Are Essential Oils Useful in Treating Alzheimer’s Disease?
The human brain is a complex network of nerve fibers in which individual nerve cells communicate with each other by way of chemical messenger molecules called neurotransmitters. This transmission of nerve impulses is involved in all of the brain’s cognitive functions, including learning, memory, speech, and emotions. In Alzheimer’s disease (AD), damage to the neurofibral network from formation and accumulation of protein fragments called amyloids leads to death of nerve cells, and deterioration of cognitive abilities. Once the nerve cells have died, it is very difficult, if not impossible, to regenerate them. Thus, at least for now, AD is considered incurable. In the meantime, there is considerable interest in treatments that may prevent the disease or help ease the symptoms of the disorder. There has been an increasing amount of research that indicates essential oils (EOs) may be of use in this regard.
So, what might EOs do to help?
There are three ways, all three believed to be involved in the processes leading to AD.
- Promoting neurotransmission – The neurotransmitter molecules are slightly altered while doing their job, and they must be recycled and reused. In AD this regeneration process is damaged. So the supply of messenger molecules decreases. This alters normal nerve activity, producing symptoms such as anxiety, decreased attention span, depression, agitation, etc. Commonly prescribed anti-AD drugs such as donepezil act to block the process that degrades the neurotransmitters. Very interestingly, certain EOs have been shown to act the same way. In particular, the EOs from smartweed and sage-leaved rock rose were very effective in this regard. Lavender EO has been shown to improve attention span, and decrease anxiety and agitation in dementia patients. For anxiety it was as effective as the widely prescribed drug Ativan. Aromatherapy workhorse lavender comes through again!
- Preventing amyloid damage – Scientists have been able to synthesize the villainous amyloid protein fragments, feed them to rats, and shown that such animals develop memory problems. When these same animals were injected with thymol or carvacrol, components of many EOs, the memory impairment was reversed. In another similar animal experiment, inhalation of coriander EO markedly improved anxiety and depression. Of course no one can do these experiments with humans, but the evidence in these animal experiments is very interesting and encouraging.
- Antioxidant activity – In the aging brain the deterioration of certain cell components leads to the buildup of so-called “reactive oxygen species” (ROS) which wreak havoc on many cellular structures, and result in what is known as “oxidative stress”. Some research has shown that the buildup of ROS is the root cause of the changes ultimately resulting in AD. In AD, it is also known that the amyloid precursor is a potent producer of ROS. This is why doctors and health experts advise all of us to get plenty of antioxidants – things that destroy ROS. EOs with known antioxidant activity include lavender, thyme, clove, eucalyptus, cinnamon, juniper, basil, chamomile, coriander, and cumin.
The research described above, as well as much work not mentioned, strongly suggest that EOs may provide an excellent alternative, natural, widely available, and inexpensive treatment for AD, particularly for easing the symptoms of the disease. As noted in previous posts, this doesn’t mean that a particular EO will work for everyone. The work to date does suggest that there needs to be long-term, large, controlled clinical studies to determine the efficacy of such treatments, and validate their usage for the larger health community.
In the meantime, there would seem to be no downside to their use in individual cases. Coriander can spice up most any dish very nicely, and might provide some neuroprotection. Lavender oil can freshen the air and reduce anxiety. And there are no side effects!
At the very least, the idea of improving cognitive function with natural essential oils is pretty exciting. Questions? Leave a comment! And for general guidelines about essential oils, see our FAQ page.