Methodist Healthcare - November 20, 2023
A woman smells an essential oil.

Some people believe that certain essential oils can boost immune function and keep illness at bay — but what does the research say?

What are essential oils?

The word "essential" comes from "essence," or the core part of something. Aptly named, essential oils are created by pressing or distilling parts of a plant to produce concentrated extracts. These oils contain chemical compounds from the plant and carry its characteristic fragrance. For this reason, people often use essential oils as perfume by diluting them and rubbing them onto the skin or putting them in a diffuser to release the scent into the air. Soaps, massage oils, lotions, shampoos and even household cleaning products may also contain essential oils. These oils are different from cooking oils, and they're generally not taken orally.

Essential oils aren't regulated or standardized. So, these products can vary from one manufacturer to another or even from batch to batch from the same manufacturer. Oils made with chemical solvents or alcohol aren't considered essential oils since this can change the oil's chemical makeup and scent (and sometimes introduce irritants).

What do essential oils do?

Aromatherapy is the practice of using essential oils to improve physical, mental or emotional well-being. Different smells can affect mood or trigger memories, and some scents influence mental alertness or stress reactions. For example, the smell of lavender can induce relaxation in some people. Scientists don't know whether this results from lavender's chemical makeup acting on the brain, its pleasant scent or its potential connection to happy, relaxing memories. Aromatherapy is sometimes combined with massage or acupuncture to manage cancer treatment or symptoms, including anxiety, nausea and vomiting.

Common essential oils and their reported effects

In addition to lavender, other common essential oils may have health benefits. For example:

  • Lemon oil may boost mood in people under stress.
  • Peppermint oil is sometimes used for treating headaches and muscle aches, reducing stress or improving mental function. When taken via a specially coated tablet, it may reduce symptoms of irritable bowel syndrome.
  • Some people use eucalyptus oil for conditions such as flu, asthma and bronchitis, but no evidence shows it works.

Most essential oils are generally considered safe when used as directed. However, there have been some reports of "hormone-like effects" with lavender and tea tree oil when applied in high doses over a long period of time. Never swallow tea tree oil.

Can you use essential oils for immunity?

Some studies have found that the chemicals in herbal essential oils may interact with cells that play a role in inflammation and immunity. However, these are mostly laboratory studies or studies performed on livestock or fish. Studies performed on humans are limited and don't indicate a clear association between essential oils and health benefits.

Supporting your immune system year-round

Essential oils can help create a soothing environment in your home, but there are better methods to protect yourself from illness than using essential oils for immunity. Here are some great ways to boost your health, reduce your chances of getting sick and support your recovery:

Eat healthy foods

A healthy diet includes vitamins and minerals that your immune system needs to fight off illness. Choose fruits, veggies, whole grains, lean proteins and low-fat dairy. Limit high-fat and fried foods, salt and added sugar. Generally, it's better to get your vitamins and minerals from food rather than from dietary supplements.

Stay active

Moving around during the day helps improve sleep and reduce anxiety. It may also support immune system function.

Catch some Z's

When you don't get enough sleep, you can put stress on your immune system.

Stop smoking and limit alcohol

Smoking makes it harder for your body to fight off infections and illnesses, and too much alcohol can weaken immunity.

Get your shots

Stay up to date with vaccines against the flu, COVID-19, pneumonia and more. Your doctor can advise you on which vaccines you should have based on your age and other factors.

So, go ahead and put a sachet of lavender under your pillow, or release the scent of peppermint to perk up your workday. But, it's best to avoid relying on essential oils for immunity.