Essential Oils and Epilepsy: What Does the Science Say?

by Jade Shutes

Epilepsy is a neurological disorder characterized by recurrent, unprovoked seizures. It affects millions of people worldwide and can have a significant impact on quality of life. While anti-epileptic drugs are the primary treatment for controlling seizures, some people with epilepsy are interested in exploring complementary therapies like essential oils. But what does the scientific evidence say about the effectiveness and safety of essential oils for epilepsy?

A recent systematic review published in 2019 analyzed the current research on essential oils and epilepsy, including human case studies, animal models, and in vitro studies. The review aimed to identify which essential oils may have anticonvulsant properties and could potentially benefit people with epilepsy, as well as which oils may trigger seizures and should be avoided.

Promising Essential Oils for Epilepsy

The review found that several essential oils showed anticonvulsant effects in animal models of epilepsy. These included oils from plants like lemongrass (Cymbopogon citratus), lavender (Lavandula angustifolia), clove bud (Syzygium aromaticum), dill (Anethum graveolens), and sweet wormwood (Artemisia annua).

What do these oils have in common? They contain certain chemical compounds that seem to be responsible for their anti-seizure effects:

    • Asarone: Found in sweet wormwood and Acorus gramineus (Japanese sweet flag), asarone increased seizure threshold and reduced seizure severity in rodents. Chronic administration of asarone completely prevented seizures in a model of temporal lobe epilepsy.
    • Carvone: A compound in oils from herbs like dill and Carum carvi (caraway), S-(+)-carvone increased latency to convulsions in mice.
    • Citral: A major component of lemongrass oil, citral delayed seizure onset and reduced seizure severity in several animal models. Its effects were blocked by a GABA receptor antagonist, suggesting it works by enhancing GABA neurotransmission.
    • Eugenol: The main constituent of clove bud oil, eugenol decreased the duration and intensity of seizures and prevented neuron loss in the hippocampus of epileptic rodents. Electrophysiology studies found eugenol inhibits sodium currents and the generation of action potentials.
    • Linalool: Found in lavender, linalool vapor inhalation completely prevented seizures in mice given a convulsant drug. Linalool seems to modulate GABA and glutamate neurotransmitter systems to reduce neuronal excitability.

Other notable essential oil compounds with anticonvulsant activity in preclinical studies include terpinen-4-ol from tea tree oil, alpha-pinene from Angelica archangelica (wild celery), and 1-nitro-2-phenylethane from Dennettia tripetala.

While these findings from animal and in vitro experiments are promising, it’s important to note that clinical studies are lacking. There have been no randomized controlled trials investigating essential oils as a treatment for epilepsy in humans. A few case studies have been published, but these are only anecdotal reports that don’t prove effectiveness.

More research, especially placebo-controlled clinical trials, is needed to determine whether essential oils are a safe and reliable option for managing seizures in people with epilepsy. The mechanism of action of these oils also needs to be better elucidated, although modulation of GABA and glutamate neurotransmission and inhibition of sodium channels are plausible based on current evidence.

Essential Oils to Avoid for Epilepsy

On the flip side, the review also identified several essential oils that may lower the seizure threshold and trigger seizures in both epileptic and healthy individuals. These “proconvulsant” oils tended to contain certain terpene compounds like thujone, 1,8-cineole, camphor, and pinocamphone.

Some of the essential oils that people with epilepsy may want to avoid due to their potential to induce seizures include:

    • Sage (Salvia officinalis): Sage oil, which contains thujone, camphor and 1,8-cineole, has been reported to cause tonic-clonic seizures in children after ingestion of small amounts. Animal studies found a dose of 0.5 g/kg was sufficient to trigger seizures.
    • Hyssop (Hyssopus officinalis): The compound pinocamphone in hyssop oil has been linked to convulsions in humans. The convulsant dose in rodents was 0.13 g/kg.
    • Rosemary (Salvia rosmarinus): Rosemary oil is high in camphor, which can induce seizures. There are case reports of breakthrough seizures in epileptic patients after topical use of rosemary oil.
    • Eucalyptus (Eucalyptus spp.): Rich in 1,8-cineole, eucalyptus oil has proconvulsive effects and there are several reports of seizures after exposure, including one in a 12-month old after bathing.
    • Cedar (Juniperus virginiana) and Thuja (Thuja plicata): These oils also contain thujone and have been implicated in causing seizures when taken orally.

It’s concerning that essential oils like these are readily available without warnings about the risks for people with epilepsy. Many are common ingredients in natural products marketed for stress relief, better sleep, or improved concentration. Accidental ingestion of these oils by children is also worrying, as even topical exposure has triggered seizures in some cases.

If you have epilepsy, it’s best to err on the side of caution and avoid essential oils high in convulsant terpenes like thujone, 1,8-cineole, camphor, and pinocamphone. Always check with your doctor before using any essential oil product, as even “calming” oils could potentially interact with anti-epileptic medications.

The Bottom Line

Based on the current scientific evidence, certain essential oils like lemongrass, lavender, and clove show promising anticonvulsant effects in animal models of epilepsy. Compounds such as asarone, carvone, citral, eugenol, and linalool seem to be responsible for these benefits, likely by modulating neurotransmitter systems and altering neuronal excitability.

However, some commonly used essential oils like sage, hyssop, rosemary, eucalyptus, cedar and fennel may lower the seizure threshold and should be avoided by people with epilepsy. These oils contain terpenes like thujone, 1,8-cineole and camphor which have been reported to trigger seizures.

While the preclinical research is encouraging, there is currently no solid clinical evidence supporting the use of essential oils as a primary treatment for epilepsy. Large placebo-controlled trials are needed to establish the efficacy and safety of these natural products in humans.

For people living with epilepsy, the mainstream treatment continues to be anti-epileptic drugs prescribed by a neurologist or epileptologist. Complementary therapies like essential oils should be approached cautiously and only used under the supervision of both a qualified aromatherapist and physician. Never discontinue or change the dose of seizure medications without consulting your doctor.

As research advances, we may discover new essential oils or isolated compounds that can help control seizures with fewer side effects than conventional drugs. Combination therapy using oils with different mechanisms of action may also hold promise. But for now, essential oils remain an intriguing but unproven option for epilepsy management.

Promoting relaxation and reducing stress is perhaps their most appropriate use for people with seizure disorders at this time. And for sure, this is one of the amazing therapeutic benefits of utilizing essential oils.

References:

Bahr, T. A., Rodriguez, D., Beaumont, C., & Allred, K. (2019). The effects of various essential oils on epilepsy and acute seizure: a systematic review. Evidence-based Complementary and Alternative Medicine: eCAM, 2019, 6216745. https://doi.org/10.1155/2019/6216745

Mathew, T., John, S. K., Kamath, V., & Shaji, A. (2019). Comment on “The effects of various essential oils on epilepsy and acute seizure: a systematic review”. Evidence-based Complementary and Alternative Medicine: eCAM, 2019, 6829428. https://doi.org/10.1155/2019/6829428