This book focuses on foods, exercise, and other steps that can prevent memory problems. But there are also medications and supplements that are used to try to reverse memory problems. For the most part, their effects are modest.
Here are the treatments that are commonly used or are now under active study.
A group of drugs called cholinesterase inhibitors boost the brain chemical acetylcholine and aim to slow the progression of Alzheimer’s disease. Their effect is usually small. For about half of people whose condition is in the mild to moderate range, they delay worsening of symptoms by six months to one year. Approved cholinesterase inhibitors include:
Tacrine was the first to be developed, but is rarely prescribed nowadays because of its ability to cause liver problems. Donepezil is approved by the Food and Drug Administration for all stages of Alzheimer’s disease. Rivastigmine and galantamine are approved to treat mild to moderate cases.
These medications are generally safe but occasionally cause loss of appetite, nausea, vomiting, diarrhea, dizziness, confusion, and heart arrhythmia.
Newer than the cholinesterase inhibitors, memantine (Namenda) works by blocking the action of a neurotransmitter called glutamate. It can be used in combination with cholinesterase inhibitors. However, so far memantine’s benefits are not impressive. In 2011, researchers from the University of Southern California analyzed the results of three prior research studies, finding little evidence of benefit in mild to moderate Alzheimer’s disease.1 The drug can occasionally cause dizziness, confusion, headaches, and constipation.
Insulin inhaled through the nose is being studied as a treatment for people with mild cognitive impairment or Alzheimer’s disease. If this sounds surprising, there actually are good reasons to think it might help.
First, people with diabetes are at higher risk of developing Alzheimer’s disease, and the key problem in diabetes is that insulin is malfunctioning or absent. It also turns out that insulin plays important roles in the brain. It helps build the synapses that link one cell to another and protects synapses from the effects of beta-amyloid.
The reason for giving insulin through the nose is that it can quickly travel to specific parts of the brain without affecting the rest of the body. So it does not affect your blood sugar the way an insulin injection would.
Researchers at the University of Washington in Seattle put it to the test. In a group of older volunteers with memory problems, the researchers did special brain scans to measure how well various parts of the brain were functioning. They also tested their memory by asking them to listen to a detailed story, then recall as much of it as they could twenty minutes later.2 And they asked family members to rate how well the volunteers were doing.
They found that insulin treatment improved memory and protected the brain regions that were declining in untreated patients. The study was small and rather brief (four months); additional studies are under way to see how well insulin works over longer periods.
It is also worth remembering that the dietary approaches that are linked to reduced risk of Alzheimer’s disease also help prevent and reverse diabetes.3,4 As our research team showed several years ago, a low-fat, plant-based diet increases the body’s sensitivity to insulin.5
Researchers are testing methods to help the immune system clear away beta-amyloid from plaques in the brain. In this sort of treatment, an antibody is infused intravenously, triggering neighboring immune cells to engulf the amyloid and remove it.6,7
The good news is that these antibody treatments do indeed remove amyloid, which is an amazing achievement. The bad news is that removing amyloid has not so far been shown to significantly improve Alzheimer’s symptoms. In other words, the patients’ brain scans look better, but they remain impaired.
Researchers are hopeful that treatments of this type will eventually prove effective. In the meantime, the difficulty of developing these treatments reinforces the importance of a back-to-basics approach that looks at what habits predict Alzheimer’s disease risk—high intake of saturated fat and metals, a lack of exercise, and so on—and focusing on changing those factors as early as possible.
The neurofibrillary tangles that Alois Alzheimer first observed in brain cells in 1906 are now the targets of new medications.8 They aim to prevent or reduce the changes in tau proteins that lead them to clump together.
These drugs have shown considerable promise in premarket testing, greatly slowing the decline in mental function in Alzheimer’s patients without demonstrating severe side effects. However, studies with larger numbers of patients are needed to establish how effective and safe these treatments are.
Ginkgo is an herbal extract commonly used as a memory booster. Derived from the leaves of the Ginkgo biloba tree, it is thought to be rich in antioxidants that protect the brain. The ginkgo tree itself is striking—it grows to a height of up to one hundred feet, and some trees are believed to be thousands of years old.
Unfortunately, ginkgo does not seem to prevent cognitive decline. Even though early studies did hold promise,9 a team at the University of Pittsburgh and other research centers put ginkgo to a rigorous test. They brought in 3,069 people ages seventy-five and older and gave half of them ginkgo and the other half a placebo. The ginkgo dose was reasonably high—120 milligrams twice a day. But over the next six years, ginkgo proved a disappointment. It did nothing at all to prevent or delay the onset of memory problems or to slow the rate of cognitive decline.10,11
Could it help people who already have Alzheimer’s? Most studies have shown no benefit.12 This does not rule out the possibility that taking ginkgo over a longer period—perhaps starting early in life—might help. But based on these findings, it is hard to be optimistic about ginkgo.
If you do try ginkgo, it is important to know that it can interact with some commonly prescribed medications. It can add to the effect of blood thinners such as aspirin, ibuprofen, or warfarin, make antiseizure medications less effective, and accentuate the side effects of antidepressants. So even though it is an herbal preparation, it is essential to treat it like a drug and to speak with your physician before taking it.
Phosphatidylserine is a commonly sold nutritional supplement. Tests of its benefits for memory have yielded mixed results. Japanese researchers gave it to a group of elderly people with mild cognitive impairment to see if it would boost their memory.13 It showed no benefit in people with mild memory problems, but did seem to help people with more serious memory deficits. A small study in Israel found much the same thing.14 However, a larger study in the Netherlands found no benefits.15 Bottom line—there’s not yet much evidence favoring phosphatidylserine.
Because metals—especially copper, iron, and zinc—have been found in the beta-amyloid plaques in the brains of people with Alzheimer’s disease, researchers have looked for ways to remove these metals from the body. One method under study is chelation, which is already a standard treatment for heavy metal poisoning. Its name comes from the Greek word for “claw,” referring to the ability of chelating chemicals to “grab” toxic molecules and remove them from the body.
A typical treatment involves administering a chelating agent, either orally or intravenously, and then allowing it to capture the offending toxin and carry it out through the kidneys into the urine. It is important to be very well hydrated, so as to avoid dangerous concentrations of the toxins as they pass through the kidneys.
Although chelation is well established for certain applications, such as lead or mercury poisoning, its use as an Alzheimer’s treatment is still exploratory. Some findings have been promising, but we do not yet have enough information to know how helpful it might be.
So where does this leave us? Given the grave prognosis that Alzheimer’s disease and other forms of dementia carry, it makes sense to push hard for effective treatments and to be rather liberal in putting treatments to use.
That said, the treatments that are currently available have been disappointing. If anything, they underscore the need for preventive steps so that treatments are not needed.