LOS ANGELES, CA (Catholic Online) - "'Senior' moments that people often joke about are true," Dr. Gary Small, geriatric psychiatrist at the David Geffen School of Medicine at the University of California, Los Angeles says. Small, who was not involved with the said that "If you follow people over time, you'll see there are structural changes that happen in the brain as they age."

Previous studies suggested that impaired cognitive function could be an early sign of dementia. One recent study showed cognitive performance strongly predicted a 75 percent diagnosis of Alzheimer's disease, a common form of dementia after six years.

According to the Alzheimer's Association, about one in eight older Americans has Alzheimer's disease. They anticipate the numbers will grow each year as more and more people continue to live longer.

Researchers say the new study demonstrates the importance of a healthy lifestyle, particularly paying attention to cardiovascular health -- which may help stave off the effects of brain aging.

"A decline in mental function is inevitable," Steven Ferris, a psychologist at New York University's Langone Medical Center says. "Following a healthy lifestyle can help a certain degree of mental functioning, but there requires more research to prove this."

A healthy lifestyle includes exercise, which increases blood flow to the brain, which provides it with much-needed nutrients. Eating foods that are good for the heart, such as fruits, vegetables and whole grains is also vital, as it could protect brain cells from age-related decline.

Test subjects were screened for memory, vocabulary, hearing and visual comprehension skills. People were given cognitive tests three times over the course of the study. The researchers also took differences in education levels into account.

Researchers found that over the 10-year study, there was a 3.6 percent decline in mental reasoning scores in people who were between the ages of 45 and 49 at the study's start, a 9.6 percent decline in the abilities of men ages 65 to 70 years at the start, and a slightly smaller, 7.4 percent decline, in women of those ages.

Results showed that cognitive test scores declined in all categories except vocabulary, and scores declined faster in older people.

"This study follows the same people over a long period of time to see if their cognitive performance changes," Ferris said. "And these changes are beginning earlier than what people previously thought," he said.

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