When the way that you make sense of the world around you begins to falter, it can be confusing and frustrating, to say the least. Dementia can affect the most fundamental parts of human cognition — including memory, language, and even the ability to make simple decisions like what you want for breakfast.
Today, there is still no cure for the condition, but a handful of prescription medications can lessen symptoms. Another, more controversial, treatment is aromatherapy. Some research has found that essential oils can help calm down dementia patients. There is also evidence that certain oils may even improve cognition. Though the body of work behind these treatments is still growing, early findings suggest that aromatherapy may be a non-invasive way to give patients some kind of relief.
“They have been used for such a long time,” says Snezana Agatonovic-Kustrin, a chemist at I.M. Sechenov First Moscow State Medical University in Russia who has conducted research on essential oils and dementia. “But no one looked into the details.”
Which Essential Oils Are Good for Dementia?
The two most-studied essential oils for dementia treatment are lemon balm and lavender. Earlier this year, a Taiwanese research group published an investigation into how patients at a daycare center for dementia responded to daily aromatherapy with these two oils. The scientists found that the patients who received aromatherapy were significantly less agitated.
Other emerging research backs up the benefits of such scents. Another study out of Japan, published in the journal Psychogeriatrics, found that aromatherapy using lavender, lemon, orange, and rosemary essential oils significantly improved dementia patient’s cognitive function. Meanwhile, a pilot trial with Spanish sage oil on 11 dementia patients in the United Kingdom showed a significant improvement in cognition, as well.
Other oils have been tested on in vitro cells or in rodents, but have yet to make it to human trials. Bergamot, Rosemary, and the oil of a middle-eastern shrub called Ferulago angulata have all shown promise in these experiments.
Still, other essential oils have yet to be tested at all, but nonetheless have properties that researchers expect might prove useful for dementia patients. These include eucalyptus, cypress, and thyme.
What Scientists Don’t Know About Aromatherapy and Dementia
Aromatherapy as a treatment for dementia has yet to be tested on a large scale. A 2020 review of the research behind aromatherapy for dementia stated that “in order for clear conclusions to be drawn, better design and reporting and consistency of outcome measurement in future trials would be needed.”
So, the evidence isn’t exactly clear, but the work that has been done is certainly promising. Currently, researchers can confidently say that some patients, in some situations, experienced relief from aromatherapy.
“It won’t heal the patient, but it will help,” Snezana Agatonovic-Kustrin says.
How Do Essential Oils Help Dementia and Alzheimer’s Patients?
For some people, essential oils might sound like a fringe, hippie-dippy treatment. But the way they function in your brain is actually similar to drugs like Donepezil, a prescription for Alzheimer’s disease, the most common type of dementia.
How, exactly, can aromatherapy benefit our brains? The story starts with the neurotransmitter acetylcholine, which helps govern memory. Alzheimer’s disease is thought to stem from a loss in function of the neurons that produce acetylcholine. To counteract this, drugs like Donezapil boost acetylcholine levels by blocking up an enzyme called acetylcholinesterase that breaks down the neurotransmitter.
There is evidence that essential oils can do, essentially, the same thing. Separate studies found that both lemon balm and lavender slow down acetylcholinesterase’s ability to break down acetylcholine. Other essential oils, including key lime and stinkwort, have a similar effect. These may be good candidates for clinical trials in the future.
Of course, this is just one theory about how essential oils work in the brains of dementia patients. Another is based on the fact that many essential oils are antioxidants — molecules that protect your body against harmful “free radicals” that are produced when we are exposed to tobacco smoke, X-rays, and air pollution. Yet another theory posits that essential oils stimulate the aging brain through a process called “olfactory enrichment.”
How Do Essential Oils Travel From the Air to Your Brain?
For essential oils to have a chemical effect on a human brain, they have to get there first. Luckily, most essential oils are exceptionally good at passing through the human body. It all comes down to two factors: For starters, the molecules that make up essential oils are quite small. Plus, essential oils are what chemists call “lipophilic” — meaning they like to glom on to the fats that make up cellular membranes throughout the human body.
Agatonovic-Kustrin explains that these properties allow essential oil molecules to enter the bloodstream through the tissues inside your nose when inhaled. However, it is probably even more effective to rub essential oils directly on the skin; essentially, exposing the oils to more surface area leads to a greater concentration in the blood.
“Once they get into the bloodstream, they can then penetrate into the brain,” Agatonovic-Kustrin says. “Some passively, because they’re small and lipophilic. Some probably even by active transport.”
Could Essential Oils Be Used to Treat Other Conditions?
Because of these properties, essential oils could prove to be exceptionally useful in the treatment of neurological conditions, in addition to other medical applications. Studies have even found them to be effective at boosting the effects of topical drugs.
Still, research on essential oils remains hard to come by. Agatonovic-Kustrin thinks that some of this may be due to a bias against traditional medicine in the research community. “It’s really hard to find funding. It’s always a struggle,” she says. “Most of the research I have done just because I was curious.”
Agatonovic-Kustrin hopes that the insights from her and her colleagues' work will drive interest in further research into essential oils. What little we know about these ancient molecules certainly opens the door to future research questions. One day, perhaps, lavender and lemon balm will sit on the shelf next to pharmaceuticals in hospital supply closets.