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While research suggests there are health benefits, the FDA doesn’t monitor or regulate the purity or quality of essential oils. It’s important to talk with a healthcare professional before you begin using essential oils and be sure to research the quality of a brand’s products. Always do a patch test before trying a new essential oil.

Your immune system plays an important role in keeping you healthy. When your immune system is weakened, it can make you more vulnerable to becoming ill. Because of this, it’s important to do what you can to help your immune system work to its full potential.

You may have heard that essential oils (EOs) can help boost your immune system.

In this article, we’ll take a closer look at what’s known about EOs and immunity, focusing on what the research has to say about which EOs may boost your immune system the most.

Before we discuss EOs and immunity, it’s important to know a little bit about your immune system. Overall, your immune system is a complex network of tissues and cells that works to defend you against harmful factors, such as:

Your immune system is activated when it encounters something it considers to be a harmful foreign substance. This is known as an antigen. An example of an antigen is the spike protein found on the surface of the novel coronavirus, SARS-CoV-2.

Once an antigen is recognized, an immune response is generated. This involves signaling between the different cells of the immune system by both cell-to-cell contact and by signaling molecules called cytokines.

The types of immune response

There are two types of immune response — innate and adaptive. While they both work closely together, they each have different functions.

The innate response is non-specific and happens immediately. Think of the cells of the innate immune system as first responders. There are many types of innate immune cells. A few examples are:

Innate immune cells recognize patterns on foreign substances and can go on to activate the adaptive response. The innate immune response also often leads to inflammation, which is typically promoted by the release of specific cytokines.

The adaptive immune response is specific and associated with memory. After exposure to an antigen, the adaptive immune system learns how to respond to it again in the future. Examples of cells in the adaptive immune response are B cells and T cells.

EOs are concentrated substances extracted from plants. They can come from a variety of sources, including, but not limited to:

  • leaves
  • flowers
  • bark

Typically, EOs are used in aromatherapy, either by inhaling them or by applying a diluted solution to the skin. They’re used for a variety of purposes, such as:

  • reducing stress
  • promoting sleep
  • easing pain

EOs are very complex substances. For example, a single EO can contain up to 400 different compounds. Some of these compounds may have a variety of effects on the body.

One of these effects may be adjusting how the immune system behaves. This is referred to as immunomodulation. It may include things like:

  • stimulating certain parts of the immune system
  • increasing the activity of specific immune cells
  • interfering with pathways associated with inflammation

Much of the information about EOs boosting immune function is anecdotal. That means it comes from personal experience rather than from scientific research.

Generally speaking, research into how exactly EOs interact with the immune system is pretty limited. However, some studies have found potential immune benefits for specific EOs that require further investigation.

It’s important to note, however, that a lot of the research that’s been done with EOs and immunity has been conducted on rats, mice, or laboratory-grown cells. Very few of these studies have been conducted on human participants.

Below, we’ll examine what scientific research has uncovered regarding four of these EOs.

Eucalyptus essential oil comes from the leaves of the eucalyptus tree (Eucalyptus globulus). It has anti-inflammatory and antioxidant properties, and it has a long history of use for ailments like a cough and respiratory infections.

Some research indicates that eucalyptus EO can enhance phagocytosis, a process immune cells use to engulf, or “eat,” a germ. It may also help reduce cytokines associated with inflammation that are produced by some immune cells.

A 2008 study found that eucalyptus EO boosted phagocytosis and reduced levels of inflammatory cytokines in laboratory-grown innate immune cells. It also promoted phagocytosis and increased the numbers of some innate immune cells in rats.

A 2017 study supports this, also reporting that eucalyptus EO affected innate immune cells, specifically macrophages. It found that eucalyptus EO significantly reduced cytokines associated with inflammation and enhanced phagocytosis.

Lastly, a 2020 study looked at the effect of different doses of eucalyptol, a component of eucalyptus EO, in rats. While low or moderate doses stimulated phagocytosis in T cells, higher doses actually hindered the process.

Summary

Eucalyptus EO may increase the activity of some types of innate immune cells. It also appears to reduce the levels of inflammatory cytokines produced by these cells.

Clove essential oil comes from the dried flower buds of the Syzygium aromaticum tree. It has anti-inflammatory, antioxidant, and pain-easing properties. Clove EO has been used for hundreds of years in traditional medicinal practices to ease pain and help wounds.

A 2011 study investigated clove EO in rats. It found that clove EO reduced the immune response related to T cells and innate immune cells, lowering inflammation levels. Meanwhile, the immune response associated with antibodies and other proteins was boosted.

A 2015 study looked into the effects of clove EO on laboratory-grown macrophages. It found that clove EO could promote some inflammatory cytokines while hindering others. The exact effect depended on the dose of clove EO and whether the macrophages had already been activated.

A 2021 study looked into the effects of clove EO in a mouse model of campylobacteriosis, a type of bacterial food poisoning. Researchers found that, compared with mice receiving a placebo, mice that were given clove EO had:

  • lower levels of bacteria in their small and large intestines
  • less severe illness
  • fewer signs of cell death and inflammation in their large intestine
  • reduced levels of immune cells like macrophages, monocytes, and T cells in their large intestine
  • lower levels of inflammatory cytokines both in and outside their intestines
Summary

Clove EO appears to affect the immune response by reducing inflammatory cytokines produced by some immune cells. However, at higher doses, it may actually increase some inflammatory cytokine production.

Lavender essential oil is obtained from the flowers of the lavender plant (Lavandula angustifolia). It has anti-inflammatory, antimicrobial, and stress-reducing properties. It has traditionally been used to:

  • lower anxiety
  • promote sleep
  • help with skin problems

A 2016 study looked at lavender EO’s ability to activate macrophages in response to infection with staph bacteria. The researchers found that lavender EO:

  • enhanced phagocytosis of staph bacteria by macrophages
  • reduced bacterial growth within macrophages
  • lowered the release of inflammatory cytokines by macrophages

A 2017 study investigated the use of lavender EO massage in 52 pregnant woman. Compared with the control group, participants who received a lavender EO massage had higher levels of IgA, a marker of immune function, in their saliva.

Lastly, a 2018 study assessed topical lavender EO in a mouse model. It was found that lavender EO reduced inflammation levels at low doses in a variety of tests. It’s believed to do this through interfering with inflammatory pathways.

Summary

Lavender EO boosts some markers of immune function. It may also decrease inflammation and enhance the activity of some types of immune cells.

Tea tree essential oil is made from the leaves of the tea tree (Melaleuca alternifolia). It has anti-inflammatory and antimicrobial properties. Tea tree EO has been used historically for a variety of conditions, such as skin problems and respiratory illnesses.

A 2015 study in laboratory-grown macrophages found that a concentrated tea tree oil solution hindered the production of inflammatory cytokines by these cells.

Later research from 2017 found that tea tree oil affects how the genes that encode some of these molecules are expressed in macrophages. This could help explain the reduction in inflammatory cytokines following exposure to tea tree oil.

Summary

Tea tree EO reduces the production of inflammatory cytokines by macrophages. This, in turn, may reduce inflammation levels.

Although we’re still learning more about how EOs can affect the immune system, there are other tried-and-tested things you can do to help boost your immune system. These include:

  • Eating a nutritious diet. Try to focus on making nutritious food choices, as the nutrients from these foods can help bolster your immune function. Some examples of foods to emphasize in your diet include:
    • fresh fruits and vegetables
    • whole grains
    • low fat dairy products
    • lean protein sources
  • Limiting certain foods. There are also some types of foods to try to limit or avoid, as they may increase inflammation in your body. These include foods that are high in:
  • Using supplements. Some dietary supplements, such as vitamin C, zinc, and probiotics, may boost immune function. However, be sure to talk with a doctor before introducing new supplements to your diet.
  • Managing weight. Excess weight is associated with inflammation and lower immune function. If you have overweight or obesity, talk with a doctor about healthy ways to lose weight.
  • Lowering stress. High levels of stress and anxiety can negatively impact your immune system. That’s why it’s important to find healthy, effective ways to reduce your stress. Some examples include exercise, yoga, and meditation.
  • Getting enough sleep. Not getting enough sleep may impact your immunity. Try to prioritize your sleep and form a nighttime routine that promotes good sleep.
  • Exercising regularly. Getting regular exercise can benefit your immune system by helping to manage weight, reduce stress, and improve your sleep.
  • Drinking alcohol in moderation. Drinking alcohol in excess can weaken your immune system. If you drink alcohol, try to do so in moderation.
  • Quitting smoking. Smoking increases the risk of many health conditions and may lead to problems with your immune system. If you smoke, talk with your doctor about developing a quit plan.
  • Getting vaccinated. Vaccines are vital tools for providing immunity against various infectious diseases, including COVID-19 and the flu.

It’s possible you may have heard that using EOs, particularly eucalyptus EO, can protect you from contracting the coronavirus that causes COVID-19. However, there’s currently no scientific evidence to support this.

In fact, the Food and Drug Administration (FDA) has already issued warning letters to several companies that have promoted their EO products as being able to treat or prevent COVID-19.

The most effective way to prevent becoming ill with COVID-19 is to get vaccinated. If you have questions or concerns about COVID-19 vaccination, don’t hesitate to discuss them with your doctor.

Some research has found that certain EOs may be able to boost the immune system. These EOs include:

  • eucalyptus
  • clove
  • lavender
  • tea tree oil

However, much of the research that’s been done on these EOs is still in its early stages and has been done on laboratory-grown cells or animals. Because of this, further research is needed to discover how exactly EOs can impact the human immune system.

Until then, there are many strategies you can use every day to help boost your immunity. This includes eating a nutritious diet, maintaining a moderate weight, reducing stress levels, and getting vaccinated against infectious diseases.