Who are the people ginkgo is most likely to help, besides Alzheimer's sufferers?

Probably people who are no longer in their youth. Most of us suffer some memory loss as we get older, and there is a strong possibility that ginkgo can be of use in that case. The fundamental issue that remains unresolved is whether memory deterioration is a necessary part of the aging process or whether the memory loss that usually occurs after the age of about 40 is a result of controllable factors in our bodies and our lives. To determine that, we have to look at the brain itself and how it ages?

What happens to the brain as it ages?

The best way to explain this is to start with what happens to the brain at the beginning of life. This is something that new technology is only now beginning to reveal to us. Using something called positron-emission tomography (PET), pediatric neurobiologists can now "watch" the activity in various sections of an infant's brain in a noninvasive procedure. What they have discovered is that the brain's 100 billion neurons have formed more than 50 trillion connections at birth. This "basic wiring," as writer Sharon Begley put it in a 1997 Newsweek article, is dictated by the baby's genes. It makes certain that the baby's heart will beat and its lungs breathe. Amazingly, that's about all it does. In the first months of life, the brain will make 20 times that original 50 trillion connections. One thousand trillion is a lot of connections, and even the body's 80,000 different genes couldn't possible make them all. They are made primarily by the baby's experience with the world. The more stimulation a baby has--in the form of games such as "peek a boo" and "this little piggy"--the more connections are made.

Does all this connection forming take place at the same time?

No. What is happening during this time is actually the structuring of the mind, physiologically as well as psychologically, and it takes place in stages. This process is called synaptogenesis and it involves the formation of synapses, those tiny gaps between neurons that we discussed earlier. At right around 2 months, it begins in the motor cortex. That's when babies lose their "startle" and "rooting" reflexes and begin to perform purposeful movements. At about 3 months, synaptogenesis reaches its peak in the visual cortex. You will see the baby begin to focus its eyes on specific objects. It isn't until about 8 or 9 months that synaptogenesis begins to complete itself in the hippocampus, which is where memory lives.

Does that mean we start remembering when we are 8 or 9 months old?

Yes, in a sense. As 9-month-old infants, we can remember, for example, that if we squeeze a rubber toy it will make a noise. We can make the kind of mental connection that allows us to master simple learning processes. This is not to say that we form long-term memories that we will be able to retrieve when we are in our twenties. There are those who say we do, that the memories are there somewhere and the problem lies in our ability to retrieve. Someday we will probably know the truth about it, but now we can only say that infants are forming memories of some kind in the second half of their first year. At the same time, the prefrontal cortex, which is the home of logic and forethought, starts forming synapses at an astounding rate. For the next 10 years of the child's life, that synaptogenesis will, according to Begley, consume twice as much energy as an adult brain. Considering that the adult brain uses 20% of the body's energy (while taking up only about 3% of its bulk), that's an impressive amount of energy and one reason that good nutrition is so important in a child's mental development.

When does all this brain structuring stop?

That's the amazing thing. It doesn't. We used to think that it did, but we now know that, although it comes to a sort of natural end during adolescence, it can be restarted. All those billions of neurons get assigned tasks early on, but it is possible for the brain to reassign tasks if necessary, as in the case of damage to one part of the brain. The brain, while fragile (those neurons are not capable of reproducing themselves), also seems to be remarkably adaptable.

Still, most of each brain's structure is determined in the first decade or so of life. The brain learns what life is like and adapts itself to deal with what it finds. If life, for a particular child, is marked by danger and uncertainty, the brain learns to produce the chemicals that keep us wary and alert to danger. If life is regular, dependable, and filled with comfort and safety, the brain becomes better at producing the chemicals that allow us to remain calm and anxiety-free. That is a bit of an oversimplification, of course, but in essence that's the way the process seems to work.

How is memory affected by a child's negative experience?

It has been discovered that, in adults who were abused as children, the hippocampus is smaller than in other adults. The hippocampus, remember, is the seat of memory. Scientists believe this is the result of stress hormones washing through the brain. Clearly, the reverse is true of children who are cherished and nurtured.

How does memory functioning change as we grow up and grow old?

Although there is controversy surrounding this subject--as there is with any aspect of cognition and/or aging at the moment--there is a useful distinction to make here. Human intellect may be seen as having two aspects: crystallized intelligence and fluid intelligence. Crystallized intelligence involves the skills we learn through education and practice. Reading, for example, is a "crystallized" skill. Fluid intelligence includes nonverbal reasoning, motor skills, and problem-solving abilities that change and evolve as the individual matures physically. Coping with a flooded bathroom is, no pun intended, a "fluid" skill.

Now, an excellent article in the Western Journal of Medicine, entitled "Memory, Thinking, and Aging: What We Know about What We Know," explains that "crystallized abilities--such as knowledge of general facts and vocabulary--sharply increase during the early years of formal education and then stabilize or gradually improve throughout adulthood." For most of us, this rings true in terms of our own experience. We learn an enormous amount of life-changing information in grade school and continue to learn, although less rapidly, all through our lives. Watching a program on the Discovery channel when we are in our fifties, we learn that eagles and timber wolves have been taken off the endangered-species list and we add it to whatever general knowledge we may have about wildlife. And we remember it. A pundit being interviewed on a talk show uses the word "intransigent," and we look it up or ask someone what it means. And it becomes part of our vocabulary.

On the other hand, according to Sharon Begley in her 1997 Newsweek article, "fluid abilities improve throughout childhood, then gradually decline in adult years, with more deterioration in old age due to neuronal loss, changes in physiologic brain function, and increased rates of disease and injury." This too has a commonsense appeal when we realize that this category includes reaction time, speed of perception, and the ability to focus and concentrate. We may get wiser as we get older, but we seldom get sharper.

So we get a little fuzzier as we go along, but when does real deterioration of memory and other thinking skills start?

This is where we really get into controversy. Many psychologists and physicians consider memory loss in people over 40 to be a clinically definable, physiological condition. This "condition" is called Age-Associated Memory Impairment (AAMI) or Age Related Cognitive Disorder (ARCD). AAMI is recognized by the National Institutes of Health. Dr. Thomas Crook, at the Memory Assessment Clinic of Bethesda, Maryland, has been working for several decades to analyze memory and age. He and his team have worked out a number of tests that are designed to measure and evaluate memory decline in age. According to Robert Smith, in an article in Total Health, these tests are "objective and precise, yet they are savvy and built around common everyday tasks like grocery shopping, driving, reading, meeting a stranger and later having to match the face with the name, and so on." Crook has tested people, in both the United States and Europe, chosen at random and grouped by age. Their studies confirm that there is a decade-by-decade decline in cognitive abilities. In the appendix to this book, several tests of the kind used by Crook and other researchers are included, with age-related scoring. You might be interested in testing yourself.

Does this decline in memory happen to everybody?

That's the big question, of course. Crook and his followers believe that it does. They define ARCD as a non-disease, age-related decline. The National Institutes of Health also believes that there is a physically determined change in memory. There are many arguments in favor of this view. However, there is an opposing view that is quite plausible and gaining currency in the medical community. Many medical professionals and cognitive researchers believe that there is no preordained deterioration of the molecular and cellular mechanisms of memory. They insist that any damage to the brain is caused by factors other than age.

What are the factors that these scientists believe are damaging our brains?

To a great degree, they are the factors in our life and environment that cause free-radical damage. In her book Stop Aging Now!, health-writer Jean Carper writes, "Many prominent investigators now view aging not as an inevitable consequence of time, but as a disease itself--the ultimate conglomerate disease caused by a lifetime of environmental assults to cells . . . . Aging occurs when cells are permanently damaged by continual attacks from chemical particles called free radicals. Simply, the cellular damage accumulates over the years, until the totality of destruction reaches the point of no return--diseases clustered at the end of life and eventually death." In other words, "age" is not a matter of time, but of free-radical damage.

Is the brain particularly vulnerable to free-radical damage?

Yes, it is, for a couple of reasons. To begin with, free radicals are the product of a process called oxidation. It's very much the same process that makes apples turn brown or butter become rancid. As we explained before, a free radical is an oxygen molecule which has lost one of its electrons. Because the brain uses 20% of the body's oxygen intake, it is often exposed to possible damage. Second, neurons are unable to reproduce themselves; therefore, dead and damaged brain cells are not replaced. They are gone forever. And though it's normal to lose a certain number of brain cells gradually, over time, no one can afford to lose more than they have to.

What are some of the causes of free-radical damage, and therefore memory loss, in the brain?

In his enlightening article "No Way to Treat the Mind," Steven Rose cites a recent Dutch study from the University of Limberg, Maastricht, which reports that "memory decline in otherwise healthy people as they age is associated with mild head injury, general anaesthesia, or 'social drinking' earlier in life."

Smith makes a similar point and cites Dr. Robert Sapolsky, a researcher at Stanford University. Sapolsky points out that other causes of mental deterioration include sustained emotional stress, glutamate (as in monosodium glutamate), smoking, pollutant substances, and lifestyle drugs (both legal and illegal). All of this is consistent with free-radical damage.

So, memory loss may be due not to age itself, but to the free-radical damage that accumulates as we get older?

That's one theory, and it's an important one. But in some ways it's like saying that wrinkles are not caused by age but by sun. That's true, but to most of us it doesn't make any difference. We have been exposed to the sun all our lives. We will continue to be exposed to it for the rest of our lives, and we have wrinkles as we get older. Period. As for the causes of memory loss, most of us have had experience with one or all of the three contributing factors mentioned in the Dutch study. Presumably "mild head injury" includes whacking your head on the sidewalk when you fall off your bike at the age of 12. Certainly most of us had general anaesthesia when we had our tonsils out, and some of us have had to undergo surgery in later life. Social drinking, of course, is very widespread in this culture. As for Sapolsky's list, most of us, of course, have been exposed to a number of these in our lifetimes. Therefore, even if you don't accept age as a clinical condition causing mental deterioration, it is probably safe to say that most people--by the age of 40--could use a little help in the memory department.

Life may begin at 40, but do good memories end there?

We said a little help. Unless you have Alzheimer's disease or some other specific form of what is called dementia, you probably won't notice any serious changes until you're over 70. And even then your verbal abilities and other crystallized intelligence should remain unchanged.

The largest study of aging and cognitive changes is being carried out in Seattle. It is called the Seattle Longitudinal Study (SLS) and has been observing more than 3,000 mentally healthy adults since 1956. Each subject is given a battery of tests every 7 years in five areas: verbal meaning, spatial orientation, inductive reasoning, number skills, and word fluency. So far, the SLS has discovered that performance in all these areas begins to decline by about the age of 74. However, most participants in the study keep or increase their level of performance in at least one area. In other words, if you are particularly good at Scrabble, you will probably still be able to beat your teenaged nephew when you're in your seventies, even if you're not as quick as he is at figuring out how to put together a set of prefabricated shelves.

What do these thinking skills have to do with memory?

Memory is involved in all cognition. Think about it. Without memory, you would not be able to put one word after another. You have to remember the first word in order to add the second. Without memory, you would not be able to add two plus two or keep a thought in your mind long enough to come to a conclusion. It might be too much to say that thought is memory, but it's close.

What if I don't want to resign myself to this gradual memory loss?

The most obvious answer is to take antioxidants to combat free-radical damage. Ginkgo biloba is an important one. The LeBars researchers theorize that it was the antioxidant properties of ginkgo that produced positive results in the study of Alzheimer's patients. Ginkgo is a potent, safe source of antioxidants.

What other sources of antioxidants are there?

There are a number of others. Plants and the food we derive from plants are the major sources of these valuable substances. Indeed, fruits and vegetables are the first line of defense against free-radical damage.

To begin with, plant foods provide the antioxidant vitamins E, A, and C. In addition, there are other antioxidants available in specific foods. For example, tomatoes contain the antioxidant lycopene, soy-protein foods contain isoflavones, red wine contains polyphenols, broccoli contains sulphoraphane, and strawberries contain ellagic acid. Green and black teas also contain polyphenols in large amounts. Five cups of tea supplies the same quantity of antioxidants as two servings of fruit or vegetables. When trying to obtain antioxidants from food, go for what is freshest and protect the nutrients in your food until you can get them into your body.

Are there any antioxidant supplements I can take?

Many neuroscientists recommend vitamin E supplements. Daily doses of 2,000 IU, in at least one study, improved the ability of early Alzheimer's patients to cook, dress, and eat, and it was quite probably the antioxidant properties of the vitamin that caused the improvement.

Could ginkgo counteract "normal" memory loss in any other way?

Quite possibly. To explore its potential, we could do worse than to look at the factors that researchers have discovered in older people with good mental fitness.

What are the factors that contribute to mental fitness as we age?

For just over a decade, the MacArthur Foundation Network on Successful Aging has been sponsoring research into this question. Fifteen scientists around the country have been carrying out studies into factors as varied as genetics, psychology, environment, and sociology. In one study, almost 1,200 healthy adults between the ages of 70 and 80 were tested for 22 different variables. The tests took place in 1988 and then again in 1981. What the director of the study--Marilyn Albert, Ph.D., of Harvard University Medical School--discovered were four crucial factors. They were the following:

Level of education

Level of physical activity

Lung function

Feelings of self-efficacy.

Two of these four factors directly involve increasing the amount of oxygen that reaches the brain. Both physical activity and good lung function contribute to feeding the brain the oxygen it needs. So, too, does ginkgo. What's more, because of its vasodilator properties, ginkgo can help bodies that are no longer young keep up their level of physical activity.

So you're not suggesting that I take ginkgo instead of exercising?

Absolutely not. And we're not suggesting that you take ginkgo instead of continuing your education, formal or otherwise. An interesting article in Psychology Today, entitled "Making Our Minds Last a Lifetime," quotes memory researcher James L. McGaugh, "There's growing neurobiological evidence that supports the commonsense notion of 'use it or lose it.' The brain may be more like a muscle than we ever thought."

Decades of experience with physical-fitness fads and foibles has taught us that the best way to get a strong, fit body is to exercise it. The same appears to be true of the mind. Other contributing factors such as nutrition are important, but they cannot make up for a mind that is allowed to get flabby with underuse. Taking ginkgo will almost certainly help you keep your mind in good trim. Reading books that challenge you to think and push your skills of comprehension a little harder than you're used to will probably help just as much.