Aromatherapy using lavender oil or lemon balm appears to help calm agitation in patients with severe cases of Alzheimer's disease, according to a review of several studies.
An article published on Saturday in BMJ, the journal of the British Medical Association, cited three studies, all of them showing significant benefits from letting patients smell the substances or rub them on their skin. Agitation in demented patients is often treated with powerful antipsychotic drugs that have significant side effects, the article said.
One author, Dr. Clive Ballard of Newcastle General Hospital, said that while the treatment was called aromatherapy, it was not based on the substance's odor, since people with severe Alzheimer's generally lose the sense of smell.
Rather, Dr. Ballard said, it appears that chemicals called terpenes found in lavender (Lavendula officinalis) and lemon balm (Melissa officinalis) allow brain circuits shut down by the disease to be reactivated.
The researchers also said that treatment with bright lights had been found safe and effective for treating sleep disturbances in Alzheimer's patients, but that a variety of other alternative treatments did not seem to work.
Dr. Ballard said people considering using lavender or lemon balm should be aware that different varieties could have different levels of terpenes and recommended close reading of the labels of commercially produced products.
Drawing (Illustrations by Stuart Goldenberg)