Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content
Content starts here
Leaving Website

You are now leaving and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

What We Know (and Don’t Know) About Alzheimer's Disease

Research has delivered only limited insights into causes and treatments

spinner image Disrupt Dementia Banner with the text: Sparking bold new solutions for the world's brain health crisis


spinner image A doctor's hands holding a model of a brain.
Getty Images

Genes, lifestyle and age are some of the factors known to play a role in Alzheimer's Disease, but more study is needed.

spinner image Image Alt Attribute

AARP Membership

Join AARP for $12 for your first year when you sign up for Automatic Renewal. Get instant access to members-only products and hundreds of discounts, a free second membership, and a subscription to AARP The Magazine

Join Now

Here's what we know:

The risk factor 

Age is the greatest risk factor for Alzheimer’s. For most, symptoms first appear after age 65, though brain-imaging scans show that the buildup of specific types of proteins related to Alzheimer's can start wreckage long before visible symptoms emerge.

Some of the genes linked to Alzheimer's 

One is APOE, which has several forms. APOE e2 reduces your risk of Alzheimer’s, while another, APOE e4, increases your risk. If you receive a copy of APOE e4 from each of your parents, you’ll have the greatest odds of getting Alzheimer’s. 

How you live matters 

Researchers have determined that nutritious food, exercise, sleep, socializing and other positive aspects of life are good preventive medicine for Alzheimer’s. One study showed that life changes can reduce your chance of developing Alzheimer’s by 35 percent. 

Who you are matters 

Socioeconomic factors, including education, income and even where you live, play a role in whether Alzheimer’s takes hold. Race matters, too: African Americans are twice as likely to develop Alzheimer’s as Caucasians; Hispanics are 1.5 times more likely.

But we don't know: 

What causes the disease

Scientists have yet to learn what triggers the early deposit of abnormal proteins in the brain or how it damages brain neurons. It’s also unknown why a small percentage of people who have plaque buildup don’t end up getting Alzheimer’s.

How these genes work 

Researchers have yet to figure out the complex genetic processes that are behind Alzheimer’s. Scientists only know that the disease is likely the result of not just one gene but of dozens of genes — and of the complex interactions that occur among them.

A medicine that works 

There are no drugs available to cure or slow down Alzheimer's, though some may briefly help with its symptoms. Fully 99 percent of clinical trials of Alzheimer’s drugs fail, and some major pharmaceutical companies have stopped trying to develop this class of drugs.

What other factors might matter 

More study is needed to determine if social factors are causal or if they somehow help build up resilience to the disease through “cognitive reserve,” a sort of stockpile of brain strength, says Jennifer Manly at Columbia University in New York.

Discover AARP Members Only Access

Join AARP to Continue

Already a Member?