People don't drink enough water...drink 8 glasses a day...be sure you hydrate frequently during exercise... But what if you were now told that the water you drink may well be laced with a deadly toxin. Still thirsty? A NY Times article explores arsenic in our water.

Poison Pen September 20, 2013, 2:13 pm 24 Comments

The Arsenic in Our Drinking Water

By DEBORAH BLUM

 

 

Jim Wilson/The New York Times Elementary school students in Seville, Calif., take a water break. Drinking water in many parts of California’s Central Valley is contaminated with arsenic.

 

Deborah Blum writes about chemicals and the environment. 

 

The baby with the runny nose, the infant with a stubborn cough — respiratory infections in small children are a familiar family travail. Now scientists suspect that these ailments — and many others far more severe — may be linked in part to a toxic element common in drinking water. 

The element is naturally occurring arsenic, which swirls in a dark, metalloid shimmer in soil and rock across much of the United States and in many other countries. It seeps into groundwater, but because the contamination tends to be minor in this country, for many years its presence was mostly noted and dismissed by public health researchers.

They’ve changed their minds. Long famed for its homicidal toxicity at high doses, a number of studies suggest that arsenic is an astonishingly versatile poison, able to do damage even at low doses.

Chronic low-dose exposure has been implicated not only in respiratory problems in children and adults, but in cardiovascular disease, diabetes and cancers of the skin, bladder and lung.

Trace amounts in the body interfere with tumor-suppressing glucocorticoid hormones, studies show, which is one reason that arsenic exposure has been linked to a range of malignancies. Arsenic also interferes with the normal function of immune cells. It damages lung cells and causes inflammation of cells in the heart.

Researchers first became aware of these problems in so-called hot spot countries like Bangladesh, where arsenic levels in water can top 1 part per million. Decades ago, public health agencies there sought to replace microbe-contaminated surface water with well water. Only later did geological surveys reveal significant aquifer contamination from bedrock arsenic.

Scientists now report health risks at lower and lower levels of exposure in that country. In July, researchers at the University of Chicago found that residents of Bangladesh chronically exposed to arsenic at a mere 19 parts per billion showed signs of reduced lung function. At levels of 120 p.p.b. or higher, their ability to take in oxygen resembled that of long-term smokers.

“Bangladesh is unfortunately a living laboratory for the health effects of arsenic,” said Habibul Ahsan, the lead author of the study and director of the Center for Cancer Epidemiology and Prevention at the University of Chicago.


Dr. Ahsan, a native of Bangladesh, is one of the organizers of a long-term study of arsenic and health in that country, which now has 30,000 people enrolled. In 2010, he reported that 24 percent of all deaths from chronic disease in his study population could be attributed to drinking arsenic-contaminated well water.

“We need to take arsenic exposure very seriously,” Dr. Ahsan said.

That seems to be today’s watchword. Researchers have begun a widespread re-evaluation of arsenic as a public health threat not only in water, but in the food supply. The Food and Drug Administration recently set a limit of 10 p.p.b. for arsenic in apple juice, and the agency is now evaluating the risks posed by foods like rice, which tend to pick up arsenic from the soil. At the request of the Environmental Protection Agency, the National Academy of Sciences has begun an intensive review of arsenic risks. The academy study group is chaired by Joseph Graziano, a professor of environmental health sciences at Columbia University who researches the link between arsenic in drinking water and cognitive deficits in children.

Researchers also are taking a much closer look at drinking water, from Southwestern states like Nevada, where wells sometimes contain arsenic at more than 500 p.p.b., to the upper Midwest and New England, where a belt of arsenic-infused bedrock taints aquifers in stretches from the coast of Maine to a point midway through Massachusetts. Water in parts of the Central Valley of California, America’s breadbasket, has been found to be tainted with arsenic as well.

While municipal water suppliers are required to meet the E.P.A.’s safety standard of 10 p.p.b. for arsenic in drinking water, no such regulation exists for private wells. Nationwide, researchers say, about 13 million people get drinking water from private wells with arsenic levels above the federal standard.

And studies here are beginning to show a pattern of harm not unlike that seen in Bangladesh. One study of private wells in Michigan, tainted with arsenic in the 10 to 100 p.p.b. range, found increased mortality rates linked to everything from diabetes to heart disease. Another focusing on cardiovascular disease in small communities is due to be published next week.

At Dartmouth College, the New Hampshire Birth Cohort Study is following women through pregnancy into parenthood, comparing the health of children in families drinking from private wells with those who rely on municipal water supplies.

In a study published in July in Environmental Research, researchers measured arsenic exposure during pregnancy and then tracked respiratory infections in infants up to four months of age. The higher the arsenic exposure in the mother, the scientists found, the greater the number of respiratory infections in their infants, especially ones that required a visit to the doctor or prescription medicine.

The results describe a pattern similar to that seen in Bangladesh, where scientists have found a greater than 50 percent increase in severe lower respiratory infections among infants of mothers with high levels of arsenic, compared with those with the least exposure.

“We were surprised to find the connection so visible at the lower exposures seen here,” said Margaret Karagas, a Dartmouth epidemiologist and the senior author of the study. The Dartmouth pregnancy cohort study has also found a link between low-level exposure to arsenic and low birth weight in infants.

“If people have private wells, they need to have them tested for arsenic,” she said. “You want to know what’s in your water.” Meanwhile, Dr. Karagas and other experts are looking at the ways that arsenic in the food supply might add to an individual’s cumulative exposure.

“We need to start looking at all the sources,” Dr. Ahsan said.

After watching a number of people line up at a local street fair so that they can buy over-priced wrist magnets in an effort to "cure" their arthritis, I needed to find out more. And so I researched the literature and reached my own conclusion. Now a new study supports exactly what I had surmised...they just don't work.

 

 

Body September 19, 2013, 11:52 am 8 Comments

Magnets Fail to Relieve Arthritis Pain

By NICHOLAS BAKALAR

 

 Many people use copper bracelets and magnetic wrist straps to alleviate the pain of arthritis, but a new randomized, double-blinded, placebo-controlled study concludes they do not work.

British researchers randomized 65 patients with rheumatoid arthritis to receive one of four treatments: wearing a powerful magnetic wrist strap, a weak magnetic strap, a non-magnetic strap and a copper bracelet. Each patient wore each device for five weeks and completed pain surveys. The study appears in the September issue of PLoS One.

The patients reported pain levels using a visual scale, ranging from “no pain” to “worst pain ever,” and recorded how often their joints felt tender and swollen. Researchers used questionnaires to assess physical limitations, and tested for inflammation by measuring blood levels of C-reactive protein and plasma viscosity.

There was no statistically significant difference in any of these measures regardless of which type of device patients were wearing.

Stewart J. Richmond, a researcher at the University of York who led the study, acknowledged that the devices may have some benefits as a placebo.

“People swear by these things,” he said. “Is it ethically correct to allow patients to live in blissful ignorance? Or is it better to provide them with the facts? We can’t deceive patients. We have to be honest with them.”

Got back pain? Been told you have fibromyalgia? Considering that "shot" to help relieve the pain? A new study finds that those minimally invasive injections are of little use, with high failure rates and very little long term benefit.

Pain Management

Spine Treatments Little Help in Fibromyalgia

Published: Sep 16, 2013 | Updated: Sep 16, 2013

 

By Nancy Walsh, Staff Writer, MedPage Today

Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner

Individuals seeking care for back pain whose symptom pattern was typical of fibromyalgia derived little benefit from minimally invasive spine therapies such as epidural steroid injections, researchers found.

Among patients presenting to a back pain treatment center, 42% met the American College of Rheumatology (ACR) survey criteria for fibromyalgia, according to Chad M. Brummett, MD, and colleagues from the University of Michigan in Ann Arbor.

In a final model based on multivariate analyses, factors that were independently associated with a diagnosis of fibromyalgia were female sex, neuropathic pain, physical function, anxiety, and pain interference (P<0.01 for all variables), they reported.

"The independent predictors from the multivariate models are some of the most commonly described predictors of poor outcomes in minimally invasive spine interventions and post-surgical pain. Hence, there may be a common underlying pathophysiology or 'diagnosis' driving these findings," the researchers wrote online in Arthritis & Rheumatism.

In recent decades the popularity of minimally invasive spine treatments has skyrocketed, with increases of more than 100% being reported for epidural steroid injections and of more than 500% for facet joint interventions such as injections and medial branch blocks.

However, these procedures have high failure rates, with estimates ranging from 25% to 45%, and a recent meta-analysis found little long-term benefit for spine injections for sciatica.

Previous research has suggested that poor response is associated with young age, use of opioids, previous spine surgery, and lengthy duration of symptoms, as well as somatization and depression.
It also has become clear that certain chronic pain conditions, most notably fibromyalgia, are characterized by alterations in centralized CNS pain processing, implying that local treatments are less likely to be successful.

"Injections and peripherally targeted analgesics would be expected to provide less benefit in a patient with altered central pain processing than in those with predominantly peripheral pathology," the researchers noted.

Patients with fibromyalgia also typically have reduced levels of pain-inhibiting neurotransmitters such as serotonin and high levels of transmitters such as glutamate that can increase pain sensations.

To explore whether this centralized pain phenotype was common among spine patients and might help aid in patient selection for localized treatments, Brummett's group enrolled 443 patients with complaints ranging from neck pain to lumbago and lumbar spinal stenosis.

Fibromyalgia was diagnosed according to the ACR 2010 criteria, which was based on a widespread pain index and a symptom severity scale and no longer included the original tender point criteria.
A continuous fibromyalgia score consisted of the sum of the pain index and severity scale score.

Other diagnostic evaluations included the Brief Pain Inventory, which measures pain severity and interference, PainDETECT for neuropathic pain, the Hospital Anxiety and Depression Scale, and physical function according to the Oswestry Disability Index.

On univariate analysis, patients who met the criteria for fibromyalgia were more often younger (47 versus 52 years, P=0.001), not employed (25% versus 41%, P=0.005), and to have financial compensation (33% versus 18%, P=0.0005).

They also had higher scores for pain severity and interference, neuropathic pain, anxiety and depression, and worse physical function (P<0.0001 for all), which represented "profound phenotypic differences" compared with nonfibromyalgia patients, the researchers observed.

On a multivariate linear regression analysis, looking at an association between the continuous fibromyalgia score, pain variables, and phenotype, significant associations were seen for female sex (P=0.0002), pain interference (P=0.0047), neuropathic pain (P<0.0001) and anxiety (P<0.0001).

And on a logistic regression analysis that considered fibromyalgia as a binary variable, significant associations existed for neuropathic pain (P=0.0002), physical function (P=0.024) and anxiety (P<0.0001).

The final model had a high area under the curve receiver operating characteristic (C statistic) for fibromyalgia of 0.80.

"Taken together, these data make a compelling case for the study of a modified treatment approach. For example, previous studies have demonstrated efficacy for serotonin-norepinephrine reuptake inhibitors in chronic low back pain," the researchers wrote.

"Nonpharmacologic interventions, such as cognitive-behavioral therapy and exercise have also demonstrated excellent effect sizes that often exceed pharmacologic interventions in fibromyalgia and other pain states," they added.

Limitations of the study include its single site and cross-sectional design, and further objective research will be needed such as neuroimaging to corroborate these findings.

Nonetheless, the researchers concluded, "It is possible that a simple self-report measure could aid in the prediction of outcomes in some of the most common minimally invasive spine interventions."

The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the American Society of Regional Anesthesia and Pain Medicine, and the University of Michigan.
The authors reported consulting and receiving support from companies including Purdue Pharma, Merck, Forest, Nova, Pierre Fabre, Ili Lilly, UCB, Bristol-Myers Squibb and Pfizer.

Parents often have the most difficult of times responding to the pain of recurring earaches in their kids because it seems like nothing they do helps. Now a new study indicates that the best treatment (and prevention) might be as simple as a daily dose of Vitamin D, particular if the child has low serum levels of the vitamin. If you're a parent, its certainly worth investigating this natural therapy.

 

Vitamin D Cuts Kids' Recurrent Ear Infection

Published: Sep 13, 2013

By Cole Petrochko, Staff Writer, MedPage Today

Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

DENVER -- Children with low levels of vitamin D and recurrent ear infections had a reduced risk for acute otitis media with vitamin D supplementation, researchers reported here.

Compared with children randomized to placebo, patients with recurrent acute otitis media (AOM) who received 1,000 IU daily had significantly lower risk of experiencing one or more episodes of AOM (26 incidents versus 38 incidents, P=0.03), and the risk of uncomplicated acute otitis media was markedly smaller in the vitamin D group (P<0.001), according to Susanna Esposito, MD, of the Universita degli Studi di Milano in Italy, and colleagues.

"In clinical practice, this means that in children with recurrent otitis media, we can check their levels of vitamin D and for those with low serum levels of it consider supplement use as a treatment for their condition," she said during a presentation at the Interscience Conference on Anti-Microbial Agents and Chemotherapy.

Particularly among younger children, ear infections are a common hazard. Research published earlier in September 2013 concluded that all children younger than 2 years should receive antibiotic treatment for acute otitis media, while recommendations from the American Academy of Pediatrics in February 2013 told pediatricians to follow stricter diagnostic criteria and to observe patients who have uncomplicated disease.

"What we learn about nutrition and how that impacts infectious disease" may have a broader impact on recommendations for nutrition and other elements of childcare going forward, noted Craig Rubens, MD, PhD, of Seattle Children's Hospital Research Institute in Washington.

The authors conducted a randomized study of 116 children with recurrent otitis media who were treated with daily doses of oral 1,000 IU of vitamin D or with placebo over 4 months and whose episodes of acute otitis media were monitored for 6 months.

Recurrent disease was defined as three or more episodes in the 6 months prior to the study or four or more episodes in the 12 months prior to the study.

Participants had a mean age of 33.4 months in the placebo group and 34.3 months in the vitamin D group. Most were white (98.3% and 100%, respectively) and had been breast feeding for 3 or more months (72.4% and 84.1%). All had been vaccinated with the influenza vaccine, and the majority had received a heptavalent pneumococcal conjugate vaccine (82.8% for both groups).

Mean vitamin D blood concentrations were 25.8 ng/mL and 26.5 ng/mL, respectively, which were both below the recommended level of 30 ng/mL, Esposito noted.

The average number of episodes of acute otitis media over 12 months prior to the study was roughly five between groups (five versus 4.97), and roughly one-third of the cases were complicated by perforation (36.2% for both).

At 6-month follow-up, blood vitamin D was significantly higher in those treated with supplements versus placebo (36.2 ng/mL versus 18.7 ng/mL, P<0.001). Additionally, there were significantly fewer children who had one or more episodes of acute otitis media in the group treated with supplement, particularly among those with uncomplicated disease (10 versus 29, P<0.001). There was no significant difference between groups for those whose disease was complicated by perforation.

She added that treatment was well-tolerated and that the number of adverse events was not significantly different between groups (five events with placebo versus six with vitamin D, P=0.75).

Got kids? Want to help them "get smarter?" In a Boston Globe story, a study published in Frontiers in Human Neuroscience explains how and why eating breakfast may benefit your child's learning. In short, longer sleep patterns deplete glycogen storage that now needs to be replaced as your child starts the day.

 

How Eating Breakfast Makes Your Child Smarter

 

Posted by Joan Salge Blake  September 3, 2013 03:04 PM

Photo Source:  Academy of Nutrition and Dietetics

It’s common knowledge that kids should rise and dine to ace their academics. Research has shown that eating breakfast can improve a child’s cognitive performance in the classroom, particularly memory and attention span.  More interestingly, a study just published in Frontiers in Human Neuroscience, explains why and how a morning meal impacts the brain. 

According to the researchers in this study, children have a higher rate of metabolizing glucose in their brains as compared to adults. Glucose is the fuel that feeds the body. This higher rate of using glucose, coupled with their longer nighttime slumber, puts children at a higher risk for depleting their storage of glucose, called glycogen, in their body overnight.  Thus, eating breakfast, or “breaking the fast” so-to-speak, is physiologically important to provide children with the energy-charged glucose to kick start and fuel their brains.  According to the Academy of Nutrition and Dietetics (AND), over 40 percent of American children do not eat breakfast on a daily basis.

As a parent, providing breakfast isn’t an issue.  Rather, it's coming up with breakfast ideas that kids will actually eat that is a hair-pulling challenge.  On this front, I solicited advice from my nutrition colleagues who are wizards when it comes to meal ideas. 

Here are their brain-fueling breakfast suggestions for kids of all ages, including you:

Denver Omelet in a Mug

Dave Grotto, RDN, busy author and father of two teenage girls, often has less than 5 minutes in the morning to prepare breakfast.  He relies on one of his favorite Hungry Girl quick recipes, Denver Omelet in a Mug to serve them a fast and satisfying breakfast.  Best of all, cleanup is a cinch.

As a mother of three and author of MyPlate for Moms, Elizabeth Ward, RDN, starts her family’s day with her most fave Pumpkin Smoothie.   Combine 1 cup each of low fat milk and canned pumpkin along with 2 teaspoons brown sugar, 1/2 teaspoon vanilla extract, a pinch ground cinnamon, and 2 ice cubes in a blender.   Serve with whole grain toast.   The beauty of this smoothie is that it provides a serving of veggies, which are often hard to squeeze in the AM.

Culinary nutritionist and author of 1,000 Low-Calorie Recipes, Jackie Newgent, RDN, recommends starting the day off with her Banana-Nut Toastie. Spread a nut butter between 2 slices of whole grain bread.  Top one slice of bread with sliced bananas, a few dark chocolate chips, and an optional pinch of cinnamon or cayenne.   Cover with the other slice of bread and grill in a skillet or Panini press.  Who wouldn’t like a tad of antioxidant-rich dark chocolate to start their day?

Grab-and-Go Granola Bar

Need a healthy breakfast on-the-go?  Try this high fiber, easy-to-make Grab-and-Go Granola Bar created by Janice Newell Bissex, RD and Liz Weiss, RD, of Meal Makeover Moms.  This is just one of their many healthy recipes available on their new app for busy families.

Grilled Cheese French Toast is a household favorite for Elisa Zied, RD, author of Younger Next Week and mother of two hungry boys.  To make this cheese stuffed toast, sandwich a slice of Swiss or cheddar cheese in between two slices of whole wheat bread.  Dip the sandwich in a scrambled egg and brown in a fry pan coated with nonstick cooking spray.   Served with fruit and nonfat milk.

According to Keri Gans, RDN, author of The Small Change Diet, “A homemade Yogurt Parfait could be the perfect breakfast option for the busy family, especially with varied taste buds.  Each family member can create their own parfait by choosing a cup of low-fat Greek yogurt topped with a high-fiber cereal, fresh fruit, and a sprinkle of nuts.”  Set up a breakfast bar in the kitchen and let them do the assembling.  Defrosted frozen berries are an easy way to keep fruit on hand should you run out of fresh during the week.

Lastly, Karen Ansel, RDN, a mother and media spokesperson for AND, suggests a Hummus Breakfast Bagel.  Spread hummus on half of a whole wheat bagel and top with tomato slices. “By using hummus instead of cream cheese, you can work in protein and healthy fat, ” claims Ansel.  Consuming both protein and fat at breakfast will help keep you and your kids full until lunch.

Please share you breakfast favorites below.

Here’s to a productive school year!

With Type-2 diabetes becoming common as a secondary condition to obesity, we know we can reverse the diagnoses through diet and exercise. Now a new study supports the benefit of decreasing the risk for diabetes by eating certain fruits. More and more it appears working to stay well is a better alternative than acquiring debilitating diseases due to neglect.

Food September 4, 2013, 12:51 pm 162 Comments

Some Fruits Are Better Than Others

By NICHOLAS BAKALAR

 

                                                                                                                             Lars Klove for The New York Times

Eating fruits is good for you, but new research suggests that some fruits may be better than others, and that fruit juice is not a good substitute.

Recent studies have found that eating a greater variety, but not a greater quantity, of fruit significantly reduces the risk for Type 2 diabetes. This made researchers wonder whether some fruits might have a stronger effect than others.

Using data from three large health studies, they tracked diet and disease prospectively over a 12-year period in more than 185,000 people, of whom 12,198 developed Type 2 diabetes. The analysis appears online in BMJ.

After controlling for many health and behavioral factors, researchers found that some fruits — strawberries, oranges, peaches, plums and apricots — had no significant effect on the risk for Type 2 diabetes. But eating grapes, apples and grapefruit all significantly reduced the risk. The big winner: blueberries. Eating one to three servings a month decreased the risk by about 11 percent, and having five servings a week reduced it by 26 percent.

Substituting fruit juice for whole fruits significantly increased the risk for disease.

“Increasing whole fruit consumption, especially blueberries, apples and grapes, is important,” said Dr. Qi Sun, an assistant professor of medicine at Harvard and the senior author of the study. “But I don’t want to leave the impression that fruit is magic. An overall healthy lifestyle is essential too.”

Having had my own knee scoped earlier in the year, I was surprised to learn that I had what was described as a chronically torn ACL. Not having any clue as to when it was torn, I was equally surprised that it had not healed (though I continue to exercise on it.) Now a new article in the New York Times tells why.

Why A.C.L. Injuries Sideline So Many Athletes

By GRETCHEN REYNOLDS

J. M. Horrillo/Getty Images

Gretchen Reynolds on the science of fitness.

For athletes, few sounds are more ominous than the percussive pop that can signal a ruptured knee ligament.

Tears to the anterior cruciate ligament sideline more athletes for longer periods of time than almost any other acute injury. Seasons, even careers, end when the A.C.L. tears.

Until recently, however, researchers couldn’t explain why torn A.C.L.’s were so difficult to treat. But studies recently completed at Boston Children’s Hospital and Rhode Island Hospital in Providence help to elucidate why the A.C.L., almost alone among ligaments, doesn’t heal itself. The findings also shed light on how that situation could potentially be changed, and blown knees more easily repaired.

The particular problem with the A.C.L. — which runs diagonally through the knee, helping to maintain joint stability — is that it is a tiny tissue asked to handle intolerable loads when an athlete’s knee violently twists and torques during contact sports or tumbling falls. The American ski racer Lindsey Vonn tore her A.C.L. during a competition last winter and is still rehabilitating her knee, in preparation for the 2014 Winter Olympics.

The more puzzling aspect of the A.C.L., though, is that it doesn’t get better. Other ligaments in the knee, including the medial collateral ligament, which is often torn along with the A.C.L., reknit after an injury. But the A.C.L. does not, and so past attempts at what doctors call “primary repair,” or fixing the torn ligament by stitching it back together, have generally failed.

In the past few decades, surgeons have instead replaced torn A.C.L.’s with new, rejiggered tendons formed from other portions of the person’s own leg, or from cadaver tissue. Known as A.C.L. reconstruction, this surgery provides patients with a well-functioning knee, but not the knee they once had. (It is also possible to skip surgery and live without an A.C.L., although most athletes opt for reconstruction.)

Early-onset knee arthritis is common in people with a reconstructed A.C.L. — in part, researchers speculate, because no matter how carefully the replacement tissue is braided onto the knee bones, the joint’s architecture changes, causing slight alterations in gait and balance that may eventually wear away cartilage.

So “the holy grail of orthopedic sports medicine,” according to an editorial in this month’s issue of The American Journal of Sports Medicine, has remained finding a way to repair a person’s own damaged A.C.L.

First, though, scientists had to determine why repairs failed, which became the driving mission of research by Dr. Martha Murray, an orthopedic surgeon at Boston Children’s Hospital and Harvard Medical School, and her colleagues. The team began by studying the knee’s interior
microenvironment and noting that the A.C.L. was constantly awash in synovial fluid, which lubricates the knee.

They then picked apart the synovial fluid microscopically and found that it contained an enzyme that dissolved blood clots. This attribute is desirable; you don’t generally want blood clumping inside your joints.

But blood clots can also speed healing, because they “provide a bridge” between the torn edges of damaged tissue over which new tissue can grow, repairing the tear, Dr. Murray said. The knee’s medial collateral ligament, for instance, which is not bathed in synovial fluid, develops a blood clot after a tear and repairs itself. No such clots cling to a torn A.C.L., and it never becomes whole.

So Dr. Murray and her colleagues set out to make a blood clot that could be made to stick to the torn ligament. They found that by dripping blood onto a tiny sponge, they could build a clot that, when covered by a natural collagen matrix, was shielded from synovial fluid. Sutured to both ends of a torn A.C.L., this matrix could provide the scaffold needed to allow healing.

So far, the procedure has been successful in animal studies with Yucatán miniature pigs. In the newest study from Dr. Murray’s lab, published this month in The American Journal of Sports Medicine, a group of these animals had their A.C.L.’s surgically cut and then either left unrepaired, reconstructed with other tissue, or repaired with the blood-clot scaffolding. After 12 months (the equivalent, Dr. Murray says, of at least five years for people), the knees of the pigs with repaired A.C.L.’s were healthier than those of the animals whose ligaments had been untreated, and as stable as those of the pigs with reconstructed ligaments.

More important, the animals that had received the blood-clot scaffolding showed less cartilage damage and incipient arthritis in their knees than did the joints of the pigs that had undergone reconstruction surgery.

Of course, pigs are not people. They are four-legged, for one thing, and not very reliable about following rehabilitation schedules. Their A.C.L.’s had also been neatly slit, not torn and frayed as often happens in human injuries.

It is also important to note that experiments in people using similar scaffolds to repair torn rotator cuffs — which, like A.C.L.’s, do not heal on their own — have produced mixed results.

Still, Dr. Murray is optimistic that this procedure could one day allow injured athletes and others to retain their natural knee ligament and heal more rapidly and with less risk of later knee problems than is currently possible. As a surgeon, she said, “I go into the clinic and see 20 kids every day who’ve torn their A.C.L.” They all want to return to sports and full activity, she said, “and I want to be able to offer them something better than we have now.”

She hopes to be able to begin a human trial next year.