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How to Sharpen Your Mind

By Sarah Fremerman

The day ayurvedic physician Virender Sodhi was born, his father fed him leaves of bacopa monniera, also known as the Brahmi plant, crushed into juice and mixed with a few drops of honey. According to ancient Ayurvedic medical tradition, this creeping herb which grows in marshy areas throughout India is believed to increase intelligence, and bacopa leaves have been fed to newborn infants for over 5,000 years. 

    "Maybe that's why I'm so intelligent," the doctor joked recently. Bacopa–along with other herbal remedies such as ashwagandha–is renowned in India as a brain tonic that promotes longevity. In Ayurvedic medicine, bacopa is known as a rasayana, or "rejuvenator"—in modern medical terms, an adaptogen—a substance that helps correct imbalances in the body's immune system, restores its natural ability to respond to stress, and promotes overall vitality.

    Sodhi who practices Ayurvedic medicine in Bellevue, Washington, is a well-spoken advocate for his own Ayurvedic array of what have come to be known among the trendy and the adventurous as "smart drugs" or "smart nutrients"–more precisely, nootropics (Greek for "mind-turning"). These substances include everything from the herbs ginkgo biloba and Siberian ginseng to vitamins and minerals, phospholipids (a crucial building-block of brain cell membranes), omega-3 fatty acids, amino acids, and hormone supplements, not to mention several synthetic prescription drugs (piracetam and hydergine are among the most popular) that usually are obtained from abroad by mail-order because they are not approved by the Food and Drug Administration for the purpose of cognitive enhancement.

    The first strong wave of interest in brain supplements followed publication of the book Smart Drugs and Nutrients (Smart Publications, 1990) by Ward Dean, M.D., a specialist in anti-aging medicine, and John Morgenthaler, a science writer. Dean and Morgenthaler sparked a good deal of curiosity and soon won a small but almost religiously enthusiastic group of followers. The authors had searched through medical journals and collected whatever scientific evidence they could find to support the use of several natural and synthetic drugs and nutrients as cognitive enhancers. (Cognitive, a term rarely heard ten years ago, refers to the entire process of knowing, including thought, judgment, and memory.)

    Since then more studies have been published. Also, the oldest baby boomers have reached the age (50) when their minds aren't what they once were. These factors together have helped make smart supplements a hot market item. One health foods store employee reported that ginkgo has sold like crazy since recent scientific reports of its cognitive value appeared in the news.

    Step into any health foods store and you'll find plenty of brain tonics for sale-products with names like GinkgoIQ, Thinker's Edge, MegaMind, and Brain Booster. The ingredients of a product called Remind, developed by Seattle nutritional doctor Jonathan Wright, M.D., contain (among others) a smattering of the heavy-hitter "smart" ingredients: the herbs ginkgo biloba and Siberian ginseng; acetyl-L-carnitine (a substance that works with the amino acid L-carnitine to transport fatty acids into the energy-generating mitochondria in cells); DMAE (a substance crucial to the production of acetylcholine, a major brain neurotransmitter); and phosphatidyl serine and phosphatidyl choline (phospholipids important mainly for the fluidity, or flexibility, of brain cell membranes).

    Many claim this is more than a case of powerful marketing. Smart nutrients do make you smarter, according to Steven Fowkes, executive director of the Cognitive Enhancement Research Institute in Menlo Park, California, and co-author of Smart Drugs II (Smart Publications, 1993), with Morgenthaler and Dean. However, said Fowkes, you have to find out which ones are right for you.

    Fixing your brain, he says, is a little like fixing a car. You have to replace the part that's not working the way it's supposed to. "You have to see what works. It's a matter of trial and error."

    Enthusiastic users swear they can detect differences—they think more clearly, play a better game of Tetris, match names with faces, and remember where they put their keys.

    Dane Miller, 40, an employee at Vitamin Express, a nutritional supplement store in San Francisco, said he has noticed a marked difference in his ability to concentrate while taking ginkgo biloba extract. And Miller takes notes on how customers do after taking smart nutrients.

    "I've sold ginkgo to people taking psychiatric bar exams, people under a lot of mental pressure," he said—and many keep coming back for more. "One guy who was on ginkgo and phosphatidyl choline came back and said, `I passed my psychiatric board exams on these supplements!"'

    Kurt Appleton, a 65-year-old man in Washington state, asserts that ginkgo has worked for him too. "My short-term memory is not as good as it used to be," he said ruefully. "But now I'm able to find things faster—misplaced keys, papers I've been working on. When I was taking this stuff during a three-month period, I was amazed."

    And a CPR instructor and mother of two in Rohnert Park, California, Herlinda Heras, said she swears by nutritional supplements like DMAE, acetyl-L-carnitine, and other amino acids to keep her brain in shape. She reported that DMAE improved her concentration. "It makes things seem very clear, lucid," she said.

    For Heras, the effects of acetyl-L carnitine are even more pronounced. "Things work in my mind like a flow chart when I take ALC," she explained. She finds she can immediately think of solutions to problems much more easily than usual–especially when taking a combination of ALC, Siberian ginseng, and ginkgo biloba extract.

How They Work

Not everyone has been swept away by smart nutrients (see "12 Experts"). Some think the idea is pure fantasy; others say taking them (especially in exotic combinations) could be dangerous. But to understand why people like Heras have so many positive things to say about smart nutrients, it helps to know how the brain thinks and remembers. It's possible that smart nutrients work for some people and not others, depending on how well their brains are working to begin with.

    While scientists still cannot explain many of the brain's mysteries, a few theories are well substantiated. They know, for example, that thoughts and memories consist of long chains of brain cells, called memory traces, linked by a flow of electric current.

    In his book Brain Longevity (Warner Books, 1995), Dharma Singh Khalsa, M.D., writes that although no one is quite sure how these chains are created, one relatively recent and now well-established discovery is that a memory may be stored in several parts of the brain at once. Thus, for memory to be functioning optimally, it is essential that several different parts of the brain be able to communicate fluidly and easily with one another. Communication between neurons (brain cells) is one key to brain health, and a number of smart nutrients theoretically work because they facilitate the movement of messages through the brain.

    The long chains of neurons in a memory trace don't actually touch each other, but are separated by tiny gaps called synapses. A thought, in the form of an electrical impulse, flows from one cell to the next by jumping across these gaps in the form of chemicals called neurotransmitters. Of the hundred or so neurotransmitters in the body, six are now known to be crucial for brain function; and, while all the neurotransmitter functions are interrelated and work in tandem with each other, the one generally known thus far to be most crucial for memory and cognition is acetylcholine. A number of smart nutrients play some role in the body's manufacture of acetylcholine or in its activity.

    All this intricate communication between brain cells demands fluid and healthy connections between them— abundant supplies of neurotransmitters, and healthy dendrites. Dendrites are the long, slender branches on the brain cells, where the electrical signals are actually transmitted. Their function is crucial, according to Khalsa.

    "For the most part, the more dendrites, and connections, you have–and the healthier the dendrites are the smarter you are," he said. Among the substances that may strengthen dendrites is the herb that Sodhi says Indians take from birth, bacopa monniera. Ashwagandha has the same effect, according to Sodhi.

    Researchers also agree that one factor essential for optimal brain function is the flexibility of cell membranes, which allows brain and nerve cells to communicate easily with each other and allows nutrients to enter the cell more easily. Nutrients that promote membrane flexibility include omega-3 fatty acids such as docosahexaenoic acid (DHA) as well as naturally occurring phospholipid molecules like phosphatidyl choline and phosphatidyl serine. Smart nutrient proponents often recommend taking a dietary supplement of these fats–or, some say, just make sure you're getting enough of them through your diet by eating fresh fish (the quintessen tial "brain food") at least three times a week—especially salmon, tuna, sardines, and other fish known to be rich in these fatty nutrients.

    Another key factor to consider is oxidation, which many scientists call the cause of all aging. As nutritionist Carl Germano, R.D., C.N.S., and neurologist Jay Lombard, D.O., suggest in The Brain Wellness Plan (Kensington, 1997) oxidation is the same process that rusts metal and spoils butter. It happens when a charged particle called a free radical pairs up with another molecule and "steals" one of its electrons causing that molecule to become chemically unstable. Free radicals normally float around in the body as part of its natural defense system, zapping invaders like viruses and bacteria that can cause illness.

    But free radicals also have a nasty habit of attacking and dismantling the body's own tissues; and fatty tissues, especially those most prevalent in the brain, are particularly susceptible to free radical damage. Things that spawn free radicals in the body include smoking, exposure to chemical pollutants, alcohol, radiation, and fatty foods. Antioxidants are a broad class of compounds that work to reduce excess amounts of damaging free radicals by neutralizing them or by stimulating the body's own antioxidant systems. Some powerful antioxidants for the brain include carotenoids, polyphenols (found in green tea), folic acid, and vitamin E–most of which are found widely in fruits, vegetables, and other foods–as well as selenium, coenzyme Q10, and ginkgo biloba which are commonly taken as nutritional supplements.

Will They Work For You?

Some people are bound to notice a bigger difference than others when taking smart nutrients, depending on a number of possible factors: How much DHA they include in their diets could be important; antioxidant intake or free radicals could be another factor; so could general health of the circulatory system, levels of neurotransmitters, health of dendrites, and so on.

    Of course, age has a lot to do with these aspects of brain health. Some researchers believe the brain naturally deteriorates as it ages, pro How to Sharpen Your Mind ducing a common condition known as Age Associated Memory Impairment (AAMI). Others, however, argue that specific diseases cause the brain to slow down and memory to decline–aging itself, they maintain, is not harmful, and we could remain clear-headed for a lot longer than we now think possible, if we could only figure out a way to cure degenerative conditions such as dementia and Alzheimer's disease.

    Yet another possibility, as Khalsa suggests, is that if you're suffering from poor concentration and short-term memory, but you're too young to have AAMI, you may just be low on acetylcholine. He proposes supplementing your diet with the main ingredients your brain needs to manufacture acetylcholine: lecithin, B vitamins, vitamin C, and certain minerals. Khalsa also recommends yoga and breathing exercises to promote the supply of oxygen and glucose to the brain–two other elements crucial for acetylcholine production.

    Still another possibility is that brain health reflects overall health—a poor diet, lack of exercise, and stress will cause the brain, along with the rest of the body, to suffer. Brain cells require oxygen and nutrients like the rest of the body's cells, and if the whole body is underfed, the brain will not work to its capacity.

    Given these theories, it's reasonable to think that some people would benefit from smart nutrients more than others. If someone is deficient in a nutrient that is crucial for acetylcholine production, and she begins eating foods and taking supplements that work together to produce acetylcholine, it makes sense that her brain will begin to function better.

The Flip Side

However, agreement on this, and agreement on which, if any, smart nutrients one should take to strengthen dendrites or improve neuronal communication, appears to be a long way off, as the sidebar " 12 Experts" below makes clear.

    "The notion of a smart drug in science fiction terms is very appealing, because this is supposedly a drug you take that increases your IQ, it increases your performance, your function, and it has no side effects," said Ashley Bush, M.D., Ph.D., a psychiatrist and research neuroscientist at Harvard Medical School. "If that were possible, then there would seem to be very few reasons not to take it."

    "Known stimulants such as physostigmine (the original `smart drug'), and even cocaine and alcohol in low concentrations, temporarily increase brain function and improve IQ. The downside is toxicity, side effects, and addiction. These are not healthy approaches, and no consistently safe long-term approach has been found."

    Other researchers point out that a lot of research on highly touted memory-enhancing nutrients is still in the early stages. Some substances have only been tested on laboratory animals, not yet on humans. Larry Cahill, Ph.D., a research neurobiologist at the Center for the Neurobiology of Learning and Memory at the University of California Irvine, said that just because a drug or nutrient may enhance learning in laboratory animals, or short-term memory in Alzheimer's patients, does not mean it will work in a normal person.

    A memory drug could one day exist, Cahill conceded. "But there is no evidence yet, to my knowledge, that any substance improves cognition in normal, healthy humans," he said. Cahill remains skeptical about taking too many supplements without being sure they're doing you any good.

    Others caution against looking for immediate results. "These are subtle, minor kinds of changes, that occur only over a long period," said Efrem Korngold, O.M.D., a practitioner of Chinese medicine at the Chinese Medicine Works in San Francisco. "People expect to get very quick results, and that's unusual." No matter how badly you want a quick result, or how convinced you are that you've seen one, he said, natural supplements tend to work slowly, without immediately apparent effects. While you might feel the effects of a powerful synthetic drug immediately, herbs and nutritional supplements have a more systemic effect, not as specialized but more likely to promote overall health and well-being.

    Korngold also suggested that people often overlook the more basic causes of a muddled mind. "The greatest and cheapest enhancer of cognitive function is good sleep," he asserted. Strangely though, he added, "people now need supplements to achieve it." Korngold sees smart drugs and nutrients as what he calls "the current metaphor for inadequacy." In an information age, with the world moving faster and faster, people have come to view their brains and bodies as machines, he said, from which they demand a high level of efficiency and productivity. Often we push ourselves too far. Many of Korngold's patients' complaints and deficiencies, he said, can be traced to fatigue or overwork–constantly pushing the machine of the human body into overdrive.

  If you wish to give smart nutrients a try, the accompanying guide breaks them down into several groups according to history of use and scientific support for efficacy. Included also is the brain "buzzer" category, substances like caffeine that temporarily make us feel smarter, but which actually do nothing to improve brain function more than temporarily. Before taking any smart nutrients, refer to the sidebar "Before You Take Supplements..."

Witch Hazel

 Twelve Experts Tell What They Take

So you think you're confused. The following twelve experts could not agree on anything, not on what to take, what works, or what doesn't work. Some experts take 50 supplements a day, some take a handful, and others think diet and exercise are all anyone needs. Note: we've listed the major supplements each expert takes, but not all of those are solely for promoting brain function. Many are antioxidants to protect against the effects of aging – or they're for cardiovascular health, or vision, or to strengthen the immune system. It's difficult to single out "brain nutrients," some experts believe, because many natural supplements offer an array of overlapping benefits.

Barbara Levine, PH.D.

Chief of Nutrition, New York Hospital-Cornell Medical Center. Age: "Forever Young."

Can you improve your IQ? "I think that your IQ is going to be established relatively early on," she says. "Taking DHA supplements before an exam might be reasonable." And getting enough DHA is crucial for infant brain development: "That's one of the reasons that pregnant women should not cut down on their fat too much. The brain is 60 percent DHA. Americans have among the lowest levels of DHA in serum and breastmilk." Each day she takes calcium (1000 mg) and DHA (200 mg).

Larry Cahill, PH.D.

Research Neurobiologist at the Center for the Neurobiology of Learning and Memory at the University of California-Irvine. Age 37.

"The bottom line is that there is no drug or supplement that I'm aware of that consistently and reliably enhances memory in humans." He adds, "There is anecdotal evidence, and it's possible that someday a memory drug will be discovered." But for now? Cahill suggests that you make your learning as stimulating as possible. "You'd be surprised how well your memory works for that which you care about," says Cahill. "And also my advice would be, don't go out and spend a lot of money on things that are going to make a lot of entrepreneurs wealthy and give you very expensive urine." Cahill takes no supplements, relying instead on a healthy diet to nourish his brain.

Ashley Bush, M.D., PH.D.

Research Neuroscientist at Harvard Medical School. Age 39.

"These people are hoping that you'll buy these drugs or nutrients believing that it's going to increase your IQ. But it doesn't, in the way that we understand IQ. Some known compounds increase your performance on the IQ tests. But it's a very temporary effect." Daily, he takes: folic acid (400 micrograms) to prevent heart disease; vitamin E (400 IU), an antioxidant; vitamin C (500 mg); selenium (200 micrograms) to ward off cancer; aspirin (82 1/2 mg) as protection from heart disease; coenzyme Q10 (30 mg), an antioxidant; DHA (100 mg), to prevent Alzheimer's disease; ginkgo biloba extract (240 mg), an antioxidant. And coffee.

Joseph Coyle, M.D.

Chairman, Consolidated Department of Psychiatry, Harvard Medical School, Age 54.

His advice: "I think studying a little harder is the best way to go on this one." Coyle says antioxidants can keep your brain healthy–" but how many antioxidants one needs to take to be perfectly protected is unclear." Every day he takes: aspirin (82 micrograms) to ward off heart disease; selenium (200 micrograms), an antioxidant; and vitamin E (1200 IU), an antioxidant–all with his morning orange juice.

Thomas Crook, PH.D.

President and Chief Executive Officer, Psychologix, Inc., A Psychological And Medical Research Company in Scottsdale,

Arizona. Age 53.

On smart drugs: "By and large a bunch of nonsense. What you have with the so-called `smart drugs' is an attempt to show that through pharmacology you can improve upon nature. Maybe you can, but no one has ever shown that.' Crook concedes that one supplement appears to enhance memory and cognition in patients with memory deficits: "Phosphatidyl serine stands out. I'm not sure I can fully explain it." While PS may do a lot for a 55- to 75-year-old suffering from Age Associated Memory Impairment, he adds, it probably won't do much for a healthy 25-year-old stockbroker who just wants to improve his performance and his salary. Crook's daily brain regimen? "I don't take any kind of drug, not even vitamins in the morning. I work out a couple of hours a day and eat a good diet."

Carl Germano, R.D., C.N.S.

Clinical Certified Nutritionist and Co-Author of the Brain Wellness Plan (Kensington Book, 1997) Age 44.

On smart nutrients: "It would be a crime for me as nutritionist to endorse that approach. A nutritionist will never approach a disease or process using a single magic bullet. People are kidding themselves when they try to use a single nutrient to accomplish a single goal." What does he take every morning? "If you've got about an hour I could tell you." Takes 15 to 20 supplements every day. A sampling includes: one multiple antioxidant formula, coenzyme Q10, magnesium, and a product called Brain Modulators that contains PS, DHA, ginkgo, ALC, and vitamin B12.

Michael Jansen, M.D.

Author of The Vitamin Revolution In Health Care

(Arcadia Press, 1996) Age 53.

"Basically, you want to do something that protects the brain from oxidative damage." Recommends a good diet, exercise, and (among others) the following supplements: B vitamins, vitamin E, ginkgo biloba extract, phosphatidyl serine, glutamine, vitamin C, and natural carotenoids. Jansen has been taking about 25 different supplements twice a day since 1975, and reports positive results. His daily regimen includes: ginkgo biloba; many vitamins; flavonoids; saw palmetto; mixture of bilberry and amino acids, for eyes; coenzyme Q10, an antioxidant; amino acids (carnitine, glutamine, taurine); elderberry extract, for the flavonoids; and melatonin occasionally, to improve quality of sleep.

Efrem Korngold, O.M.D.

Practitioner of Chinese Medicine, Chiness Medicine Works, San Francisco, California, and Co-author of Between Heaven and Earth: A Guide To Chinese Medicine (Ballantine Books, 1991) Age 52.

"I believe that cognitive enhancement is possible, and that these substances are useful, but not that they're sufficient. I think cognitive function is a product of health in general." He concludes, "There are no shortcuts." He nevertheless admits, "I take ginkgo, and I've noticed that my ability to recall names and words, which was declining, has improved. The effect is subtle." Korngold recommends: vitamin C, vitamin E, selenium, mixed carotenoids, ginkgo biloba, bilberry, hawthorn berry, grape pit extract; and eating organic vegetables. He takes: ginkgo biloba, and (for body and brain) an herbal formula he created called Move Mountains, which contains five herbs—Chinese ginseng, astragalus, shizandra, lycee root, and androvian (Chinese orchid).

David Kyle, PH.D.

Founder and Senior Vice President of Research and Development, Martek Bioscienses Corporation. Age 45.

"I would recommend DHA for everybody in this country, for the following reason. Over the last 40 years, dietary levels of DHA have been depleted by about 50 percent. Especially if you're a non-fish-eater." At present, he adds, the DHA content of breast milk in many American women is very low, which could be detrimental to infant brain development. Kyle's advice: "Eat fish three or four times a week! If you don't, you might need supplementation." Daily, he takes: 200 mg of DHA, and occasionally vitamin C.

John Morgenthaler

Co-author of Smart Drug and Nutrients (Smart Publications 1990) and Smart Drugs II: The Next Generation (Smart Publications, 1993).

"In a sense, everything is a smart nutrient, including food." He experiments with many smart drugs and nutrients, and believes that cognitive ability in a normal, healthy person can definitely be enhanced. Morgenthaler recommends these natural brain nutrients: acetyl-L-carnitine, pregnenolone, DMAE, ginkgo biloba, phosphatidyl serine. Here are just a few of the many supplements Morgenthaler takes daily: green tea extract (2000 mg), which contains flavonoids; acetyl-L-carnitine (2000 mg) to enhance cognition; a megadose multivitamin; saw palmetto (300 mg) for prostate health; melatonin, to improve sleep; kava kava occasionally, for relaxation; depranyl, occasionally, for winter blues.

Andrew Weil, M.D.

Author of Spontaneous Healing (Knopf, 1995) Age 55.

On smart drugs: "They're harmless, but their effectiveness is questionable. I've tried a lot of these things for memory and I can't tell that they've made any difference . . . [The claims are] just thin, and really not substantiated by research." He has tried DMAE, and the prescription drugs hydergine and vasopressin. How to increase smartness? "You can do brain exercises and puzzles," Weil suggests. "Most people just don't practice using their minds." He recommends chess, verbal puzzles, and scrambled word games. Recommends the same "antioxidant cocktail" he takes every morning: vitamin C (1000 mg); vitamin E (800 IU); mixed carotenes (1 capsule); selenium (200 IU); and coenzyme Q10 (100 mg). Also suggests omega-3 fatty acids and green tea.

Virender Sodhi, M.D. (Ayurved)

Ayurvedic Physician in Bellevue, Washington, Age 40.

"These herbs, ashwagandha and bacopa, can improve general brain function. I see so many patients every day who started remembering names, information, et cetera." Sodhi recommends only the safest, time-tested herbs for his patients. "The reason why I'm so confident is that you have fifty centuries of use to back it up," he adds. A lot of recent scientific discoveries are really rediscoveries, according to Sodhi. "I think we're reinventing the wheel." Every day he takes: multivitamin B complex; trifala, for digestion; ashwagandha, as a general tonic; and bacopa, as a tonic and brain food.

Guide to the Smart Nutrients

Here, broken down into categories by their history of use and proven effectiveness, are the major smart nutrients people are taking today.

What It Is Also known as "Indian ginseng," ashwagandha is the aromatic root of Withania somnifera, a tall branching shrub with pale yellow-green flowers, cultivated in India and North America.

Reported Effects Ashwagandha is believed to nurture and clear the mind, calm and strengthen the nervous system, promote sound sleep, and rejuvenate tissues throughout the body. Like ginseng, the powers of this root as a rasayana, an all-around promoter of health and balance, are legendary. Ashwagandha is said to fortify all systems in the body, including the mind.

How It Works This root contains alkaloids and steroidal lactones, which relax the central nervous system, while combating stress and promoting overall balance. And it contains several key amino acids that can bolster the brain's own natural supplies: glycine, valine, tyrosine, proline, and alanine.

The Evidence Used for thousands of years as a folk remedy in India, ashwagandha has only recently been subjected to scientific testing. In one How to Sharpen Your Mind double-blind randomized clinical study in New Delhi, researchers studied the aging process of 101 healthy male adults, ages 50 to 59, for one year. Results showed that in the men who were taking ashwagandha, the aging process was slowed–their hair was less grey, their red blood cell counts higher, serum cholesterol levels lower; and three-quarters of the men taking the herb reported improvement in sexual performance: And a 1997 study at the University of Leipzig in Germany using male rats showed that an extract of ashwagandha affects acetylcholine metabolism in the brain, which could explain its cognitive enhancement abilities.

Caveats No dangerous side effects have been associated with ashwagandha, but large doses may cause irritation to mucous membranes or gastrointestinal upset. Also, because this herb may exaggerate the effects of barbiturates, it should not be used in conjunction with sedatives. Pregnant women should not take ashwagandha, except under the supervision of a doctor.

Where to Find It You can find ashwagandha in various forms, including the dried root, powder, capsules, tablets, or liquid extract. The supplement is available in most health foods stores. About 2 to 6 grams of the powdered root is considered to be a reasonable daily dose, and it may be taken daily.

What It Is Ginseng is another adaptogen, used for thousands of years throughout Asia, Europe, and America. There are many types of ginseng, but some herbalists and physicians suggest that Siberian ginseng may be the most potent type, and Siberian ginseng is thought to be especially effective for improving cognitive function.

Reported Effects This herb is a mild stimulant, so it is sometimes recommended for people feeling lethargic or having trouble concentrating, or just for an energizing boost. As a tonic, it promotes long-term overall health, including that of the mind.

How It Works Ginseng works to normalize conditions and regulate energy in both body and brain. In his book Brain Longevity (Warner Books, 1997), Dharma Singh Khalsa, M.D., calls ginseng a "balanced stimulant," because it stimulates both the adrenergic (adrenal) nervous system and the cholinergic ("calming") nervous system.

The Evidence In several studies, subjects taking ginseng have demonstrated marked improvements in reaction speed and performance on cognitive function tests.

Caveats Taking ginseng may not be advisable for those with high blood pressure. Also, ginseng is probably effective when taken occasionally as a pick-me-up, rather than as part a daily regimen.

Where To Find It Ginseng is sold in health foods stores and Asian grocery stores nationwide, usually a root, powder, tea, or in capsule or table form. Depending on your health and reasons for taking ginseng, a reasonable dose may range anywhere to 750 mg to 1500 mg daily.

Bacopa Monniera

What It Is Bacopa Monniera, more commonly known as the Brahmi plant (which means "Creator" in Sanskrit), is one of the most popular brain tonics in the pantheon of Ayurvedic remedies. In India, people of all ages have been taking bacopa for over 5,000 years.

Reported Effects While ashwagandha is considered in India (like ginseng is in China) to be an all-around health tonic and adaptogen, bacopa is known specifically as a "smart" nutrient that improves the intellect. So if you want to get smarter, says Ayurvedic physician Virender Sodhi, M.D. (Ayurved), bacopa is a good herb to try. Bacopa also plays many other roles in Ayurvedic medicine—as a diuretic, tranquilizer, and treatment for asthma, depression, insanity, and epilepsy, among other conditions.

How It Works No one is quite sure how bacopa influences brain chemistry, and research is still in the early stages. Because bacopa is an adaptogen, it works to achieve balance in the body and strengthen the immune system's ability to respond to stress. And it is thought to act as a sedative, influencing the central nervous system by stimulating a "calming" neurotransmitter in the brain. Bacopa may also stimulate the production of serotonin in the brain, which could explain its reputation as an effective antidepressant. According to Sodhi, bacopa also helps to regenerate dendrites in brain cells.

The Evidence Indian devotees of the herb don't need studies to prove its efficacy—the plant's name has long been a household word. But in recent years several rat and clinical studies have substantiated claims that bacopa enhances learning and memory. In one study on laboratory rats using a T-maze trial, rats fed a bacopa extract showed remarkable learning and memory enhancement, compared to both a control group and another group that had been fed valium.

Caveats Bacopa contains alkaloids whose chemical action resembles that of strychnine, and excessively high doses of these substances can be toxic. In normally prescribed dose levels, however, it is generally known to be harmless. "Most of these herbs are very safe," Sodhi said, "even in overdoses." He figured that you would have to take about 25 percent of your body weight's worth of bacopa for it to have a toxic effect.

Where to Find It Popular in India, where it also goes by the name of a supplement called Memory Plus, bacopa is available in the United States in health foods stores, alone or in combination with other herbs. The recommended dosage is 70 mg, if taking this dosage once in the morning and once in the evening. If taking the whole powdered herb, take 1/2 teaspoon once in the morning and once in the evening.

Acetyl-L-Carnitine

What It Is Acetyl-L-carnitine is a molecule found naturally throughout the body that helps to transport fats into the mitochondria, the tiny energy "factories" in all living cells. ALC is closely related to carnitine, a natural amino acid that is also available as a nutritional supplement (ALC is considered the more potent of the two); it is also related to choline (discussed later), in both chemical structure and clinical effects.

Reported Effects Take ALC to enhance cognition and stimulate creativity–it is thought to improve communication between the right and left hemispheres of the brain, thereby promoting intuitive and balanced thinking.

How It Works Though the action of ALC in the brain is not yet fully understood, some researchers believe it works by helping to facilitate the activity of important neurotransmitters such as acetyl choline and dopamine in the brain.

The Evidence Clinical studies with ALC have shown it to be effective in restoring memory and cognitive ability in patients with Alzheimer's disease, and a few recent studies even suggest that ALC may produce a similar effect in healthy adults. In a placebo-controlled clinical study on 279 patients suffering from mild to moderate cognitive decline, those taking ALC significantly improved their scores on cognitive function tests, while those taking the placebo showed no improvement. And in a 1992 study in Italy on a group of 8 males and 9 females, ages 22 to 27, ALC was shown to improve reflex speed and increase accuracy in playing a video game.

Caveats Pregnant and lactating women are advised not to take ALC, except under a doctor's supervision.

For Optimal Benefit ALC may be most effective when taken with phosphatidyl serine, according to Khalsa. The two substances work together to aid production of acetylcholine in the brain.

Dietary Sources Dietary sources of ALC include milk, fish, meat, and other animal foods high in protein; however, it is difficult to obtain therapeutic amounts from the diet alone.

Where to Find It ALC and its closely-related neighbor carnitine are available over the counter at most health foods stores. ALC usually comes in 500 mg tablets, and a normal recommended dose is up to 1000 mg per day. The only drawback to ALC is its expense—a one-month supply may cost up to $95. Take daily, but take in cycles, a few months on, a few months off.

Choline

What It Is Choline is a precursor to the neuro transmitter acetylcholine, essential for memory and cognition. Also, it is a phospholipid that helps promote neuronal membrane fluidity, which is important for communication between brain cells. One form of this fat, phosphatidyl choline, is the active ingredient in lecithin–an emulsifier commonly found in processed foods, and derived from either soy or animal sources. In the brain, phosphatidyl choline also plays a role m repairing and maintaining neurons. Choline, lecithin, and phosphatidyl choline are all sold as dietary supplements. According to Khalsa, most people ingest about 1,000 mg of lecithin every day as part of a normal diet, but that amount is not sufficient to promote optimal brain function throughout life.

Reported Effects Choline, in its various forms, is widely reputed to enhance cognition and memory not only in people with mild memory impairment, but in normal healthy people as well.

How It Works Phosphatidyl choline, the active ingredient in lecithin, helps to replenish the body's supply of the neurotransmitter acetylcholine, which is crucial for memory, learning, and cognition. Because choline is a precursor to the neurotransmitter acetylcholine, Chinese medical doctor Efrem Komgold, O.M.D., observed, "Taking choline as a supplement is like supplying the body with a raw material. It can use what it needs."

The Evidence Many studies have been conducted on choline. In one early clinical study published in the journal Science in 1978, subjects demonstrated improved performance on intelligence and memory tests after ingesting choline.

Caveats Some forms of choline, such as choline bitartrate or choline chloride, can produce unpleasant side effects such as a fishy odor or diarrhea. Lecithin is known to spoil easily, so check dates to be sure what you're buying is fresh.

For Optimal Benefit For maximum effectiveness, Khalsa recommends combining lecithin with vitamin B5 and the nutrient DMAE (discussed below), because these three together foster production of acetylcholine in the brain.

Dietary Sources You might be surprised to find lecithin among the ingredients listed on the labels of chocolate candy, instant foods, and baked goods. Interestingly, lecithin does for food just what it does in the human body–it improves fat distribution (the flow and melting of chocolate, for example), reduces viscosity, and lengthens shelf life because of its antioxidant properties. Choline, the essential ingredient in lecithin, is found in grains, beans, cauliflower, and lettuce.

Where to Find It Choline, lecithin, and phosphatidyl choline are widely available in health foods stores. A supplement product should contain about 30 to 55 percent PC. You can take about 3 grams per day of choline. Lecithin too can be safely taken in large doses; Khalsa recommends a dose of about 1,500 mg daily for a healthy person with no significant cognitive impairment or deficit, who just wants to enhance cognitive function. Higher doses may benefit patients suffering from memory loss or deficit.

DHA (Docosahexaenoic Acid)

What It Is Docosahexaenoic acid is a polyunsaturated omega-3 fatty acid, an essential building block of brain tissue that is crucial for communication between neurons.

Reported Effects According to Barbara Levine, Ph.D., chief nutritionist at New York Hospital-Cornell Medical Center, DHA plays a vital role in brain development in infants and children. She said taking the fatty acid can have a beneficial effect on adults, too. In Japan, students frequently take DHA pills before examinations to improve their academic performance, and the labels of many foods—from soda to canned tuna–advertise the fact that they are nutritionally enriched with DHA.

    Because its role in the brain and nervous system is so wide-ranging, DHA can improve concentration, and may help to alleviate a number of disorders, including depression, Attention Deficit Hyperactivity Disorder (as a milder substitute for the drug Ritalin), dyslexia, aggressive behavior, and memory loss in healthy people, as well as those suffering from Alzheimer's disease. Note that if you're experiencing excessive thirst and dry skin, these are common indicators of an omega-3 fatty acid deficiency.

How It Works Brain cell membrane fluidity is essential for "talk" between the cells—which is, how thoughts and memories are transmitted. DHA helps keep cell membranes fluid, and also helps to replenish brain tissue.

The Evidence In October 1997, David Kyle, Ph.D., of Martek Biosciences Corporation in Baltimore, Maryland, reported the results of a new study, which showed that low blood serum levels of DHA are a significant risk factor for Alzheimer's dementia. In a separate study, researchers also demonstrated that dietary supplementation of DHA improves memory in Alzheimer's patients. And other studies have linked low DHA levels to aggression, ADHD in children, clinical depression, and dyslexia.

Caveats A vegetarian diet puts you at risk for low levels of DHA, because there are no adequate vegetarian sources of the fatty acid. Seaweed contains a small amount of DHA, and flaxseed oil is a good source of linolenic acid, a precursor to DHA– but these alone probably don't supply adequate dietary levels of DHA.

Dietary Sources Eating "fatty" fish like salmon or tuna three or four times a week is a good way to make sure you're getting enough omega-3 fatty acids. Eicosapentaenoic acid (EPA), another omega-3 fatty acid found in fish and especially in fish oil, is a precursor to DHA. Because EPA acts as a blood thinner, pregnant women, children, and older people are advised to avoid taking it.

Where To Find It You may decide to try supplementing your diet with DHA, which is available at any health foods store, either in the form of fish oil capsules or capsules of pure DHA in sunflower oil (marketed under the name Neuromins). Andrew Weil, M.D., author of Spontaneous Healing (Knopf, 1995), recommends avoiding fish oil supplements, which may contain mercury or other toxins in concentrated forms. Algae-derived capsules contain pure DHA. You can take either 100 mg or 200 mg per day to keep your brain healthy. Because DHA plays a key role in infant brain development, Kyle recommends 200 mg daily for pregnant and lactating women.

Ginkgo Biloba

What It Is The ginkgo tree, native to China and now found throughout the world, has been around longer than any other species of tree on the planet, for about 300 million years. You've probably seen the ginkgo, with its cloven fan shaped leaves that turn bright yellow in autumn. Ginkgo leaves have been used as a general tonic in Chinese herbal medicine for thousands of years.

Reported Effects While some people describe remarkable improvements in cognition and clear-headedness after taking ginkgo, the herb is also recommended as a way for a normal, healthy person to counteract oxidative stress in the brain, promote circulation in the brain, and slow the aging process. And a couple of recent studies with patients suffering from Alzheimer's disease and other forms of cognitive impairment have shown that ginkgo can actually reverse some memory impairment and improve cognitive ability.

How It Works Ginkgo is known mainly for its ability to improve blood circulation in the body and brain. A number of proponents of ginkgo state that increased cerebral blood flow improves memory and cognition.

The Evidence A study published in the Journal of the American Medical Association in October 1997 showed that ginkgo biloba extract can help to slow cognitive decline in patients suffering from Alzheimer's disease. And in 1995, in another placebo-controlled clinical study on Alzheimer's patients over a three-month period, patients taking ginkgo showed marked improvement in memory and attention span.

    On the other hand, there's some debate on whether increased blood flow to the brain really enhances cognition. Thomas Crook, Ph.D., president and chief executive officer of Psychologix, Inc., a medical and psychological research company in Scottsdale, Arizona, said he's not convinced that ginkgo has any effect on cognition. In a study sponsored by the National Institutes of Health, Crook and his colleagues "found there is no relationship between oxygen levels in the blood and cognition."

Caveats No side effects have been observed in people using ginkgo over a long period of time. Note that many clinical studies on ginkgo use extremely high concentrated doses of the herb. Dietary supplements you can buy over the counter in the United States usually contain a lower ratio of ginkgo extract, so comparable dosages of these supplements may not produce the same effects.

Where To Find It Ginkgo biloba extract is widely available in health foods stores. For a normal, healthy person who wishes to slow or prevent cognitive decline, 90 mg is considered a reasonable daily dose. Patients with significant memory or cognitive impairment may try taking a dose of 120-160 mg daily, divided into three equal doses throughout the day.

Phosphatidyl Serine

What It Is Phosphatidyl serine is a phospholipid, a form of fat found in every cell in the body, but especially abundant in the brain. PS is closely related to other phosopholipids, such as phosphotidyl choline, and functions in much the same way.

Reported Effects Fans of PS claim that it improves memory, learning, concentration, verbal skills, mood, and the ability to cope with stress. According to Crook, who views PS as the most convincingly demonstrated "smart nutrient" now available, PS may reverse up to 12 years of age-related mental decline.

How It Works PS works to keep neuronal cell membranes flexible so that nutrients enter the cells more easily; it increases glucose metabolism in the brain (which aids in the production of the neurotransmitter acetylcholine); and it increases the number of neurotransmitter receptor sites in the brain.

The Evidence Crook and his colleagues recently studied the effect of phosphatidyl serine on a group of 149 patients who had been identified as suffering from Age Associated Memory Impairment. Compared to a placebo group, those who took PS showed improvement in performance of simple memory tasks such as matching names with faces, recalling telephone numbers, and recovering misplaced objects. Most of the studies on PS have been done with patients suffering from dementia or other forms of cognitive deterioration. Right now there is no evidence that PS would have the same effect on a young, healthy person.

Caveats Those on anticoagulant medication should note that PS has been known to produce negative reactions when combined with anticoagulants. Mild nausea is also reported as an occasional side effect.

For Optimal Benefits As mentioned above, Khalsa states that PS and ALC taken together maximize each other's benefits, since they work together to maximize brain rejuvenation and energy production.

Dietary Sources PS is found in lecithin, an additive in many foods, including chocolate, instant foods, and baked goods. One theory holds that by eating foods the body needs to make its own phosphatidyl serine—the amino acid methionine (nuts, seeds, corn, rice and other grains), folic acid (leafy green vegetables), essential fatty acids (fish, flaxseed oil), and vitamin B12 (eggs, dairy, fish, or meat)—your body will produce sufficient amounts.

Where To Find It Look for PS as a nutritional supplement available over the counter in health foods stores. It is normally taken in doses of 100 to 200 mg twice daily.

DMAE (Dimethylaminoethanol)

What It Is This substance occurs naturally in the brain, and plays a key role in synthesis of acetylcholine.

Reported Effects Through much of the evidence is still anecdotal, many people have reported success with DMAE as a cognitive enhancer and mild stimulant.

How It Works In the brain, DMAE combines with phosphatidyl serine and vitamin B5 in helping to produce acetylcholine, the neurotransmitter essential to learning and memory.

The Evidence Though well-established in a number of human studies as a mild stimulant, most of the evidence supporting DMAE as a cognitive enhancer comes from animal research–and that leaves a lot of physicians and researchers skeptical, for the time being, about its memory- or cognitive-enhancing effects of human.

Caveats

DMAE can be overstimulating for some people, and may cause muscle tension or insomnia. Also, DMAE has been known to exacerbate epilepsy or bipolar depression, so patients with these conditions are better off avoiding it. At least one physician has pointed to studies in which DMAE was shown to shorten life span in laboratory animals, but according to Ward Dean, M.D., coauthor of Smart Drugs and Nutrients (Health Freedom Publications, 1991), this study appears to be isolated and unsubstantiated by further research.

Dietary Sources Like many other brain foods, DMAE is naturally found in fish, especially anchovies and sardines.

Where To Find It Available as a supplement in health foods stores, dosage for DMAE is about 50 to 100 mg per day, though some people report successfully taking up to 1000 mg daily.

Pyroglutamate

What It Is Pyroglutamate is a naturally occurring amino acid found in the brain, blood, and cerebrospinal fluid.

Reported Effects Like DMAE, pyroglutamate is believed to have overall cognitive enhancement properties.

How It Works Its role in brain chemistry is not yet well understood. Because it occurs naturally in the brain, replenishing pyroglutamate through dietary supplements is thought to stimulate cognitive function. No one is quite sure yet how it does this.

The Evidence Pyroglutamate has been shown to improve learning and memory, as well as counteract the effects of anxiety, in laboratory rats. In humans, one study has shown pyroglutamate to be effective in restoring alcohol-induced memory deficits; another demonstrated that it also works to counteract memory deficits in humans afflicted with multi-infarct dementia (dementia caused by reduced blood flow to brain tissue) and Age Associated Memory Impairment. However, these are early studies that have not yet been subsequently corroborated by other researchers' results.

Caveats No adverse side effects have yet been reported from taking pyroglutamate, but the effects of long-term use as a supplement are not known.

Dietary Sources This natural amino acid is found in fruits, vegetables, dairy products, and meat.

Where To Find It You can find pyroglutamate sold as a nutritional supplement in health foods stores. John Morganthaler (coauthor with Dean of Smart Drugs and Nutrients) and Dean recommend a dosage of about 500 mg to 1,000 mg per day for arginine pyroglutamate (an alternate form of the amino acid), and a little less for straight pyroglutamate.

Hormone Supplements

Hormone supplements may help boost your mood and energy levels, but their long-term effects are not yet well understood. And if you already have optimal levels, some hormones may be dangerous. Because it's difficult to assess your own condition, we suggest that you take hormone supplements only under the supervision of a doctor.

DHEA Produced in the adrenal gland, DHEA is the most abundant steroid hormone in the bloodstream. Proponents claim that it preserves youthfulness and prevents brain cell degeneration and that it has cognitive-enhancing effects as well. Sodhi warns again using DHEA, as its long-term effects are not yet well understood. Natural medicine expert Andrew Weil, M.D., also suggests that research to substantiate enthusiasts' claims is lacking. Khalsa prescribes DHEA for his patients and believes it has considerable merit, but advises that it should be used only under a doctor's supervision; and he advises young people to avoid it. "Because young people already have optimal levels of DHEA," he writes, "indiscriminate use poses a potentially dangerous risk."

Pregnenolone A natural precursor to steroid hormones, pregnenolone in the body is converted into hormones such as DHEA, testosterone, progesterone, and estrogen. A rat study in 1992 indicating its effectiveness as a cognitive enhancer piqued the interest of smart-drug users, but no human studies have been completed to date. As with all other hormones, the long-term effects of pregnenolone are not yet well understood; and its claims as a cognitive enhancer are mostly unsubstantiated by anything other than anecdotal evidence and the 1992 rat study.

Stimulants

Some nutrients widely believed to make your brain function better do just that–for a few hours. Caffeine is the most popular; people also use amino acids like phenylalanine, and herbs such as ephedra and guarana also provide a quick jolt of energy. However, they're not likely to do anything for the long-term health of your brain, according to Carl Germano, R.D., C.N.S., clinical certified nutritionist and coauthor of The Brain Wellness Plan (Kensington Books, 1997). A few common "smart,' stimulants include:

Caffeine Hugely popular, and for many addicts, irreplaceable. The most common source is coffee made from the beans of the coffee tree, originally native to Ethiopia.

Ephedra Also called Mormon tea, because Mormon settlers in North America used ephedra instead of caffeine. Also used in traditional Chinese medicine. A leafless bush found in desert climates throughout the world. American and Chinese varieties sold as an herbal supplement, alone or in energy-booster formulas, in health foods stores.

Guarana The national drink of Brazil. Sold as an herbal stimulant, guarana contains more caffeine than coffee.

Phenylalanine An amino acid. Like choline and pyroglutamate, phenylalanine is a neurotransmitter precursor. In the brain, phenylalanine is converted into dopamine, and then into epinephrine and norepinephrine, the excitatory neurotransmitters which explains its stimulating properties. Known as an energy booster, it shows up as a popular ingredient in pick-me-up "smart drinks."

Reprinted with permission from Natural Health, March-April 1998. For a trial issue of Natural Health, call 1-800-526-8440.