STORY BY

Josh Gowin

At this very moment, are you madly searching in vain for your:

• car keys
• glasses (either pair, darn it)
• cell phone (which was in your purse, but…where is your purse?)

Or did you leave them at that restaurant... you know the one, the one at the corner of what’s-that-street... ?

Failing memory sounds an alarm in all of us. As each year passes, there are more things to remember and more chances to forget. Before you call out the search party, keep in mind that you haven’t lost your mind.

Indeed, age is the greatest risk factor for Alzheimer’s disease and other challenges to our mental faculties. However, normal aging does not spell cognitive decline, and chances are good that we will continue to sparkle well into the twilight.

B.F. Skinner, the great behaviorist, said that facing old age is like reading the weather report and expecting rain: Rather than merely resigning ourselves to getting wet, we should put our umbrella by the door and prepare to make the best of it.

Here are some of the latest developments in the forecast.

My head I’d be scratchin’
while my thoughts were busy hatchin’

There’s much scientific discussion about the fate of our memories. While some worry that memory declines with age, there is good reason to believe that normal aging has little effect on our recollection capacity.

Anthony Wright, PhD, professor of neurobiology and anatomy at The University of Texas Medical School at Houston, points out that aging is also associated with an increase in a host of human maladies such as tumors, strokes and disease. “To study normal aging, you have to factor out these other causes of decline.”

Wright studies learning and memory in humans and animals, and in one study he found that monkeys process memories in the same fashion across their lifespans. In a group of monkeys, the results from the 24-year-olds “looked just like they did when they were age 6.”

In fact, there’s a good body of research that shows little to no decline in reasoning ability in normal aging until all but the final few years of our lives.

How fast we process information is a different story. In a study following the same set of people for a number of years, the only aspect which declined steadily and predictably as subjects aged was their processing speed. Other factors, such as verbal memory, verbal ability, inductive reasoning, and spatial orientation remained relatively stable, especially when controlled for changes in processing speed.

Jack Waymire, PhD, professor of neurobiology and anatomy at the UT Medical School, agrees with these findings. "In normal aging, there is very little change [as opposed to] Alzheimer's. It’s more like slowing down a bit.”

Culprit with a capital A

As our years go up, so do our chances of developing Alzheimer’s, one of the most pronounced culprits of dementia. Several estimates of prevalence suggest that nearly 50 percent of persons aged 85 and above have Alzheimer’s.

Currently, Alzheimer’s disease is a progressive and irreversible process. While we may not be able to stop its progression, we have better tools today for detecting it earlier and more reliably.

Mild Cognitive Impairment, MCI, is a state of decline that precedes the development of Alzheimer’s. It’s a transitional point between the normal process of aging and dementia where a patient presents memory complaints, but does not meet the criteria for Alzheimer’s.

Approximately 3-5 percent of adults over 65 will develop MCI each year. Deficits in episodic memory—the recollection of stories—are exhibited at least five years before the onset of clinical dementia.

Aside from forgetfulness, MCI seems to have the most effect on attention and language comprehension. MCI can be marked by a reduction in size of the hippocampus, a region of the brain highly involved in memory formation.

Normal aging is not the same as Alzheimer’s disease. Close friends, colleagues and family members are in a better position to determine if someone is having an ordinary mental slip rather than recognizable cognitive difficulties that require medical attention.

Brain changes

As we age, we don’t necessarily lose brain cells. We’ve heard that we have most of the brain cells by a young age that we’re going to get, but it’s not as simple as that.

The brain is like a web of nerve cells which function based on their connections in the nervous system. These connections can change throughout our entire lives. It’s these connections that allow us to learn new things, form new memories and perform complex tasks and immerse ourselves in complicated thought.

Studies using MRI show a gradual decline in the volume of our cortex as we age. Surprisingly, this is not due to a great loss in the number of cells, but rather to a decrease in the number of connections that each cell makes.

“These connections seem to be especially vulnerable,” notes Waymire, “though, it's not clear why.”

The primary tool used to measure short-term memory is the “digit span task”, where you are asked to remember a series of numbers and report them back. The more you can remember, the more efficient is your short-term memory. Across languages, those with short words for numbers perform better on the digit span task than do languages with long words (five is more quickly processed than 25, for instance). 

Wright suspects that time plays an important role. When reasoning problems are presented to old and young individuals, both groups come up with the correct solution, but the speed may differ. So, the decrease in performance on lab tests of short-term memory tests with age could be due to changes in processing speed. Despite these results, by and large, daily functioning is not disrupted. The abilities that people perform on a regular basis tend to be maintained over time.

Aging gracefully

As we know, we don’t stop forming memories just because we reach adulthood. We form new memories throughout our lives, and with new memories come new connections between neurons to help us store these memories. Although aging has some effect on the rate at which we lose these connections, we can strengthen and maintain the connections we do have.

In other words, use it or lose it.

In our youth, we’re forced to learn new skills, adapt to situations and become independent in the world. This challenge could be part of the rationale for why our minds work the way they do when we’re young. There’s no reason to stop challenging ourselves as we get older. Stretching our minds keeps us mentally fit.

Research just out this week suggests that cognitive decline itself may be declining. In 2003, the cognitive skills of 7,000 people were tested and then compared with those of a 1993 group. The University of Michigan researchers found that 8.7 percent of the 21st Century group exhibited difficulty with memory or performing certain cognitive tests, compared to 12.2 percent in the group tested 10 years before.  Possible explanations for this good news may be that we're now better educated (more years spent in school and more apt to remain intellectually stimulated) and also in better physical shape.

Mental activity will reinforce our memories and stimulate our intellect. As Wright puts it, the more mental power you have, “the more you can stand to lose without noticeable effects.”

Take your brain for a walk

There are other strategies we can employ to our benefit to prevent the loss of our neural connections, and thus, our memories. We’ve heard the Greek ideal of a sound mind in a sound body, but who knew there was such a relationship?

An accumulating body of work suggests that exercise plays a role in the growth and maintenance of neural connections. After exercise, researchers at UCLA found an increase in Brain Derived Neurotrophic Factor, which “induces and supports [nerve cell] growth in development and in the adult,” Waymire says.

Staying physically active as we age is one of the key ways to keep our memories intact, not to mention the role that exercise plays in reducing stress—another important factor in staying mentally young.

Heart and mind

What’s good for your heart also is good for your brain. Now you have twice the incentive to monitor your cholesterol intake.

Vascular problems are associated with high levels of inflammatory agents, which may factor into your risk for Alzheimer’s. Some recent evidence suggests that drugs known as statins (Lipitor, Zocor), used to lower cholesterol and prevent vascular problems, also may be protective for Alzheimer’s. Waymire suggests that this may have to do with the way cholesterols are processed by the brain.  

However, the most recent studies looking at this issue found no relationship between statins and the development of Alzheimer's, so no grand conclusions have yet to be drawn. Researchers did find a significant reduction in the amount of amyloid plaques, protein fragments that clump together in dense deposits in the brains of patients with Alheimer’s. This reduction in the number of amyloid plaques however didn’t affect disease prevalence.

A few people have reported that while taking a statin they experienced some cognitive impairment, which cleared up after they changed prescriptions. Some physicians said they had seen similar occurrences, but only very rarely—five or six cases over about 12 years. No studies have found a causal relationship between statin use and memory loss.

One of the most promising findings is that even with a little bit of effort to keep ourselves mentally fit, our abilities can be maintained considerably longer. Remember what used to be fun—work puzzles, learn a video game and challenge your children or grandchildren to play with you. Take a class; join a book club. Above all, find a physical activity that your body and brain can enjoy.

And, take comfort in the indisputable fact that at this very moment, much younger, agile brains across America are losing car keys, cell phones and glasses (both pair).