Loss of Smell Often Overlooked in Older Adults
In the early months of the COVID-19 pandemic, doctors noted that a loss of smell was a noticeable symptom. Dr. Carl Philpott of the University of East Anglia (UEA) in the UK has studied this effect for months and learned that while the loss of smell during a cold or allergies is caused by congestion, people with COVID-19 can usually breathe freely. The virus instead affects their central nervous system. The effect is usually temporary, but in some patients, long-term.
For years, Dr. Philpott has studied smell loss and treated patients who have smell disorders. He says that historically, clinicians haven’t taken smell loss very seriously—but they should. “Sufferers experience wide-ranging impairments to their quality of life,” he noted. “These include a negative emotional impact, feelings of isolation, impaired relationships and daily functioning, impacts on physical health and the difficulty and financial burden of seeking help.”
Smell Disorders and Alzheimer’s Disease
Loss of smell—called anosmia—can be a temporary condition, brought on by allergies, cold, or, these days, COVID-19. But it might also be of long or permanent duration, being present at birth or caused by infections, injuries, tumors, problems with the bones of the nasal area or sinuses, or neurological conditions.
A related smell disorder, parosmia, alters the way things smell. “For people with parosmia, the smell of certain things—or sometimes everything—is different, and often unpleasant,” said Dr. Philpott. “So for example, someone with parosmia could sniff at a cinnamon stick, but to them, it would smell like something horrible—perhaps rotten food, or worse.”
Smell disorders can be an early sign of Alzheimer’s disease. And age itself is a top risk factor. Our olfactory sensory neurons, the brain cells we need to smell, change with age. Smell loss affects the health and quality of life of older adults in several important ways:
- Safety. Dr. Diego Restrepo of the University of Colorado School of Medicine warned that smell loss can keep seniors from detecting spoiled food, leaking gas or toxic vapors. He said this makes it especially important to keep smoke alarms in good working order, and to take extra precautions when cooking with natural gas.
- Nutrition. Dr. Restrepo cautioned that as seniors lose their sense of smell, they are at greater risk of malnutrition since food is appetizing due to smell as much as to taste. (People of any age can test this by evaluating the appeal of hot coffee and a fresh-baked cookie while they are suffering from a head cold.) He recommended that seniors adjust the seasoning in their food and make food more texturally and visually appealing.
- Brain health. Research on the relationship between sensory loss and brain health has mostly focused on the effects of vision and hearing loss—and the connection is quite clear. Yet experts talking about the connection between dementia and loss of smell most often focus on anosmia as an early symptom, whereas loss of smell also contributes to a cognitive load and stress that is bad for the brain. It can be not only an effect but also a cause.
- Reminiscing. “The inability to link smells to happy memories is also a problem,” reported the UEA team. “Bonfire night, Christmas smells, perfumes and people—all gone. Smells link us to people, places, and emotional experiences. And people who have lost their sense of smell miss out on all those memories that smell can evoke.”
- Emotional well-being. The UEA team noted that smell is intertwined with relationships, parenting, even a person’s confidence in their hygiene. They found that loss of smell can lead to “a diverse range of negative emotions including anger, anxiety, frustration, depression, isolation, loss of confidence, regret and sadness.”
These negative emotions are compounded when a person’s doctor doesn’t take the problem seriously. Dr. Philpott said his patients often had experienced a lot of negative, unhelpful interactions with previous healthcare providers. “Those that did manage to get help and support were very pleased—even if nothing could be done about their condition,” he said. “They were very grateful for advice and understanding.”
Dr. Philpott has been conducting research on “smell training”—therapies to help the brain relearn the ability to smell, which seem to work particularly well on older patients. Prevention is important, as well. While smell loss diminishes naturally with age, older adults can avoid certain things that hasten the loss, such as poor diet, infections, pollution and other toxic substances in the air, and sleep disorders such as sleep apnea.