Neem in the News: Alzheimer’s Disease

Neem Leaf Extract Investigated for Possible Value in Alzheimer’s and Other Neurological Disorders

Neem has been used in Ayurveda to treat many of the symptoms of Alzheimer’s Disease, including loss of memory and learning skills as well as anxiety and depression. We “translated” a report from the peer-reviewed International Journal of Applied and Basic Medical Research when it was first published in 2019, but a customer recently asked about a new report published in the Alzheimer’s & Dementia, the Journal of the Alzheimer’s Association. Going back to search for it, we found another 2019 article from the Journal of Alzheimer’s Disease Reports and a review article from Neurochemistry International that looked at how neem impacts other neurological disorders, including Parkinson’s, brain injuries and mood disorders.

THIS REPORT IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY. THESE STATEMENTS HAVE NOT BEEN EVALUATED BY THE U.S. FOOD AND DRUG ADMINISTRATION. NEEM TREE FARMS DOES NOT SELL PRODUCTS THAT ARE INTENDED TO DIAGNOSE, TREAT, PREVENT OR CURE ANY DISEASE.

Comments are particularly welcome, because neem is not known for these properties in the U.S. We had heard anecdotal reports from caregivers responsible for people with diabetes, arthritis, UTIs and other inflammatory diseases. We weren’t sure how to acknowledge those reports, not knowing if they were credible accounts or wishful thinking on the part of caregivers.

Alzheimer’s Disease—AD—is a scourge. It’s currently the 6th leading cause of death in the U.S., and the 5th leading cause of death worldwide. As lifespans have been extended and the size of the elderly population increases, the presence of AD increases along with it. It is a devastating disease for many years before death comes, with progressive loss of memory, of the ability to understand, of the ability to carry out one’s responsibilities—eventually, even the most basic self-care. Behavioral and mood changes occur in a number of people as well. There is no effective treatment and scientists are scrambling to identify ways to prevent or postpone the onset of serious illnesses.

The 2019 research that we originally reported on looked at how neem changed the behavior of mice with Alzheimer’s in reducing symptoms of the disease, including memory loss, anxiety, understanding and depression. The second report from 2019 looked at how neem limonoids, specifically nimbin, inhibit the growth of tau aggregation, a key target for several pharmaceutical drugs that failed in clinical trials.

The 2021 Alzheimer’s Association report looked at symptoms but focused on how neem changed the brain pathology of mice, specifically how antioxidants in neem, used both as a preventative and as a treatment after Alzheimer’s was induced with aluminum. Those researchers concluded that neem leaf supplements (200 mg/kg of body weight in Wistar rats) reduced the neuroinflammatory response to the aluminum treatment in the fronto-hippocompal and cerebellar cortices, probably in an antioxidant role.

The 2021 Neurochemistry article reviewed research beginning with a 350-year-old palm leaf Ayurvedic manuscript that describes neem bark being used for “central nervous system psychiatric disorders and paralysis.”

Some of the many benefits attributed to neem during its long history of traditional use in Ayurvedic medicine have been studied and verified in animals, and this includes benefits with valuable potential for AD patients—and those who care for them. And in fact, neem leaf has been studied in animal models of several other degenerative brain diseases with very encouraging results. (An animal model is a small animal—usually a rat or mouse, sometimes a rabbit—whose functioning has been altered to be as close as possible to humans with that particular disease.) The benefits of neem leaf that the authors of the original 2019 study thought could be extremely helpful for AD patients were reducing anxiety, improving memory and understanding. They discovered another benefit as they conducted the study—reducing depression. This had not been documented before.

Because there is disagreement about what is actually causing the brain damage in AD, these researchers created two animal models of AD using lab rats. The altered behavior and emotions of the animals were the same, but the way the brain damage was created that produced these results differed. Before the AD was created, the animals in each future-AD group were divided into those who were given a neem leaf extract for seven days before their AD transformation, and those who were given a placebo—it looked the same, but it was a neutral substance. After the animals had received their seven days of neem or placebo, they were transformed into AD animals and then put through various challenges.

There is lots of data already collected as to how normal healthy rats perform on these standardized tests, so the changes and losses that occurred with these AD animals was clear to see. These tests involved being in an open area, elevated maze, swim test, water maze and shock avoidance. Each had multiple components, and some had several variations as well. Some called on various types of memory. Others required the animals to be calm in order to function well. And one test can actually produce despair.

The AD animals that had consumed neem leaf for seven days did substantially better on all of these tests. They were not nearly as anxious and their memory was significantly better, which duplicated results in previous studies of different brain diseases. And in a first-time observation—these neem-treated AD animals were also less depressed. This was clear from the test that can produce despair.  

The anxiety reduction in the neem-treated animals was comparable to what the results would have been if the animals had been given Valium. And the better learning was comparable to improvements seen with Aricept, the most common prescription treatment for AD.

Studying the animals’ brains afterward provided strong evidence that neem leaf has “important antioxidant activity.”

As a side note, the researchers made their neem leaf preparation themselves, starting with their own plants. “Fresh green leaves of A. indica were collected from the Ayurvedic garden of our institute in the month of April.” They also analyzed their final product to identify all of the bioflavonoids and phytosterols it contained, and their exact percentages, in part to make sure that all of their neem-treated animals would be given the identical product.

The key in reversing AD in these experimental studies seems to be neem’s antioxidant activity, but the study is a preliminary report and does not explain the full mechanism of activity.

Personally, as a 62-year-old woman with a family history of early-onset dementia, I’m taking it daily rather than after exposure to someone with a bug the way I had been.

Over the years, we’ve heard comments about neem helping AD but didn’t document them because we hadn’t seen this study and assumed they were more wishful thinking than actual results. We welcome comments on this article, particularly from people who are caring for people who take neem for issues like arthritis or UTIs.