Want to live past 90? Here is what a researcher learned from the ‘oldest old’

By Megan Nicolai / The Orange County Register Published Feb 27, 2015 at 12:02AM

What prolongs your life or prevents dementia might not be what you expect.

Claudia Kawas, a geriatric neurologist at UC Irvine, California, has been working on a longitudinal study of people age 90 and older since 2003 called the 90-plus study. Kawas spoke in front of a packed crowd of 200 at the Newport Beach Public Library about what she’s found in her research on what can help a person’s longevity and what can reduce a person’s risk for dementia.

In the U.S. right now, 2 million people are older than 90. That could hit 10 million by 2050, according to research Kawas highlighted during the lecture.

“We’ve got a real burgeoning group of individuals in this age range, and we know very little about them,” Kawas said.

About 30 years ago, USC researchers sent a 14-page questionnaire to residents of Leisure World, now Laguna Woods. About 13,000 people ranging from age 55 to 100 responded and answered four follow-up questionnaires about lifestyle, benefit and exercise. About two-thirds were female.

Kawas said the study didn’t show much benefit in taking vitamins A, E, C or calcium for longevity. Tea had no effect, but neither did soda.

On the other hand, people who drank modest consumption of alcohol — from one or two drinks a week to one daily drink — seemed to live longer on average. People who also consumed 200 to 400 milligrams of caffeine per day — about one small Starbucks coffee a day — lived longer on average.

A person’s body mass index also had an interesting effect on longevity. Being overweight was a negative until 80, but beyond that age it showed a benefit of a 3 percent reduction in mortality. And beyond age 80, underweight individuals had a 50 percent increase in mortality.

Exercise, even just an average of 15 minutes per day, helped, and 45 minutes was the best. Leisure activities — pretty much anything that got people moving — also helped.

Kawas said the 90-plus study at UC Irvine was an extension of the questionnaire that aimed to look at quality of life in the oldest population. About 1,600 people older than 90 entered the study, and the researchers began finding out some interesting details.

Beginning at 65, a person’s risk for dementia doubles with every five years of life. Kawas’ research showed that trend continued past 90.

High blood pressure also has an effect on a person’s risk for dementia — but probably not in the way you’d expect. Kawas said that a person who developed hypertension in her 80s or 90s actually saw a reduction in the risk for dementia by as much as 60 percent.

Researchers don’t know what causes that phenomenon — it could be the drugs used to treat hypertension, or maybe older populations simply need more pressure on aging blood vessel walls.

“We’re busily untangling all of this right now, because we don’t really know what the reason is,” Kawas said. She’s working to figure out what mechanisms cause that trend.