1 in 15 adults over age 40 experience phantom odors

Read a study documenting how 'old people' smell increases with age

Analysis of body odors from individuals aged 26 to 75 confirmed that 2-nonenal, an unsaturated aldehyde with an unpleasant, greasy, and grassy odor, was detected only in subjects aged 40 and older.

'Old people' smell is real—it's a chemical buildup when fatty acids on the skin oxidize

The chemical composition of body odor seems to change with age. Later in life, we harbor higher concentrations of a chemical compound called 2-nonenal that forms when omega-7 fatty acids on the skin oxidize, and the skin's natural antioxidant defenses weaken. Commonly called "nonenal", it's the smell widely associated with aging, and it's often described as a grassy or greasy odor.

Roughly 15 of every 1,000 people in the US have smell disorders

Anosmia is a lack of a sense of smell. It can be present at birth, related to diseases including Parkinson's, Alzheimer's, and COVID-19, or have unknown causes.

Humans can't smell the inside of their nose due to olfactory fatigue

Once a person is accustomed to a specific odor, their neurons have trouble continuing to respond to that smell because of that familiarity. That's why humans may not notice when their house smells like trash until they leave the house and then return to it.

Humans may be able to distinguish more than one trillion scents

That's according to one estimate published in 2014. This figure far exceeds earlier estimates of a human smelling ceiling around 10,000 odors. The newer figure is derived from experiments in which volunteers agreed to sniff varying scents. Researchers mixed odor components and had volunteers sniff the brews to detect subtle scent differences. (Some users may experience a paywall.)

Smell is a robust memory cue for individuals with Alzheimer's disease

Odor is more effective than both visual and verbal cues for triggering autobiographical recall in Alzheimer's disease, according to 2021 research.

Smell retraining can help people with anosmia learn to smell again

Olfactory training, which involves repeatedly smelling a selection of strong odors, teaches your brain to familiarize itself with experiencing smells over a lengthy period, typically multiple months. This can be useful for patients who lose their sense of smell for myriad reasons.

Loss of sense of smell is a common symptom of COVID-19 infection

In 2020, researchers discovered why this occurs. The virus that causes this infection attacks the cells that support smell-detecting neurons. Once infection clears, the sense of smell typically returns, though the exact timeline for that differs by patient. (Some users may experience a paywall.)

Paul Broca, a French brain researcher in the 19th century, hypothesized that humans evolved to trade in our "bestial sense" of smell for higher brain capacity.

Hereditary hyperosmia is the official term for being a super-smeller

Some sniffers with this rare trait may be more sensitive to pleasant smells, while others may be more attuned to unpleasant scents. Some research suggests that certain genetic mutations are associated with a heightened sense of smell.

A super-sniffer smelled her husband's Parkinson's disease years ahead of symptoms.

Anosmia is the total loss of the sense of smell

This type of loss—due to disease or trauma—has ripple effects, including an altered or limited sense of taste. This video details the anatomy and physiology of our sense of smell and taste and how these senses are interrelated.

A stand-in 'nose' may help people with anosmia to smell certain odors

In a 2025 paper, researchers reported they'd created a proof-of-concept device that bypasses typical olfactory pathways and instead exploits an alternative—the trigeminal nerve in the nose—to detect a few strong scents. The nerve typically helps detect the temperature of inhaled air or the presence of irritants. (Some users may experience a paywall.)

Heightened sense of smell during pregnancy is not yet well understood

Boosted smell powers and strong reactions to them are often reported beginning around the six-week mark of pregnancy. Researchers say hormonal changes likely play a role, but the change remains poorly understood.

Adults are developing food allergies that they didn’t have as children

Research published in 2019 found that almost half of 40,000 surveyed adults with food allergies developed a new food allergy as adults, underscoring that our immune systems may newly misclassify substances later in life.

How our sense of taste evolves as we age

Kids are hardwired to prefer sweets over greens, with sweetness a shorthand for calorie-rich and bitter flavor warning of potentially noxious plants. This holds true even in the womb, where fetuses have been seen via ultrasound scans grimacing as their hosts consume kale capsules. As they age into double digits and beyond, their taste cells and sense of smell diminish, leading to broader and less sensitive palates.

Carboxylic acids are one reason teens are smelly

Scientists compared the smells of babies and teenagers and identified some of the compounds that make teens smelly. Carboxylic acids present in teens, they wrote, seemed to give off an "earthy, musty, or cheesy" scent. This 2024 research could help inform future odor-control products.

On average, people smell worse if they're sick

For a small 2014 research study, a panel was tasked with sniffing the smelly t-shirts of people who had been injected with a compound known to activate the immune system and those of controls without the shot. It found that those who were acting as if unwell (due to the injection) generally smelled worse. Subsequent work found that those who sniffed unpleasant odors had a mild immune response of their own—perhaps to protect them from disease. (Some users may experience a paywall.)

Vertigo is two to three times more common in women than men

Dizziness, including vertigo, occurs among 15% to 20% of adults. Vertigo can have numerous causes, but generally it's more common with age. It's also much more common among women than in men—occuring roughly two to three times more frequently, sometimes potentially related to the hormonal fluctuations of menopause or to migraines.

Olfactory training, a widely recommended treatment for people with long-term loss of smell after a viral infection like COVID, can be performed at home using bottles of essential oils—often lemon, rose, clove, and eucalyptus—to help reorganize neural connections in the brain.

Gen Z's love for perfume is boosting sales

Teen boys are the biggest driver in perfume sales as of the summer of 2025. They have increased their spending on fragrances 26% year-over-year as the trend blossoms on TikTok via #PerfumeTok. Additionally, users of weight loss drugs GLP-1 agonists are adding to sales, as they seek olfactory over culinary sensations.

Our sense of smell affects what foods taste like and how we perceive it

Scent stimulates our olfactory sensor neurons high in the nasal cavity, and the brain attaches labels to those scents. But when we eat, chemicals from the foods travel from our mouths and throat to those neurons. We have roughly 400 odor receptors, and they can be used to decipher more than 10,000 different odors (or more than one trillion by some calculations), including the nuances of different foods.

A 'fishy' scent does lead to mistrust

In experiments where people were exposed to a literal fishy smell they were less willing to cooperate with others in economic games requiring trust, but that wasn't the case when they were exposed to another bad odor—the smell of flatulence.

Phantom limbs aren't just limited to limbs—there are phantom breasts, teeth, and more, and these sensations are often painful.

Scent is a stronger memory trigger than sight

Smell is imbued with more emotion than visual memories, and research indicates that smell triggers a significantly greater effect on amygdala activation. Scientists believe these powerful responses occur partly because smell signals bypass the thalamus and go directly to the amygdala and hippocampus, brain areas involved in emotion and memory.

Scientists are reconstructing ancient smells—including a 3,500-year-old ancient Egyptian mummy

Researchers explain how they have recreated the scent of ancient Egyptian mummies and enabled museum-goers to experience that scent on specialized cards. The exhibit will be at the Royal BC Museum in Canada in June 2026.

Nonamputees can be tricked into thinking they have phantom limbs with rubber arm experiments.

One decibel of hearing loss increases tinnitus risk by 6% for older people

That's according to an analysis of more than 18,000 people published in BMC Medicine in 2023. The tinnitus risk is not just limited to older people: The research also concluded that one decibel of hearing loss increases the risk of developing tinnitus among young adults by 3 percent.

Menopause and perimenopause symptoms may affect both the mind and the body

Women going through these aging transitions may experience some common physical and mental symptoms to varying degrees, including hot flashes, bladder control issues, brain fog, and vaginal dryness. This article dives into some of the most common symptoms women might expect during perimenopause, plus what they can do to relieve them.

Read the academic article explaining how ancient smells can be dissected and recreated

This paper explores how biomolecular data on past scents can be teased out and then transformed into olfactory museum experiences, adding another component to our understanding of archaeology.

A 2025 study explored the common words to describe body odor across 17 countries

The work identified the 25 most frequent words used to describe body odors across languages, ranked by frequency, and found that "sweaty" topped the list, followed by "sour" and "stinky."

Fear has a specific 'smell'—at least to machines

This excerpt from a Mythbusters episode takes on the smell-of-fear question, comparing the sweat composition of individuals exposed to snakes, rats, and scorpions with that of people exercising. Molecularly, the sweats are different to a gas chromatography machine, but to most noses would be indistinguishable.

Women experience heightened bone loss after menopause

Both women and men begin to lose some bone density after age 35, on average. But, for the first decade after menopause, women lose bone more rapidly due to the significantly decreased levels of estrogen, putting women at heightened risk of osteoporosis and related bone fractures.

The importance of volatile aroma compounds in the flavor quality of food

Processes such as air movement and heating cause food to lose aroma molecules, which studies have shown play a major role in our sense of taste. While losing these molecules to the environment leaves fewer to be processed during consumption to intensify flavor, it can also produce previously nonexistent aroma compounds or release previously trapped ones, altering or enhancing the food's flavor.

More than half of American adults believe in the afterlife

It’s hard to find actual data regarding ghosts, but a survey conducted by Pew Research Group in 2023, revealed that around half of the US adult population believes ghosts can interact with the living, with most thinking that spirits can help rather than harm us.

Explore the chemistry of undesired body odors

This graphic highlights some of the main compounds in different body odors, including halitosis (bad breath), flatulence, and foot odor.

Why young women experience the most workplace ageism

While one might assume that older women face the most unfair treatment due to age in the workplace, some research from McKinsey & Co. suggests otherwise. The consulting firm found that while ageism impacts older women and men at similar rates, women in their 20s and 30s report much higher instances of ageism than both older women and their young, male colleagues. Learn more from the research here.

Roughly 10% of the world's population is older than 65 (2023 data)

With recent advances in medicine, sanitation, and nutrition, expected lifespans have rapidly risen around the globe—resulting in a rapidly aging global population. The worldwide distribution has seen a nearly 600% jump in the population of people aged 65 and older.

Americans spent $6.6 billion on body odor products in 2023

This high figure from Euromonitor, a research firm, suggests Americans spent more on deodorant than in any other country. Beyond deodorant, there's also growing interest in "whole body" deodorant designed to mask smells from various parts of the body beyond the armpit.

Why your wine smells unpleasant

Ever had the experience of receiving a bottle of wine with a janky, less-than-favorable odor? This Esquire article ventures to answer this question and offers the explanation that the culprit is likely corked wine. Read to understand why corks can create a moldy or musty scent, and feel emboldened to send a corked bottle back for something with improved quality.

Perimenopause can last as long as 8 years

Perimenopause typically lasts about four years, beginning at around age 45; however, some women experience it as early as their 30s. Smoking and thyroid disease are factors that can trigger early perimenopause. Early menopause, which can increase health risks, occurs in about 5% of women. Researchers are still investigating why it occurs.

Super-agers: seniors 80 and above with the memory ability of people in their 50s

Studies show the number one indicator of whether someone is a "super-ager" is not diet or genetics, but the extent of their social relationships. Moreover, scans reveal noticeable physical differences in certain parts of the brain in patients with extensive social networks.

Health problems are being misdiagnosed as perimenopause symptoms

Symptoms of menopause and perimenopause (the premenopause period) can be varied enough that clinicians dismiss them in patients in their mid-30s and onward as just a symptom of hormone level change. In this story, a woman's itching was dismissed as a hormonal change, but after two years and 11 separate doctor consultations, was diagnosed as cancer. (Some users may experience a paywall.)

Ultraprocessed foods are linked with a 58% elevated risk of developing dementia.

Perceived isolation ages you

Mounting evidence suggests that socialization is a vital component of maintaining good health. Research published in 2024 from Mayo Clinic researchers analyzed the social lives of more than 280,000 adults and concluded that individuals that weren't likely to participate in extracurricular social activities and get-togethers were more likely to have a biological age older than their actual age—meaning that you may be 60 but health indicators would suggest you're older.

The most unique-smelling places on Earth

Have you ever picked a travel destination by smell? This Atlas Obscura piece cultivates a list of the most distinct-smelling spots in the world. Learn about these obscure scents to potentially book a trip to a spring that smells like rotten eggs, or a desert valley filled with frankincense trees.

Less than 1% of aging studies consider menopause and its effects

Nearly all studies researching the biology of aging don't consider menopause in their setup. In part, that's because menopause is difficult to emulate in animal models. Menopause is uncommon in the animal world beyond humans and whales. This presents a problem for medicine and science because about 75% of aging-related diseases are likely influenced by menopause.

Most people with East Asian ancestry are genetically predisposed to be less smelly.

Typhoid smells like freshly baked brown bread

Certain ailments are associated with documented scents, including diabetes, Parkinson's disease, and typhoid. The skin of people with yellow fever, for example, can smell like a "butcher shop."

Examining self-diagnosed synesthesia

A growing number of people on social media claim to have a perceptual condition that lets them smell colors, see music, or taste sounds. But do they really?