Myth ‘debunked’: The blind have more acute sense of smell

Washington, Apr 27 (ANI): An ongoing study has debunked the myth that the blind have a more acute sense of smell than the sighted.

According to the study by Mathilde Beaulieu-Lefebvre, a graduate student from the Université de Montréal Department of Psychology, vision loss simply makes blind people pay more attention to how they perceive smells.

“If you enter a room in which coffee is brewing, you will quickly look for the coffee machine. The blind person entering the same room will only have the smell of coffee as information,” says Beaulieu-Lefebvre. “That smell will therefore become very important for their spatial representation.”

The three-step study tested 25 subjects, 11 of whom were blind from birth. Participants answered a questionnaire and were subjected to two experiments: one where they had to differentiate 16 different perfumes using an olfactometer, another where they lay in a tomodensitometer to identify three smells: a rose, vanilla and butanol (a sweet alcohol).

“There is an urban legend that blind people have better smell than the sighted. We are proving this to be false,” says Maurice Ptito, a professor at the Université de Montréal School of Optometry and Beaulieu-Lefebvre”s thesis director. “However, the blind do set themselves apart when it comes to cognitive efforts.”

Using functional imagery, the team determined that the blind use their secondary olfactory cortex more than the sighted when they smell. They also use the occipital cortex, which is normally used for vision. “That”s interesting because it means the blind are recuperating that part of their brain,” says Dr. Ptito. “We”re not speaking of recycling per se, yet that part of the brain is reorganized and used otherwise.”

This research could lead to concrete applications in the re-adaptation of the blind. “For instance, smells are very peculiar in shopping centers,” says Beaulieu-Lefebvre. “A hair salon, a pharmacy and a clothing store each have their own distinctive scent. We could easily foresee developing re-adaptation programs for getting around in such places.” (ANI)

Dark coffee ‘good for your tummy’

Washington, Mar 22 (ANI): Espresso, French roast, and other dark-roasted coffee are not harmful for the tummy as was previously believed because these roasts contain a substance that tells the stomach to reduce production of acid, according to a study.

And people who resist from enjoying that much-desired morning cup of coffee, because of fear of stomach irritation can also take a sigh of relief because scientists have discovered the culprits behind that heartburn and stomach pain in every cup.

The research could lead to a new generation of stomach-friendly brews with the rich taste and aroma of regular coffee, said the scientists.

“This discovery is going to help a lot of people who suffer from coffee sensitivity. As coffee-lovers, we”re very excited about this research,” said Dr. Veronika Somoza from the University of Vienna in Austria, and Dr. Thomas Hofmann, from the Technische Universitat Munchen in Germany, who conducted the study.

Doctors think that chemicals in coffee cause the stomach to overproduce acid, while some coffee drinkers take antacids or drink decaffeinated coffee in an effort to reduce this effect, while others turn to a small but growing number of specialty coffee brews marketed as stomach friendly.

Somoza said that the processes used to produce stomach-friendly coffee also could reduce the amount of healthful substances in the coffee, including some that scientists have linked to benefits such as protection against diabetes and heart disease.

In addition, the processing can affect the robust taste and smell of coffee.

To study the irritants in coffee, the scientists exposed cultures of human stomach cells to a variety of different coffee preparations, including regular, dark-roast, mild, decaffeinated, and stomach-friendly.

They identified several substances that appeared to trigger chemical changes associated with increased acid production.

These substances include caffeine, catechols, and other ingredients.

“Our data show, for the first time, that caffeine, catechols and N-alkanoly-5-hydroxytryptamides are those coffee components that stimulate molecular mechanisms of stomach acid secretion in human stomach cells. Most of them are indeed removed by steam or solvent treatment of the raw coffee bean. We found out there”s no single, key irritant. It is a mixture of compounds that seem to cause the irritant effect of coffee,” said Somoza.

The scientists unexpectedly found that one of the coffee components, N-methylpyridium (NMP), seems to block the ability of the stomach cells to produce hydrochloric acid and could provide a way to reduce or avoid stomach irritation.

Since NMP is generated only upon roasting and not found in raw coffee beans, darker-roasted coffees contain higher amounts of this stomach-friendly coffee ingredient.

Dark- roasted coffee can potentially contain up to twice as much of the ingredient as light-roasted coffees, but its levels can vary widely depending on the variety of coffee bean and the roasting method, noted Somoza.

“Since NMP is generated upon roasting, dark-roast coffees contain high amounts of this stomach friendly coffee ingredient. Now, there is hope for a good morning start with a freshly brewed cup of optimized stomach friendly coffee,” said the researchers.

The scientists are testing different varieties of raw coffee beans and different roasting methods in an effort to boost NMP levels to make a better stomach-friendly coffee.

They hope to test the new brew in human volunteers later in 2010.

The study has been presented at the 239th National Meeting of the American Chemical Society. (ANI)