"Early Show" Medical Correspondent, Dr. Jennifer Ashton has tips on how to stay sharp well into old age.
The Seattle Longitudinal Study, one of the largest and longest, says that the brain drain doesn't really start until our early seventies. This research group has followed six thousand people, testing them every seven years since 1956.
When it came to cognitive testing, many people did better in their forties and fifties than they had done when they were in their twenties. Middle agers ranked higher in scores on deductive reasoning, spatial orientation skills (what an object would look like rotated 180 degrees), verbal memory, and problem solving.
However, middle age brains did have a little trouble with mental skills involving speed, such as rapid number computation, and perceptual speed-how fast you can push a button when prompted. With age, the brain is less susceptible to dopamine-a hormone that can cause us to be impulsive-making middle aged brains better at decision making.
Another study sponsored by the NIH (National Institute of Health) found that while most people experience some cognitive decline as they age, nearly a third of the population doesn't.
Though it is not conclusively known, Ashton explains that a theory behind why this occurs is the increase of fatty substance called myelin "which you can think of as the insulation around those brain synapses."
The older brain may work well because of life experiences, but it also has a lot to do with physiological factors such as genetics. While peak brain power may come at middle age, it can be short lived.
To keep your brain humming for longer, Ashton suggests working or volunteering, especially in an activity that involves critical thinking and social interaction-both of which stimulate brain activity.
Ashton noted that some studies have shown that working later in life wards off cognitive decline. For every year that a subject worked, there was a seven week delay in the onset of Alzheimer's symptoms.
Ashton suggests mental challenges to stimulate brain activity as well, anything from learning a new language to playing and practicing a musical instrument.
To keep your brain functioning optimally, your body must keep up too. Exercise is key when it comes to maintaining high brain activity. Physical exercise helps your heart pump blood flow into the brain. Studies have shown that biking, running, swimming, walking, and lifting weights at least once a week can help prevent cognitive decline in people who were middle-aged or older.
Naturally, your diet matters too. A study consisting of over two thousand older adults found those who ate a Mediterranean style diet that consists largely of nuts, fruit, fish, and low-fat dairy products, were less likely than others to develop Alzheimer's disease.
Protect yourself from brain drain by getting the right amount of sleep nightly. Sleep deprivation can hurt your brain. Your brain needs sleep to regenerate neurons within the cerebral cortex while other stages of sleep can for forming new memories and generating new synaptic connections. Sleep deprivation may cause your speaking ability to deteriorate. When you're overly tired, you may find yourself using repetitive words.
Chronic stress also affects the structure of the brain and function of the brain. In healthy people, chronic stress can disrupt creativity, flexible problem solving and your working memory.
Excessive alcohol use can harm the brain and have a large impact on the cerebral cortex-the part of our brain mostly responsible for higher brain functions like problem solving and decision making. It also makes a significant impact on our hippocampus (important for memory and learning) and our cerebellum (our movement coordination).
So, no more senior moment excuses -- your brain may be better now than ever.