by healthy members, thus impacting the transmission of disease.

Researchers tested this same response in human behavior and found you likely can smell if an immune response was activated.10Researchers injected participants with an endotoxin and found within a few hours they had a more aversive body odor compared to when they were exposed to a placebo. The researchers believed this chemosensory detection may represent the first experimental evidence that sickness smells.

Recommended: How to Detoxify and Heal the Lymphatic System

The researchers also noted the individuals who were sick did not sweat more. The smell from their body was not only stronger but also had a different odor.11 The smell coming from your body emanates from a variety of different areas, not just sweat or your breath. The scent that is “normal” for you will depend on your age, diet, metabolism, health and gender.12

Mats Olsson, Ph.D., lead researcher evaluating scent change in humans after exposure to an endotoxin, continued this work and found the feelings of disgust individuals experienced after smelling unpleasant smells activated a mild immune reaction.13 This, in turn, may help protect you from getting sick. He also explored other sources of scent, such as breath and urine, and found an inflammatory process was indicated by these odors and was a good indicator of some diseases.

How Does Illness Affect Body Odor?

In the original research, Olsson’s participants rated the scent of body odor, or the scent your body produces after bacteria on your skin breaks down proteins from your sweat into acids.14 Your sweat alone is virtually odorless, but the bacteria on your skin that multiply rapidly in the presence of sweat, and the subsequent breakdown of sweat into acids is what triggers the odor. Your sweat is specific to the individual, which is how dogs and other animals can identify different people.

Recommended: Holistic Guide to Healing the Endocrine System and Balancing Our Hormones

The genes that control your immune response also influence your body odor and scent production. An activated immune response may also change your excretion of metabolic byproducts that may also change your body odor.15 For instance, during stress your cortisol levels are higher, and during an immune response your androgen excretion is lower.16

Another example of body odor changing with different levels of hormones in your body is stress sweat. You likely have experienced this phenomenon at some point in your life — your body odor becomes strikingly different and worse when you are stressed. As cortisol and adrenaline, released when you’re stressed, flood your body, they may cause an increase in sweat production.17

However, this type of sweat is released from two different types of glands under your arms. Eccrine glands secrete sweat when you’re overheated, while apocrine glands contribute sweat when you’re stressed.

The difference is that sweat secreted from your apocrine glands contain more of the nutrients bacteria on your skin require to grow and multiply. These added nutrients increase the byproduct of the bacterial metabolism and change the smell and strength of the odor coming from your sweat. In the same way that a “sick smell” triggers an immune response in others, this type of sweat changes the way you’re perceived.18

Man’s Best Friend May Help Detect Disease

Dogs have been used to help people with diabetes detect abnormally high or low blood sugar before they can feel it and predict seizures before they happen. Today, researchers are working with canines to help detect the scent of cancer. Several demonstrations of how dogs are being used to detect medical changes, including the diagnosis of cancer, are shown in this short news video.

Recommended: How to Make the Healthiest Smoothies – 4 Recipes

A dog’s ability to smell is far greater than a human’s. While you have 6 million olfactory receptor cells, dogs have 300 million, and the part of the brain that is devoted to analyzing those odors is proportionally 40 times larger than yours.19 Dogs in the study in Britain detected bladder and prostate cancer 90 percent of the time or greater. In another study, dogs could detect lung cancer with up to 85 percent accuracy.20

In yet another example, a Labrador retriever was trained to detect the scent of colorectal cancer from breath and stool samples with greater than 90 percent accuracy.21 Using breath samples, the dog could detect colorectal cancer with 91 percent accuracy and had an amazing 97 percent accuracy with stool samples. The researchers concluded:22

“This study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating throughout the body. These odor materials may become effective tools in colorectal cancer screening.”

Even without training, dogs can detect differences in their owners and warn them of impending problems. In a study of 212 dog owners with medically diagnosed Type 1 diabetes, researchers found 65 percent reported their untrained dogs had warned them of an impending hypoglycemic event by barking and growling.23

Researchers have known that malignant tumors exude tiny amounts of alkanes and benzene derivatives that are not found in healthy tissue.24 In another study using dogs to detect either lung or breast cancers, the researchers found the animals were 88 percent accurate with breast cancer and 99 percent accurate with lung cancer detection, with no false positives.25 However, while the dogs provide a noninvasive way of screening for disease, many medical professionals find the practice controversial.26

Not all studies demonstrate the same accuracy, although the scent may be confounded by other odors present in the area, such as hospital odors when tests are done in the hospital. Accuracy is also slightly different between individual dogs, in much the same way that behaviors between most trained animals occur. Some researchers are interested in isolating the exact compounds detected by the dogs so training may be standardized.

Next-Gen Dog Noses

Since some studies have not been able to replicate the results, and the animals do not perform the same way 100 percent of the time, scientists have been investigating the use of electronic noses. The concept is similar to the devices built to detect explosive components used in bomb making.27 Early use of electronic noses was undertaken by police departments to identify and quantify alcohol use in drivers.

However, for electronic devices to function, researchers must first identify the chemical components of the disease that are causing the smell. Scientists believe this may standardize the process and improve diagnosis using noninvasive methods. Using an electronic method may also overcome skepticism of physicians who may not want dogs participating in the diagnosis of disease, but may be more comfortable with an electronic device similar to one in use since 1967 to test alcohol levels on your breath.28

Recommended: Start Eating Like That and Start Eating Like This – Your Guide to Homeostasis Through Diet

While electronic devices may be more acceptable in the medical community for diagnosis, dogs continue to be an important adjunct to the management of several metabolic and neurological disorders. According to George Preti, Ph.D., organic chemist at Monell Chemical Senses Center:29

“There are groups looking to fund research with dogs as detectors because dogs can pick up the odors in people, particularly children who are not properly regulating themselves, Type 1 diabetic children. They can be trained to pick up this peculiar odor on the breath at an early stage and warn people that they are having a low or going into a high of blood sugar.”

Importance of Smell to Your Health and Predicting Death

Your sense of smell may also have predictive value in determining your longevity, and changes in your sense of smell may indicate the early stages of dementia.30 Smell is inextricably linked to memories formed in the limbic area of your brain. In a study of nearly 3,000 people ages 57 to 85, researchers found that nearly all the participants who could identify only one or two of five different scents had evidence of dementia five years after the test was completed.31

The olfactory nerve is located deep in the base of the brain. When you have problems with smell, it may indicate a higher likelihood you may develop Parkinson’s disease or other neurological disorders, such as Alzheimer’s disease. According to the U.S. Centers for Disease Control and Prevention, Alzheimer’s is the sixth leading cause of death in the U.S. and has an annual research budget of $480 million.32

Recommended: Detox Cheap and Easy Without Fasting – Recipes Included

Researchers hope that by using a simple and inexpensive smell test for early identification, patients may be saved the cost of an MRI and offered early intervention to slow the progression of the disease. In an analysis of similar data from the National Social Life, Health and Aging Project,33 researchers found an inability to perceive odor was associated with a four times greater risk of death in the following five years, compared to those who had a healthy sense of smell.

The researchers took into account potential confounding factors, such as nutrition, smoking, cognitive function and alcohol abuse. The researchers concluded that your olfactory sense was one of the strongest predictors of five-year mortality. As reported in the Guardian:34

“The olfactory nerve is the only part of the nervous system that is exposed to the open air. As such, it offers poisons and pathogens a quick route into the brain, and so losing smell could be an early warning of something that will ultimately cause death.”

The loss of sense of smell is also a symptom of zinc deficiency. You can read more about this deficiency, how to test for it and the foods that may balance your zinc levels in my previous article, “Study Warns That Losing Your Sense of Smell May Mean You May Not Live Much Longer.”

What You Eat Affects Your Body Odor

(Dr. Mercola) An interesting study from a university study in Sydney, Australia, reports that what you eat influences how you smell — or rather, what you eat affects your body odor and, as a result, may affect other peoples’ response to how you smell. In addition, how you smell can also tell the story of your health, particularly in relation to the axillary (i.e., underarm) area of your body. (You may have noticed that body odor, good or bad, generally exudes from your armpits more than any other area.)

There are several reasons why people sweat. Stress, anxiety, fear, exercise, high temperatures, nervousness, anger and fever can all trigger a sweat response. Age, overall health profile and weight can, too, but even given the same factors, some people simply generate more sweat than other people on any given day. Skin spectrophotometry was used in the study1 to measure levels of carotenoids, naturally occurring antioxidant pigments, as a gauge of fruit and vegetable intake.

According to the scientists’ premise, eating lots of fruits and vegetables, which contain many potent carotenoids, will positively affect what you smell like. There are more than 700 types of natural carotenoids, the most well-known being beta-carotene. You probably have about 10 or 20 different carotenoids circulating through your bloodstream at any given time.2

The study included a food frequency questionnaire. Fast-forwarding to the conclusion, the upshot was that people — in this case, men — generally emit more pleasant-smelling sweat, described as having “more floral, fruity, sweet and medicinal qualities,” when they eat more produce as opposed to carbs. Females were given the task of evaluating the sweat samples.

On the purely physical side of the attractiveness equation, yellower, more carotenoid rich-skin was generally thought to be more appealing.3 Many think that what someone eats may affect, for good or for ill, the smell of their breath, but doesn’t modify their body odor, but the study showed that it definitely does.

In fact, some people avoid eating onions or garlic because they have that perception. But that’s not what happens, The Salt points out: “Body odor is created when the bacteria on our skin metabolize the compounds that come out of our sweat glands.”4

Related: Understanding Stress, Chronic Stress, and Adrenal Fatigue

So Vegetable Sweat Smells Better — What Else?

Study author Ian Stephen, of Macquarie University in Sydney, Australia, noted that the smell of someone’s sweat gives off more than just odor: It also conveys a person’s health status and immune fitness, and may even influence someone’s ability to attract a mate. “We’ve known for a while that odor is an important component of attractiveness, especially for women,” Stephen said, explaining that in the study, several descriptors were given to the female sweat smellers to prompt their perceptions of what they detected.

“Women basically found that men who ate more vegetables smelled nicer.”5 Interestingly, the men who had a penchant for pasta, white potatoes and bread had the strongest-smelling and least pleasant-smelling sweat of all — including compared to a high intake of fat, meat, eggs and tofu.

Consumption of the latter group of foods (fat, meats, egg and tofu) was actually associated with more pleasant smelling sweat when self-reported dietary data was factored in. Stephens’ study wasn’t the first to test whether a person’s diet influences their body odor.

A study by researchers in the Czech Republic, published in 2006,6 reported that women prefer the smell of men on a non-meat diet compared to those who ate meat. The male study subjects were placed into two groups, one group on “meat” and the other on “non-meat” diets for two weeks, wearing pads in their armpits to collect their perspiration during the final 24 hours. The 30 females assisting them were asked to assess the sweat samples for their pleasantness, attractiveness, masculinity and intensity.

A month later, the same group of guys repeated the drill but switched their diets. The scientists concluded that red meat consumption has a negative impact on perceived body odor and, further, on hedonicity — perceived body odor stored in the memory,7 and the premise remained consistent when the men’s diets were changed. In the featured study, meanwhile, meat intake did not appear to affect how pleasant the women rated men’s sweat, although they did find it to be more “intense” among the meat-eaters.8

Related: Start Eating Like That and Start Eating Like This – Your Guide to Homeostasis Through Diet

Never Let ‘Em See You Sweat

One study indicated that women aren’t the only ones to make judgments based on the smell of another person’s sweat. The Monell Chemical Senses Center conducted a study on how, for both sexes, the smell of someone’s body odor influences social judgments. Case in point: Research shows that body odor can be perceived by others as a “psychosocial” stress indicator, which may lead men to negatively judge a woman’s emotional state and make further psychological evaluations, such as judging her competence.

Forty-four women provided sweat samples under the following conditions: untreated exercise sweat, untreated stress sweat and treated (with a commercial antiperspirant) stress sweat. The results were quite interesting, the study reports:

Axillary odors obtained from women experiencing psychosocial stress could negatively influence personality judgments of warmth and competence made about other women depicted in video scenarios. A separate group of male and female evaluators rated the women in the videos while smelling one of the three types of sweat samples.

Women in the video scenes were rated as being more stressed by both men and women when smelling the untreated versus treated stress sweat. For men only, the women in the videos were rated as less confident, trustworthy and competent when smelling both the untreated stress and exercise sweat in contrast to the treated stress sweat. Women’s social judgments were unaffected by sniffing the pads.”9

The researchers concluded that the study has implications in regard to influencing “multiple types of professional and personal social interactions and impression management” and led to better “understanding of the social communicative function” of what people smell like. Needless to say, the implications of how some people can judge someone else’s body odor, good or bad, are huge, especially if they trust their own interpretations.

Related: The Power of Our Hormones and How To Balance Them

Don’t Sweat the Small Stuff

In today’s world, bathing regularly and using deodorant and antiperspirant is commonplace. There are probably not many who intentionally go around smelling like last week’s workout T-shirt. But a hundred years ago, B.O. — the bad kind — was just a fact of life. Keeping it under control was a fruitless endeavor (pun intended). Blocking your armpit sweat glands has been the American way for several generations.

It first emerged when a high school student from Cincinnati attended an exposition in Atlantic City in the summer of 1912 to see if she could promote the liquid antiperspirant her surgeon father had created. The doctor’s invention was to alleviate sweaty hands — a bit of a problem when you’re trying to perform surgery when air conditioning, although invented 10 years prior, wasn’t considered a requirement in every hospital.

Edna Murphey had tried the product herself and found that it did the job on both wetness and odor. She named it Odorono (Odor? Oh No!). But Victorian sensibilities hadn’t yet caught up to the fact that people can smell bad for any number of reasons. Body odor also wasn’t necessarily considered something that should be repressed, or even if it could be, remained off limits in terms of discussion. Response was tepid.

Mum was a more successful roll-out, marketed as early as 1888 for its ability to kill odor-causing bacteria. But that was an era when bathing and excessive amounts of perfume were the only answers to body odor. Dress shields, a pair of thin, half-moon-shaped pads (usually cotton or even rubber) strapped to the upper arms to soak up the offending underarm moisture was the best solution anyone could think of.

Related: Holistic, Natural Remedies for Hyperhidrosis

That smelling bad wasn’t necessarily desirable was a novel concept. Luckily, the expo where Murphey endeavored to market her father’s product was a long one and so was that particular summer. Customers figured they may as well give it a try, so while sales were pretty stinky at first, they soon flourished. In a few months, Murphey had $30,000 to spend on much-needed publicity. Smithsonian magazine noted:

“Although the product stopped sweat for up to three days — longer-lasting than modern day antiperspirants — the Odorono’s active ingredient, aluminum chloride, had to be suspended in acid to remain effective. (This was the case for all early antiperspirants; it would take a few decades before chemists came up with a formulation that didn’t require an acid suspension.)”10

Odorono still had problems, though, a really big one being aluminum chloride being used as the main ingredient, although for different reasons than today. The wrinkle was soon ironed out by a psychological “bazinkle” — a clever marketing ploy persuading people they had an odor problem that everyone around them was too kind to tell them about. That did it. Sales skyrocketed by 112 percent in a single year.

How Diet, Deodorant, Antiperspirant, Chemicals and Fabric Can Be Related

It’s probably no surprise that a century later, the deodorant/antiperspirant industry was a booming $18 billion enterprise. Ironically, body odor became a bigger problem within a few years of deodorant hitting the scene for one simple reason: the invention of synthetic fabric.

A European study observed that polyester fabric worn by athletes had a profoundly increased tendency to absorb sweat smells. It stated: “The polyester T-shirts smelled significantly less pleasant and more intense, compared to the cotton T-shirts.”11 Worse, some fabrics scientists tested were even treated with toxic triclosan.

Related: How To Make Your Own Natural Deodorant at Home – Recipe

But there’s also the problem of the chemicals often used to make deodorant and antiperspirant. Both aluminum chloride and aluminum chlorohydrate can interfere with estrogen receptors in breast cancer cells, and estrogen plays a well-known role in breast cancer. Parabens used as a preservative have also been linked to cancer.

There’s also the fact that sweating is a natural and beneficial bodily response on many levels, and blocking it via antiperspirant is not a good idea. An all-natural deodorant can be made by mixing equal amounts of baking soda, softened coconut oil and either organic cornstarch or arrowroot powder.

If you have sensitive skin, you might try using a little less soda. Make sure the mixture stays mixed, as warm weather can cause some ingredients to “settle.” To incorporate a fragrance, a few drops of lavender essential oil (or your favorite) can also be added. Simply washing your armpits with soap and water is also an effective way to remove odors. Between making your own all-natural deodorant and eating lots of vegetables and fruit, your perspiration will take on a sweet-smelling quality, and so will your health.