smell Archives - Amazing Health Advances

6 Things You Didn’t Know About the Science of Smell

The AHA! Team — Mon, 17 Feb 2025 06:36:45 +0000

Zachy Hennessey via Israel21c – Here are some of the coolest things Israeli researchers have sniffed out about the underappreciated sense of smell. You may not think it’s so important, but scientific research has done a lot to prove that your sense of smell has a lot of value besides checking if that two-week old cream cheese is starting to go bad (it is). We here at ISRAEL21c have been covering breakthroughs in smell research for over a decade; below are seven of the more incredible olfactory discoveries over the last few years that are sure to pique your interest — and your nose. 1. Like ‘white noise,’ there’s ‘white smell’ In 2012, a team of researchers from the Weizmann Institute of Science (led by the noted olfactory researcher Prof. Noam Sobel) discovered that it’s possible to make a smell that our brains perceive as completely neutral — a so-called “white smell.” Just like white noise and the color white itself are blends of audio frequencies and light waves, respectively, white smell can be created by taking an amalgamation of about 30 different points across the scent spectrum and blending them together. They even invented a fancy name for the new smell: Laurax. That’s going right to the top of my “names for obscure smells” list, right above “Petrichor” (the smell that comes after a long-awaited rain), and right below “Yuckamolis” (my four-year-old’s description of the smell of my feet). 2. If you can’t smell, you’ll die faster Bad news if your sniffer’s out of commission: According to research published this year in Nature Communications, people who don’t have a sense of smell have a reduced life expectancy. Researchers at Weizmann found that people who don’t have a functioning olfactory sense have unique breathing patterns that could be linked to depression, anxiety and other negative health outcomes which, all in all, add up to a minus on life’s upper limits. A bit off our topic, but nonetheless fascinating, the same paper reveals the critical importance of sighing to good health. The researchers explain that “to maintain life, patients need not only to breathe rhythmically, but also sigh every 5 min[utes] or so, as this is critical for preventing collapse of alveoli in the lungs.” 3. Your nose has spots for different smells You may have heard that different parts of your tongue can taste different flavors. Well, the same goes for your nose. Back in 2011, Sobel and a group of Weizmann researchers found that there are specific areas in your nose dedicated to processing pleasant and unpleasant smells. This means that there are objective ways to measure whether an odor is actually bad and not a matter of personal taste: if the “yucky” sensors are the ones that process the smell of rotten fish, for example, then it’s a safe bet that rotten fish is definitively a bad smell. “We uncovered a clear correlation between the pattern of nerve reaction to various smells and the pleasantness of those smells. As in sight and hearing, the receptors for our sense of smell are spatially organized in a way that reflects the nature of the sensory experience,” Sobel noted. 4. Our friends smell like us Research conducted by — you guessed it — the Weizmann Institute in 2022 discovered that we tend to be friendlier with people who smell like we do. Using a fancy electronic nose, researchers discovered that close friends often share similar body odor patterns, a finding that goes beyond mere coincidence. The team put this theory to the test with both existing friends and strangers, finding they could predict with 71 percent accuracy which people would form social bonds based on smell similarity alone. 5. The smell of women’s tears makes men less aggressive Weizmann scientists also discovered that women’s tears contain chemicals that significantly reduce aggressive behavior in men. In the experiments, men who sniffed women’s tears (without knowing what they were smelling) showed 44% less aggressive behavior in a revenge-based game compared to when they sniffed saline. As we all (definitely) know, a similar phenomenon has been observed in other animal populations, like mice. The crazy thing is, humans don’t even have the biological parts necessary to detect the signals that lady tears give off — our noses just pick up on the odorless chemicals and our brains know what to do in response. Considering this discovery, I wouldn’t be surprised to see a lot more sports bars having a spray bottle of woman tears on hand to cool off rowdy patrons. 6. Your nose could keep you on life support If you’re in a coma — first of all, I’m impressed that you’re reading this, but also — your nose may be able to communicate with the doctors around you. Scientists at (drumroll please…) the Weizmann Institute and Loewenstein Rehabilitation Hospital discovered that, by measuring changes in patients’ nasal airflow when exposed to different odors (like fragrant shampoo or rotten fish), those who showed even slight reactions to smells had a 100% rate of regaining consciousness during the four-year study period. The test also predicted with 92% accuracy which patients would survive for at least three years. This discovery is a big deal because current methods of diagnosing consciousness in brain-injured patients can be wrong up to 40% of the time, which affects critical decisions about life support and pain management. The new “sniff test” is simple, inexpensive and can be done at a patient’s bedside. The bad news is that this seriously amplifies the negative effects of entry No. 2 on this list. There’s truly no rest for the smell bereft. To read the original article click here.

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A Half Teaspoon of Dried Rosemary May Improve Cognitive Function

AHA Publisher — Fri, 19 Jun 2020 07:00:04 +0000

Michael Greger M.D. FACLM via Nutrition Facts – In Hamlet, Act 4, Scene 5, Ophelia notes that rosemary is for remembrance, an idea that goes back at least a few thousand years to the ancient Greeks, who claimed that rosemary “comforts the brain…sharpens understanding, restores lost memory, awakens the mind…” After all, “plants can be considered as chemical factories that manufacture all sorts of compounds that could have neuroprotective benefits”. So, let’s cut down on processed foods and eat a lot of phytonutrient-rich whole plant foods, including, perhaps, a variety of herbs. Even the smell of certain herbs may affect how our brain works. Unfortunately, as I discuss in my video Benefits of Rosemary for Brain Function, I’ve found much of the aromatherapy literature scientifically unsatisfying. There are studies offering subjective impressions, for example, but while sniffing an herbal sachet is indeed “easy, inexpensive, and safe,” is it effective? The researchers didn’t even compare test scores. However, even when there was a control group, such as one study where researchers had people perform a battery of tests in a room that smelled like rosemary, lavender, or nothing, and even when the researchers did compare test results, the lavender appeared to slow down the subjects and impair their performance, whereas the rosemary group seemed to do better. Perhaps that was just because of the mood effects, though, as I show at 1:36 in my video. Maybe the rosemary group did better simply because the aroma pepped them up in some way—and not necessarily in a good way, as perhaps the rosemary was somehow overstimulating in some circumstances? Now, there have been studies that measured people’s brain waves and were able to correlate the EEG findings with the changes in mood and performance, as well as associate them with objective changes in stress hormone levels, as you can see at 2:05 in my video, but is that all simply because pleasant smells improve people’s moods? For instance, if you created a synthetic rosemary fragrance with a bunch of chemicals that had nothing to do with the rosemary plant, would it have the same effect? We didn’t know…until now. Aromatic herbs do have volatile compounds that theoretically could enter the blood stream by way of the lining of the nose or lungs and then potentially cross into the brain and have direct effects. A 2012 study was the first to put it to the test. Researchers had people do math in a cubicle infused with rosemary aroma. The subjects got that same boost in performance, but for the first time, the researchers showed that their improvement correlated with the amount of a rosemary compound that made it into their bloodstream just from being in the same room. So, not only did this show that it gets absorbed, but that such natural aromatic plant compounds may have a direct effect on changes in brain function. If that’s what just smelling it can do, what about eating rosemary? We have studies on alertness, cognition, and reduced stress hormone levels inhaling rosemary. “However, there were no clinical studies on cognitive performance following ingestion of rosemary”…until now. Older adults, average age of 75, were given two cups of tomato juice, with either nothing, a half teaspoon of powdered rosemary, which is what one might use in a typical recipe, a full teaspoon, two teaspoons, more than a tablespoon of rosemary powder, or placebo pills to go even further to eliminate any placebo effects. “Speed of memory is a potentially useful predictor of cognitive function during aging,” and, as you can see at 4:08 in my video, researchers found that the lowest dose had a beneficial effect, accelerating the subjects’ processing speed, but the highest dose impaired their processing speed, perhaps because the half-teaspoon dose improved alertness, while the four-teaspoon dose decreased alertness. So, “rosemary powder at the dose nearest normal culinary consumption demonstrated positive effects on speed of memory…” The implicit take-home message is more isn’t necessarily better. Don’t take high-dose herbal supplements, extracts, or tinctures—just cooking with spices is sufficient. A conclusion, no doubt, pleasing to the spice company that sponsored the study. No side effects were reported, but that doesn’t mean you can eat the whole rosemary bush. In one study, an unlucky guy swallowed a rosemary twig that punctured through the stomach into his liver, causing an abscess from which two cups of pus and a two-inch twig were removed. So, explore herbs and spices in your cooking. Branch out—just leave the branches out. That twig is like a plant-based equivalent of Migrating Fish Bones! To read the original article click here. For more articles from Dr. Greger click here.

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Self-Test Your Sense of Smell to Help Detect Coronavirus

AHA Publisher — Tue, 07 Apr 2020 07:00:32 +0000

Abigail Klein Leichman via Israel21c – SmellTracker, developed in Israel, is an online platform that enables self-monitoring of smell for detecting early signs of COVID-19. Is your sense of smell suddenly not working very well? Not to panic you, but sudden olfactory loss has emerged as a significant symptom in about 60 percent of COVID-19 patients. In fact, in France, people reporting a dramatic drop-off in their ability to smell are automatically assumed coronavirus-positive. Based on this data, Weizmann Institute scientists, in collaboration with Wolfson Medical Center in Holon, developed SmellTracker – an online platform that enables self-monitoring of smell in order to detect early signs of COVID-19. SmellTracker was cooked up in the olfactory research lab of Prof. Noam Sobel in the Weizmann Institute’s Department of Neurobiology. His team previously developed a mathematical model that accurately characterizes an individual’s unique “olfactory fingerprint.” Using this existing algorithm, SmellTracker guides users on mapping their sense of smell with the help of five scents found in virtually every home (spices, vinegar, toothpaste, baking extracts, peanut butter and others). The test is available in English, Hebrew and Arabic, and is also expected to be available in Swedish, French, Japanese, Spanish, German and Persian. The five-minute online odor test can discover sudden changes in odor perception that may be an early indication of COVID-19. The test has already identified potential coronavirus cases that were later confirmed. As more data is collected, the researchers are more likely to be able to characterize a unique olfactory fingerprint for the early detection of COVID-19. The venture, launched with backing from the Ministry of Defense, will be promoted in the coming days in Sweden, France and other countries. Sobel’s lab also is distributing “scratch and smell” kits among confirmed coronavirus patients to map their sense of smell. To read the original article click here. For more articles from Israel21c click here.

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