It's easy to take your sense of smell for granted -- that is, until it's gone. Anosmia, or the inability to smell, isn't a life-threatening condition, but it significantly affects quality of life and can lead to depression and anxiety.
Affecting both your sense of smell and taste, anosmia has a considerable effect on pleasurable experiences like eating your favorite foods. Even a hike in the woods or intimacy can become less satisfying without the ability to appreciate odors in your environment.
What Causes Anosmia?Anosmia increases with age. While about 3.2% of U.S. adults over the age of 40 are affected, this increases to 14% to 22% of those aged 60 years and older. As you age, your sensitivity to smell may decrease, and loss of sense of smell is associated with neurodegenerative diseases such as Alzheimer's disease and Parkinson's. In fact, low ability to smell is associated with an increased risk of neurodegenerative diseases.
However, anosmia is most often caused by inflammatory and obstructive disorders, which cause 50% to 70% of anosmia cases. This includes rhinitis, nasal polyps and sinus diseases, which cause inflammation of the mucosa or direct obstruction.
Anosmia is commonly associated with viral infections, including influenza and coronaviruses, and can also be caused by head trauma and exposure to toxic agents, such as tobacco and pesticides, and certain medications, particularly beta-blockers, anti-thyroid drugs, dihydropyridine, ACE inhibitors and intranasal zinc.
Life-Altering Consequences of AnosmiaIn cases of anosmia that occur after upper respiratory tract infections, spontaneous recovery occurs in 32% to 66% of patients, although supportive therapy can help to encourage spontaneous regeneration. Without treatment, anosmia can lead to significant behavioral and psychological changes.
In a survey of Dutch people with anosmia, for instance, 44% said they lived in fear of exposure to smoke or natural gas due to their inability to detect it with their nose, and, in fact, those with anosmia had their risk of experiencing a hazardous event increase three-fold compared to people with a normal sense of smell.
- Reduced appreciation of food and drink
- Increased feelings of depression and loneliness
- Reduced appetite
- Exaggerated personal hygiene, such as showering multiple times a day or using excessive amounts of perfume
- Negative effects on relationships with a partner, friends and family
Six Natural Options for AnosmiaTo help regain your sense of smell, a variety of herbal and therapeutic options are available.
1. Smell Training
Smell training involves sniffing four different odors -- typically from the categories flowery, fruity, spicy and resinous -- twice a day for a period of about four to six months. Often, essential oils of rose, lemon, clove and eucalyptus are used for smell training due to their concentrated scents.
It's believed that smell training may increase the expression or growth of olfactory receptor neurons, helping to bring back the ability to smell. In a meta-analysis of 13 studies, smell training led to significant positive effects for all olfactory abilities, with researchers noting, "[S]uch training should be considered an addition or alternative to existing smell treatment methods."
Another meta-analysis found a significant improvement in olfactory discrimination and olfactory identification following smell training. It's also been suggested that changing the odors used periodically during smell training may increase its success. In addition to essential oils, a range of other odors have also been used with success, including:
2. Alpha-Lipoic Acid
The antioxidant alpha-lipoic acid (ALA) was also useful in restoring sense of smell in people with anosmia following upper respiratory tract infection. Patients took ALA supplements at a dose of 600 milligrams (mg) a day for an average of 4.5 months. At the end of the study, 26% had a moderate increase in olfactory function while 35% had a "remarkable" increase.
"The results indicate that alpha-lipoic acid may be helpful in patients with olfactory loss after upper respiratory tract infection," researchers noted in the journal Laryngoscope.
3. Ginkgo Biloba
The herb ginkgo biloba helped to restore sense of smell in an animal study when used in combination with an anti-inflammatory drug, It's believed that ginkgo's antioxidant effects may explain its usefulness for anosmia.
Among 28 patients with post-viral olfactory loss, the addition of ginkgo led to greater efficacy in treatment compared to treatment with the steroid prednisolone and mometasone furoate (corticosteroid) nasal spray alone.
4. Lavender Syrup
Lavender syrup, which is often used in Persian medicine, is believed to have a cleansing effect on the brain and a strengthening effect on the brain and body. In a pilot clinical trial, 23 patients with post-viral olfactory dysfunction took 9 milliliters of lavender syrup for three weeks. Lavender syrup led to significant improvements in olfactory function compared to the control group.
5. Zinc Gluconate
Zinc deficiency may induce anosmia, and it's been found that supplementation with zinc gluconate for one month leads to significantly higher recovery rates of olfactory function compared to treatment with prednisolone alone.
Turmeric, known for its active ingredient curcumin, has impressive antioxidant and anti-inflammatory properties. In a peer-reviewed case report, a doctor and medical student from Tulane University School of Medicine in New Orleans report two patients who experienced fast restoration of taste and smell after taking one dose of turmeric.
In one case, a 25-year-old man with post-viral anosmia took a capsule with 1,000 mg of turmeric extract (95% curcuminoids) and 10 mg of black pepper extract, which improves absorption. "He experienced complete restoration of smell and taste, with both senses rated 10/10, ten minutes after supplement ingestion," researchers explained.
In a second case, a 28-year-old man with post-viral near-anosmia took a capsule containing 1,000 mg of turmeric extract (95% curcuminoids), 1,000 mg of Boswellia serrata plant extract and 15 mg of black pepper extract. According to the study, "Twelve hours after taking the turmeric supplement, the subject reported experiencing a restoration of both smell and taste to intensity of 6/10 each, with 10/10 being achieved three days later."Natural options for anosmia such as smell training and herbal supplements can be done at home, potentially leading to a significant improvement in your quality of life. However, if you're struggling with anosmia, a knowledgeable health care practitioner can also work with you to devise a holistic treatment plan to help restore your sense of smell and, in so doing, optimize your overall well-being.
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