Entries in Smell (6)


‘Old People’s Odor’ Exists, But Not Unpleasant

Comstock/Thinkstock(PHILADELPHIA) -- Elderly people do emit a characteristic odor, but it turns out they might actually smell better than younger people, according to a new study published online in PLoS ONE.

Researchers at Monell Chemical Senses Center in Philadelphia found that people could distinguish among the body odors of different age groups.

They asked 41 people to evaluate odors collected from the armpits of study participants from three different age groups -- people between the ages of 20 and 30; between 45 and 55; and between 75 and 95.

The evaluators rated the odors from the younger groups as more unpleasant than the odors from the elderly participants, and they also found that the older people’s odors were less intense.  The evaluators could also determine that odors came from old people, but could not correctly attribute the odors from the other groups.

These findings, said co-author Johan Lundstrom, confirm the popular belief of an “old people smell.”

“We do have an old people odor, but when taken out of the popular context, it doesn’t smell as bad,” said Lundstrom.

The study also found that younger men smelled worse than younger women, but among the participants older than 75, men and women smelled pretty much the same.

It’s not clear exactly what’s behind the ability to discriminate between the age groups and the sexes, the authors wrote.

“An older study found that there is one chemical that varies with age, but we don’t know if that’s the chemical people are picking out,” Lundstrom said.

It’s also possible that the loss of testosterone, changes in the skin, changes in the sweat glands or a combination of these factors play a role in why the sexes don’t smell much different at older ages.

There may be an advantage to being able to discern the smell of old age among animals.

For example, the authors wrote, “older male insects have a higher reproductive success than their younger competitors,” and “reproductive success is a highly sought-after trait.”

The authors also believe it’s likely that had the evaluators been aware that the odors came from elderly people, they may have rated them as more unpleasant.

Future research, they continued, will focus on identifying the mechanism behind age-related body odor discrimination.

Copyright 2012 ABC News Radio


Pork and Genes: How Pork Smells Genetically Determined, Says Study

iStockphoto/Thinkstock(NEW YORK) -- If you find the smell of pork revolting, it could be because that's how you're genetically programmed to perceive it, according to a new study.

Scientists found that there's a gene responsible for how a compound in pork smells to humans. The gene determines whether pork smells like ammonia, urine and sweat, or if it smells more like vanilla. The compound, androstenone, is similar to testosterone and found in high concentrations in male pigs.

The researchers gave study subjects pork containing androstenone and separated them into two groups -- those who found the smell offensive and those who didn't. Genetic analysis of the subjects revealed that those who didn't like the smell had two copies of a specific form of a gene known as OR7D4. The others had only one copy of the gene.

But, it turns out, most people don't even notice the smell of androstenone.

"In North America and Europe, pigs are castrated, so the concentration of androstenone is quite low," said Hiroaki Matsunami, a co-author and associate professor of molecular genetics and microbiology at Duke University Medical Center. "The only time you find a high concentration of androsteone is when you eat wild boar meat."

That could soon change, however. The researchers noted that the European Union is considering a ban on castration because of concerns over animal welfare, and this debate has rekindled interest in how humans perceive the smell of pork and why two people may smell it differently.

"The data raise the possibility that more consumers will dislike male meat as a result of a castration ban," the authors wrote.

Androstenone is also found in other male animals, but it's found in particularly high amounts in swine, Matsunami said.

How food smells, as everyone knows, also affects how food tastes, and this research helps confirm just how much the nose knows when it comes to taste.

"When food is in your mouth, odors come from the back of the throat up to the nose," said Gary Beauchamp, director of the Monell Chemical Senses Center in Philadelphia. "Taste is very complex. It depends on smell and other factors, such as personal experience and genetic background."

While the study is particularly interesting to scientists, it also demonstrates how genes play a role in many biological processes, including the senses.

"It's a very clear example of how people live in different sensory worlds, and some of the basis of that is our genetic differences," Beauchamp said.

Copyright 2012 ABC News Radio


People Who Lack Sense of Smell May Be More At Risk of Depression

Design Pics/Thinkstock(DRESDEN, Germany) -- People born without a sense of smell experience higher social insecurity and are at increased risk of depression than those who have functioning olfaction, a new study finds.

Approximately 14 million Americans suffer from some sort of lack of smell, according to the Anosmia Foundation.  Now, researchers from the University of Dresden Medical School in Germany have analyzed the questionnaires of 32 study participants with anosmia and found that participants born with isolated congenital anosmia, or ICA -- a lack of the sense of smell since birth in otherwise healthy people -- worried more about social situations than the control group.

Those with congenital anosmia reported worrying about their own body odor, were more likely to avoid eating with others and showed slightly higher scores for depression than those who could smell.

"ICA patients differ only slightly in daily life functions related to olfaction," study authors wrote.  "These differences are increased social insecurity, enhanced risk for depressive symptoms and enhanced risk for household accidents."

What makes these patients interesting when evaluating them in a clinic is that they have never known what it is like to smell, so it can be difficult for a physician to even ask them questions about it, said Dr. Eric Holbrook, of Massachusetts Eye and Ear Infirmary with Harvard Medical School.

"One common comment that I hear from adults who come to me with this problem is that they remember that they would lie to friends about being able to smell a strong odor while in a social gathering," said Holbrook.  "This seems mundane to people who can smell, but it stresses how these patients feel like they don't fit in at times."

Usually people who are most affected by lack of smell are those who could smell at one point and then lost the ability to smell, said Dr. Allen Seiden, director of the Taste and Smell Clinic at University of Cincinnati.  Otherwise, those who have never experienced smell may not experience such feelings of loss.

Copyright 2012 ABC News Radio


Bad Body Odor May Be Genetic, Treatable

Hemera Technologies/Thinkstock(PHILADELPHIA) -- People with intense body odor may have a rare but treatable genetic condition, according to a new study.

Researchers from the Monell Chemical Senses Center in Philadelphia found that 118 of 353 people who complained of bad body odor had trimethylaminuria — a metabolic disorder caused by a mutation in a single gene, FMO3.

“This research raises awareness of both the disease and also the proper methods of diagnosis and treatment,” study author Paul Wise, sensory psychologist at Monell, said in a statement. The results were published in the American Journal of Medicine.

The FMO3 gene mutation thwarts digestion of the common food chemical trimethylamine, which causes the stinky chemical to build up and ooze out in sweat, urine and breath. The foul smell gives the condition its nickname: stale fish syndrome.

Trimethylaminuria is extremely rare because the gene defect has to be inherited from both parents, according to the National Institutes of Health.  But for people with unexplained body odor, and who struggle in their social and professional lives as a result, getting tested for the condition could provide relief.

“Health care professionals must arrive at a correct diagnosis to suggest appropriate treatment,” said Wise.

Although there’s no cure for trimethylaminuria, avoiding foods high in trimethylamine, such as milk, eggs, certain meats, soy products and cabbage can help reduce the odor.

Copyright 2011 ABC News Radio


What Scent Arouses Men Most? The Proof Is in the Pie

Photo Courtesy - Getty Images(CHICAGO) -- Women know the way to a man's heart is through his stomach, but new research indicates the way to a man's bedroom is through pumpkin pie.

Staffers at Chicago's Smell and Taste Treatment and Research Center tested 40 aromas on men ages 18 to 64 to determine which one aroused them the most, and the smell of pumpkin pie beat even women's fragrances.

"The number-one odor that enhanced penile blood flow was a combination of lavender and pumpkin pie." said the center's director, Dr. Alan Hirsch.

Hirsch says pumpkin pie was the single strongest stimulant of the 40 tested.

Dr. Hirsch says every food odor tested aroused the male participants.

Copyright 2010 ABC News Radio


Researchers: Heavy People More Sensitive to Food Smells

Photo Courtesy - Getty Images(LONDON) -- British researchers have discovered that the heavier a person, the more sensitive they are to the smell of food.

Scientists at the University of Portsmouth say the relationship between weight and food smelling sensitivity might help explain why some are encouraged to eat more.

“It could be that for those people with a propensity to sort of gain weight, it's actually helping them to sustain food intake perhaps a little bit like an appetizer effect,” said team leader Dr. Lorenzo Stafford.

Stafford hopes his research may lead to new ways of thinking about and treating people with weight problems, and it may help to explain why some struggle to stay slim.

Copyright 2010 ABC News Radio

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