Five Myths About Alzheimer’s Disease

The reality: There is no known cure for Alzheimer’s disease, but saying that doctors can do nothing is also wrong.

Alzheimer’s treatment now includes medications that manage cognitive or behavioral symptoms as well as disease-modifying immunotherapies that can slow decline in selected people with early disease.

Symptom-managing medications still have an important role

Cholinesterase inhibitors such as donepezil, rivastigmine, galantamine and benzgalantamine may help reduce or control some cognitive and behavioral symptoms in people with mild to moderate Alzheimer’s.

Some can also be used at later stages depending on the medication and individual patient.

These medicines affect acetylcholine, a brain chemical involved in memory and thinking.

They do not remove the underlying Alzheimer’s pathology and they do not work equally well for everyone.

Memantine is generally used for moderate to severe Alzheimer’s disease.

It affects glutamate signaling and may help some people maintain certain cognitive or daily functions longer. It may also be used in combination with donepezil.

That distinction matters.

A medication can provide meaningful symptom relief even if it does not stop the underlying disease.

There is also an FDA-approved medication for Alzheimer’s-related agitation

Brexpiprazole is an atypical antipsychotic approved by the FDA to treat agitation associated with Alzheimer’s disease.

Agitation can include restlessness, verbal aggression or physical aggression and may become especially difficult for families to manage.

Medication is not automatically the first response to every behavioral change.

The National Institute on Aging recommends considering possible triggers and non-drug strategies first when appropriate. Antipsychotic medications also carry important risks and should be prescribed and monitored by a clinician.

Families dealing with these behaviors can also review our guide to managing agitation in someone with dementia.

Lecanemab and donanemab changed the treatment landscape

Lecanemab and donanemab are FDA-approved anti-amyloid immunotherapies for people in the early symptomatic stages of Alzheimer’s disease.

They target beta-amyloid and reduce amyloid plaques in the brain.

In the phase 3 lecanemab trial published in The New England Journal of Medicine, people with early Alzheimer’s who received lecanemab experienced statistically less decline on a measure of cognition and function over 18 months than participants receiving placebo.

Donanemab was also tested in a large phase 3 trial of people with early symptomatic Alzheimer’s.

The 2023 JAMA trial found that donanemab slowed clinical progression compared with placebo, with the size of the effect varying according to the population and outcome measure examined.

These medications do not restore lost memory, stop progression completely or cure Alzheimer’s.

The benefit is a slowing of decline.

These drugs are not appropriate for everyone with dementia

Lecanemab and donanemab were studied for early Alzheimer’s disease, including mild cognitive impairment due to Alzheimer’s and mild Alzheimer’s dementia.

They are not general treatments for every type or stage of dementia.

Doctors also need evidence that Alzheimer’s-related amyloid is present before treatment.

Depending on the clinical situation, confirmation may involve an amyloid PET scan, cerebrospinal fluid testing or an appropriate biomarker evaluation.

Both medications can cause amyloid-related imaging abnormalities, commonly called ARIA.

These can include brain swelling or small areas of bleeding. Many cases do not cause symptoms, but serious and potentially life-threatening complications can occur.

MRI monitoring is therefore part of treatment.

The decision involves weighing eligibility, likely benefit, health conditions, genetic factors, MRI findings, treatment burden and potential risks with a specialist.

Insurance coverage can also affect access

Cost and coverage should be discussed before treatment begins.

The National Institute on Aging notes that Medicare Part B covers part of the cost of lecanemab and donanemab for patients who meet certain medical criteria.

Other insurance coverage may vary.

A diagnosis matters more now because treatment options have changed

One reason treatment myths can be harmful is that they encourage families to believe there is no reason to investigate memory changes.

Earlier evaluation can identify other conditions, establish whether Alzheimer’s is the likely cause and determine whether the person is at a stage when specific treatments could be considered.

Our guide to seeking an Alzheimer’s evaluation explains what modern diagnosis can involve and why the idea that Alzheimer’s can only be confirmed after death is outdated.

The reality: Aspartame has not been established as a cause of Alzheimer’s disease or memory loss.

Aspartame is an artificial sweetener used in many foods, drinks and medications.

The FDA first authorized certain uses of aspartame in 1974 and approved it as a general-purpose sweetener in 1996.

Aspartame is sometimes defended with the claim that a definitive trial proved it has no effect on memory.

The evidence is not that simple. A more accurate conclusion is that major regulatory reviews have not established a causal relationship between approved aspartame consumption and Alzheimer’s disease.

What does the FDA currently say?

The FDA describes aspartame as one of the most studied food additives in the human food supply and states that its scientists do not have safety concerns when it is used under approved conditions.

The agency maintains an acceptable daily intake of 50 milligrams per kilogram of body weight per day in the United States.

What about the WHO review of aspartame?

In 2023, the International Agency for Research on Cancer, or IARC, classified aspartame as “possibly carcinogenic to humans” based on limited evidence concerning cancer.

That classification generated significant attention, but it did not establish that ordinary aspartame consumption causes cancer and it did not establish a link with Alzheimer’s disease.

The FDA explicitly disagreed with IARC’s conclusion that the studies supported classifying aspartame as a possible human carcinogen.

FDA scientists said they identified significant shortcomings in the studies IARC relied upon.

The FDA also notes that Health Canada and the European Food Safety Authority have evaluated aspartame and consider it safe at currently permitted use levels.

At the same time, the Joint FAO/WHO Expert Committee on Food Additives reviewed aspartame and found no sufficient reason to change its established acceptable daily intake of 0 to 40 milligrams per kilogram of body weight per day.

The different conclusions illustrate why it is important to distinguish a hazard classification from an assessment of risk at actual exposure levels.

None of these 2023 reviews established aspartame as a cause of Alzheimer’s disease.

Avoid turning one nutrition question into an Alzheimer’s prevention strategy

Families understandably want to identify something they can remove from the kitchen to prevent dementia.

Alzheimer’s is considerably more complex.

Current research points to interactions among aging, genetics, cardiovascular and metabolic health, environment and other biological factors rather than one food additive being responsible for most cases.

Diet can still matter for overall health.

The distinction is that supporting cardiovascular and metabolic health is very different from claiming that eliminating a particular sweetener will prevent Alzheimer’s.

Our evidence review of what diet can and cannot do for Alzheimer’s looks more broadly at MIND-style eating patterns, ketogenic approaches and nutrition after diagnosis.

Another frequently promoted food-based claim involves coconut oil.

Families can read our review of the evidence on coconut oil and Alzheimer’s disease before treating it as a therapy.

The reality: Current evidence does not establish normal exposure to aluminum cookware, foil, cans, antacids or antiperspirants as a cause of Alzheimer’s disease.

Concern about aluminum and Alzheimer’s became widespread during the 1960s and 1970s.

The theory became culturally persistent, leading some families to replace pots, avoid aluminum foil or worry about canned beverages.

The Alzheimer’s Association notes that studies have failed to confirm a role for aluminum in causing Alzheimer’s and that most researchers have shifted their attention to other areas of investigation.

Why did the aluminum theory become popular?

Early scientific observations raised questions about aluminum in the brain and whether environmental exposure might contribute to neurodegeneration.

Those preliminary questions were often transformed in popular discussion into a much stronger claim: aluminum products cause Alzheimer’s.

That causal claim was never established.

Science often begins by identifying an association or possible mechanism.

Researchers then test whether that observation remains convincing across better-designed studies and whether it can explain disease in humans. Many early hypotheses become less plausible as evidence accumulates.

Replacing cookware is not an evidence-based Alzheimer’s prevention strategy

There is no good evidence that throwing away aluminum pans or avoiding beverage cans prevents Alzheimer’s.

Families interested in reducing dementia risk are better served by discussing established health factors with a medical professional, including blood pressure, cardiovascular disease, diabetes, physical activity, smoking and other aspects of overall health.

Genetics also influences risk, although having a family history does not mean Alzheimer’s is inevitable.

Our article on genetics and dementia risk explains the difference between genes that increase susceptibility and the rare genetic variants that can directly cause familial Alzheimer’s.

The reality: Traumatic brain injury can be associated with an increased risk of dementia later in life, but a head injury does not mean a person will inevitably develop Alzheimer’s disease.

It is sometimes said that a severe head injury with loss of consciousness has been proven to cause Alzheimer’s.

The relationship is more complicated. Research identifies TBI as a risk factor, not a guaranteed cause, and the strength of the association varies by injury severity, number of injuries, age and the dementia outcome being studied.

Moderate and severe injuries have the clearest long-term association

The Alzheimer’s Association summarizes research in older adults showing that a history of moderate TBI was associated with about 2.3 times the risk of developing Alzheimer’s compared with no history of head injury.

A history of severe TBI was associated with about 4.5 times the risk.

Those figures describe associations observed in key studies.

They do not mean that everyone with a moderate or severe TBI will develop Alzheimer’s.

The evidence on a single mild TBI is less settled than older summaries suggest

The Alzheimer’s Association currently states that there is no evidence that a single mild TBI increases dementia risk.

However, the broader research literature is not completely uniform on that point.

A 2024 umbrella systematic review and meta-analysis reported an association between mild TBI and later dementia, with a pooled odds ratio of 1.96.

The association with Alzheimer’s disease specifically was weaker than the association with dementia overall.

Age may also matter.

A large study published in JAMA Neurology found that mild TBI was associated with increased dementia risk among adults age 65 and older.

Other cohort research has also reported an association after mild TBI.

These observational studies cannot prove that one mild head injury directly causes dementia.

Differences in populations, how injuries are recorded, follow-up periods and other health factors can influence results.

The fairest conclusion is that the relationship between a single mild TBI and later dementia remains an active area of research, with evidence suggesting particular concern in older adults.

Repeated head injuries are another concern

Repeated mild traumatic brain injuries may have long-term consequences, particularly in people exposed repeatedly through contact sports, military service or other activities.

Repeated head trauma has been associated with chronic traumatic encephalopathy and related neurological problems.

Risk does not mean destiny

Even among people who have experienced moderate or severe TBI, not everyone develops dementia.

A head injury is one potential risk factor among many.

It is also important not to assume that cognitive symptoms appearing after an injury are automatically Alzheimer’s.

Brain injury itself can cause persistent difficulties with memory, concentration, mood, speech, balance or executive function.

Take head injuries seriously when they happen

Anyone who develops symptoms after a significant blow to the head should receive appropriate medical assessment.

Emergency symptoms can include worsening confusion, repeated vomiting, seizure, prolonged loss of consciousness or neurological deterioration.

Preventing additional injuries also matters.

Fall prevention, helmets for appropriate sports and activities, seat belts and attention to medication-related dizziness can all reduce the chance of traumatic injury.

Older adults and their families can review practical strategies for preventing falls at home and in daily life.

For older adults, an unexplained change in memory or function should not automatically be attributed to a remote injury.

Families should consider a comprehensive evaluation, particularly when symptoms are progressing.

Our overview of possible signs of Alzheimer’s disease can help families recognize patterns worth discussing with a clinician.

The reality: Alzheimer’s disease is progressive and ultimately fatal, although determining the immediate cause of death can be more complicated than simply writing “Alzheimer’s disease.”

The National Institute on Aging identifies Alzheimer’s as one of the leading causes of death in the United States.

As the disease progresses, damage extends far beyond short-term memory.

People eventually may lose the ability to communicate, walk safely, eat independently, control bowel and bladder function and recognize their surroundings.

In advanced disease, they often require complete assistance with daily care.

Families preparing for these changes can read more about what to expect during late-stage Alzheimer’s.

Why advanced Alzheimer’s affects the whole body

The brain coordinates functions throughout the body.

As Alzheimer’s becomes severe, neurological damage can interfere with movement, swallowing and the ability to respond appropriately to illness or discomfort.

Difficulty swallowing is particularly important.

Food, liquid or saliva can enter the lungs instead of the stomach, a process called aspiration. This can lead to aspiration pneumonia.

NIA identifies aspiration pneumonia as a common cause of death among people with Alzheimer’s disease.

Families can learn more about why eating and swallowing can become difficult with dementia.

Other complications can include infections, dehydration, malnutrition, immobility and injuries.

Older adults may also have cardiovascular disease, cancer, diabetes or other illnesses at the same time. This is why a death certificate may list pneumonia or another complication as an immediate cause even when advanced Alzheimer’s contributed substantially to the person’s decline.

Fatal does not mean every stage should be treated as the end of life

Someone diagnosed with early Alzheimer’s may live for years and continue participating in relationships, activities and decisions.

The course varies considerably from person to person.

Families should therefore avoid treating a new diagnosis as though the person has suddenly reached the final stage.

Support should match current abilities and needs.

Understanding how dementia stages can change care needs can help families plan without assuming that every symptom will appear immediately or in exactly the same order.

Hospice may become appropriate near the end of life

When Alzheimer’s becomes advanced and a person’s goals shift toward comfort, families may eventually discuss hospice with the medical team.

Hospice eligibility is based on the person’s clinical condition and expected prognosis, not simply the fact that Alzheimer’s has been diagnosed.

Families beginning that conversation can learn more about what hospice care involves.

Knowing the facts helps families plan realistically

Accurate information about Alzheimer’s should create neither false hope nor unnecessary hopelessness.

There is no cure today. There are treatments. Some risk factors can be addressed. A diagnosis does not predict an exact timeline.

A person can still experience pleasure, familiarity and connection as abilities change.

Families can use that information to discuss medical care, living arrangements, finances and future support before a crisis forces decisions.

Our Alzheimer’s 101 guide provides a broader introduction to symptoms, disease progression and caregiving.

• National Institute on Aging. “How Is Alzheimer’s Disease Treated?” National Institutes of Health.
• National Institute on Aging. “Alzheimer’s Disease Fact Sheet.” National Institutes of Health.
• van Dyck, Christopher H., et al. “Lecanemab in Early Alzheimer’s Disease.” The New England Journal of Medicine, 2023, 388(1):9–21.
• Sims, John R., et al. “Donanemab in Early Symptomatic Alzheimer Disease: The TRAILBLAZER-ALZ 2 Randomized Clinical Trial.” JAMA, 2023, 330(6):512–527.
• U.S. Food and Drug Administration. “Aspartame and Other Sweeteners in Food.” U.S. Food and Drug Administration.
• World Health Organization and Food and Agriculture Organization of the United Nations. “Aspartame Hazard and Risk Assessment Results Released.” July 14, 2023.
• Alzheimer’s Association. “Alzheimer’s and Memory Loss Myths.” Alzheimer’s Association.
• Alzheimer’s Association. “Traumatic Brain Injury.” Alzheimer’s Association.
• Mavroudis, Ioannis, et al. “The Association Between Traumatic Brain Injury and the Risk of Cognitive Decline: An Umbrella Systematic Review and Meta-Analysis.” Brain Sciences, 2024, 14(12):1188.
• Gardner, Raquel C., et al. “Dementia Risk After Traumatic Brain Injury vs Nonbrain Trauma: The Role of Age and Severity.” JAMA Neurology, 2014, 71(12):1490–1497.

Disclaimer:

This article provides general educational information and is not medical advice. Alzheimer’s treatment decisions, including the use of disease-modifying medications or medications for agitation, require individualized assessment by a qualified healthcare professional. Seek prompt medical attention after a significant head injury or for sudden confusion, weakness, speech changes or another abrupt neurological symptom.