Do you lose your sense of smell as you get older? Here's what the science says

According to the National Institutes of Health, over 50% of individuals aged 65 and over experience some impairment in their sense of smell. So, do you lose your sense of smell as you get older? This guide explores the reasons behind this common sensory change.

Quick Summary

Yes, a decline in the sense of smell, known as presbyosmia, is a natural part of the aging process, particularly after age 70. This happens as nerve endings in the nose decrease and are often compounded by other factors like medications, lifestyle, and underlying health conditions.

Key Points

• Age is a Major Factor: The sense of smell naturally declines with age, a condition known as presbyosmia, due to the loss of nerve endings and decreased mucus production.

• Not Just Aging: Many other factors can cause smell loss, including medications, viral infections (like COVID-19), nasal polyps, and head trauma.

• Indicator of Other Conditions: Olfactory dysfunction can be an early warning sign for neurodegenerative diseases like Parkinson's and Alzheimer's.

• Health and Safety Risks: A poor sense of smell can lead to safety hazards like not detecting gas leaks or spoiled food, and can cause malnutrition.

• Smell Training May Help: For some, especially those with post-viral loss, smell training using essential oils can help retrain the olfactory system.

• Medical Evaluation is Key: If you notice a change in your sense of smell, consulting a doctor is essential to rule out treatable underlying causes.

The Aging Olfactory System

While many associate aging with changes in vision and hearing, the sense of smell is also significantly impacted. The physiological reason for this decline, called presbyosmia, is linked to several changes within the olfactory system. As we age, the number of nerve endings in the nose responsible for detecting odors decreases. Simultaneously, the production of nasal mucus, which helps capture odor molecules, slows down. With fewer nerve endings and less mucus, the signal-to-brain pathway becomes less effective, making it harder to detect and differentiate scents. This process is generally gradual, which is why many people don't notice a significant change until it has progressed considerably.

More Than Just Age: Other Contributing Factors

While age is a primary driver, many other elements can accelerate or compound the loss of smell in older adults. These factors often have a greater impact than natural aging alone and, in some cases, can be treated.

Medical Conditions

Numerous health issues can affect a person's ability to smell. Central nervous system diseases are a major concern. For instance, olfactory dysfunction is an early symptom for a high percentage of patients with Parkinson's and Alzheimer's disease. Chronic conditions that cause inflammation in the nasal passages, such as sinus infections, allergies, and nasal polyps, can also block airflow and impair olfaction.

Medications

Hundreds of prescription and over-the-counter medications can alter taste and smell. Common culprits include some antibiotics, statin drugs for cholesterol, and certain blood pressure medications like ACE inhibitors. The effect of these drugs can develop over time, making it difficult to pinpoint the cause without a doctor's evaluation.

Lifestyle and Environmental Exposure

Certain long-term lifestyle choices and environmental factors can damage the delicate nasal tissues over time, accelerating smell loss:

• Smoking: Tobacco use causes inflammation and can damage the olfactory receptors. Quitting smoking is one way to potentially improve or restore some function.
• Chemical Exposure: Prolonged exposure to harmful airborne particles, chemicals, or toxins can harm the nasal tissues.
• Head Injury: Traumatic brain injury can sever the delicate nerve endings that connect the nose to the brain, sometimes causing a permanent loss of smell.

Nutritional Deficiencies

Malnutrition and deficiencies in certain micronutrients can affect the nervous system, including the olfactory pathways. Studies have shown that a deficiency in Vitamin D, and potentially other trace metals like zinc and copper, may be associated with an increased risk of smell impairment in older adults. Addressing nutritional status is an important part of a holistic approach to senior health.

The Health and Safety Implications of Smell Loss

Beyond reducing the enjoyment of food, a diminished sense of smell poses several health and safety risks for older adults. Anosmia or hyposmia can leave a person unable to detect dangers like smoke from a fire, a natural gas leak, or spoiled food. Furthermore, because taste is so closely linked to smell, reduced olfactory function can lead to a decreased appetite and, consequently, malnutrition or unwanted weight loss.

What Can Be Done to Address Smell Decline?

Fortunately, depending on the cause, there are several steps that can be taken to manage or even improve a diminished sense of smell. Consulting with a healthcare provider, such as an ENT specialist, is the first step to identify the root cause.

Comparison of Smell Loss Causes

Cause	Onset	Typical Age	Likelihood of Improvement	Other Symptoms
Age-Related (Presbyosmia)	Slow, gradual	After age 70	Low, but can be managed	Often unnoticed early on
Post-Viral Infection	Rapid, after illness	Any age	Often recovers over months	Initial cold/flu symptoms
Nasal Obstruction (Polyps)	Slow, gradual	30-60 years	High, with surgery/meds	Congestion, difficulty breathing
Neurodegenerative Disease	Gradual	Typically older adults	Not usually reversible	Neurological symptoms (e.g., tremors, memory loss)
Medication Side Effects	Variable	Any age	Good, if medication is changed	Varies by drug type

Smell Training

Smell training, or olfactory training, is a proven therapy for those with persistent post-viral smell loss and may also help with age-related decline. It involves a simple, at-home exercise where you repeatedly sniff four different strong scents (e.g., rose, eucalyptus, citrus, cloves) for 10-20 seconds each, twice a day for several months. This helps stimulate and retrain the olfactory receptors and the brain's processing centers.

Lifestyle Changes and Nutrition

Quitting smoking is one of the most effective ways to protect and potentially restore your sense of smell. Paying attention to your diet and addressing any nutritional deficiencies is also beneficial, as sufficient Vitamin D and zinc levels are important for olfactory health.

Practical Safety Measures

If you or a loved one has a diminished sense of smell, it's crucial to implement safety precautions to mitigate the risks. This includes installing smoke and carbon monoxide detectors with working batteries and checking food expiration dates carefully. When in doubt about a food's freshness, it's safest to throw it out.

For more information on the impact of aging on sensory functions, the National Institute on Aging provides valuable resources and insights: https://www.nia.nih.gov/

Conclusion

Losing your sense of smell is a common aspect of getting older, but it's not always an irreversible process. While natural degeneration plays a part, other factors like medications, lifestyle, and underlying conditions often contribute significantly. By understanding the causes and taking proactive steps like smell training and addressing any health issues, seniors can manage these changes and continue to enjoy a high quality of life. The key is to see a doctor if you experience any notable or persistent changes to your sense of smell, as a treatable cause might be at play.

Frequently Asked Questions

Is it normal to lose your sense of smell as you get older?

Yes, some loss of smell sensitivity, known as presbyosmia, is a normal part of aging. However, the severity varies, and it often begins to decline noticeably after age 70.

What medical conditions are linked to losing your sense of smell in old age?

Besides natural aging, conditions like nasal polyps, chronic sinus infections, and serious neurodegenerative diseases such as Parkinson's and Alzheimer's can cause or worsen smell loss.

Can medications cause loss of smell in older adults?

Yes, hundreds of medications are known to affect taste and smell. Some common examples include certain blood pressure medications, antibiotics, and statins. It's important to discuss any changes with your doctor.

How can I regain my sense of smell if it's due to aging?

While it may not be fully recoverable, smell training—repeatedly smelling a variety of scents—can help retrain your brain's olfactory centers. Quitting smoking can also lead to improvement.

What are the risks of having a poor sense of smell as an older adult?

Safety is a major concern, as it can prevent you from detecting smoke, gas, or spoiled food. There's also a risk of malnutrition and weight loss due to a decreased appetite.

When should I see a doctor for loss of smell?

You should see a doctor if your smell loss is not due to a temporary cause like a cold or allergy, persists for more than a week or two, or if it is accompanied by other neurological symptoms.

Does losing your sense of smell affect your sense of taste?

Yes, your sense of smell is crucial for experiencing the full flavor of food. When smell is diminished, food often tastes bland or different, which can affect appetite and nutrition.