Trending
DEAR DR. ROACH: My 82-year-old husband is unable to smell or taste. This has been the case since 2024, when he was hit by a car while out for a walk. He sustained a compression fracture to his spine. While he wasn’t knocked out, he did get thrown backward and sustained some trauma to his head. Since then, he’s had no sense of smell or taste.
I see him drifting further and further into depression, and I believe it’s primarily because he no longer has the pleasure that is associated with taste. He has seen our general physician and an ear, nose and throat doctor. He’s been given some scented items, which he diligently used to try to reactivate his smell and taste. He also uses nasal rinses. These treatments have resulted in him occasionally tasting the first bite that he takes, then nothing.
Recently, I’ve read about successful studies using stem cells to revive olfactory senses. What knowledge do you have of these studies or of any other possibilities to revive his sense of taste and smell? -- D.L.D.
ANSWER: Loss of smell often leads to a subjective loss of taste, as smell is a very important part of tasting. People who’ve had a temporary loss of smell from a bad sinus infection may recall everything tasting bland.
Loss of smell was a big issue during the first wave of COVID in 2020. The use of olfactory training (the treatment using the scents that his doctors gave him) is pretty effective with COVID. But unfortunately, a loss of smell after head trauma has a worse prognosis. However, the fact that he’s had some benefit with the treatment is a good prognostic sign, and I recommend that he keep these treatments up.
I found studies in mice using stem cells for restoring a sense of smell, but I didn’t find any clinical trials or recruiting in humans. I read about trials using platelet-rich plasma and found some clinical trials that are listed as “not yet recruiting” (on ClinicalTrials.gov). The trials that have been done so far haven’t shown dramatic results.
DEAR DR. ROACH: I’m interested in your opinion about using photobiomodulation (PBM) on macular degeneration. -- R.G.B.
ANSWER: Macular degeneration is a very common disease of the eye, affecting about 8% of the world’s population. The major risk factor is age, but there are also genetic risks. There are two main forms -- “dry,” which makes up 75% of cases, and “wet” (the remaining 25%).
Early treatment with injectable drugs is the standard treatment for wet age-related macular degeneration (AMD), but there haven’t been very effective treatments for dry AMD beyond a specific vitamin regimen called AREDS or AREDS2. A new treatment is PBM, which uses low intensity light to the retina. It’s thought to be absorbed by an enzyme in the mitochondria called cytochrome c oxidase, which reduces inflammation and protects the mitochondria.
Early studies on PBM weren’t particularly promising, but a 2024 study showed promise. There was a benefit found in visual acuity when PBM was compared to a “sham” treatment, which seemed like PBM to the study subjects and investigators but didn’t use the PBM light. Another 2024 trial didn’t find a benefit.
The device is authorized by the Food and Drug Administration; however, a major organization, the American Academy of Ophthalmology, has rated the evidence to be of “insufficient quality” for recommendation. They’re awaiting further trials.
If you were interested in proceeding, you should discuss it with your ophthalmologist, and it should be in addition to -- not instead of -- standard therapies. A recent study showed that a Mediterranean-style diet decreased both the risk of getting AMD and its progression. Quitting smoking also helps.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu. (c) 2026 North America Syndicate Inc.
All Rights Reserved