Acid reflux can diminish both taste and smell, and the connection is stronger than most people realize. Research consistently shows that people with gastroesophageal reflux disease (GERD) and its close relative, laryngopharyngeal reflux (LPR), score lower on standardized smell and taste tests than people without reflux. In one study, about 60% of GERD patients had measurable taste abnormalities and 40% had smell abnormalities, compared to just 8% in healthy controls for each.
How Common Are Taste and Smell Problems in Reflux Patients
The numbers are surprisingly high. A study comparing patients with GERD, gastroparesis (delayed stomach emptying), or both conditions against healthy volunteers found that reflux alone was associated with taste disturbances in roughly 60% of patients and smell disturbances in about 40%. When GERD and gastroparesis occurred together, those rates climbed to around 70% for taste and 52% for smell. Healthy controls, by comparison, had an 8% rate for each. Taste and smell complaint scores also correlated with reflux symptom severity: the worse someone’s heartburn and regurgitation, the more likely they were to report changes in how food tasted or smelled.1PubMed Central. Taste and Smell Disturbances in Patients with Gastroparesis and Gastroesophageal Reflux Disease
These findings do not come from a single isolated study. A scoping review that pooled results across multiple controlled investigations found that olfactory thresholds were significantly lower in patients with laryngopharyngeal reflux than in controls. In three of those studies, not only the ability to detect faint smells but also the ability to identify and distinguish between different odors was impaired in the reflux group. Survey-based research echoed the pattern, finding that self-reported olfactory problems tracked with reflux symptom severity.2Maedica (Bucur). Laryngopharyngeal Reflux and Olfaction Disorders. Is There Any Connection? A Scoping Review
A separate prospective controlled study confirmed the pattern using validated smell identification tests, finding that reflux patients scored significantly lower on psychophysical olfactory evaluations compared to controls. Interestingly, the olfactory cleft itself, the narrow passage at the top of the nasal cavity where smell receptors live, looked structurally normal on imaging in these patients. That finding suggests the problem is not a simple anatomical blockage but something more subtle happening to sensory function.3PubMed. A Prospective Controlled Study Investigating Odor Identification in Laryngopharyngeal Reflux
Which Tastes and Smells Are Affected
Reflux does not wipe out all flavors equally. The research points to a selective pattern. One study that tested patients across all four basic tastes (sweet, salty, sour, and bitter) found that only bitter taste was significantly diminished in the reflux group. Sweet, salty, and sour tastes were statistically unaffected. On the smell side, the same study found that the ability to detect faint odors (the smell threshold) was impaired, while the ability to identify or tell apart specific odors was not significantly different from controls.4PubMed Central. Laryngopharyngeal Reflux Has Negative Effects on Taste and Smell Functions
That selective bitter taste loss is clinically interesting. Bitter taste receptors are distributed across the tongue but are concentrated toward the back, right where regurgitated stomach contents are most likely to make repeated contact. The fact that sweet taste remains relatively intact while bitter drops off suggests localized tissue irritation rather than wholesale sensory nerve damage.
This selectivity may also explain why some reflux patients notice a general dulling of flavor without being able to pinpoint which taste changed. Because what we experience as “flavor” is really the brain integrating taste, smell, and texture simultaneously, a modest drop in smell sensitivity combined with a selective loss of bitter can make food seem flat and unappealing without any single sense obviously failing.
How Reflux Reaches the Nose and Throat
Classic GERD is thought of as a problem confined to the esophagus, with acid causing heartburn below the chest. But when stomach contents travel higher, past the upper esophageal sphincter, and contact the throat, voice box, and even the back of the nasal passages, that is laryngopharyngeal reflux. LPR often causes no heartburn at all, which is why it is sometimes called “silent reflux.” Instead, symptoms tend to be throat-clearing, hoarseness, chronic cough, and a sensation of something stuck in the throat. The sensory losses we have been discussing fall under this LPR umbrella.
The key culprit appears to be pepsin, a digestive enzyme produced in the stomach. Unlike acid, which is partially neutralized as it travels upward, pepsin can remain biologically active even at neutral pH. Animal studies have demonstrated that pepsin causes significant damage to airway tissue whether the environment is acidic or not. In mouse models, exposure to pepsin at a neutral pH still caused thickening and keratinization of the laryngeal lining, loss of cilia (the tiny hair-like structures that help clear mucus), and changes in cell structure. At more acidic pH levels, the damage was worse, with total epithelial loss from necrosis and inflammatory cell infiltration.5PubMed Central. Oral and inhaled fosamprenavir reverses pepsin-induced damaged in a laryngopharyngeal reflux mouse model
This is why silent reflux can cause real sensory damage even in people who never feel burning. The pepsin does not need acid to injure tissue. And it does not stay in the throat. Research has found significantly elevated pepsin levels in the nasal mucosa of patients with chronic rhinosinusitis, suggesting that stomach-derived pepsin can deposit itself high up in the nasal passages.6PubMed. PepsinA as a Marker of Laryngopharyngeal Reflux Detected in Chronic Rhinosinusitis Patients Once lodged there, pepsin can trigger inflammation in the tissue lining the nasal cavity, which over time can impair the environment surrounding olfactory receptors.
The Chronic Sinusitis Connection
One of the less obvious pathways linking reflux to smell loss runs through chronic sinus inflammation. Reflux does not just irritate the throat; it contributes to chronic pharyngitis and sinusitis in some people. A study evaluating olfactory function in adults with GERD found a statistically significant correlation between accompanying chronic pharyngitis, chronic sinusitis, and how poorly patients scored on odor tests.7PubMed. An evaluation of olfactory function in adults with gastro-esophageal reflux disease
This makes the relationship between reflux and smell loss partly indirect. It is not always the refluxed material itself bathing smell receptors; sometimes it is the chronic swelling and mucus production that reflux triggers in the sinus lining. Persistent sinus inflammation can reduce airflow to the olfactory cleft, physically preventing odor molecules from reaching receptors. It can also alter the mucus layer that odor molecules must dissolve into before receptors detect them. If you have reflux and also deal with recurrent sinus congestion, postnasal drip, or a stuffy nose that never fully clears, sinus inflammation may be an important contributor to any smell changes you notice.
Can Treatment Restore Taste and Smell
The encouraging news is that reflux-related taste changes are at least partly reversible with treatment. A randomized controlled study comparing proton pump inhibitor (PPI) therapy to a weaker acid-suppressing drug (an H2-blocker) in patients with laryngopharyngeal reflux found that PPI treatment significantly improved patients’ reported taste perception. Objective testing backed this up: PPI therapy lowered the recognition thresholds for bitter taste on the front of the tongue and for salty, sour, and bitter tastes on the back of the tongue. H2-blocker therapy, by contrast, produced no significant improvement on the front of the tongue and improved only bitter taste on the back, and even that improvement was weaker than what PPIs achieved.8The Tohoku Journal of Experimental Medicine. Proton Pump Inhibitor Ameliorates Taste Disturbance among Patients with Laryngopharyngeal Reflux: A Randomized Controlled Study
The fact that stronger acid suppression produced better taste recovery suggests that ongoing acid and pepsin exposure is what maintains the sensory deficit. Remove the irritant, and the tissue and sensory nerves can heal. This also aligns with the animal data showing that pepsin-mediated damage depends partly on acidity: lowering the pH of refluxed material with PPIs may reduce the damage pepsin can do even if small amounts still reach the throat.
Smell recovery is less well-studied, and the evidence is thinner. No large randomized trial has specifically measured whether PPI therapy restores olfactory scores to normal. Given that smell loss in reflux patients is linked to chronic sinus inflammation, the recovery timeline may depend on whether sinus disease is also managed. Nasal corticosteroid sprays, saline irrigation, and treatment of any underlying sinusitis are reasonable adjuncts for someone whose reflux has been damaging their sense of smell, though the specific evidence for this combined approach in reflux-related olfactory loss has not been tested in controlled trials.
Why Many People Do Not Realize Reflux Is the Cause
One of the more frustrating aspects of this connection is that many people who lose taste or smell due to reflux do not suspect reflux as the culprit. There are a few reasons for this. First, laryngopharyngeal reflux frequently causes no heartburn. If your image of acid reflux is a burning sensation after eating pizza, you might never connect your dull sense of taste to your stomach. Second, taste and smell changes tend to develop gradually. Unlike the sudden smell loss seen with a cold or with COVID-19, reflux-related sensory changes creep in over months, making them easy to attribute to aging, medication side effects, or nothing at all. Third, doctors themselves may not ask about taste and smell during a reflux evaluation. The diagnostic focus is typically on throat symptoms, voice changes, and endoscopic findings, not on chemosensory testing.
It is worth being proactive about this. If you have been diagnosed with GERD or LPR and also notice that food tastes blander than it used to, or that you struggle to pick up familiar smells, mention it. Formal taste and smell testing is available through otolaryngologists and can help determine whether your sensory function is genuinely impaired or whether the change is more subjective. At minimum, knowing the connection exists means you can work with your doctor to optimize reflux treatment and monitor whether your senses improve.
Other Causes to Rule Out
Acid reflux is a real cause of taste and smell loss, but it is far from the only one, and your doctor will want to consider alternatives before settling on reflux as the explanation. A systematic review of taste disorder treatments noted that interventions span a wide range of underlying causes, including zinc deficiency, thyroid dysfunction, medication side effects, and nerve damage, all of which can produce taste changes that overlap with what reflux causes.9SpringerLink / Clin Oral Investig. Taste disorder’s management: a systematic review
Medications are a particularly common source of taste disturbance. Certain antibiotics, blood pressure drugs, chemotherapy agents, and even some over-the-counter supplements can alter how food tastes. Dry mouth, whether from medication or from conditions like Sjögren’s syndrome, also impairs taste because saliva is needed to dissolve taste molecules and carry them to receptors. Neurological conditions, head injuries, nasal polyps, and post-viral olfactory loss (now widely recognized after COVID-19) are other common causes of smell and taste problems that can coexist with or mimic reflux-related changes.
The practical takeaway is to avoid tunnel vision. If you have reflux and notice taste or smell changes, reflux may well be involved, but a thorough evaluation should still consider zinc levels, medications, sinus anatomy, and other possible contributors. Sometimes more than one factor is at play, and addressing only the reflux while ignoring a zinc deficiency or a problematic medication leaves part of the problem unsolved.
Reflux and Feeding Difficulty in Infants
Although the taste-and-smell research focuses on adults, reflux also causes oral and feeding problems in infants that may involve a sensory component. Babies with gastroesophageal reflux sometimes develop outright refusal to eat, arching their backs and turning away from the breast or bottle. The proposed explanation is that reflux causes pain during or after swallowing, and the infant learns to associate eating with discomfort. Over time, this can lead to what clinicians call oral aversion, a conditioned refusal of food that persists even after the reflux itself improves.10PubMed. Gastroesophageal reflux: one reason why baby won’t eat
A more recent study in neonatal intensive care unit populations found that neonates diagnosed with reflux had a significantly higher rate of feeding difficulties than controls, about 42% versus 30%.11PubMed. The effects of untreated reflux on the incidence of dysphagia, oral aversion, and feeding difficulty in the NICU population While this is not the same as measured taste or smell loss, the overlap between reflux, oral aversion, and disrupted feeding behavior in young children is clinically important. Some researchers have proposed that visceral hypersensitivity, a state in which the nerves in the upper digestive tract become abnormally sensitive to normal stimuli, may be one mechanism linking reflux to feeding refusal in these infants. Whether this heightened nerve sensitivity extends to taste or smell perception in very young children has not been directly tested.
Pepsin as a Biomarker and Emerging Target
The finding that pepsin can be detected in the nasal mucosa of patients with chronic rhinosinusitis has opened up new ways of thinking about reflux-related sensory damage.6PubMed. PepsinA as a Marker of Laryngopharyngeal Reflux Detected in Chronic Rhinosinusitis Patients In those patients, pepsin concentrations in nasal secretions were roughly double those found in controls, and the enzyme was found predominantly in the epithelial layer and mucus-producing glands of the nasal tissue. This is significant because it means reflux material does not simply wash over nasal surfaces transiently; pepsin can become embedded in the tissue and continue causing local inflammation between reflux episodes.
Researchers have begun exploring whether blocking pepsin’s activity could protect upper airway tissue. Animal work using fosamprenavir, a drug originally developed as an HIV protease inhibitor, showed that it could reverse pepsin-induced damage to laryngeal tissue in mice.5PubMed Central. Oral and inhaled fosamprenavir reverses pepsin-induced damaged in a laryngopharyngeal reflux mouse model This is still early-stage research and nowhere near clinical use for reflux patients, but it signals that the field is moving beyond just suppressing acid and toward targeting the specific enzyme responsible for tissue damage. If pepsin inhibitors eventually make it to human trials, taste and smell recovery could be a meaningful outcome to track, given that current acid-suppression therapy with PPIs helps but does not fully resolve sensory complaints in all patients.