Introduction

One study concluded that when mice with Alzheimer’s disease inhaled menthol, their cognitive abilities improved.

Reversing Brain Damage

It appears that a chemical compound found in some herbal plants and often extracted from mint or phloem may reverse some of the brain damage that is commonly associated with this disease.

Decrease in IL-1β Levels

Specifically, the researchers observed a decrease in levels of the protein interleukin-1 beta (IL-1β), which helps regulate the body’s inflammatory response, a response that can provide natural protection but leads to damage if not properly controlled.

The Potential of Scents

The team behind the study, published in April 2023, says it shows the potential of using certain scents as a treatment for Alzheimer’s disease. If we can figure out which smells trigger a response in the brain and immune system, we can use them to improve health.

“We focused on the role of the olfactory system in the immune system and central nervous system and confirmed that menthol is an immune-stimulating odor in animal models,” says immunologist Juan José Lasarte from the Center for Applied Medical Research (CIMA) in Spain. “Brief exposure to this compound for six months prevented cognitive decline in mice with Alzheimer’s disease, and most interestingly, it also improved cognitive performance in healthy young mice.”

Inhalation of Menthol

Having previously observed that inhaling menthol boosted the immune response in mice, the team showed that it could also improve cognitive performance in animals, as observed in a series of practical tests in the laboratory.

Preventing Cognitive Decline

In mice with Alzheimer’s disease, a six-month course of menthol was enough to prevent decline in cognitive and memory abilities.

Regulating IL-1β Protein Levels

In addition, menthol appears to increase IL-1β protein levels in the brain to safe levels.

When the researchers artificially reduced the number of regulatory T cells, or Tregs, which are known to help keep the immune system in check, some of the same effects were observed, opening up a potential path that future treatments could take.

“Menthol exposure and Treg cell blockade caused a decrease in IL-1β, a protein that may be responsible for the cognitive decline observed in these models,” neuroscientist Ana García Aosta of the Center for Applied Health Research said at the time.

She continued: “In addition, specific blockade of this protein with a drug used to treat some autoimmune diseases also resulted in improved cognitive performance in healthy mice and mice with Alzheimer’s disease.”

The Olfactory System and the Brain

Scientists have already established numerous connections between smells and our immune and nervous systems. This relationship is difficult to fully understand, but we do know that our olfactory system can greatly influence the brain. Certain smells can trigger certain reactions in the brain, causing chemical reactions that affect memory, emotions, and more.

In fact, diseases related to the central nervous system, such as Alzheimer’s disease, Parkinson’s disease, and schizophrenia, are often accompanied by loss of smell.

Further Research Required

This new study adds some promising data, but more research is needed in mice as well as humans.

Immunologist Noelia Casares, from the Center for Applied Health Research, said: “This study is an important step towards understanding the relationship between the immune system, the central nervous system, and odor. The results suggest that odors and immune modulators may play an important role in the prevention and treatment of Alzheimer’s disease and other diseases associated with the nervous system.”

Source

The study was published in the journal Frontiers in Immunology.

Source: ScienceAlert