To Improve Memory, Tune It Like an Orchestra

To Improve Memory, Tune It Like an Orchestra

Anyone above a certain age who has drawn a blank on the name of a favorite uncle, a friend’s phone number or the location of a house key understands how fragile memory is. Its speed and accuracy begin to slip in one’s 20s and keep slipping. This is particularly true for working memory, the mental sketch pad that holds numbers, names and other facts temporarily in mind, allowing decisions to be made throughout the day.

On Monday, scientists reported that brief sessions of specialized brain stimulation could reverse this steady decline in working memory, at least temporarily. The stimulation targeted key regions in the brain and synchronized neural circuits in those areas, effectively tuning them to one another, as an orchestra conductor might tune the wind section to the strings.

The findings, reported in the journal Nature Neuroscience, provide the strongest support yet for a method called transcranial alternating current stimulation, or tACS, as a potential therapy for memory deficits, whether from age-related decline, brain injury or, perhaps, creeping dementia.

In recent years, neuroscientists have shown that memory calls on a widely distributed network in the brain, and it coordinates those interactions through slow-frequency, thrumming rhythms called theta waves, akin to the pulsing songs shared among humpback whales. The tACS technology is thought to enable clearer communication by tuning distant circuits to one another.

The tACS approach is appealing for several reasons, perhaps most of all because it is noninvasive; unlike other forms of memory support, it involves no implant, which requires brain surgery. The stimulation passes through the skull with little sensation. Still, a widely available therapy is likely years away, as the risks and benefits are not fully understood, experts said.

“This study suggests that age-related impairment in one particular form of short-term memory largely reflects a failure of synchronization,” said Michael Kahana, a brain scientist at the University of Pennsylvania who was not involved in the research. If the technique can boost other forms of memory, “it could be a game changer for the treatment of age-related memory decline and possibly even dementia,” Dr. Kahana said.

In the new study, Robert M.G. Reinhart and John A. Nguyen, neuroscientists at Boston University, invited two groups of subjects, young adults and people in their 60s and 70s, to the lab for baseline measures of their neural firing rhythms. The scientists tailored the tACS program to optimize rhythmic “coupling” between frontal and temporal cortex areas in each individual’s brain. These brain regions specifically support working memory.

After 25 minutes of gentle stimulation, delivered by electrodes built into a skullcap, the older subjects performed just as well on memory tests as young adults.

The participants tested their own working memories repeatedly, completing 10 sessions on a computer-based program that mimicked the old Highlights magazine game: stare at an image, then decide if subsequent images are identical or have subtle differences.

They performed under several conditions, including without stimulation; with “sham” stimulation, as a placebo control, and with the targeted tACS. The results were striking. Young people reliably outperformed their elders in the no-stimulation and sham conditions. But with the aid of the tACS, the older participants did just as well as their younger counterparts. And their working memory remained sharp for as long as the researchers continued testing it, for 50 minutes.

“We show here that working-memory decline in people in their 60s and 70s is due to brain circuits becoming uncoupled, or disconnected,” said Dr. Reinhart, in a call with reporters. He added that the findings “show us that negative, age-related changes in working memory are not unchangeable. We can bring back the superior function you had when you were much younger.”

The tACS tuning prompted greater improvements in older people than in younger ones, the study found, which suggests that the tool is more a corrective than an enhancer of memory. In another experiment, Dr. Reinhart and Dr. Nguyen found that, by using the tACS technology to decouple key brain regions, they could temporarily muddle the working memory of young participants.

The new findings come at a time when increasing numbers of people are experimenting with brain stimulation at home, placing electrodes on different areas of their skull, depending on how they’re feeling. They share tips online about how best to use stimulation when feeling depressed, or impulsive, or mentally foggy — with mixed results. Experts said that the sort of stimulation used in the new study is far from a do-it-yourself approach.

“Reinhart and Nguyen use a very complex, sophisticated system here in a very carefully controlled environment,” Bradley Voytek, a neuroscientist at the University of California, San Diego, said in an email. “Do not try this at home! This is a promising start, not a panacea for memory problems.”



This article was originally published in The New York Times. Read the original article.

The Right Diet for a Runner Is the One That Works for You

The Right Diet for a Runner Is the One That Works for You

Earlier this week, I read an article about what runners should eat while training for a 10-mile race. One piece of advice it offered: Take a banana and bagel to eat before the start of the race.

I don’t mind bananas. I have a bunch of them in my kitchen. But the few times I’ve eaten one before running, I tasted leftover banana for the entire run. Gross. I’d much rather drink a glass of whole milk before a run (which I’m sure has some of you thinking “gross!” too).

That’s because there is no one runner diet. There are no absolutes except that you’ll probably want to eat something if you’re going to run for a long time. That was the big challenge of writing our How to Feed a Runner Guide, which is why it’s more about setting up guidelines to help you figure out what works for you than dictating absolutes. I didn’t want to declare that one way is the right way when there are as many right ways as there are runners.

It’s not a finite process, either. I’ve been running for more than a decade and I’m still experimenting. While writing the guide, one expert suggested eating dates for pre-run fuel, so I tried it. That worked, but then I tried dried apricots, which I liked better. When my nephews did not finish all of the Wegmans animal cookies I had gotten for them to eat on a vacation, I tried a few before a five-mile run, and now they’re a pre-run staple. And there’s nothing I love more than nonalcoholic peach cider after a long, hot summer run.

But that’s me. That may not be you. The only way to figure out what works for you is to try things out — and long before race day, so you know whether a banana before a race is a good idea for you, or makes you say “gross!” like it does for me.



This article was originally published in The New York Times. Read the original article.

Is the Saturated Fat in Chocolate as Bad as the Fat in Meat?

Is the Saturated Fat in Chocolate as Bad as the Fat in Meat?

Q. Eating dark chocolate is encouraged for its health benefits. I’ve been buying chocolate with 75 percent to 90 percent cocoa content. But the label notes a high amount of saturated fat. Is this as harmful as the saturated fat in meat?

A. The fat in chocolate is not as harmful as the fat in meat, said Alice Lichtenstein, director of the Cardiovascular Nutrition Laboratory at the Jean Mayer U.S.D.A. Human Nutrition Research Center on Aging at Tufts University. It comes from cocoa butter and is made of equal parts of oleic acid, a heart healthy monounsaturated fat found in olive oil, and stearic and palmitic acids. Stearic and palmitic acids are forms of saturated fat, which has been linked to heart disease, but stearic acid does not raise cholesterol, and palmitic fat makes up only a third of the fat in chocolate. (Beef has proportionately more palmitic fat.)

The cocoa bean is also rich in flavonoids, nutrients found in many fruits and vegetables that protect plants from toxins and that, as antioxidants, repair cellular damage from free radicals. The flavonoids in cocoa and chocolate, called flavanols, may also lower blood pressure, improve circulation to the brain and heart, and make platelets less likely to clot. Unlike dark chocolate, milk chocolate has little of one crucial flavanol, epicatechin, left in it after processing.

One study that garnered a lot of attention, sponsored in part by the candy company Mars, found that older adults who consumed a drink rich in cocoa flavanols for three months performed better on a memory test than others who drank a low-flavanol mix.

But don’t eat chocolate thinking it’s a health food, Dr. Lichtenstein said. The benefits in it, known as phytochemicals, are present in many plant foods, and chocolate is high in calories. In the memory study, for example, older adults consumed the equivalent of 300 grams of dark chocolate a day, which typically would contain about a day’s worth of calories. A serving (three squares, 30 grams) of Lindt’s Excellence Dark Noir chocolate with 70 percent cacao contains 170 calories and 12 grams of fat, of which 7 grams is saturated fat

“It’s unlikely that someone could consume enough dark chocolate on a regular basis to have a biological effect and still have an adequate diet,” said Dr. Lichtenstein, adding that it would be “unfortunate” if someone ate dark rather than milk chocolate in anticipation of a specific health benefit. “I don’t think we have adequate evidence,” she said. “If somebody enjoys chocolate, they should eat a small to moderate amount of whatever chocolate they prefer.”



This article was originally published in The New York Times. Read the original article.

The Heart of a Swimmer vs. the Heart of a Runner

The Heart of a Swimmer vs. the Heart of a Runner

Do world-class swimmers’ hearts function differently than the hearts of elite runners?

A new study finds that the answer may be yes, and the differences, although slight, could be telling and consequential, even for those of us who swim or run at a much less lofty level.

Cardiologists and exercise scientists already know that regular exercise changes the look and workings of the human heart. The left ventricle, in particular, alters with exercise. This chamber of the heart receives oxygen-rich blood from the lungs and pumps it out to the rest of the body, using a rather strenuous twisting and unspooling motion, as if the ventricle were a sponge being wrung out before springing back into shape.

Exercise, especially aerobic exercise, requires that considerable oxygen be delivered to working muscles, placing high demands on the left ventricle. In response, this part of the heart in athletes typically becomes larger and stronger than in sedentary people and functions more efficiently, filling with blood a little earlier and more fully and untwisting with each heartbeat a bit more rapidly, allowing the heart to pump more blood more quickly.

While almost any exercise can prompt remodeling of the left ventricle over time, different types of exercise often produce subtly different effects. A 2015 study found, for instance, that competitive rowers, whose sport combines endurance and power, had greater muscle mass in their left ventricles than runners, making their hearts strong but potentially less nimble during the twisting that pumps blood to muscles.

These past studies compared the cardiac effects of land-based activities, though, with an emphasis on running. Few have examined swimming, even though it is not only a popular exercise but unique. Swimmers, unlike runners, lie prone, in buoyant water and hold their breaths, all of which could affect cardiac demands and how the heart responds and remakes itself.

So, for the new study, which was published in November in Frontiers in Physiology, researchers at the University of Guelph in Canada and other institutions set out to map the structure and function of elite swimmers’ and runners’ hearts.

The researchers focused on world-class performers because those athletes would have been running or swimming strenuously for years, presumably exaggerating any differential effects of their training, the researchers reasoned.

Eventually they recruited 16 national-team runners and another 16 comparable swimmers, male and female, some of them sprinters and others distance specialists.

They asked the athletes to visit the exercise lab after not exercising for 12 hours and then, when on site, to lie quietly. They checked heart rates and blood pressures and finally examined the athletes’ hearts with echocardiograms, which show both the structure and functioning of the organ.

It turned out, to no one’s surprise, that the athletes, whether runners or swimmers, enjoyed enviable heart health. Their heart rates hovered around 50 beats per minute, with the runners’ rates slightly lower than the swimmers’. But all of the athletes’ heart rates were much lower than is typical for sedentary people, signifying that their hearts were robust.

The athletes also had relatively large, efficient left ventricles, their echocardiograms showed.

But there were interesting if small differences between the swimmers and runners, the researchers found. While all of the athletes’ left ventricles filled with blood earlier than average and untwisted more quickly during each heartbeat, those desirable changes were amplified in the runners. Their ventricles filled even earlier and untwisted more emphatically than the swimmers’ hearts did.

In theory, those differences should allow blood to move from and back to the runners’ hearts more rapidly than would happen inside the swimmers’.

But these differences do not necessarily show that the runners’ hearts worked better than the swimmers’, says Jamie Burr, a professor at the University of Guelph and director of its human performance lab, who conducted the new study with the lead author, Katharine Currie, and others.

Since swimmers exercise in a horizontal position, he says, their hearts do not have to fight gravity to get blood back to the heart, unlike in upright runners. Posture does some of the work for swimmers, and so their hearts reshape themselves only as much as needed for the demands of their sport.

The findings underscore how exquisitely sensitive our bodies are to different types of exercise, Dr. Burr says.

They also might provide a reason for swimmers sometimes to consider logging miles on the road, he says, to intensify the remodeling of their hearts.

Of course, the athletes here were tested while resting, not competing, he says, and it is not clear whether any variations in their ventricles would be meaningful during races.

The study also was cross-sectional, meaning it looked at the athletes only once. They might have been born with unusual cardiac structures that somehow allowed them to excel at their sports, instead of the sports changing their hearts.

Dr. Burr, however, doubts that. Exercise almost certainly remakes our hearts, he says, and he hopes future experiments can tell us more about how each activity affects us and which might be best for different people.

But even now, he says, “an important message is that all of the athletes showed better function than a normal person off the street, which supports the message that exercise is good for hearts.”


This article was originally published in The New York Times. Read the original article.

Sydney Brenner, a Decipherer of the Genetic Code, Is Dead at 92

Sydney Brenner, a Decipherer of the Genetic Code, Is Dead at 92

Sydney Brenner, a South African-born biologist who helped determine the nature of the genetic code and shared a Nobel Prize in 2002 for developing a tiny transparent worm into a test bed for biological discoveries, died on Friday in Singapore. He was 92.

He had lived and worked in Singapore in recent years, affiliated with the government-sponsored Agency for Science, Technology and Research, which confirmed his death.

A witty, wide-ranging scientist, Dr. Brenner was a central player in the golden age of molecular biology, which extended from the discovery of the structure of DNA in 1953 to the mid-1960s. He then showed, in experiments with a roundworm known as C. elegans, how it might be possible to decode the human genome. That work laid the basis for the genomic phase of biology.

Later, in a project still coming to fruition, he focused on understanding the functioning of the brain.

“I think my real skills are in getting things started,” he said in his autobiography, “My Life in Science” (2001). “In fact, that’s what I enjoy most, the opening game. And I’m afraid that once it gets past that point, I get rather bored and want to do other things.”

As a young South African studying at Oxford University, he was one of the first people to view the model of DNA that had been constructed in Cambridge, England, by Francis H. C. Crick and James D. Watson. He was 22 at the time and would call it the most exciting day of his life.

“The double helix was a revelatory experience; for me everything fell into place, and my future scientific life was decided there and then,” Dr. Brenner wrote.

Impressed by Dr. Brenner’s insights and ready humor, Dr. Crick recruited him to Cambridge a few years later. Dr. Crick, a theoretical biologist, liked to have with him someone he could bounce ideas off. Dr. Watson had played this role in the discovery of DNA, and Dr. Brenner became his successor, sharing an office with Dr. Crick for 20 years at the Medical Research Council Laboratory of Molecular Biology at Cambridge.

The fundamental elements of molecular biology were uncovered during this period, many of them by Dr. Crick or Dr. Brenner. Their chief pursuit for 15 years was to understand the nature of the genetic code.

Dr. Brenner, left, received the Nobel Prize from King Carl Gustaf of Sweden at the Concert Hall in Stockholm in December 2002. Dr. Brenner shared it with two other scientists and believed he had deserved a second Nobel, for his work on the decoding of DNA.CreditHenrik Montgomery, via Associated Press
Dr. Brenner, left, received the Nobel Prize from King Carl Gustaf of Sweden at the Concert Hall in Stockholm in December 2002. Dr. Brenner shared it with two other scientists and believed he had deserved a second Nobel, for his work on the decoding of DNA.CreditHenrik Montgomery, via Associated Press

Dr. Brenner made a decisive contribution to solving the code with an ingenious series of experiments in which he altered the DNA of a virus that attacks bacteria.

He showed that by making a series of three mutations, the virus would first lose, then regain, its ability to make a certain protein, as if the cell’s reading of the DNA “tape” had come back into correct phase. The experiment showed that DNA is a triplet code, with each group of three DNA letters specifying one of the 20 kinds of amino acids of which proteins are composed. Dr. Brenner gave these triplets the name codon.

Other researchers were then able to figure out which codon specified each of the 20 amino acids. It fell to Dr. Brenner to identify two of the three triplets that signal “Stop” to the cell’s protein-making machinery.

Dr. Brenner was also the first to conclude that there must be some means for copying the information in DNA and conveying it to the cellular organelles that manufacture proteins. That intermediary, now known as messenger RNA, was discovered in 1960 in an experiment devised by Dr. Brenner and others.

With the fundamental problems of molecular biology solved, as they saw it, Dr. Brenner and Dr. Crick looked for new areas of inquiry. Dr. Brenner decided to approach the brain, but he realized he needed a simpler animal to study than the fruit fly, a standard organism used in laboratories.

He settled on Caenorhabditis elegans, or C. elegans, a tiny, transparent roundworm that dwells in the soil, eats bacteria and completes its life cycle in three weeks. That worm has spun off many developments, starting with the decoding of the human genome.

Using the worm, Dr. Brenner and his colleagues first worked out methods for breaking a genome into fragments, multiplying each fragment in a colony of bacteria, and then decoding each cloned fragment with DNA sequencing machines. His colleagues John Sulston and Robert Waterston completed the worm’s genome in 1998, and they and others used the same methods to decode the human genome in 2003.

Another major project, made possible because of the worm’s transparency, was to track the lineage of all 959 cells in the adult worm’s body, starting from the single egg cell. This feat, accomplished so far for no other animal, made clear that many cells are programmatically killed during development, leading to the discovery by H. Robert Horvitz of the phenomenon of programmed cell death.

The topic assumed an importance that transcended worm biology when it emerged that programmed cell death is supposed to occur in damaged human cells, and that cancer can thwart this process.

For their work on programmed cell death, Dr. Brenner, Dr. Sulston (who died last year) and Dr. Horvitz were awarded the Nobel Prize in Physiology or Medicine in 2002. But many people, including Dr. Brenner himself, believed he should have been awarded a Nobel much earlier for his and Dr. Crick’s work on the genetic code.

Dr. Brenner, seated second from right, with other 1971 winners of the prestigious Lasker Award in medical science. The others, from left, are the medical researcher Edward D. Freis and the geneticists Seymour Benzer and Charles Yanofsky. At rear are the heart surgeon Dr. Michael E. DeBakey, who was chairman of the Lasker jury, and Mary Lasker, president of the Albert and Mary Lasker Foundation.CreditEddie Hausner/The New York Times

Dr. Brenner, seated second from right, with other 1971 winners of the prestigious Lasker Award in medical science. The others, from left, are the medical researcher Edward D. Freis and the geneticists Seymour Benzer and Charles Yanofsky. At rear are the heart surgeon Dr. Michael E. DeBakey, who was chairman of the Lasker jury, and Mary Lasker, president of the Albert and Mary Lasker Foundation.CreditEddie Hausner/The New York Times

“On more than one occasion, in fact, he has claimed that he is delighted to have been awarded two Nobel Prizes — the first he never received!” his biographer, Errol C. Friedberg, wrote.

Sydney Brenner was born to Jewish immigrants in Germiston, a small town near Johannesburg, on Jan. 13, 1927. His father, Morris, a cobbler who could not read or write, had fled Lithuania to escape conscription in the czar’s army. His mother, Leah (Blecher) Brenner, was an émigré from Latvia.

Sydney was taught to read by a neighbor. When a customer at his father’s shop learned that Sydney, at age 4, could read English fluently but that his father could not afford to send him to school, the customer paid the boy’s tuition.

At 15, Sydney won a scholarship to study medicine at the University of the Witwatersrand in Johannesburg. The scholarship covered only his fees, but he managed to afford university life by earning the equivalent of five cents a day by attending synagogue to help form a minyan, the quorum of 10 men required for public prayer.

During his medical training he became interested in scientific research while growing disenchanted with clinical medicine. After finishing medical school in 1951, he won a scholarship to Oxford to work on bacteriophages, the viruses that attack bacteria.

The scholarship required him to return to South Africa. In 1952, he married a fellow South African, May (Covitz) Balkind, who was divorced and had a son by an earlier marriage. She went on to a career as an educational psychologist, and she and Dr. Brenner had three children of their own.

Dr. Crick was eventually able to find Dr. Brenner a post in Cambridge, and in 1956 he returned with his family to England for good.

Dr. Crick, a physicist by training, was a theoretician, but Dr. Brenner was deeply interested in the practice of biology as well. He loved the laboratory, and he loved designing elegant experiments. As a student in South Africa, he had built his own centrifuge. If he had wanted to stain a cell, he first had to synthesize the dye.

At Oxford, “he threw himself into bacteriophage research with the energy of a man digging a tunnel out of prison,” Horace Freeland Judson wrote in “The Eighth Day of Creation” (1979), a history of molecular biology.

Dr. Brenner’s most ambitious project after the genetic code — understanding the brain of the worm — was in a formal sense a failure. His colleague John White, after a decade peering through a microscope, established that the worm’s brain consists of 302 neurons, with more than 7,000 connections between them. But the job of then computing the worm’s behavior, which was Dr. Brenner’s goal, has so far proved too daunting.

Dr. Brenner at home in the La Jolla section of San Diego in 2003. For many years he divided his time between California and Cambridge, England, before taking up permanent residence in Singapore.CreditRobert Burroughs

Dr. Brenner at home in the La Jolla section of San Diego in 2003. For many years he divided his time between California and Cambridge, England, before taking up permanent residence in Singapore.CreditRobert Burroughs

Dr. Brenner’s wife died in 2010. His survivors include their three children, Belinda, Carla and Stefan. His stepson, Jonathan Balkind, died last year.

In the early 1990s, Dr. Brenner went to work at the Scripps Research Institute in San Diego on a fellowship. In 1996, with a multimillion-dollar grant from the Philip Morris Company, he established and directed the nonprofit Molecular Sciences Institute in Berkeley, with a mission, in part, to track research in various genome sequencing projects.

From 1994 to 2000 he wrote an opinion column for the journal Current Biology. He originally called it Loose Ends but later changed the name to False Starts when it was moved to the front of the publication.

Among his many honors, besides the Nobel, was the prestigious Lasker Award in medical science, given to him in 1971.

Dr. Brenner held positions at Cambridge and at the Salk Institute in San Diego, where he was appointed, as he termed it, “extinguished professor.”

He had divided his time between Cambridge and California until, with his health declining, he took up permanent residence in Singapore while working as an adviser to the research agency. In 2003 he was named an honorary citizen of Singapore. He had been advising the Singapore government on science policy since the 1980s and was instrumental in the founding of the Molecular Engineering Laboratory there.

British and Singaporean news organizations said that Dr. Brenner, a former heavy smoker, had been treated for lung disease in recent years.

Known for his wit, Dr. Brenner boasted that aside from science, “the other thing I’m rather good at is talking.”

It was hard for any listener not to fall under his spell. He spoke slowly and precisely in a lingering South African accent, his sentences long and perfectly constructed and often ending with a joke. Insights into the nature of the cell would alternate with his playful inventions, like Occam’s broom — “to sweep under the carpet what you must to leave your hypotheses consistent” — or Avocado’s number, “the number of atoms in a guacamole.”

For a short time he had been director of the Cambridge Laboratory of Molecular Biology, but he did not much enjoy working as an administrator.

“You become a mediator between two impossible groups,” he said, “the monsters above and the idiots below.”

This article was originally published in The New York Times. Read the original article.

Are My Allergies All in My Head?

Are My Allergies All in My Head?

Q. Are my allergies all in my head?

A. No. But emotional factors can make allergies better or worse.

Doctors have long suspected a connection between allergies and the psyche. In 1883, Dr. Morell Mackenzie, a pioneer in the field of ear, nose and throat medicine, observed, “It has long been noticed that attacks of prolonged sneezing are most apt to occur in persons of nervous temperament.”

In the 1940s, doctors discovered that allergic patients could be tricked into experiencing allergy attacks. In one case, a doctor exposed a patient to a goldenrod plant, without telling the patient that the plant was artificial. The patient immediately developed sneezing, runny nose and nasal congestion. These symptoms resolved quickly once the doctor revealed his deception to the patient.

Observations such as this stimulated interest in hypnosis as a possible treatment for allergies. In 1958, the prestigious medical journal The Lancet reported a case of a woman whose allergies were cured by hypnosis. But initial enthusiasm for this technique waned after other doctors were unable to replicate these results. Eventually, hypnosis was abandoned as a treatment for allergies.

Still, doctors continued to note a high incidence of apparently psychosomatic symptoms among allergic patients. In a British survey of more than 10,000 people conducted in the 1990s, for example, 20 percent indicated that they developed itching, hives and other allergic symptoms in response to various foods. But fewer than 2 percent reacted to these foods on formal skin testing.

Placebo studies have proven uniquely useful in differentiating psychic symptoms from allergic ones. In 2011, investigators studied the effect of placebo inhalers in patients with mild-to-moderate asthma, a condition that frequently coexists with allergies. They found that patients perceived the same degree of relief with the placebo inhaler as they did with the actual asthma inhaler. Yet, their lung function tests improved only with the active medication.

2018 German study confirmed the effectiveness of placebos in patients with allergic rhinitis, the medical name for hay fever. Allergic symptoms such as itching, sneezing and runny nose improved even though the patients were aware that they were receiving a placebo.

What is one to conclude from all these studies? First, while emotions and psychological stress do not cause allergies, they can worsen symptoms. Next, while mind-body techniques may be useful adjuncts in easing symptoms, they are not sufficient to treat the underlying problem. Finally, placebo studies show the physician-patient relationship itself can be therapeutic. Maintaining a close relationship with a doctor you like may be one of the best way to maximize the benefits of allergy drugs and therapies.

This article was originally published in The New York Times. Read the original article.