[Paleopsych] Psychology Today: A Taste of Genius
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Wed Sep 21 22:34:49 UTC 2005
A Taste of Genius
First, the summary from the "Magazine and Journal Reader" feature of the daily
bulletin from the Chronicle of Higher Education, 5.8.2
A glance at the current issue of Psychology Today: Food for thought
A healthy diet may help to strengthen the brain, and not just the
body, writes Lauren Aaronson, a regular contributor to the magazine.
In examining why that is so, she also lists eight foods that can help
carry people into their 80s, and offers six ways to help keep the
brain in shape.
Eating cold-water fish, like salmon, is one way, writes Ms. Aaronson,
because they contain nutrients that foster supple cellular membranes
-- the walls that regulate the flow of molecules into neurons, the
main cells of the brain. Absent a healthy flow, she says, the brain
has a more difficult time learning new or remembering old information.
Sugary food like grapes and honey can also help improve memory, says
Ms. Aaronson, because the brain is one of the few organs that draw
almost all of their energy from glucose. Experiments have shown, she
says, "that a dose of glucose-sweetened lemonade boosts recall of
events, words, movements, drawings, and faces, among other things,
with effects lasting long enough to get you through a two-hour exam."
Carbohydrate-rich foods like breads and pastas have similar effects,
she says, much to the chagrin of Atkins dieters.
"There's no question that proper feeding primes our brains to reach
their fullest potential and maintain their wits for a lifetime,"
writes Ms. Aaronson. As the line between food and medicine becomes
blurred, though, keeping the U.S. Food and Drug Administration's
pharmaceutical standards away from foods may become a challenge in the
future, she says.
Taste Of Genius , By: Aaronson, Lauren, Psychology Today, Jul/Aug2005, Vol.
38, Issue 4
FROM AVOCADO TO ZUCCHINI, DIET IS THE NEW DRUG, AS SCIENTISTS DISCOVER THAT THE
BENEFITS OF FOODS GO WAY BEYOND BASIC NUTRITION, IT MAY BE THAT YOUR BRAIN HAS
THE MOST TO GAIN FROM WHAT YOU EAT.
WHEN I WAS 7 YEARS OLD, I READ IN THE SEQUEL to Little Women that oatmeal made
you smart. So I demanded that my mother feed me oatmeal on the day of my
spelling test. I ate oatmeal before every test I ever took from elementary
school through grad school. I even made my mother mail me oatmeal when I had a
big exam during my semester abroad; later I thanked both my mom and Quaker
Oats: I got a perfect score.
My mother chalked up my success to superstition. But I still believe that the
oatmeal itself made a difference. And now it looks like science will prove me
and the book's heroine, Jo March, right.
Like just about anything we eat, oatmeal influences the way our brains
function. Food, after all, gives our bodies the raw materials to build
everything from noses to neurons and the ability to operate them efficiently.
Some materials make for better outcomes than others, as a flood of recent
Fibrous oatmeal, for instance, slowly and steadily ushered the cereal's cargo
of carbohydrates into my system as glucose. My brain snapped up that sugar from
the bloodstream and deployed it both as fuel to power its operations and as a
component of key chemical messengers, the very neurotransmitters that carry
thoughts and memories. Oatmeal revved up my brain and stabilized my mood,
memory and concentration--all without the spiky highs or crashing lows of foods
like candy bars that dump their payload of sugar quickly.
Unbeknownst to me, my morning oatmeal also supplied ferulic acid. A potent
antioxidant lurking in the germ and bran of grains, ferulic acid appears to be
a general protector of brain cells, keeping them stipple and responsive by
nullifying toxins that stiffen them with age--and possibly even reversing some
of the cognitive decline of aging.
A bowlful of gruel is hardly the fashionable food of choice. But oatmeal sits,
however lumpily, at the cutting edge of a revolution in the way we think about
food. Nutritional science is demonstrating that some edibles--call them
functional foods--do far more than provide essential nutrients for normal
maintenance and development. They furnish biologically active components that
create high-class physiologic effects, such as disarming toxins, and impart
health benefits. They have the capacity to reduce disease risk--"with minimal
involvement of health professionals," the nation's food scientists say.
"Food has a greater impact on health than previously known," declares a report
released last March by the Institute of Food Technologists. "New evidence-based
science linking diet to disease and disease prevention" has "blurred the line
between food and medicine." Nutrients influence body processes at the molecular
level, turning our very genes on and off. The emerging understanding of
molecular nutrition, says the IFT, "has the potential to revolutionize diet,
nutrition and food products, and health care."
Scarcely a week goes by now when scientists don't make some discovery about the
health-enhancing properties of food, from the cancer-fighting abilities of
brussel sprouts to the anti-Alzheimer's effects of anchovies. For the nation's
nutritional scientists, that presents a significant problem: There's no longer
a clear boundary between foods and drugs. In some cases--antioxidant-rich
cranberry juice, for example--the health claims for nutrients actually have to
be soft-pedaled, lest they trigger regulations that require foods to undergo
the same approval process as drugs. The IFT is urging the Food and Drug
Administration to adopt reasonable procedures for demonstrating safety and
efficacy of foods that are, well, more than foods--what some people call
Oatmeal in fact inspired one of the earliest druglike claims for a food. In
1997 the Quaker Oats box began touting the cholesterol-lowering effects of the
cereal after the FDA evaluated studies linking whole grains to reductions in
the blood fat.
Food-boosted health now goes way beyond the heart, all the way to the head. Of
course, brain virtuosity also hinges on physical and mental activity, as well
as on factors not yet understood. But there's no question that proper feeding
primes our brains to reach their fullest potential and maintain their wits for
Everyday nutrients are involved in a dazzling array of sophisticated actions at
tile molecular level. Nevertheless, the latest research on functional foods
highlights six strategic lines of defense on the route from mouth to mind. Some
functional food superstars make use of more than one mechanism.
The Telltale Heart: Jogging the Hind
Food doesn't have to reach your head to improve your memory. "There's getting
to be a general consensus that what is good for your heart is good for your
brain," says lames Joseph, a neuroscientist at the Human Nutrition Research
Center at Tufts University in Massachusetts.
"Your brain accounts for just 2 percent of your body weight, but it eats up
about 20 percent of your oxygen intake. Since it's such a hungry organ, your
brain depends on a strong cardiovascular system to ferry in supplies. Healthy
blood pressure and cholesterol levels keep your arteries clear, leaving them
free to transport nutrients to your brain. Clear arteries also reduce risk of
stroke, which kills neurons when a blocked or ruptured vessel cuts off blood
Any steps you take to improve the delivery of oxygen to your heart--that
two-mile jog, for example--automatically pump up your brain. The steps include
well-known dietary cardiovascular strengtheners like fiber-rich foods, which
lower cholesterol; leafy greens rich in B vitamins and folate, which reduce
levels of vessel-harming homocysteine; omega-3 fatty acids, which may prevent
arrhythrajas; and exercise, which reduces blood pressure, helps control
blood-fat levels and keeps weight in check.
Brain-boosting steps may also include downright counterintuitive measures.
Women who have one alcoholic drink a day--be it wine, beer or that
cosmopolitan--have a much lower risk of cognitive decline than either
teetotalers or heavy drinkers, according to a recent study at the Harvard
School of Public Health. It's the effect of alcohol on your blood. By elevating
levels of "good" cholesterol, thereby lowering the risk of stroke, small
amounts of alcohol may protect both your cardiovascular system and the brain it
Sweet Memory: Oat Cuisine
Your brain is the only organ that draws nearly all its energy from glucose, the
sugar in ripe grapes and honey, for example, and produced in quantity from
pasta and other starchy carbohydrates. That sweet substance also fuels the
formation of sweet memories, or at least reliable ones.
Lab experiments reveal that a dose of glucose-sweetened lemonade boosts recall
of events, words, movements, drawings and faces, among other things, with
effects lasting long enough to get you through a two-hour exam. Other research
extends these findings from doctored drinks to regular food. Any
carbohydrate-rich dish, such as a bagel or a thick slice of bread, may prompt
similar memory enhancements for healthy adults.
While a candy bar provides a burst of brain energy, that flash quickly subsides
and your blood-sugar level plummets, fueling the desire for another ride on the
blood-sugar roller coaster. Both body and brain may do better with foods that
score low on the glycemic index, a rating that measures how fast and how high a
food increases blood glucose levels after it's consumed. Because they surrender
their starches slowly, such fiber-rich foods as barley, beans and Jo March's
oatmeal all provide a steadier--and less fattening-stream of energy than a
Over the long term, less-fattening foods benefit body, blood and brain. A
healthy weight helps prevent diabetes and impaired glucose tolerance,
conditions associated with a decline in cognitive capacity. Compared to
glucose-intolerant adults, people with a well-maintained energy supply hang on
longer to their memories.
Signal Savers: Salmon Tales
Neurons, the main cells in your brain, are a bit like New York City: bustling
with activity but walled off from the outside by rivers and membranes,
respectively. For neurons to survive and contribute to the world, their walls
need to let vital goods pass in and out.
A healthy cell in its prime has a supple membrane that allows important
molecules to cross unimpeded, as if over the Brooklyn Bridge at midnight. As a
cell ages, though, the materials in the membrane stiffen and make it less
pliable. With bridges and tunnels closing down, toll-boothlike receptors on the
surface of the membrane don't collect as many incoming signals from
message-carrying neurotransmitters as they should. You might feel such effects
as sluggishness in learning the new and recalling the old, poor sleep, lowered
pain threshold. Impaired body-temperature regulation could make you
uncomfortable in ordinary settings.
The neuronal membrane is made up primarily of fats, the very same fats that you
fork into your mouth. In fact, your brain has your body's second-highest
concentration of fat, right after actual fatty tissue--think butt and
The kinds of fats in the foods you eat influence the character of your cell
membranes. Cholesterol and saturated fats harden membranes, while essential
polyunsaturated fatty acids--omega-3s and omega-6s--render them supple. A
healthy mix of essential fatty acids seems to enhance learning by facilitating
the smooth passage of signals through neuronal membranes.
Most Americans take in plenty of omega-6 fatty acids, via nearly ubiquitous soy
and corn oils. But the typical American diet lacks sufficient omega-3s, notes
David I. Mostofsky, a neuroscientist at Boston University. Within days after
you add omega-3s to your diet, membranes are rejuvenated in composition.
Salmon and other coldwater fish and (perhaps less appetizingly) algae are rich
sources of the omega-3 fats that your body can utilize directly from
food--known as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).
Walnuts and flaxseed are rich in a related substance, alpha-linolenic acid,
which can be converted more or less efficiently to EPA and DHA in the body.
Human breast milk is rich in all three fatty acids, and DHA provides critical
insulation for an infant's developing nervous system.
Under the direction of Gregory Cole, the Alzheimer's Disease Research Center at
the University of California at Los Angeles is preparing to test whether
omega-3 fatty acids can deter Alzheimer's disease, the number one cause of
cognitive decline. So far, the fats have successfully fended off dementia in
Tests of omega-3s are underway for a variety of other conditions, ranging from
sleep disorders and anxiety, to depression and impaired immune responses.
"Nobody fully understands why they should have so many different functions,"
muses Mostofsky. Perhaps it's because the neuronal membrane controls access to
all other nerve-cell functions.
Power Makers: Meat and Milk
Once nutrients make their way into a neuron, small furnaces within the cells
turn them into energy by combusting glucose and oxygen. The cellular furnaces,
known as mitochondria, create energy less efficiently as you age. As
mitochondria sputter, cells have less energy to power critical activities like
the repair of everyday damage and replication of DNA. The downslide in cell
metabolism likely contributes to the cognitive decline seen with age.
What's more, mitochondria spew cell-damaging free radicals of oxygen into their
environment, and the more they age, the more renegade free radicals they
generate. "It's like an old car engine that's spitting out black smoke,"
explains Bruce Ames, professor of biochemistry and molecular biology at the
University of California at Berkeley.
Give mitochondria a tune-up, reasons Ames, and they'll turn out more energy and
fewer free radicals. He focuses on two food-based mitochondrial boosters:
acetyl-L-carnitine and lipoic acid. Acetyl-L-carnitine, a version of an amino
acid found in meat, milk and avocado, helps shuttle laity acids into
mitochondria. Lipoic acid, found in beef, spinach and broccoli, quenches free
radicals. In cahoots, these compounds in high concentrations combat memory loss
in lab rats, Ames reports. He's testing a combination pill for people.
Another dietary factor--or, more precisely, lack thereof--may beef up
mitochondrial function. Low caloric intake, shown to prolong the life span of
rats, also seems to revive mitochondrial function, perhaps because mitochondria
with fewer nutrients to burn emit fewer free radicals.
It may also do more--promote the growth of entirely new neurons. Mark P
Mattson, chief of the neurosciences lab at the National Institute on Aging and
flag bearer for low-cal research, advises people who are overweight to cut back
on calories. The benefits are less clear for people who are already of normal
Youth Keepers: The Berry Elixir
Along with an increase in free radicals, aging can bring a decrease in the
body's ability to deal with these errant molecules, which have a particular
affinity for attacking cell membranes. And in a vicious cycle, the damage
caused by unchecked free radicals--a.k.a., oxidative stress-ends up compounding
the aging process.
"Every major disease that kills people in this country has an oxidative stress
component," says Joseph of Tufts University. For him and other researchers
interested in preserving the brain's ability to function, oxidative stress
seems like a natural enemy. The scientists also have natural allies: fruits and
vegetables. They contain a whole circus troupe of antioxidants, colorful
substances that arrest free radicals by nullifying their rogue electrons.
Some antioxidants are already familiar faces in nutrition. Vitamins C and E,
for instance, are the main antioxidants in the brain. But they're getting new
respect as potential keepers of brain health, since they appear to guard aging
neuronal membranes from free radicals.
Other antioxidants have only recently stepped into the limelight. Many are
natural chemicals that plants have evolved to protect themselves from disease.
The major antioxidants in plants, known as flavonoids, come in two main
flavors: anthocyanins, in brightly colored fruits, and their colorless cousins,
anthoxanthins, found notably in green tea (epigallocatechins) and soybeans
With a rich load of anthocyanins, the most colorful produce also tends to be
the most potent. Blueberries, blackberries and cranberries offer more
antioxidant protection than the legendarily nutritious brussel sprout. Their
antioxidants also have anti-inflammatory actions, soothing overagitated immune
cells that may hamper brain activity.
In practice, the petite blueberry reverses some of the effects of aging on the
brain, boosting short-term memory and spatial learning--reviving the ability,
of doddery lab rats to move through mazes. People who eat a cup of blueberries
a day perform well on tests of motor skills. Purple grape juice, similarly rich
in flavonoids, similarly boosts performance. Grape juice and red wine also
promise to stave off heart disease, in part because of the activity of another
powerful antioxidant, resveratrol.
The garishly yellow spice turmeric excites researchers beyond its vibrancy of
color. Its active component, curcumin, has both antioxidant and
anti-inflammatory properties; further, it may act as an iron chelator, removing
harmful buildup of metal associated with neurodegenerative diseases. Recent lab
tests suggest that it directly targets the brain plaques linked to Alzheimer's
disease. "It's binding to the supposedly toxic stuff," and disarms it, explains
Greg Cole of UCLA.
Adding to the excitement surrounding the flashy turmeric seed, Cole is
currently evaluating the effectiveness of curcumin as an Alzheimer's treatment.
His trials may help explain why India, where turmeric commonly tints curry
dishes, has a particularly low rate of Alzheimer's.
Whether hot curry dishes or cool glasses of juice, whole foods may hold on to
nutrient benefits that concentrated supplements cannot. "There is some evidence
that the vitamins from food are more efficient," says D. Allan Butterfield, a
biochemist at the Sanders-Brown Center on Aging at the University of Kentucky.
Signs of Success: Eggheads
Some of the latest research in nutrition zeroes in on the classiest work of the
brain: learning and remembering.
Nutrients provide the building blocks of neurotransmitters, the chemicals that
carry messages between brain cells--messages like "Grow" or "Pssst, pass this
on." Both glucose and vitamin B1, for instance, feed production of
acetylcholine, a neurotransmitter that appears to play a large role in memory
formation. Adequate amounts of B1, as well as the other B vitamins, are
necessary for everyday brain health.
Still, upping levels of nutrients may boost specific neurotransmitters in your
brain, abetting the cell-to-cell signaling that delivers, say, a memory to
mind. "If I give you more choline [a fatlike essential nutrient related to the
B vitamins, found in eggs, liver and soybeans], your brain cells will
immediately make more acetylcholine," says Richard Wurtman, professor of
neuropharmacology and director of the Clinical Research Center at Massachusetts
Institute of Technology. In lab rats a surge in acetylcholine leads to memory
improvements a month later. Normal human brain function requires adequate
intake of choline, but it's not clear whether extra choline brings extra
cognitive benefits--although, interestingly, Alzheimer's patients show
drastically reduced acetylcholine levels.
Some familiar antioxidants may also boost learning by abetting the signaling
that takes place inside brain cells and modulating the expression of genes,
influencing the survival and growth of nerve cells. Blueberries appear to help
rat brains from within, in ways that even surpass their antioxidant activity,
says scientist Joseph of Tufts University.
Green tea may similarly protect neurons through related signaling mechanisms.
Both edibles are still under investigation, since cell signaling ranks among
the newest frontiers at the intersection between nutrition and neuroscience.
As hot as the frontier now is, it turns out that the idea that food may be our
brain's best medicine isn't novel at all. Jo March, the oatmeal muse who
altered my eating habits for life, got there well before the scientists. "Don't
worry, my dear," she says in Jo's Boys. "That active brain of yours was
starving for good food; it has plenty now."
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