The 90+ Study


Co-Principal Investigators:
Claudia Kawas, MD
Maria Corrada, ScD

Annlia Paganini-Hill, PhD
Dana Greenia, RN, MS

The Oldest-old

The 90+ Study was initiated in 2003 to study the oldest-old, the fastest growing age group in the United States.  The 90+ Study is one of the largest studies of the oldest-old in the world. More than 1,600 people have enrolled.  Because little is known about people who achieve this milestone, the remarkable increase in the number of oldest-old presents a public health challenge to promote the quality as well as the quantity of life.

Interested in volunteering for The 90+ Study? Please click this link for eligibility requirements: Volunteer for the Study

To donate to The 90+ Study, please click this link for donation options: Donate to the Study

The 90+ Study Participants

All participants in The 90+ Study were once members of The Leisure World Cohort Study (LWCS), which was started in 1981.  The LWCS mailed surveys to every resident of Leisure World, a large retirement community in Orange County, California (now incorporated as the city of Laguna Woods).  Using the 14,000 subjects from the LWCS, researchers from The 90+ Study decided to ask an important question:  What allows people to live to age 90 and beyond?

Studying the Oldest-old

Participants of The 90+ Study are visited every 6 months by neuropsychological testers and neurological examiners. Our researchers at the Clinic for Aging Research and Education (CARE), located in Laguna Woods, obtain information about diet, activities, medical history, medications and numerous other factors. Additionally, participants are given a series of cognitive and physical tests in order to determine how well people in this age group are functioning.

Goals of the study

Determine Factors Associated with Longevity:  What makes people live to age 90 and beyond?  What types of food, activities or lifestyles are associated with living longer?

Epidemiology of Dementia in the Oldest Old: How many people aged 90 and older have dementia?  How many become demented each year?  What are ways to remain dementia-free into your 90s?

Rates of Cognitive and Functional Decline in the Oldest Old: How do memory loss and disability affect those in their 90s?  How can people prevent memory loss and disability at this age?

Clinical Pathological Correlations in the Oldest Old:  Do the brains of people in their 90s show evidence of memory loss and dementia?  Do people with dementia have differences in their brains that can be detected and treated?  Determining Modifiable Risk Factors for Mortality and Dementia: What kinds of things can people change in their lives to live longer?  Can people change their risk of dementia through diet, exercise or supplements?

Major findings

Researchers from The 90+ Study have published many scientific papers in premier journals.  Some of the major findings are:

  • People who drank moderate amounts of alcohol or coffee lived longer than those who abstained.
  • People who were overweight in their 70s lived longer than normal or underweight people did.
  • Over 40% of people aged 90 and older suffer from dementia while almost 80% are disabled. Both are more common in women than men.
  • About half of people with dementia over age 90 do not have sufficient neuropathology in their brain to explain their cognitive loss.
  • People aged 90 and older with an APOE2 gene are less likely to have clinical Alzheimer’s dementia, but are much more likely to have Alzheimer’s neuropathology in their brains.


“Longevity: Tales from the Oldest Old”

Presented by Claudia H. Kawas, M.D.
October 30, 2014


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