Can Smell Training Restore Your Sense of Smell After COVID-19? Here’s What You Need to Know

The COVID-19 pandemic has left a lasting impact on millions of people worldwide, and one of the more peculiar and often frustrating symptoms that many have experienced is the loss of smell, known medically as anosmia. While for some, this symptom resolves itself within weeks, others have found themselves grappling with a persistent loss or distortion of smell, known as parosmia, for months or even years after their initial infection. This lingering condition can significantly impact quality of life, affecting everything from appetite to emotional well-being.

But is there hope for those still struggling to regain their sense of smell? Emerging research suggests that a technique known as "smell training" might offer a promising solution. This comprehensive guide will delve into what smell training is, how it works, the science behind it, and practical steps you can take to potentially restore your olfactory function after COVID-19.

Understanding Anosmia and Parosmia: The COVID-19 Connection

Anosmia and Parosmia: What Are They?

Anosmia is the complete loss of smell, while parosmia refers to the alteration or distortion of smells, often leading to unpleasant or inaccurate perceptions of common scents. Both conditions have been widely reported among COVID-19 survivors. Unlike traditional colds or flu, where smell loss is typically due to nasal congestion, COVID-19-related anosmia appears to be more directly linked to the virus's effects on the olfactory system.

How COVID-19 Affects Smell

COVID-19's impact on the sense of smell is thought to occur through several mechanisms. The virus can cause inflammation in the nasal passages and potentially damage the olfactory neurons responsible for detecting and transmitting smell signals to the brain. In some cases, the virus may also affect the brain itself, where smell processing occurs. This multifaceted attack on the olfactory system explains why some individuals experience prolonged anosmia or parosmia even after their other COVID-19 symptoms have resolved.

What Is Smell Training?

Smell training, also known as olfactory training, is a therapeutic technique that involves the repeated and deliberate sniffing of specific scents over a period of time to help retrain the brain to recognize and interpret smells correctly. It’s akin to physiotherapy for your sense of smell.

The Origins of Smell Training

The concept of smell training isn't new; it has been used for years to treat various forms of smell loss, including post-viral anosmia, which can occur after infections like the common cold. However, its application has gained renewed attention in the wake of the COVID-19 pandemic due to the large number of people affected by smell disorders.

How Does Smell Training Work?

Smell training works on the principle of neuroplasticity—the brain's ability to reorganize itself by forming new neural connections. The repeated exposure to specific scents is thought to stimulate the olfactory pathways, encouraging the brain to "relearn" how to process and identify these smells.

The standard smell training protocol involves using four distinct scents that are easy to distinguish and represent different odor categories. These scents typically include:

1. Rose (floral)
2. Lemon (citrus)
3. Clove (spicy)
4. Eucalyptus (resinous)

Participants in smell training are advised to sniff each scent for about 20 seconds, twice daily, for a period of several weeks to months. The key to success is consistency and patience, as the process can be slow, but many individuals report improvements over time.

The Science Behind Smell Training

Research and Evidence Supporting Smell Training

Several studies have provided evidence supporting the efficacy of smell training in treating post-viral smell loss. A 2009 study conducted by Professor Thomas Hummel at the University of Dresden was one of the first to demonstrate the potential benefits of smell training. The study found that participants who engaged in smell training for 12 weeks showed significant improvements in their sense of smell compared to those who did not.

In 2020, a review published in the journal Rhinology analyzed the outcomes of several studies on smell training and concluded that it could be beneficial for individuals with post-infectious smell disorders, including those related to COVID-19.

How Effective Is Smell Training for COVID-19-Related Anosmia?

While more research is needed to fully understand the long-term effects of smell training on COVID-19-related anosmia, early evidence suggests that it can be an effective tool. A study published in the Journal of Clinical Medicine in 2021 followed 72 COVID-19 patients with persistent smell loss who underwent smell training. The researchers found that 75% of participants reported significant improvement in their sense of smell after 12 weeks of training.

It's important to note, however, that results can vary, and smell training may not work for everyone. Factors such as the severity of the initial smell loss, the timing of when training is started, and individual differences in neuroplasticity all play a role in determining the outcome.

Practical Steps to Start Smell Training

If you're considering smell training to help regain your sense of smell after COVID-19, here are some practical steps to get started:

1. Choose Your Scents: The traditional scents used in smell training are rose, lemon, clove, and eucalyptus. You can purchase essential oils or use natural sources like fresh lemon or clove spice. Make sure the scents are strong but not overwhelming.
2. Create a Routine: Consistency is key to smell training. Set aside time each day, ideally in the morning and evening, to focus on your training. Find a quiet space where you can concentrate without distractions.
3. Sniff with Intention: As you sniff each scent, try to recall what the scent should smell like, even if you can't perceive it fully. This cognitive engagement is thought to enhance the training's effectiveness.
4. Track Your Progress: Keep a journal to record any changes in your sense of smell over time. Note which scents you can detect, any distortions, and how your perception evolves.
5. Be Patient: Smell training is a gradual process, and improvements may take weeks or even months. Stay committed to the routine, and don't be discouraged by slow progress.
6. Consider Professional Guidance: If you're unsure about how to start or if you're not seeing results, consult with an otolaryngologist (ENT specialist) who can provide guidance and possibly suggest adjustments to your training regimen.

The Psychological Impact of Smell Loss and the Role of Smell Training

The Emotional Toll of Smell Loss

Losing your sense of smell can have a profound impact on your emotional and psychological well-being. Smell is closely linked to memory and emotion, and its loss can lead to feelings of isolation, depression, and anxiety. The inability to enjoy the scent of food, nature, or loved ones can diminish your overall quality of life.

How Smell Training Can Help

Beyond the potential physical benefits, smell training can also provide psychological relief by giving you a sense of control and a proactive way to address your condition. Engaging in a daily routine that offers the possibility of improvement can reduce feelings of helplessness and provide a therapeutic focus during recovery.

Other Treatments and Complementary Approaches

Medication and Supplements

While smell training is the most widely recommended approach, some individuals may benefit from additional treatments. For example, corticosteroids may be prescribed to reduce inflammation in the nasal passages. Some studies have also explored the use of omega-3 supplements, which are believed to support nerve regeneration.

Olfactory Rehabilitation Programs

In addition to smell training, specialized olfactory rehabilitation programs led by ENT specialists can offer more personalized and comprehensive treatment plans. These programs may include smell training along with other therapeutic techniques and medical interventions.

Lifestyle Adjustments

For those experiencing parosmia, where smells are distorted, certain lifestyle adjustments can help. Avoiding foods and environments that trigger unpleasant smells, practicing mindfulness techniques, and maintaining good nasal hygiene are all strategies that can support recovery.

Conclusion: Is Smell Training Worth a Try?

Smell training offers a low-risk, potentially effective way to regain your sense of smell after COVID-19. While it's not a guaranteed cure, the growing body of evidence suggests that it can be a valuable tool in the recovery process. If you've been struggling with lingering anosmia or parosmia, smell training is worth considering as part of your overall approach to recovery.

However, it's essential to approach smell training with realistic expectations and a commitment to consistency. Progress may be slow, and not everyone will experience full restoration of their sense of smell. Nevertheless, the potential benefits—both physical and psychological—make it a worthwhile endeavor.

If you're interested in trying smell training, start with the basic steps outlined in this guide, and consult with a healthcare professional to tailor the approach to your specific needs. With time, patience, and dedication, you may find that smell training helps you reconnect with the world of scents that COVID-19 temporarily took away.