Brain boosters & busters. (Special Feature).

Your spouse can't keep up with conversations the way he or she used to. You find yourself fumbling for the right word with alarming frequency. You couldn't set the time on the VCR if your life depended on it.

They say that age brings wisdom. Does a loss of mental fire-power come along for the ride?

"We can't make one sweeping generalization about what happens to our mental powers as we get older," says Alan Zonderman of the Baltimore Longitudinal Study of Aging, which has been monitoring more than 1,200 people as they grow older. Some abilities decline, some may not change, and others may actually improve, he says.

* Memory. "There is a genuine loss of memory as we get older," says Zonderman. "We've found, as others have, that memory begins a gradual decline sometime in the 50s for both immediate and delayed memories."

Immediate memory is usually measured in minutes. ("You need to have a phone number repeated or written down because you don't dare try and remember it," Zonderman explains.) Delayed memory is measured in minutes or hours. ("You can't remember what was on the shopping list that you left on the kitchen counter.")

Most everybody notices the decline, says Zonderman, though it tends to bother some people more. "You'll see people in their 60s and 70s stammering for a particular word, while others will just think of a synonym and bull their way through, and still others will get all embarrassed and worry that they're getting Alzheimer's disease."

But "senior moments" like these are not a sign that you're going to develop dementia, says Jeffrey Cummings, director of the Alzheimer's Center at the University of California at Los Angeles (UCLA).

"In a senior moment, the person cannot recall in a timely way the information that's there," says Cummings. "But if they have a clue or enough time, they'll remember." In contrast, people who are likely to go on to develop Alzheimer's disease aren't able to recall the information even when given hints or more time. "`That's because in these people the memory was never laid down,' says Cummings. "There's nothing to recall." (See Sept. 2002, cover story.)

* "Fluid" intelligence. Have you ever had to drive someplace where you've never been before, and where your only guide was street or road signs? That's using what scientists call "fluid" intelligence. "It's the ability to reason under novel circumstances," says Scott Hofer of Penn State University. "And it's vulnerable to the effects of aging."

* Spatial sense. As we age, people (especially women) find it harder to orient themselves in space and to do things that involve spatial abilities--like figuring out from a map which way to turn or trying to assemble a piece of furniture from the instructions, says Penn State researcher K. Warner Schaie.

* Verbal ability. "Verbal ability is stable, or even increases, until the 80s, when it begins a slow decline," says Zonderman.

"The use of language and vocabulary is an ability that grows the more we read and socialize," says Hofer. "Knowledge builds on knowledge into a structure that is relatively stable through most of our lives."

The take-home message: Your brainpower should stay fairly stable until your 80s.

"In most people, we haven't found a significant cognitive decline prior to their 60s," says Schaie, who has monitored thousands of people in the Seattle Longitudinal Study. By their 80s, though, virtually everyone shows some decline. "It's very unusual to find an 80-year-old who is functioning the same as he or she did 20 years earlier," says Schaie.

But from your 60s to your 80s, "how much you slip really depends on a lot of things, some of which you can control and some of which you can't," he adds.

Here's what you can control. Some are brain-boosters, some are brainbuster ... and some do little more than lighten your wallet.

BRAIN BOOSTERS

Physical Activity

"If you're a lifetime fitness buff, you will have more grey and white brain matter in the right places when you're older than someone who's been a couch potato their whole life," says psychologist Arthur Kramer of the Beckman Institute at the University of Illinois at Urbana-Champaign.

"Keeping aerobically fit can have a significant effect on our cognitive function as we age, and it's pretty easy to do."

In a study that hasn't been published yet, Kramer and his colleagues compared the brain scans of 55 people who were middle-aged and older. "We found quite dramatic differences in brain volume between those who have been fit for their whole lives, those who haven't been, and those in-between," he says.

People tend to lose brain tissue as they get older, mostly from the front and sides, where memory and the higher levels of mental function reside. "These are the very areas we found that were more preserved in those who kept fit," says Kramer.

Of course, that doesn't prove that physical fitness helps save brain cells, since people who retain more brain matter--for whatever reason--may also be more likely to stay active.

Still, the exercise-memory connection is consistent with research that has tested people before and after they completed fitness programs.

"We just finished a review, not yet published, of fitness-training studies from the past 35 years," says Kramer. "We found that regular exercise has substantial benefits for the mind, particularly on what's called executive control." That includes planning, scheduling, and being able to coordinate several skills or tasks within a short period of time.

People who did a combination of aerobics and strength-training performed better than people who did aerobics only. The exercise was more effective if it lasted longer than 30 minutes a session.

Those results jibe with Kramer's own research. "We took 124 sedentary-but-healthy adults over the age of 60 and assigned them to either aerobic exercise or toning and stretching," he says.

After six months, the aerobics group showed about a 15 to 20 percent improvement over the toners and stretchers in their ability, to focus on the task at hand and to ignore irrelevant information, as well as in their working memory (that's the ability to remember something--like a phone number--despite distractions). (1)

"They walked for more than 30 minutes a day, three times a week," says Kramer.

"Walking works well, especially for those who have spent a lot of time on the couch with a remote control in their hand," he adds.

Mental Stimulation

"To maintain cognitive function at a high level, you need continuing mental stimulation," says K. Warner Schaie of the Seattle Longitudinal Study.

"We find that people who do jigsaw puzzles are better at spatial orientation than people who don't do them," he adds. Ditto for square-dancers, probably because they have to orient themselves in space and follow a sequence of steps.

To test whether stimulating people's minds can halt or reverse a mental decline, Schaie and his colleagues enrolled 229 men and women aged 64 to 95 in a project to teach them reasoning and spatial abilities. (2)

"There are two of the skills that start declining beginning in the mid-60s," says Schaie. About half the participants had slipped in one or both over the preceding 14 years. The inductive reasoning program helped them recognize patterns in order to predict what should come next. The spatial orientation training taught them to mentally rotate two-dimensional figures in order to match them with other figures.

"With training, about 40 percent of both the men and women reversed their 14-year slide," says Schaie. "And the women, who had always lagged behind the men in spatial skills, not only made up what they had lost, they actually caught up to the men."

The success of Schaie's program is now being tested on 3,000 men and women aged 65 and older at six research centers across the country.

Spending time with other people can also keep your mind sharp. "People with good support systems have more opportunities for stimulating activities," says Schaie. For example, "the smaller your support system, the less likely you are to go to the theater or to a movie because you have nobody to go with."

WALLET LIGHTENERS

Ginkgo Biloba 

Ginkgo biloba can "help you stay sharp, focused and alert--so that you'll feel confident, healthy and free to live your life to its full potential."

At least that's what the makers of the Ginkoba brand say on their Web site. If nothing else, ginkgo seems to fire the imagination of ad writers. The evidence tells a less dramatic story--especially for Ginkoba.

"Ginkgo provides no measurable benefit in memory, attention, or concentration in healthy older adults when taken following the manufacturer's instructions," says Paul Solomon, a psychologist at Williams College in Massachusetts.

Solomon and his colleagues have just completed the largest and most thorough study of ginkgo on memory and attention in healthy older people. (3)

They gave 14 standard tests of learning, memory, attention, concentration, language, and mental status to 219 men and women who were over 60 year of age. Then they gave half the people 120 mg a day of Ginkoba and the other half a placebo. Six weeks later, the researchers repeated the tests to see if taking ginkgo made any difference.

It didn't. The Ginkoba-takers did no better than the placebo-takers on any of the 14 tests. And neither the Ginkoba-takers nor their families or friends were more likely to notice an improvement than the placebo-takers or their families and friends.

Earlier studies of ginkgo were inconsistent. Some found no effect. Others found an impact on memory or concentration that was "rather small," says Paul Gold, a psychologist at the University of Illinois at Urbana-Champaign. (4-6)

Gold's conclusion: "Before we can justify recommending ginkgo, there needs to be more research showing that it works."

Phosphatidylserine (PS)

You can buy it as a pricey supplement. You can find it in products with names like Brain Gum, Brain Sustain, and Think Young. It's hyped in a bestseller called "The Memory Cure." And a supplement manufacturer has asked the FDA for permission to claim that it "may reduce the risk of cognitive dysfunction in the elderly."

Phosphatidylserine (PS, for short) is a fat-like substance that's an important component of the membranes that cover every cell in the brain. Our bodies produce it, though it's also found in foods like eggs and dairy products.

Some researchers believe that PS levels decline as we get older, which may contribute to our fading memories.

"PS does seem to be important for the capacity of brain cells to receive and transmit signals," says Mark McDaniel, a psychologist at the University of New Mexico in Albuquerque. But he adds that taking PS "wouldn't necessarily translate into noticeable differences in memory functioning."

Some results have been encouraging. In 1991, for example, 57 participants who tested poorly for memory were given 300 mg a day of PS. (7) After 12 weeks they were better able to match a name to a face, remember telephone numbers, and recall misplaced objects than when they took a placebo.

But there's a wrinkle. Until the mid-1990s, researchers used PS that had been extracted from cow brains. Given what we now know about how mad cow disease spreads, that would be foolhardy. Today, PS is refined from soybeans.

The first well-controlled study of soy PS hasn't gotten it off to a rousing start. Researchers in the Netherlands gave 300 mg or 600 mg a day to 120 men and women aged 58 years and older who were suffering from a greater than typical memory decline for their age. (8) After 12 weeks, the volunteers didn't perform any better on memory tests than similar people who were given a placebo.

"We can't rule out the possibility that PS enhances memory for at least some older adults with memory impairment," says McDaniel. "But we also cannot confidently conclude that PS has positive effects on memory."

DHA 

"Hey Lady ... You've Been Robbed!" Robbed of DHA by your low-fat diet, warn the ads for a DHA pill called Neuromins. If you don't watch out, "Your concentration, memory; learning ability and visual function may suffer." DHA, short for docosahexaenoic acid, is an omega-3 fat that's a major component of cells in the brain and eye. The best sources are fish, particularly fatty ones like salmon, tuna, and mackerel. (DHA is one of the two key fats in fish oil. The other is EPA, or eicosapentaenoic acid.)

Expect the pressure to buy DHA to intensify during the next few years. The two biggest DHA manufacturers in the U.S. merged last spring and announced that some brands of milk, yogurt, bread, cheese, and other foods would soon be fortified with DHA in what they predict is a $1 billion a year market.

Infants clearly require large amounts of DHA for their developing brains and eyes. They normally get it from their mothers during the third trimester and in breast milk. (This year, infant-formula and baby-food manufacturers have begun adding DHA to some of their products.)

But DHA is also a popular ingredient in Senior Moment, Neuro-Nectar, Brainz, and other memory pills and tonics. Can DHA supplements help the adult brain? "That's the million-dollar question," says Robert Anderson of the University of Oklahoma Health Sciences Center in Oklahoma City.

"The brain could have any polyunsaturated fatty acid it wants, but it absolutely prefers DHA over any other and goes to great lengths to hold on to it," he says. "Most of us intuitively feel that there must be a good reason why the brain wants these high levels of DHA."

In fact, lower levels of DHA have been found in people suffering from depression, Alzheimer's disease, and alcoholism, according to DHA researcher Norman Salem of the National Institutes of Health in Rockville, Maryland.

"But so far, there are no studies showing that taking DHA can help," says Julie Conquer, director of the human nutraceutical research unit at the University of Guelph in Canada.

And no one has published any good evidence that DHA can help pump up the memories of healthy people, she adds.

Martek Biosciences (which makes Neuromins) funded a study of DHA and mental ability in healthy people in the 1990s, but the research was never published. The company doesn't know (or won't say) what happened to it.

RELATED ARTICLE: Brain busters.

Our brains shrink and our neurons short-circuit as we get older. Right? Not necessarily. Some of the decline people experience may be due not to aging, but to the cumulative impact of years of high blood pressure, clogged arteries, and repeated interruptions of blood flow to the brain, says Scott Hofer of Penn State University. Among the conditions that can dim your cerebral firepower:

* Alcoholism. Very heavy drinking over a long period of time leads to reduced blood flow through the brain and premature mental decline.

* Depression. In a survey of more than 5,000 women aged 65 and older in Northern California, those who were moderately depressed were 60 percent more likely to experience a measurable deterioration in their mental abilities during the next four years than those who weren't depressed. Women who were severely depressed were more than twice as likely to suffer a decline. (1)

* Diabetes. "Every researcher who has studied the ability of older adults to learn new lists of material has found that those with diabetes don't learn as well as those without diabetes," says Christopher Ryan of the Pittsburgh School of Medicine.

Women who have had Type 2 diabetes for more than 15 years are up to twice as likely to suffer a major cognitive decline as non-diabetic women. (2) And elderly diabetics are more likely to develop dementia than elderly people without the disease.

"The diabetic brain features many symptoms that are best described as accelerated brain aging," says G.J. Biessels of the Magnus Institute of Neurosciences in the Netherlands.

* Heart disease. High blood cholesterol and the clogged arteries it causes speed up the shrinkage and loss of brain cells. Among more than 1,000 postmenopausal women, those with the highest LDL ("bad") cholesterol levels were nearly twice as likely to show a mental decline over a four-year period as those with the lowest LDL. (3)

* Head surgery. "Patients who undergo coronary artery bypass operations commonly report that they're just not the same mentally afterwards," says Ola Selnes of Johns Hopkins University in Baltimore. "They seem to have problems following directions, doing mental arithmetic, and planning complex activities." In a study of 261 coronary bypass patients at the Duke University Medical Center in Durham, North Carolina, 24 percent showed a significant mental decline six months after surgery. Five years later, it had climbed to 42 percent. (4)

* Hypertension. Over time, high blood pressure damages the brain as well as the heart. In three large studies that tracked 6,400 men and women in Massachusetts, Hawaii, and Sweden, those who had hypertension in middle-age didn't perform as well on memory and intelligence tests when they reached their 70s as people who didn't have hypertension in middle-age. (5) Hypertension can cause mini-strokes and can stiffen blood vessels, which can reduce blood flow to the brain.

* Sleep apnea. These short interruptions of breathing during sleep, usually accompanied by snoring, deprive the brain of oxygen dozens of times a night. That increases the risk of damage to brain cells. When Swedish researchers used surgery to treat 53 sleep apnea patients, their memories improved. (6)

* Stress. Chronically high levels of the stress hormone cortisol can damage an area of the brain called the hippocampus, which is involved in learning and memory. Among 136 elderly women in Southern California whose performance on a memory test declined over a seven-year period, the deterioration was six times faster in those with the highest cortisol levels than in those with the lowest levels. (7)

(1) Arch. Gen. Psychiatry 56: 425, 1999.

(2) Arch. Intern. Med. 160:174, 2000.

(3) Arch. Neurology 59: 378, 2002.

(4) New Eng. J. Med. 344: 395, 2001.

(5) Diabetes Care 20: 1388, 1997.

(6) Acta Otolaryngol. 122: 86, 2002.

(7) J. Amer. Geriatr. Soc. 48:1655, 2000.

RELATED ARTICLE: The bottom line.

* To keep sharp, stay physically and mentally active.

* There is no convincing evidence that ginkgo, phosphatidylserine (PS), or DHA can preserve or improve memory or other mental abilities in healthy adults.

* Chronic diseases like hypertension, diabetes, heart disease, depression, sleep apnea, and alcoholism increase your chances of suffering a steeper than normal mental decline as you age.

(1) Nature 400: 418, 1999.

(2) Psychology and Aging 1: 239, 1986.

(3) J. Amer. Med. Assoc. 288: 835, 2002.

(4) Int. J. Neuropsychopharmacol 4: 131, 2001.

(5) J. Altern. Complement. Med. 6: 219, 2000.

(6) Psychopharmacology 152: 353, 2000.

(7) Neurology 41: 644, 1991.

(8) Nutritional Neurosciences 4:121, 2001.

On the Cover

In this colored scanning electron micrograph, killer T-lymphocytes (orange), which are part of the body's immune system, have released a chemical that is killing a cancer cell (pink). As the cell dies, it releases small spheres (in pink).