Enjoyment of good food is one of the greatest sensory pleasures of our lives. The delectable aromas unleashed by cooking and the anticipation of tasting first bites and dining are a part of our daily lived experiences to enjoy whether alone or with others.
The taste buds on our tongues are comprised of cells that detect salty, sweet, sour, bitter, and umami (savory) that transmit signals to the brain. Our sense of taste is almost wholly dependent on our sense of smell. As much at 90% of what we perceive as taste is the olfactory nerve at work. While eating, smells of food are released into the nasal cavity, enhancing the taste. This explains diminished taste experiences while battling a cold with nasal and sinus congestion. Inflammation associated with nasal congestion inhibits the olfactory receptors’ ability to detect odorants. Note how your sense of taste gradually returns as you recover.
Any damage or harm to the olfactory bulb results in diminished perception of taste, making eating far less pleasurable or satisfying. Head trauma or nasal and sinus infection can damage delicate nerve fibers, diminishing sensation of smell. Chemical exposures such as solvents, toxic fumes, and pesticides can interfere with transmission along the olfactory nerve. Chronic exposure can lead to long term or permanent loss of smell.
Deficiencies in B vitamins, particularly B12, zinc and copper, among other micronutrients, may alter taste sensations. Correcting zinc deficiencies can help relieve smell and taste disorders.
Decreased saliva production, which affects as much as 40% of people over 65 years of age, diminishes the ability to detect odors and aromas. Saliva is necessary to start digestion in the mouth, dissolving flavor molecules so taste buds can taste them. A side effect of medications such as antihistamines, decongestants, antidepressants, diuretics, antibiotics, and even chemotherapy drugs is reduced saliva production. Sjogren’s disease, an autoimmune condition, greatly reduces saliva production.
The diuretic effects of caffeine will lower saliva production. Check your intake of caffeinated beverages if you’re noticing a decrease in smell ability. Alcohol intake and use of alcohol-containing mouthwash can cause dry mouth. If you use mouthwash, opt for alcohol-free preparations.
Finally, aging may cause natural degenerative changes to the olfactory nerve, leading to a decline in taste. You may notice a reduced sense of taste or become less sharp or effective at detecting flavors. Denture wearers also notice this phenomenon.
To your health!
Leyla Muedin, MS, RD, CDN
