Q My husband lost his sense of taste and smell and then tested positive for COVID-19. What can you tell us about this side effect? MV, Greenville
A Taste and smell are so important to the enjoyment of food and to a person’s nutritional status. Patrick Dugom, a Brody medical student searched for answers for you. Here is what he learned.
Every time you are screened for COVID-19 you are asked, “Have had a loss of taste or smell?” But is this a sign of something dangerous? We rely on these senses daily and their sudden absence can be concerning. Researchers say these senses are much more important than we might think. In fact, it is thought that out of the five classical senses, taste is likely the only one that is essential to life. Since most of what we taste is dependent on our sense of smell, it too, is critical for survival and enjoyment.
A loss of taste and smell is a commonly reported symptom in people with mild cases of COVID-19. The virus presents itself differently in different people and many are only mildly symptomatic. Interestingly, these are the people who appear to be most affected by loss of taste and smell.
There isn’t a lot of evidence about the loss and recovery of taste and smell from COVID-19. It seems random. It is thought it could be an early sign of the infection, but others don’t notice the loss until several days after testing positive. Somewhere between 2 and 6 out of 10 people with COVID-19 lose the sensations. Fortunately, 3 out of 4 regain it fully but it’s not clear how long it takes.
The patients we talked with said that they started to have some taste after about 10 days. One study showed that most recover by four weeks. For those few who report losing taste and smell for months — some many months — experts suggest that the virus could have killed their olfactory sensory neurons. When inhaling through the nose, these olfactory sensory neurons detect traces of chemicals in the air. So, without these neurons, smell is greatly reduced or absent. Another possibility is that the virus produced an inflammatory reaction of the nasal mucosa — the tissue that lines the nasal cavity.
You might be wondering if there is anything you can do to make these senses come back faster. In short, it appears you just must wait for these senses to come back on their own. In the meantime, you may need to think harder about keeping yourself appropriately nourished. Patients we talked with said they had to be thoughtful about what, how and when they ate.
One was concerned she might add too much sugar, fat, or salt to her food, further complicating management of her blood pressure, blood sugar and weight, so she carefully tracked her intake. She was right to be concerned since the lack of taste can worsen nutritional status leading to further health problems.
The inability to smell rotten food could lead to eating spoiled food and illness. A patient felt it was important to have his wife smell his milk to make sure it wasn’t spoiled. The loss of taste and smell can also hinder appetite. Another said her favorite foods became unappealing because they no longer provided the same pleasurable sensations. She focused on including foods of different textures to provide enjoyment in eating. She didn’t like the texture of meat that had no flavor, so to get protein she had yogurt for breakfast along with the different textures from berries and granola.
The blandness of food can diminish appetite and prevent you from getting adequate nutrients, so one patient — who could pick up notes of sour and spice — squeezed lemon juice on and added hot sauce/red pepper flakes to his foods. He said that helped maintain an interest in eating enough food. Eating spicy foods heightens sensitivity. A New York Times food critic reported using Sichuan peppercorn and chile to stimulate taste and interest in food.
On patient reported being very thirsty. She was careful to drink what she needed to stay hydrated since she knew drinking too much water blunted her appetite. We read that “scent training” — inhaling a strong smell and focusing on what the scent should smell like — also referred to as “olfactory training” — may be helpful, especially to those with long COVID. There is an ongoing clinical trial to determine if fish oil supplements could regenerate damaged nerves and bring back taste and smell. Unfortunately, so far, trials with compounds thought to be helpful in nasal health like vitamin A, zinc, alpha lipoic acid, and gingko biloba have had no effect.
If you are gaining or losing weight, or if your sense of taste has not returned in several months, a session with a Registered dietitian nutritionist (RDN) would help you plan your eating while on your road to recovery. We appreciated the input from Rachel Gergely, one of the Clinical RDNs at Vidant Medical Center for this article.