Training the Brain to Taste Again: How Specialized Chewing Gum is Fighting Post-Covid Anosmia

For many who contracted Covid-19, the virus left behind a ghostly void where the senses of taste and smell once resided. While most recovered within weeks, a significant minority experienced long-term anosmia (loss of smell) and ageusia (loss of taste), turning the world "grey" and stripping away the emotional connection to food, family, and memory.

Recent results from a pilot study at the University of Nottingham offer a glimmer of hope for those who have spent years in this sensory vacuum. By utilizing specially formulated chewing gums designed to "train" the brain, researchers are seeing promising results in restoring these vital connections.

The Science of Sensory Retraining

Led by Dr. Nicole Yang, the clinical trial focused on the theory that sensory perception can be recovered by encouraging the repair of brain connections associated with smell and taste. The approach is akin to physical therapy for the brain: by exposing the olfactory and gustatory systems to intense, varied stimuli, the researchers aimed to jumpstart the neural pathways that had fallen dormant or been damaged.

To achieve this, the team developed "super-strength" chewing gums. Unlike standard gum, these were formulated to:

Maintain flavor longer: Ensuring a sustained stimulus for the brain.
Shift flavors: The gums were designed to change flavor as they were chewed, forcing the brain to adapt and distinguish between different notes.
Target multimodal profiles: The trial used a combination of spicy, minty, sour, and sweet flavors to hit various sensory receptors.

A Case Study in Recovery: Dr. Paul Wicks

One participant, Dr. Paul Wicks, a medical researcher who lost his senses in August 2022, provides a poignant look at the impact of the trial. For years, Wicks lived in a world where the spiciest curries had no flavor and the smell of his children's hair was gone. He noted that the loss was not just about food, but about memory formation, as smells are deeply intertwined with how we recall life events.

After six weeks of chewing the specialized gums every morning and evening, Wicks experienced a breakthrough. The moment of recovery was sudden and vivid: "I tasted a blueberry in my oats for breakfast one day and this sweet flavour exploded."

By the end of the 12-week trial, Wicks reported that his senses had returned to their pre-Covid levels, noting that even the "assault" of smelling cut grass and dog waste—typically unpleasant scents—felt like a victory because it signaled the return of a functioning sensory system.

Trial Results and Limitations

The pilot study was small, consisting of 16 participants, but the reported success rates were high:

67% of participants saw an improvement in their sense of smell.
83% reported an improvement in their sense of taste.

Because the trial was "decentralized," participants conducted the training from home, making the intervention highly accessible. However, the small sample size means that larger, funded trials are necessary to confirm these findings and determine if the results are statistically significant across a broader population.

Community Perspectives and Technical Nuances

Technical discussions surrounding the story highlight several interesting points regarding how we perceive "taste" versus "smell."

The Capsaicin Question

Some observers noted a common point of confusion in the reporting: the difference between taste and chemesthesis. As one commenter pointed out, the "spiciness" of a curry is caused by capsaicin, which triggers pain receptors rather than taste buds. This suggests that while the flavor (the aromatic profile) of a curry might be lost to anosmia, the burn of the spice often remains, as it is a different biological mechanism entirely.

The Danger of Sensory Loss

Beyond the loss of pleasure, the community emphasized the practical dangers of anosmia. Users shared stories of the inability to detect gas leaks, smoke, or spoiled food—critical safety warnings that the body normally provides automatically.

Parosmia and Hyposmia

Not all sensory loss is binary. Some survivors reported parosmia—a condition where smells are distorted, making familiar things like shampoo or soda smell strange—or hyposmia, a partial loss of smell. These nuances suggest that sensory retraining may need to be tailored to the specific type of impairment a patient is experiencing.

Looking Forward

The University of Nottingham team is currently seeking funding for a larger trial to validate these results. If successful, this "multimodal flavor training" could move from a clinical trial to an over-the-counter therapeutic tool, providing a low-cost, non-invasive way for millions of people to reclaim their connection to the sensory world.