What does the data REALLY say about essential oils?

Almost everyone who has walked in to the studio has at some stage commented on how nice it smells. It’s no secret that I love diffusing oils.

I know, I know. The claims about essential oils — that they can help with sleep, mood, hormone levels, and more — can sound like scammy, woo-woo nonsense. The worst “health” advice the internet has to offer.

So, I took it in my own hands to sift through the current scientific evidence on essential oils, to determine whether they actually do anything, except simply smelling nice!

Interestingly, there’s intriguing scientific data suggesting that some of the potential benefits of essential oils might just be a reality.

For example:

• I’ve seen several case studies showing 25-35 percent increases in testosterone among hypogonadal (low-testosterone) men who ingested essential oil from blue spruce.
• Frankincense essential oil comes from resin of the boswellia tree. Boswellia is highly touted in the supplement world for joint pain and arthritis.

Sure, you argue, small scale trials and simple case studies don’t “prove” or “disprove” anything. But these are more than speculation and anecdotes.

In my opinion, they’re enough to start a conversation, maybe even spark laboratory scientists to start looking more deeply into what essential oils do in larger groups and more controlled settings.

As always, it usually takes science a little while to catch up. But for now, let’s take a deeper look into essential oils.



What are essential oils?

Essential oils are the volatile liquids found in a variety of plants, trees, shrubs, and citrus fruit rinds. They’re what give herbs, flowers, and fruits their distinctive scents. They’re also some of the oldest known “natural health products”.

For several thousand years, people all over the world have been extracting these oils using methods such as steam distillation, cold pressing, resin tapping, or absolute extraction.

Essential oils aren’t there by accident, or just because a flower decided to smell nice. The chemical components help the plants function and fight pathogens, disease and stress.


For instance, these components can:

• act as chemical messengers and hormones;
• protect the plant from bacteria, fungi, and viruses; and
• protect the plant from environmental stressors such as heat.

These active compounds are such small molecules that humans can easily absorb them through the skin, nasal passages, lungs, and digestive system.

Since plant physiology is similar enough to our own, we can get therapeutic benefit from some of the oils’ constituents.
Of course, every essential oil affects the human body in different ways, based on the dozens (or hundreds) of compounds in each oil.

For example, peppermint has more than 40 known constituents. (And probably a bunch of unknown ones). It’s been shown to:

• soothe the digestive system,
• relax tight muscles,
• be mentally and physically stimulating, and
• help lower blood lactate levels during exercise.

How do essential oils work?

The three most common methods for using essential oils are:

• topical application,
• inhalation, and
• ingestion.

Most pure essential oils can be used all three ways — but be careful: Not all essential oils are pure.

Inhalation
Essential oils are most known for their odor (hence the term aromatherapy).

Inhaling essential oils stimulates any of more than 1,000 receptors in the nasal cavity, which transfer signals through the olfactory bulb to the limbic system, the center for our emotions. From there, they can affect the autonomic nervous, endocrine, and immune systems.

When essential oils reach the lungs, they pass from the alveoli into the capillary blood vessels. Once in the bloodstream, they are small enough to pass through the blood-brain barrier.

Inhaling certain essential oils may:

• help improve mood, emotions, and libido;
• support sleep quantity and quality;
• increase focus or alertness; and/or
• reduce feelings of stress or occasional anxiety.

Topical application
You can apply essential oil on its own or diluted with a “carrier oil” (such as avocado, coconut, olive, or sesame).


Diluting essential oils:

• minimizes the sensation on the skin and slows absorption (especially important if you’re using the oil on a child),
• allows you to spread the oil across a larger surface, and
• helps the oil’s effect last longer.

After penetrating the skin, essential oils can act locally (for instance, on your knee if you’ve rubbed the oil on your knee).
Or they can act systemically, throughout the body. If you’re looking for a systemic effect, one of the best places to apply the oil is the soles of the feet, since the pores there are large and essential oils are thus absorbed quickly.

Topical use of certain essential oils may:

• help target specific areas such as the sinuses, lymph system or the stomach
• have many of the benefits associated with inhalation; and/or
• relieve muscle soreness or joint stiffness from workouts, or other minor aches and pains.

Ingestion
The ingestion of essential oils might be one of the most debated topics in alternative health today.

I would not, under any circumstance, recommend ingesting cheap, perfume-grade essential oil. Although most pure essential oils can be ingested, there isn’t always a good reason to do it.

Research indicates that ingesting certain essential oils may:

• help us digest and absorb food;
• help relieve occasional digestive distress;
• help relieve symptoms of digestive issues like gingivitis, colitis, Irritable Bowel Syndrome and dysbiosis;
• support the immune system; and/or
• support normal inflammatory levels.

Where’s the science?

One of the arguments against essential oils is that there isn’t enough research on them: Without multiple double-blind, placebo-controlled studies, what do we really know?

Simply put, this isn’t true. There has been a significant increase in published research on essential oils in recent years.

Scientists are beginning to test various oils and their constituents.

Unfortunately, we’ll probably never see as many double-blind, placebo-controlled trials on essential oils as there are on pharmaceuticals or patented supplements, as essential oil research is very expensive.


Making matters worse, no one wants to pay for the research. Supplements and pharmaceuticals are often patented. Companies that own the patents do whatever studies they need to prove that their products work. But plants that essential oils come from are living things in the public domain and therefore can’t be patented. Where there’s no patent, there’s often no profit.

Specific oils and their benefits

Here’s a summary of some of the more interesting published research available to date on essential oils.

Peppermint

May improve athletic performance
In studies, one drop of peppermint on the tongue, or in mineral water was associated with:

• improved grip strength, vertical jump, and standing long jump, visual and auditory reaction time, and heart rate variability both five minutes and 60 minutes after use
• improved lung capacity and blood lactate after 10 days of daily ingestion. Carbohydrate metabolism increased, suggesting an increase in energy production in muscle tissue. Heart rate during exercise also improved.

Inhalation of peppermint:

• decreased quarter-mile run time
• increased push-up performance and grip strength

May improve GI health

• Peppermint has been shown to relieve discomfort and occasional abdominal pain by relaxing the smooth muscle of the digestive tract.

Lavender

Lavender is the most often used essential oil in the world. It’s also the most adulterated, as the demand far exceeds the supply. The oil is distilled from the flowers.


May improve sleep
Inhaling lavender before or during the early stages of sleep:

• enhanced deep sleep, and/or
• improved sleep quality.

May improve relaxation and calm
Inhaling lavender:

• can lower autonomic nervous system arousal (i.e. the stress response), including lowering blood pressure, heart rate, and skin temperature;
• has been shown to lower cortisol levels; and/or
• can stimulate alpha wave brain activity (which tends to happen when our brain is “idling” — daydreaming or meditating)

When lavender and rosemary (which have somewhat similar scent profiles) were compared, lavender was relaxing while rosemary was stimulating.


May decrease pain
Among women who’d had Caesarean sections, those in the lavender group showed a significantly lower level of perceived pain at four, eight and 12 hours post-op.

Citrus

Citrus oils are cold-pressed from the rind of the fruit.


May calm us and boost our mood
Oil of bergamot (which is part of the citrus family) can calm the nervous system; support sleep, increase relaxation and alleviate occasional feelings of anxiety.
Orange essential oil may do the same.

May stimulate us
Lemon and grapefruit, on the other hand, may boost our mood, wake us up, and get the brain moving. (Which is perhaps why many cleaners are lemon-scented.)


Other interesting findings

In studies:

• Pepper, tarragon, fennel and grapefruit fire us up: Each of these essential oils each stimulated sympathetic nervous system (SNS) activity 1.7 to 2.5-fold. Pepper oil increased adrenaline concentrations.
• Rose and patchouli oils chill us out: These inhibited SNS activity. Rose decreased adrenaline levels.
• Jasmine improved sleep quality. Jasmine is often used as a perfume, as many find its aroma seductive.
• Inhalation of neroli (bitter orange) by postmenopausal women lowered blood pressure, increased sexual desire, lowered stress levels and stimulated the endocrine system.
• The essential oil of Laurus noblis (bay laurel), which is typically thought of as a spice for cooking, when inhaled, enhanced alertness and reactions to unpredictable stimuli.
• Animal research shows that ingesting essential oils can aid in relieving symptoms from digestive issues such as colitis and intestinal dysbiosis.
• About 2-3 drops per day of lemongrass reduced cholesterol levels in adults with high cholesterol levels.
• Essential oils high in beta-caryophyllene (found in cloves, rosemary, hemp, and hops) have antioxidant and anti-inflammatory properties. Beta-caryophyllene (BCP) is most highly-concentrated in copaiba, from a group of South American trees in the Copaifera genus. Interestingly, this constituent is also found in cannabis.

Now, if you’ve made it this far, the chances are, you’re thinking;

“Great! Essential oils have merit, I’m going to start using them and all my woes will disappear”


Not quite.


It’s incredibly important to remember:

You need to start with healthy-lifestyle basics.
While essential oils can have a powerful effect on our health, they can’t do it alone. We still must support our bodies with proper nutrition, exercise, and lifestyle choices.

Once those are solid, essential oils might help you get that extra little bit of improvement. Oils may even make fitness and health come easier, since they can boost your mood and help you recover better.

Be wary of grandiose health claims.
Nothing cures everything. Even if something has very real effects, those effects will probably be small to moderate.

It goes without saying, but I’m going to say it anyway: Medical problems should be dealt with under the advisement of a competent healthcare practitioner. Though essential oils may help with certain symptoms or issues, they are not a replacement for medical therapy if that is what is advised from your healthcare practitioner.

Use high-quality oil.
It’s estimated that only 2 percent of essential oils are of therapeutic quality. The rest are made simply to smell nice.
When we talk about health benefits, we’re referring to high-quality, therapeutic essential oils, not the cheap stuff.



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