American Girl's newest doll accessory is about so much more than toys.

Most of us have gotten a whiff of something and instantly felt at ease. Or, we've experienced a surge of serotonin after walking past a bakery, flower garden, or (gasp) gas station. Our sense of smell is deeply ingrained in the memory centers of our brain and just one sniff can alter our mood.

The olfactory system is really quite something. There is literally a super short nerve (first cranial 1) that, according to the Cleveland Clinic, "starts in the brain and ends in the upper, inside part of your nose." It gives the ability to process odor, while working with a whole system of olfactory receptors which receive the tiny molecules emitted by substances. (There's a whole system of membranes, bulbs, and neurons which work together to absorb a smell and make sense of it in your brain.)

What's extra interesting is that if this nerve is damaged, the long-time effect has been linked to Alzheimer's and other memory-loss diseases. Rather, an early sign of such a disease is anosmia (lack of smell), so whether it's causal or a symptom, it's theorized that smell and memory are intricately neurologically linked.

Beyond just memory (which factors into our moods, of course), there are many experts who claim specific scents affect different parts of the brain, and the science behind it is quite fascinating.

The power of scent. www.youtube.com, Real Men, Real STyle

But why and how different scents have such different effects on aspects of our lives are some remaining questions. Think of it like this. When you're taking medicine, whether it's for a physical ailment or mental health, different neurotransmitters are targeted. Smell is no different, which is why aromatherapy is so popular. From "The Science of Scents": "From the olfactory epithelium, nerve impulses are transmitted to the limbic system, a region in the brain associated with emotions, memories, and behavior. This direct connection explains why scents can evoke powerful emotional responses and trigger memories. Different aromas stimulate specific areas within the limbic system, influencing mood, stress levels, and even cognitive function."

Professor Kathy Willis writes in a piece for the BBC's Countryfile section about the importance of plants and their "science-backed" effect on overall wellbeing.

LAVENDER

Lavender flowers in the evening. Photo by Daiga Ellaby on Unsplash

Lavender can literally help you sleep better. Willis shares, "Experiments in sleep chambers have shown that during the nights when participants had aromas of lavender puffed into their rooms while sleeping, their brain wave activity indicated that they slept for longer intervals of time and also had more slow-wave deep sleep."

Dr. Elizabeth Ko, medical director at the UCLA Health Integrative Medicine Collaborative, adds that lavender oils for older people can greatly improve racing minds. "If you’re experiencing anxiety, try lavender. Inhaling lavender or diffusing it in your space may temporarily relieve feelings of stress and anxiety."

ROSEMARY

This scent actually has the opposite effect. Willis claims that many studies have shown that the "scent compounds of rosemary influence the neurotransmitters in our brain that are responsible for wakefulness and alertness."

Kate Rockwood backs up this claim, writing on Oprah.com, "Researchers at Northumbria University in England found that participants who sniffed essential oil of this (rosemary) herb performed significantly better on prospective memory tests, meaning they were less likely to forget future tasks."

PINE

Feeling anxious? The smell of pine can significantly reduce that. In experiments where respondents were exposed to the smell of pine, Willis shares that "even after as little as 90 seconds, participants showed clear evidence of physiological relaxation and reduced anxiety."

ROSE

A red rose with drops of dew. Photo by Edward Howell on Unsplash

This one is super cool. One experiment, described by Willis, had subjects drive a simulated car. During their drive, different scents were pumped into the "car" to assess whether they could reduce anxiety or create alertness. The smell of rose, peppermint, and civet were used, but "it was the smell of roses that indicated the best performance: slower speeds, less crashes, and the participants feeling more relaxed and cautious when behind the wheel."

CITRUS

This smell energizes and uplifts. An article on the Maison 21G, a perfumery website, "How Fragrances Affect Your Mood: Understanding the Power of Scents" further explains how deeply rooted smell is to our mental health and adds some more powerful scent connections to the list. Of citrus, they explain, "fragrances (with citrus) can help improve mood, increase alertness, and reduce feelings of fatigue."

Ko adds, "Citrus oils like bergamot or lemon tend to be uplifting and promote happiness."

EUCALYPTUS

We often think of these plants as having healing qualities (and may notice it in the ingredients of products meant to provide calm to the skin or hair.) There's a reason for that. The perfumery site claims, "Eucalyptus has a fresh, cooling scent that is known for its ability to clear the mind and promote focus. (It) can also help alleviate congestion and promote clear breathing, making it a popular choice for those suffering from colds or allergies. This invigorating scent is perfect for maintaining mental clarity and focus, especially during times of stress."

CINNAMON

cinnamon sticks and powder sit on a table. Photo by Rens D on Unsplash

Want to feel sexy? Who would have thought the spices you sprinkle atop eggnog could do the trick? "Cinnamon boasts a warm, spicy scent that can evoke feelings of comfort and warmth. This fragrance has been linked to increased alertness, focus, and even a mild aphrodisiac effect."

Rockwood adds, "Scientists at Wheeling Jesuit University discovered that when people smelled cinnamon, their attention improved and they had a better working memory. That could come in handy when you're trying to remember which party guest wanted your banana bread recipe."

PAIN RELIEF

Dr. Ko also specifically shares, "When researchers reviewed the results of over 170 trials, the findings suggested that inhaled essential oils may have some benefits for pain. The Arthritis Foundation suggests that certain oils work better than others for pain relief."

BERGAMOT blended with LAVENDER

(It's common for aromatherapists to blend scents to create a desired response. Again, doctors blend medications all the time until they find the right balance.)

GINGER

This scent, Ko suggests, is excellent when paired with a massage.

GREEN APPLE

If you have a headache, try the scent of green apple. Ko mentioned this as having specific properties that target cranial pain.

While aromatherapy obviously can't be the end all for serious physical or mental ailments, research continues to show that it can be extremely beneficial. So if all of this feels overwhelming, grab some lavender and take a whiff. You might just feel a tad calmer.