Source: Nature

 

 

Modifying an Old Technique: Researchers have developed a method to more reliably produce human embryonic stem cells, though the resulting cells have serious drawbacks.

 

 

The New York Times, by Nicholas Wade, October 6, 2011  —  Stem cell research has had many ups and downs, but a stream of setbacks had left researchers almost back at square one.

 

Now, researchers at the New York Stem Cell Foundation Laboratory have developed a method that may help recover the lost ground.

Embryonic stem cells can generate all the tissues of the body. So if such cells could be developed from a patient’s adult cells, it might be possible to make replacement cells for any diseased tissue without fear of rejection.

At first, it seemed that embryonic stem cells could be made by implanting the nucleus of a patient’s adult cell into an unfertilized human egg, or oocyte, whose nucleus had been removed. Mysterious factors in the body of the egg instruct the adult cell how to lose its specialist nature and revert to the embryonic state, where all fates are open to it.

But the method is highly inefficient and would require tens or hundreds of oocytes for each patient. A major advance was made in 2007 when Shinya Yamanaka found a way of avoiding all use of human oocytes.

He guessed how the oocyte reprograms the inserted nucleus, and showed that by injecting just four protein factors into a patient’s adult cell he could make it revert to the embryonic state. Cells made by Dr. Yamanaka’s method are called induced pluripotent stem cells, or iPS cells. At first they seemed identical, as hoped, to the embryonic cells made with the oocyte method.

But as researchers examined them more closely, they found more and more abnormalities, making the cells unsuitable for therapeutic use. In particular, iPS cells seem to retain a memory, in the form of chemical signals in the material that controls their DNA, of their previous identity. This memory trace would prevent them from morphing into other types of cell as required.

A team led by Scott Noggle and Dieter Egli of the New York Stem Cell Foundation has now gone back to the basics by trying to improve on the original method of using oocytes to generate patient-derived embryonic stem cells.

By a lucky accident as part of a control experiment, they left an oocyte’s nucleus in place when they implanted an adult nucleus. They noticed that in the presence of the oocyte nucleus, embryos with an inserted adult cell nucleus developed much further than usual. They progressed, in fact, to the blastocyst stage, the point at which embryonic stem cells can be harvested, the researchers report in the Wednesday issue of Nature.

With several species, including mice and cows, the cells easily reach the blastocyst stage, and from there the donor can be cloned when the blastocyst is implanted in a uterus. But despite all the worry about cloning humans, it has in fact been almost impossible to coax human oocytes with an implanted nucleus to progress to the blastocyst stage. The New York researchers say they have been unable to repeat the one such claim that has been published so far.

The blastocysts produced by the New York method are triploid, meaning they have the normal diploid, or double genome, of the inserted adult cell plus the single genome of the oocyte. Triploid cells are unstable and possibly cancerous and could never be injected into patients. Moreover, the process is too inefficient for therapeutic use — 63 oocytes were required to generate one normal set of embryonic cells.

“These cells are not therapeutically relevant at the moment,” Dr. Noggle said.

Their relevance is for research, to study the process of blastocyst development and in particular to explore why the iPS cells produced by Dr. Yamanaka’s method are imperfectly reprogrammed. It may be that other factors are required besides the four identified by Dr. Yamanaka. If these were to be identified, the iPS cells could be put back on track as a starting point for therapy. There would still remain many difficult steps, like ensuring that cells that are generated to repair the patient’s tissue are correctly programmed, well behaved and noncancerous.

Dr. Noggle and Dr. Egli also hope to adapt their method to produce usable patient-derived blastocysts. If the human oocyte nucleus is taken out too early, it apparently fails to provide enough of the factors needed to reprogram the nucleus. If it is left in beyond the first cell division, it fuses with the inserted nucleus and cannot be removed. It may be possible to yank it out at the last possible minute, when it has done a sufficient reprogramming job, and obtain a normal diploid blastocyst formed from the patient’s own cells.

The research “stands as a steppingstone toward success,” Dr. George Q. Daley, a stem cell expert at Children’s Hospital Boston, writes in a commentary in Nature. It also raises the “provocative question,” he says, of whether patient-derived embryonic cells made the old-fashioned way with oocytes might perform better than iPS cells.

The New York Stem Cell Foundation researchers had the advantage of access to plentiful oocytes because they worked with a Columbia University program that pays donors $8,000. Many ethicists fear that paying donors will lead to a market in organs, and they had hoped that enough oocytes would be donated for free. The National Academy of Sciences has issued stem cell guidelines saying that donors should not be paid.

But oocyte donation is an arduous process, and stem cell researchers in many states have been unable to find enough volunteers for their experiments to proceed. Since 2009, New York State has allowed donors to receive reasonable compensation for eggs donated for stem cell research.

 

Sigmund Freud MD, the father of “Talk Therapy”

 

Using sophisticated brain imaging, researchers have found that when a person looks at a visual pattern their brain “sings” — i.e., produces an electrical signal at a set frequency. (Credit: iStockphoto/Hayden Bird)

 

 

 

The New York Times, October 5, 2011, by Benedict Carey  —  People with severe schizophrenia who have been isolated, withdrawn and considered beyond help can learn to become more active, social and employable by engaging in a type of talk therapy that was invented to treat depression, scientists reported on Monday.

 

These new findings suggest that such patients have far more capability to improve their lives than was previously assumed and, if replicated, could change the way that doctors treat the one million patients for whom the disorder is profoundly limiting.

The therapy — a variant of cognitive behavior therapy, which focuses on defusing self-defeating assumptions — increased motivation and reduced symptoms. In previous studies, researchers have used cognitive techniques to help people with schizophrenia manage their hallucinations and sharpen their attention and memory. The new study is the first to rigorously test using the therapy to combat so-called negative symptoms — the listlessness, exhaustion and emotional flatness that trap many people in solitary lives, playing out their days smoking in front of the TV or holed up in their homes.

Dr. Bob Buchanan, a psychiatrist at the University of Maryland School of Medicine who was not involved in the study, said the results looked impressive. “This is a group of patients who have tried just about everything — drug treatments as well as psychosocial ones — and many clinicians and systems of care have essentially given up on them. If there’s an intervention out there that can make a difference, I think that’s an incredibly important development.”

In the study, appearing in the current issue of The Archives of General Psychiatry, researchers at the University of Pennsylvania enrolled 31 people from community health clinics in Philadelphia in a therapy program that included weekly sessions, each about an hour in length, in addition to their normal medication regimen. Each person set a goal, whether to find a job, start a relationship or go back to school. Aided by the therapist, the person then took incremental steps toward that goal, going out for coffee, visiting a local bookshop or volunteering at a community center.

“It took a long time to get patients engaged,” said Dr. Aaron T. Beck, a psychiatrist and one of the authors. “We used video games a lot at the beginning, just to give them a sense of some mastery.” Dr. Beck invented cognitive therapy decades ago, about the same time another therapist, Albert Ellis, was developing similar techniques.

The therapists in the study, all either psychiatrists or Ph.D.’s, all working from manuals guiding the technique, helped their patients correct self-defeating beliefs, like “taking even a small risk is foolish because the loss is likely to be a disaster,” and “making new friends isn’t worth the energy it takes.” After about six months, the patients began to show measurable improvement. After 18 months the benefit was clear, on the Global Assessment Scale, a standard scale tracking overall functioning.

“They made a jump of about 10 points on that scale, on average, which we consider to be moving a whole level up in terms of functioning,” said Paul M. Grant, the study’s lead author. A comparison group of 29 patients who received standard treatment — medication, and case management services as needed — showed no such improvement.

Dr. Grant’s co-authors were Gloria A. Huh, and Dr. Neal M. Stolar, along with Dr. Beck, of the University of Pennsylvania, and Dimitri Perivoliotis for the Veterans Affairs San Diego Healthcare System.

Measures of emotional vitality and sociability were not changed much. But motivation improved significantly, and some who got the cognitive therapy altered their lives for the better, in significant ways. One woman, who had been frequently hospitalized before the study, began making coffee at the clinic as a part of therapy, then took her cart to a community clinic, parlaying that into a job as a cook. She has not returned to the hospital since.

Still, the course of therapy was extraordinarily long compared with what is usually offered. A standard course for depression lasts three or four months. That may make the approach difficult for strapped institutions to provide, some experts said. And it is not clear whether community therapists will be as effective as the University of Pennsylvania’s highly trained team.

“You have to understand that this is not like therapy for depressives,” who usually get better sooner or later anyhow, Dr. Beck said. “These people do not get better; no one had any good therapy for them.”

 

 

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The scientists, at UCLA and the National Institute of Mental Health, employed magnetic resonance imaging (MRI) technology to scan a group of teenagers repeatedly as they developed schizophrenia. Using a new image analysis method that detects very fine changes in the brain, the scientists detected gray matter loss of more than 10 percent first in the parietal, or outer, regions of the brain; this loss spread to engulf the rest of the brain over five years.

Patients with the worst brain tissue loss also had the worst symptoms, which included hallucinations, delusions, bizarre and psychotic thoughts, hearing voices, and depression. Schizophrenia affects an estimated 1 percent of Americans. Its causes are unknown, and the disease typically hits without warning in the late teens or 20s.

Following is a selection of some of the pictures produced by the UCLA Laboratory of Neuro Imaging that show the impact of schizophrenia on the brain. For the full Press release and related press and journal articles go to: UCLA Researchers Map How Schizophrenia Engulfs Teen Brains

 

 

Mapping Brain Tissue Loss in Adolescents with Schizophrenia. This map reveals the 3-dimensional profile of gray matter loss in the brains of teenagers with early-onset schizophrenia, with a region of greatest loss in the temporal and frontal brain regions that control memory, hearing, motor functions, and attention. Using novel image analysis algorithms, dramatic reductions in the profiles of gray matter were detected, based on a database of 96 images from schizophrenic patients scanned repeatedly with MRI. The parallel extraction of anatomical models from all patients in the image database required 60 CPU hours, when running in parallel on an SGI RealityMonster with 32 internal CPUs. [Image by Paul Thompson, Christine Vidal, Judy Rapoport, and Arthur Toga].

 

Image 1. Frontal composite variability of normal and schizophrenia brains by gender

 

 

Image 2. Normal control vs. schizophrenia – Composite variability of 15 male subjects

 

 

Image 3. Volume of interest (VOI) superimposed over 3 orthagonal slices of the averaged schizophrenic brain

This is a technique used to compare the volume of different areas of the normal control brain to a brain that has schizophrenia. Note the volume is simply a sphere with 60mm radius centered halfway between the midline decussations of the anterior and posterior commissures.

 

 

Image 4. Cortical surface variability maps. Variability maps of cortical surface and sulcal anatomy in normal controls (n = 28; 15 males) and schizophrenic patients (n =25; 15 males) showing the both hemispheres. The color bar indicates patterns of variability in each group as the root mean square magnitude of displacement vectors from each point in the surface meshes.

 

 

Image 5. Asymmetry maps

Asymmetry maps were created in each group as defined by Sex and Diagnosis (NC = normal controls, SZ = schizophrenic patients). Sulcal mesh averages for each hemisphere were subtracted from a reflected version of the same structure in the other hemisphere to create displacement vectors. These maps
represent in color the magnitude of average asymmetry in sulcal anatomy between the two hemispheres.

 

 

Image 6. 3D average surface representation and variability maps of the lateral ventricles

Variability maps are similar in both groups with highest variability in the posterior horns (NC = normal controls, SZ = schizophrenic patients). Increases in LH ventricle length and volume were determined. The color bar encodes the root mean square magnitude of variability in millimeters.

 

 

Image 7. Displacements of the lateral ventricles and corpus callosum

Displacement maps show the magnitude of displacement (mm) between schizophrenic patients and normal controls as represented by the color bar for the lateral ventricles and corpus callosum. A significant vertical displacement of the lateral ventricles in schizophrenic patients reflects a bilateral increase in ventricular volume, and corresponds to the displacement of the corpus callosum.

 

 

Image 8. Cortical surface variability maps.

Variability maps viewed from the front showing cortical surface variability in the four groups defined by sex and diagnosis.

 

 

Additional pictures and images of brains with schizophrenia can be viewed at http://www.loni.ucla.edu/

 

Laboratory of Neuro Imaging, U.C.L.A.

A brain scan of an adolescent with schizophrenia

 

 

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Bidirectional Relationship Between Schizophrenia and Epilepsy, Study Finds
ScienceDaily.com, September/October 2011  —  Researchers from Taiwan have confirmed a bidirectional relation between schizophrenia and epilepsy. The study published in Epilepsia, a journal of the International League Against Epilepsy (ILAE), reports that patients with epilepsy were nearly 8 times more likely to develop schizophrenia and those with schizophrenia were close to 6 times more likely to develop epilepsy.

Prior clinical studies have shown a prevalence of psychosis among epilepsy patients and studies of psychiatric illness have found a strong relationship between schizophrenia and epilepsy, suggesting a shared susceptibility between the diseases that may be a result of genetic, environmental or neurobiological causes. While a number of studies have established a bidirectional relationship between depression, mood disorder and epilepsy, the current study is the first to investigate this type of relation between schizophrenia and epilepsy.

Using data from the Taiwan National Health Insurance database, the team identified 5195 patients with schizophrenia and 11527 patients with epilepsy who were diagnosed between 1999 and 2008. The patient groups were compared to age and sex-matched controls. Analysis included the incidence and risk of developing epilepsy in the schizophrenia patient group and schizophrenia in the epilepsy cohort.

The findings show that the incidence of epilepsy was higher in the schizophrenia patient group at 6.99 per 1,000 person-years compared to 1.19 in the non-schizophrenia control. Incidence of schizophrenia was 3.53 per 1,000 person-years for patient with epilepsy compared to 0.46 in the non-epilepsy group. Researchers also reported that schizophrenia incidence was slightly higher in men with epilepsy than in women with the disease.

“Our research results show a strong bidirectional relation between schizophrenia and epilepsy,” said lead author I-Ching Chou, M.D., with China Medical University Hospital and Associate Professor with China Medical University in Taichung, Taiwan. “This relationship may be due to common pathogenesis in these diseases such as genetic susceptibility and environmental factors, but further investigation of the pathological mechanisms are needed.”

 

 

 

Journal Reference:

  1. Yu-Tzu Chang, Pei-Chun Chen, I-Ju Tsai, Fung-Chang Sung, Zheng-Nan Chin, Huang-Tsung Kuo, Chang-Hai Tsai, I-Ching Chou. Bidirectional Relation Between Schizophrenia and Epilepsy: A Population-Based Retrospective Cohort Study. Epilepsia, 2011; DOI: 10.1111/j.1528-1167.2011.03268.x

 

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How Much to Drink During a Marathon

 

Getty Images:  Is there a right amount to drink during a marathon?

 

 

 

The New York Times, October 5, 2011, by Gretchen Reynolds  —  The 2011 Chicago Marathon on Sunday marks the beginning of the fall marathon season in the United States, culminating on Nov. 6 with the New York City race. In those two events alone, more than 80,000 runners will attempt to cover the 26.2-mile marathon distance. But two newly released studies suggest that there are reasons to be concerned about some of the racers’ readiness. The studies show that a worrying large percentage of distance runners may not know how to drink.

Some runners may be drinking too much water or other fluids. Others may be taking in too little. And a disconcerting majority don’t seem to be concerned about whether they are drinking a safe amount at all, according to the new reports.

Attitudes and expert guidelines about how much fluid people should drink during prolonged endurance events have changed drastically in the past 15 years. A 1996 Position Stand from the American College of Sports Medicine concluded that “athletes should start drinking early and at regular intervals in an attempt to consume fluids at a rate sufficient to replace all the water lost through sweating (i.e., body weight loss), or consume the maximal amount that can be tolerated.” Many of us who ran a marathon in the 1990s were cautioned to “stay ahead” of our thirst, with the warning that by the time we felt thirsty, we would be clinically dehydrated. (Formal definitions of dehydration vary, but most experts agree that losing more than 3 percent of your body weight can be considered dehydration.)

But in the past few years, several marathoners died as a result of drinking too much, a dangerous condition called hyponatremia, or water intoxication. Before then, hyponatremia, marked by low blood sodium levels, had been unheard of in marathon fields. Twenty years ago, a typical marathon racer strode fast and drank little. But as the event gained popularity, finishing times rose. Slower runners generally sweat less, and many have been told to drink copiously. If you ingest more fluid than you lose through sweating or urination, however, you dilute your blood’s sodium levels. Osmosis then draws water from the blood into body cells to equalize sodium levels, and those cells swell. If the cellular bloating occurs in the brain, it can be fatal.

Most experts have now begun advising marathon runners to drink less. They’ve focused on marathoners because hyponatremia is uncommon in events that last less than four hours or so (at least for middle-of-the-pack and slower competitors). Recent guidelines from the International Marathon Medical Directors Association explicitly say to drink only when you’re thirsty.

But the new studies show that many marathon runners are not paying heed. In one of the reports, which appears in the current issue of Sports Health, researchers surveyed 419 men and women who were training for the Chicago Marathon. Most were in their late 30s or early 40s, and they had been running, on average, for 10 years. A third were training for their first marathon, and 17 percent had run a single marathon before.

A majority of the 419 runners reported a notable nonchalance about proper hydration. Almost 65 percent responded that they were “not at all” concerned about keeping themselves properly hydrated during the upcoming race. Notably, when asked specifically whether they worried about the possibility of developing hyponatremia, 63 percent said that they were not.

A second survey, conducted by researchers at Loyola University Medical Center and published in June in the British Journal of Sports Medicine, reached the starker conclusion that almost half of runners may be drinking too much during their races. This survey, which recruited experienced runners from the Chicago area, asked the respondents directly about how they hydrate and why.

Just half of the runners surveyed by the Loyola researchers reported drinking only when they felt thirsty, the yardstick now recommended by most sports experts. The others drank according to a preset schedule of some kind, and almost 10 percent told the researchers that they drank “as much as possible.”

“There is still a widespread misconception that you have to quote-unquote ‘stay ahead’ of your thirst,” said Dr. James Winger, a professor of family medicine and lead author of the study. “That idea is contrary to science, and it is dangerous.”

But as his study’s results indicate, it remains surprisingly pervasive.

Even those athletes who reported in the survey that they drank when thirsty weren’t typically responding to expert recommendations, Dr. Winger says. Most would have liked to drink more, but had “experienced gastrointestinal distress,” he says, a condition that seems to be more persuasive, so far, than science at preventing athletes from overdoing fluids.

The lesson of his and other studies, Dr. Winger is quick to point out, is not that endurance athletes should avoid hydrating. “The lesson is that you should drink only when you need to, when you’re thirsty,” he says. “That is the best way to protect yourself against hyponatremia” and also against dehydration. “Thirst is a very reliable indicator” of your body’s actual hydration status, he says.

“Now we just have to persuade” those 80,000 or so runners toeing the line at Chicago, New York and other marathons in the next month “to listen to it.”

 

 

 

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  1. Published online before print July 29, 2011, doi: 10.1177/1941738111415043 Sports Health: A Multidisciplinary Approach September/October 2011 vol. 3 no. 5 451-454

Lack of Awareness of Fluid Needs Among Participants at a Midwest Marathon

  1. Sara Brown, DO*,
  2. George Chiampas, DO,
  3. Carrie Jaworski, MD and
  4. Dennis Passe, PhD§

+ Author Affiliations

1.        Loyola University Medical Center, Chicago, Illinois
2.        Northwestern Memorial Hospital, Chicago, Illinois
3.        §Scout Consulting, LLC, Chicago, Illinois
  1. * Sara Brown, DO, Loyola University Medical Center, 1016 North Ashland Avenue, Chicago, IL 60622 (e-mail: browsara@gmail.com)

Abstract

Background: Marathon running has become popular, particularly among inexperienced runners.

Hypothesis: Many marathoners are inexperienced and lack concern for potential complications of marathon running.

Study Design: Cross-sectional survey.

Methods: In sum, 419 runners completed a survey on a variety of topics regarding training for a marathon and hydration strategies.

Results: Overall, 211 females (38.3 ± 9.1 years old) and 208 males (41.6 ± 11.0 years old) participated. They trained for 6.8 ± 4.3 months and had run for 9.8 ± 9.1 years; 33.5% had no marathon experience and 16.9% had run 1 marathon. Of the injuries reported, 77.6% and 72.9% were minor musculoskeletal injuries during the current and previous running seasons, respectively. Of the 278 runners who had run a marathon, 54 (19.0%) had been treated in the medical tent, 31.5% of whom for dehydration. Furthermore, 54.9% and 64.3% of the survey participants were “not at all” concerned with musculoskeletal injury and hyponatremia, respectively. Also, 88.7% did not know their sweat rate; 67.8% did not weigh themselves; and 81.3% had no other method of hydration assessment. No significant correlations were found between concern for hyponatremia and age, sex, or experience.

Conclusions: Most participants were inexperienced, lacked concern for injury or hyponatremia, and were not using methods of hydration assessment.

 

 

 

Br J Sports Med. 2011 Jun;45(8):646-9. Epub 2010 Sep 28.
Beliefs about hydration and physiology drive drinking behaviours in runners.
Winger JM, Dugas JP, Dugas LR.

Source

Department of Family Medicine, Loyola University Medical Center, Maywood, Illinois, USA. jwinger@lumc.edu

Abstract

BACKGROUND:

Exercise-associated hyponatraemia (EAH) is a dilutional hyponatraemia that is caused primarily by the intake of hypotonic fluid beyond the dictates of thirst and exacerbated by the syndrome of inappropriate antidiuretic hormone secretion as well as an inability to mobilise osmotically inactive sodium stores. Runners who drink more than to their thirst do so for a reason, and understanding and curtailing this behaviour will probably decrease the incidence of this highly preventable condition.

OBJECTIVE:

To determine the beliefs about fluid replacement held by runners and whether these beliefs are reflected in hydration behaviours.

METHODS:

An online survey was filled out by 197 runners solicited by personal solicitation, e-mail and flyers distributed at three local races in autumn 2009.

RESULTS:

Most runners (58%) drink only when thirsty. Runners drinking to a set schedule are significantly older, more experienced and faster than those drinking when thirsty. Gastrointestinal distress is the most frequently cited (71.5%) reason to avoid overhydration. Runners have a poor understanding of the physiological consequences of hydration behaviours that frequently reflect messages of advertising.

CONCLUSIONS:

Runners at highest risk of EAH exhibit behaviour that is shaped by their beliefs about the benefits and risks of hydration. These beliefs are frequently based on misconceptions about basic exercise physiology.

PMID:

20876587

[PubMed – in process]

 

 

 

 

Nonalcoholic Beer Aids Marathon Recovery

 

Fred R. Conrad/The New York Times

 

 

 

The New York Times by Gretchen Reynolds  —   A new study reports that beer is an excellent recovery beverage for marathon runners. But you may not want to start a raucous celebration just yet. The beer was effective only if it was nonalcoholic.

Running a marathon is, of course, punishing to the body, causing muscle soreness and inflammation. Grueling exercise can also weaken the immune system, making athletes susceptible to colds and other ills in the weeks after the event. Some athletes, particularly in Europe, long had downed nonalcoholic beer during hard training, claiming that it helped them to recover, but no science existed to support the practice.

To study the matter, researchers at the Technical University of Munich approached healthy male runners, most in their early 40s, who were training for the Munich Marathon, and asked if they would — in the name of science — be willing to drink a considerable amount of beer. Two hundred seventy-seven men agreed, even when told that the beverage would be nonalcoholic. Only half of the group received the alcohol-free beer, however; the other half got a similarly flavored placebo. No one knew who was drinking what.

All of the runners downed a liter to a liter and a half — about two to three pints — of their assigned beverage every day, beginning three weeks before the race and continuing for two weeks afterward. The scientists, meanwhile, collected blood samples from the men several weeks before the race, as well as immediately before to the start, at the finish line and on select days afterward. (These were an exceptionally obliging group of racers, it seems.) They monitored levels of various markers of inflammation in the men’s blood, to see whether beer helped to blunt some of the immediate damage from running.

For the next two weeks, the men continued to dutifully swallow their nonalcoholic beer or other brew. They also reported any symptoms of colds or other upper respiratory ailments that developed during that time.

The men drinking the nonalcoholic beer reported far fewer illnesses than the runners swallowing the placebo beverage. “Incidence of upper respiratory tract infections was 3.25-fold lower” in the nonalcoholic beer drinkers, the scientists reported, in the journal Medicine & Science in Sports & Exercise. They also showed significantly less evidence of inflammation, as measured by various markers in their blood, and lower counts of white blood cells than the placebo group, an indication of overall better immune system health.

These effects matter, said Dr. Johannes Scherr, lead author of the study, because if a marathon runner’s body is less sore and inflamed after a race, and he doesn’t develop the sniffles, he can recover and return to training more quickly than he otherwise might have been able to. “It can be speculated that the training frequency could be higher (with shorter breaks after vigorous training sessions)” in those drinking beer, he wrote in an e-mail response.

Just how nonalcoholic beer eases the ravages of strenuous marathon training and racing is still being investigated. But, said Dr. Scherr, it almost certainly involves the beverage’s rich bouquet of polyphenols, chemical substances found in many plants that, among other things, “suppress viral replication” and “influence the innate immune system positively,” all beneficial for fighting off a cold.

Alcoholic beer happens to be drenched in polyphenols, too — “even more than nonalcoholic beer,” Dr. Scherr said — but has the signal disadvantage of being alcoholic. “We do not know whether the side effects of alcoholic beer would cancel out the positive effects caused by the polyphenols,” he wrote. “Furthermore, it is not possible to drink one to one and a half liters of alcoholic beer per day, especially not during strenuous training.” We all knew that, right?

Of course, other substances containing polyphenols have shown early promise, and then underperformed in follow-up studies. Quercetin, for instance, a polyphenol derived principally from apple skins, was widely touted by endurance athletes several years ago after studies found that large doses allowed untrained lab mice to run for far longer than untreated animals. But the supplement has largely failed to show benefits in human athletes. An analysis of 10 human studies of the supplement presented at the American College of Sports Medicine annual meeting in June concluded that quercetin supplementation “is very unlikely to provide an endurance performance advantage.”

But the beer experiment did not begin by looking at mice. It began with human marathoners completing a punishing, unsimulated race, and showed demonstrable benefits, in terms of minimizing postrace damage.

All of which is good news as the fall marathon season approaches. Asked if he would recommend that serious marathon runners add nonalcoholic beer to their diets, Dr. Scherr said, “When I look at the results of our study, I would have to answer ‘Yes.’”

It’s possible to get large amounts of polyphenols from other foods, he added, like those training-table staples chokeberries and mangosteens, as well as pomegranates and grapes. “But with these foods you do not consume the minerals, fluid and carbohydrates,” he said, “so nonalcoholic beer seems to be optimal” for everything, perhaps, apart from your well-deserved celebratory carouse after the race. For that, at least, the beer can be full-potency.