Healthful Habits

A sixth sense of taste? Scientists find new flavor in salty licorice
Recent research from the University of Southern California suggests there might be a new flavor distinct from the traditionally recognized tastes.
For over a century, our understanding of taste has been largely confined to five basic profiles: sweet, sour, salty, bitter, and umami. Yet, recent groundbreaking research hints at a potential sixth flavor profile that might have been hiding in plain sight: the unique taste of salmiak salt, a flavor familiar to those who’ve savored salt licorice, a treat that’s especially popular in Northern Europe.

A new taste emerges
In the early 1900s, Japanese scientist Kikunae Ikeda postulated the existence of umami as a distinct taste. It took eight decades before umami — a savory flavor primarily associated with foods containing high levels of glutamate, such as soy sauce, tomatoes, and aged cheeses — was universally embraced by the scientific world. Finally, we had the five basic tastes of the human pallette. But maybe this isn’t the end of the story.

Now, researchers from the University of Southern California have unveiled compelling evidence pointing to a new basic taste. Spearheaded by neuroscientist Emily Liman, the study found that our tongues react to salmiak salt (ammonium chloride) in a manner reminiscent yet at the same time distinct from the sour taste.

If you’ve ever ventured to Northern Europe and indulged in salt licorice, you’ve experienced this unique flavor firsthand. This unique salt has a sharp, tangy taste that’s a far cry from the sugary sweetness we typically associate with candies.

The story of how such an unconventional ingredient became a cornerstone of confectionery in this region began centuries ago. Originally, salmiak salt was used primarily for medicinal purposes. People consumed it in small amounts as a remedy for coughs and digestive issues.

But over time, Northern European countries, particularly Finland, Sweden, Denmark, and the Netherlands, began to experiment with salmiak salt in their confectionery. The result is “Salmiakki” or salty licorice, a candy that’s a blend of sweet licorice and the potent kick of salmiak salt.
For the uninitiated, the taste might be an acquired one. At least that was my impression after first trying salty licorice candy during my trip to Copenhagen. To each their own.

For years, scientists acknowledged the tongue’s pronounced reaction to ammonium chloride. Could this be a new distinct taste, on par with sweet or salty? Some thought so, yet the exact receptors responsible remained shrouded in mystery — that’s until Liman and her team entered the picture.

The team’s eureka moment came when they identified the protein OTOP1, responsible for detecting sour tastes. This protein acts as a gateway for hydrogen ions, the primary component of acids, to enter cells. When you savor the tartness of lemonade or vinegar, it’s these ions passing through the OTOP1 channel that you’re tasting.

Ammonium chloride is known to affect the concentration of acid in food. Given the connection between ammonium chloride and hydrogen ions, the researchers postulated that the former might trigger OTOP1. Their subsequent experiments corroborated this theory, revealing that ammonium chloride indeed activates the OTOP1 channel, sometimes even more effectively than acids.

M**A and talk therapy shows tremendous promise against PTSD
The illegal drug is stepping more and more into the medical spotlight.
M**A, sometimes referred to as the party drug “ecstasy”, helped over 70% of patients in a small trial overcome their PTSD. In the Phase 3 trial, researchers found that three months of talk therapy were not nearly as effective as the talk therapy plus the monitored doses of M**A.

“It’s not a panacea,” cautioned lead researcher Jennifer Mitchell, a professor of neurology at the University of California, San Francisco. But the approach shows a lot of promise.

Party drug, therapy drug
The trial followed 52 patients who completed M**A-assisted therapy and 42 patients given a talk therapy plus placebo. Out of the people in the M**A group, almost 90% responded well to therapy. They had meaningful reductions in nightmares, flashbacks, crippling anxiety, and other serious symptoms. After three months, 71% no longer even qualified for a PTSD diagnosis — compared to only 48% non-M**A group.

M**A is part of a class of party drugs that are illegal and have been banned from medical testing for decades. But the psychiatric field has long been interested in M**A and other drugs like psychedelics for their therapeutic potential. Because there was a ban on trials, for a long time this potential was not studied at all. In recent years, however, that’s started to change.

Psychedelics and M**A alter the user’s perceptions and thoughts, often inducing feelings of euphoria. From a biochemical perspective, M**A primarily affects three neurotransmitters in the brain: serotonin, dopamine, and norepinephrine. These neurotransmitters are involved in mood regulation, emotional response, and social behavior. When someone takes M**A, the drug increases the release of these neurotransmitters, leading to feelings of euphoria, emotional closeness, and decreased anxiety.

Because M**A floods the brain with serotonin — the “feel good hormone” — it is quite popular as a party drug. But the effect on serotonin could also help patients process difficult emotions. M**A also increases the communication between the amygdala and the hippocampus — and studies on patients with PTSD have found a reduction in communication between these areas.

Therapy and M**A
Oxytocin, popularly known as the “love” or “bonding” hormone, also seems to play a role, says Mitchell. It seems to foster a level of self-compassion in PTSD patients, which in turn, makes them more likely to stick with psychotherapy. This is particularly important because therapy often asks people to face their trauma, which is understandably tough.

“The problem with talking about distressing memories is that it’s too distressing,” said Rachel Yehuda, director of the Center for Psychedelic Psychotherapy and Trauma Research at Mount Sinai in New York City. “By the time people come to therapy, they’ve often developed narratives about how unworthy they are,” adds Yehuda, who was not involved in this study.

There were no severe side effects, the researchers note. Some muscle tightness, nausea, and sweating were reported in some patients — but no one dropped out due to these side effects.

Another reason why the study is notable is because it included a diverse group of patients, including marginalized minorities. Due to disparities in trauma exposure, groups that include minorities, first responders, veterans, and victims of sexual abuse have a disproportionately large risk of developing PTSD. However, these diverse populations are often underrepresented in studies.

Beyond the Storm: Hurricane Ian Boosted Threat of Flesh Eating Bacteria
From Florida to New York, these "flesh-eating" infections are on the rise.
In September 2022, Hurricane Ian struck Cuba, Florida, and the Carolinas. It was the third-costliest weather disaster on record, unleashing flooding and devastating winds. But that’s not all it did. A new study published in the journal mBio has revealed that the hurricane led to the proliferation of Vibrio bacteria, which can pose a significant risk to human health.
Vibrio bacteria are naturally present in the ocean and have a symbiotic relationship with various marine organisms like oysters and crustaceans. However, when the bacteria come into contact with humans they can cause diseases ranging from gastroenteritis to a fatal flesh-eating infection. The risk of infection increases with the consumption of raw or undercooked seafood or exposure of open wounds to seawater. Warm saltwater conditions, like those after hurricanes or floods, can elevate the chances of Vibrio exposure.

“We were very surprised to be able to detect—without any difficulty—the presence of these pathogens,” said the study’s senior author Rita Colwell, a Distinguished University Professor in the University of Maryland Institute for Advanced Computer Studies who has studied Vibrio for the last 50 years.

Although the CDC had warned about the presence of flesh-eating bacteria in post-hurricane floodwaters, this study reveals that the bacteria can thrive even after the waters recede.

The study — conducted by researchers from the University of Maryland, University of Florida, and microbiome company EzBiome — combined genome sequencing, satellite data, and environmental information to identify the presence of pathogenic Vibrio species. Researchers collected and analyzed water and oyster samples collected in October 2022. According to the Florida Department of Health, Lee County, which had the highest caseload in the state, reported 38 infections and 11 deaths linked to vibriosis.

What makes these findings particularly concerning is the detection of two specific Vibrio species, Vibrio parahaemolyticus and Vibrio vulnificus. V. parahaemolyticus can lead to gastroenteritis and wound infections. V. vulnificus is even more menacing, causing the flesh-eating infection necrotizing fasciitis, which is fatal in approximately one in five cases.

The Threat of Vibrio Bacteria
Environmental conditions following Hurricane Ian created a perfect storm for the growth of Vibrio bacteria. Increased rainfall, changes in sea surface temperature, and variations in chlorophyll concentrations in the ocean, which indicate the presence of phytoplankton and zooplankton, all contributed to an environment conducive to Vibrio proliferation. Plankton blooms, in particular, were associated with high Vibrio bacteria abundance.

The threat of Vibriosis extends beyond just the warmer regions. In August 2023, three individuals in New York and Connecticut succumbed to V. vulnificus infections. The researchers had predicted this uptick, based on climate trends in the Northeast US. As ocean temperatures rise, areas like the Chesapeake Bay could also be impacted.

These findings underscore the complex relationship between climate change and the proliferation of Vibrio bacteria. As global warming drives ocean temperatures up, we can anticipate more frequent and intense storms, similar to Hurricane Ian. This, in turn, creates conditions in which Vibrio bacteria thrive, making coastal communities more susceptible to Vibrio infections in the future.

“These Vibrios generally grow well between 15 and 40 degrees Celsius (59-104 degrees Fahrenheit), so as the temperature warms, their generation time shortens and they divide faster and faster,” Colwell said. “The warming of seawater—which mixes with freshwater, creating optimal salinities—really enhances the growth of Vibrios, so it’s a very serious concern.”

The importance of this research extends beyond the immediate health implications. The study’s use of genetic analysis, environmental data, and remote sensing demonstrates the potential to proactively detect and characterize Vibrio pathogens, which can be a game-changer in public health management. It also highlights the need for further investigation to quantify the prevalence of Vibrio bacteria in different locations, seasons, and environmental conditions.

“On the positive side, knowing that these infections are associated with the increased variability of a changing climate, perhaps now is the time to develop mechanisms to understand and mitigate it,” Colwell said. “Climate change and flooding are clearly linked to infectious disease, and we need to take it seriously.”