Archive for November, 2013

Runners and Knee Arthritis

Sunday, November 24, 2013 // Uncategorized

I’ve been a runner intermittently for the last 45 years.  I’m currently sidelined by a case of posterior tibial tendonitis.  What I don’t have and what most runners don’t have is arthritis of the knees. The two greatest risk factors for knee arthritis are a previous knee injury and obesity.  Many people (mostly non-runners)  assume that running wears out your knees prematurely.  Why it doesn’t is the point of this article from Then New York Times.

Why Runners Don’t Get Knee Arthritis

By GRETCHEN REYNOLDS

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Phys Ed
Phys Ed

Gretchen Reynolds on the science of fitness.

One of the most entrenched beliefs about running, at least among nonrunners, is that it causes arthritis and ruins knees. But a nifty new study finds that this idea is a myth and distance running is unlikely to contribute to the development of arthritis, precisely and paradoxically because it involves so much running.

It’s easy to understand, of course, why running is thought to harm the knee joint, since with every stride, ballistic forces move through a runner’s knee. Common sense would suggest that repeatedly applying such loads to a joint should eventually degrade its protective cartilage, leading to arthritis.

But many of the available, long-term studies of runners show that, as long as knees are healthy to start with, running does not substantially increase the risk of developing arthritis, even if someone jogs into middle age and beyond. An impressively large cross-sectional study of almost 75,000 runners published in July, for instance, found “no evidence that running increases the risk of osteoarthritis, including participation in marathons.” The runners in the study, in fact, had less overall risk of developing arthritis than people who were less active.

But how running can combine high impacts with a low risk for arthritis has been mysterious. So for a new study helpfully entitled, “Why Don’t Most Runners Get Knee Osteoarthritis?” researchers at Queen’s University in Kingston, Ontario, and other institutions looked more closely at what happens, biomechanically, when we run and how those actions compare with walking.

Walking is widely considered a low-impact activity, unlikely to contribute much to the onset or progression of knee arthritis. Many physicians recommend walking for their older patients, in order to mitigate weight gain and stave off creaky knees.

But prior to the new study, which was published last week in Medicine & Science in Sports & Exercise, scientists had not directly compared the loads applied to people’s knees during running and walking over a given distance.

To do so now, the researchers first recruited 14 healthy adult recreational runners, half of them women, with no history of knee problems. They then taped reflective markers to the volunteers’ arms and legs for motion capture purposes, and asked them to remove their shoes and walk five times at a comfortable pace along a runway approximately 50 feet long. The volunteers likewise ran along the same course five times at about their usual training pace.

The runway was equipped with specialized motion-capture cameras and pads that measured the forces generated when each volunteer struck the ground.

The researchers used the data gathered from the runway to determine how much force the men and women created while walking and running, as well as how often that force occurred and for how long.

It turned out, to no one’s surprise, that running produced pounding. In general, the volunteers hit the ground with about eight times their body weight while running, which was about three times as much force as during walking.

But they struck the ground less often while running, for the simple reason that their strides were longer. As a result, they required fewer steps to cover the same distance when running versus walking.

The runners also experienced any pounding for a shorter period of time than when they walked, because their foot was in contact with the ground more briefly with each stride.

The net result of these differences, the researchers found, was that the amount of force moving through a volunteers’ knees over any given distance was equivalent, whether they ran or walked. A runner generated more pounding with each stride, but took fewer strides than a walker, so over the course of, say, a mile, the overall load on the knees was about the same.

This finding provides a persuasive biomechanical explanation for why so few runners develop knee arthritis, said Ross Miller, now an assistant professor of kinesiology at the University of Maryland, who led the study. Measured over a particular distance, “running and walking are essentially indistinguishable,” in terms of the wear and tear they may inflict on knees.

In fact, Dr. Miller said, the study’s results intimate that running potentially could be beneficial against arthritis.

“There’s some evidence” from earlier studies “that cartilage likes cyclical loading,” he said, meaning activity in which force is applied to the joint, removed, and then applied again. In animal studies, such cyclical loading prompts cartilage cells to divide and replenish the tissue, he said, while noncyclical loading, or the continued application of force, with little on-and-off pulsation, can overload the cartilage, and cause more cells to die than are replaced.

“But that’s speculation,” Dr. Miller said. His study was not designed to examine whether running could actually prevent arthritis but only why it does not more frequently cause it.

The results also are not an endorsement of running for knee health, he said. Runners frequently succumb to knee injuries unrelated to arthritis, he said, and his study does not address or explain that situation. One such ailment is patellofemoral pain syndrome, which is often called ‘runner’s knee.’

But for those of us who are — or hope to be — still hitting the pavement and trails in our twilight years, the results are soothing. “It does seem to be a myth,” Dr. Miller said, that our knees necessarily will wear out if we continue to run.

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Update in Heart Disease Prevention Guidelines

Tuesday, November 12, 2013 // Uncategorized

U.S. News

Panel Unveils Shake-up in Strategy to Cut Heart Risk

Long-standing strategy jettisoned under new  guidelines

By
Ron Winslow

Updated Nov. 12, 2013 7:48 p.m. ET
The current strategy of reducing a person’s heart-attack risk by lowering cholesterol to specific targets is being jettisoned under new clinical guidelines unveiled Tuesday that mark the biggest shift in cardiovascular-disease prevention in nearly three decades.

The change could more than double the number of Americans who qualify for treatment with the cholesterol-cutting drugs known as statins.

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New clinical guidelines for reducing heart-attack risk will help change how doctors decide who should be on statin drugs. Who’s now considered to be at high risk? WSJ’s Jason Bellini has #TheShortAnswer. Image: Getty

The guidelines recommend abandoning the familiar and easy-to-understand guidance to keep LDL, or bad cholesterol, below 100 or below 70 for people at high risk—a mainstay of current prevention policy. Instead, doctors are being urged to assess a patient’s risk more broadly and prescribe statins to those falling into one of four risk categories.

The aim is to more effectively direct statin treatment to patients with the most to gain, and move away from relatively arbitrary treatment targets that are less reliable in predicting risk of attack than is widely believed.

“We’re trying to focus the most appropriate therapy to prevent heart attack and stroke…in a wide range of patients,” said                                     Neil J. Stone,                                 professor of medicine at Northwestern University Feinberg School of Medicine and head of the panel that wrote the guidelines.

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Cardiovascular disease is the Western world’s leading killer. In the U.S., it accounts for about 600,000 deaths each year, or about one in four. About 130,000 Americans die annually of stroke.

Numerous studies show that statins reduce the risk of heart attack and stroke. But solid data demonstrating the benefit of reaching specific targets are lacking, said Dr. Stone.

While lowering the LDL number remains a critical goal, the focus is on the risk reduction achieved with statins rather than the effect on LDL, said                                     Donald Lloyd-Jones,                                 chief of preventive medicine at Northwestern and a member of the guidelines panel.

Cardiologists expect the recommendations, jointly developed by the American College of Cardiology and the American Heart Association, to substantially change the conversation between doctors and millions of patients over the best way to lower their risk of heart attack or stroke.

The risk groups identified in the guidelines include patients who have already had a heart attack, stroke or major symptoms of cardiovascular disease; those with an LDL of 190 or higher, which typically has a genetic cause; people with diabetes; and anyone ages 40 to 79 who faces a 7.5% risk of having a heart attack over the next 10 years, according to a new risk score. That score—with a lower threshold than under current guidelines—takes into account cholesterol level, smoking status, blood pressure and other factors.

All are recommended to take high or moderate statin doses that would result in LDL reductions of about 30% to more than 50%. If fully implemented, the guidelines could more than double the number of people who qualify for statins, to more than 30 million, the authors said.

The new approach is likely to have a modest immediate effect on the pharmaceutical industry. All but one of the statins available, including Lipitor, have lost patent protection and are available as inexpensive generics.       Merck  & Co.’s Zetia, a non-statin cholesterol-reducer that is also an ingredient in Vytorin, could take a hit because the guidelines discourage use of agents that haven’t been proven to reduce risk of bad events, unless patients can’t tolerate the recommended level of statin treatment. Zetia hasn’t been shown to reduce bad events even though it lowers LDL.

But both supporters and critics of the guidelines worry they will confuse patients and physicians, and disrupt an easy-to-understand and successful strategy. While statins haven’t been the only factor, research shows there has been a significant reduction in heart attacks and death from cardiovascular disease in the past two decades since the drugs were introduced.

Having targets for LDL “gives doctors and patients something to shoot for” as well as a motivation to try to get there, said                                     Steven Nissen,                                 chairman of cardiovascular medicine at the Cleveland Clinic. “The elimination of target levels is going to be a huge change for physicians and patients,” he said.

The authors of the guidelines say a change was needed because the numerical targets are too blunt a tool. The targets have never been tested in a clinical trial, but a review of the evidence suggested they could lead to undertreatment of some patients and overtreatment of others, doctors said.

For instance, a high-risk patient with an LDL of 180 who reduces it with a statin to 90 will substantially reduce his risk. Yet under current guidelines he may be viewed as failing therapy by not getting to 70. Doctors often prescribe additional, non-statin cholesterol agents for patients not reaching targets with a statin alone, but there is no evidence getting another 20 points lower would bring a further meaningful reduction in risk.

Similarly, said Dr. Lloyd-Jones, an older patient who had accumulated other risk factors but had an LDL of 99 might be missed under the current strategy, even though statins could offer significant benefit.

Statins “seem to work no matter what your lipids are,” said Harlan Krumholz, a Yale University cardiologist, using a term referring to blood fats including cholesterol. He wasn’t an author of the guidelines, but he has argued for moving away from LDL targets as a cornerstone of prevention. “Knowing your number can be useful in understanding your risk, but not in chasing it as a strategy to improve your outcome,” he said.

Targeting LDL has been a strategy since the National Cholesterol Education Program was established to promote heart health in 1985. It became a dominant approach in the mid-1990s, after research demonstrated the ability of statins not only to lower LDL but to prevent heart attacks and death. As research linked higher doses of statins with further reductions in heart attacks, lower is better became the mantra for LDL.

Now, even without the emphasis on hitting LDL targets, the guidelines are expected to significantly boost statin use, in part because they add stroke reduction as a goal and thus include more women and minorities, who are more prone to strokes than heart attacks.

The researchers identified the 7.5% risk threshold as the point where the benefits of statin therapy to prevent first heart attacks or strokes clearly outweighed the risks, including muscle pain and a small risk of diabetes.

The cholesterol guideline was issued with three other heart-related recommendations to guide doctors on assessing risk, treating obesity and encouraging healthy diet and exercise habits.

The cholesterol document in particular is expected to generate controversy and will be discussed at a major session next week at the American Heart Association scientific meeting in Dallas.

“There will be a lot of controversy,” said Dr. Stone, of Northwestern University. “You can’t go anywhere new without creating a lot of questions. The hope is that we can answer those questions in a way that provides better patient care.”

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Herbal Supplements: Let the Buyer Beware

Thursday, November 7, 2013 // Uncategorized

This is from The New York Times.

Herbal Supplements Are Often Not What They Seem

By 
Published: November 3, 2013    405 Comments
Americans spend an estimated $5 billion a year on unproven herbal supplements that promise everything from fighting off colds to curbing hot flashes and boosting memory. But now there is a new reason for supplement buyers to beware: DNA tests show that many pills labeled as healing herbs are little more than powdered rice and weeds.
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Using a test called DNA barcoding, a kind of genetic fingerprinting that has also been used to help uncover labeling fraud in the commercial seafood industry, Canadian researchers tested 44 bottles of popular supplements sold by 12 companies. They found that many were not what they claimed to be, and that pills labeled as popular herbs were often diluted — or replaced entirely — by cheap fillers like soybean, wheat and rice.

Consumer advocates and scientists say the research provides more evidence that the herbal supplement industry is riddled with questionable practices. Industry representatives argue that any problems are not widespread.

For the study, the researchers selected popular medicinal herbs, and then randomly bought different brands of those products from stores and outlets in Canada and the United States. To avoid singling out any company, they did not disclose any product names.

Among their findings were bottles of echinacea supplements, used by millions of Americans to prevent and treat colds, that contained ground up bitter weed, Parthenium hysterophorus, an invasive plant found in India and Australia that has been linked to rashes, nausea and flatulence.

Two bottles labeled as St. John’s wort, which studies have shown may treat mild depression, contained none of the medicinal herb. Instead, the pills in one bottle were made of nothing but rice, and another bottle contained only Alexandrian senna, an Egyptian yellow shrub that is a powerful laxative. Gingko biloba supplements, promoted as memory enhancers, were mixed with fillers and black walnut, a potentially deadly hazard for people with nut allergies.

Of 44 herbal supplements tested, one-third showed outright substitution, meaning there was no trace of the plant advertised on the bottle — only another plant in its place.

Many were adulterated with ingredients not listed on the label, like rice, soybean and wheat, which are used as fillers.

In some cases, these fillers were the only plant detected in the bottle — a health concern for people with allergies or those seeking gluten-free products, said the study’s lead author, Steven G. Newmaster, a biology professor and botanical director of the Biodiversity Institute of Ontario at the University of Guelph.

The findings, published in the journal BMC Medicine, follow a number of smaller studies conducted in recent years that have suggested a sizable percentage of herbal products are not what they purport to be. But because the latest findings are backed by DNA testing, they offer perhaps the most credible evidence to date of adulteration, contamination and mislabeling in the medicinal supplement industry, a rapidly growing area of alternative medicine that includes an estimated 29,000 herbal products and substances sold throughout North America.

“This suggests that the problems are widespread and that quality control for many companies, whether through ignorance, incompetence or dishonesty, is unacceptable,” said David Schardt, a senior nutritionist at the Center for Science in the Public Interest, an advocacy group. “Given these results, it’s hard to recommend any herbal supplements to consumers.”

Representatives of the supplement industry said that while mislabeling of supplements was a legitimate concern, they did not believe it reached the extent suggested by the new research.

Stefan Gafner, the chief science officer at the American Botanical Council, a nonprofit group that promotes the use of herbal supplements, said the study was flawed, in part because the bar-coding technology it used could not always identify herbs that have been purified and highly processed.

“Over all, I would agree that quality control is an issue in the herbal industry,” Dr. Gafner said. “But I think that what’s represented here is overblown. I don’t think it’s as bad as it looks according to this study.”

The Food and Drug Administration has used bar-coding technology to warn and in some cases prosecute sellers of seafood found to be “misbranded.” The DNA technique has also been used in studies of herbal teas, which showed that a significant percentage contain herbs and ingredients that are not listed on their labels.

But policing the supplement industry is a special challenge. The F.D.A. requires that companies test the products they sell to make sure that they are safe. But the system essentially operates on the honor code. Unlike prescription drugs, supplements are generally considered safe until proved otherwise.

Under a 1994 law, they can be sold and marketed with little regulatory oversight, and they are pulled from shelves generally only after complaints of serious injury. The F.D.A. audits a small number of companies, but even industry representatives say more oversight is needed.

“The regulations are very appropriate and rigorous,” said Duffy MacKay of the Council for Responsible Nutrition, a supplement industry trade group. “But we need a strong regulator enforcing the full force of the law. F.D.A. resources are limited, and therefore enforcement has not historically been as rigorous as it could be.”

Shelly Burgess, a spokeswoman for the F.D.A., said that companies were required to adhere to a set of good manufacturing practices designed to prevent adulteration, but that many were ignoring the rules.

“Unfortunately, we are seeing a very high percentage — approximately 70 percent — of firms’ noncompliance,” she said, “and we are very active in taking enforcement actions against such violations.”

DNA bar coding was developed about a decade ago at the University of Guelph. Instead of sequencing entire genomes, scientists realized that they could examine genes from a standardized region of every genome to identify species of plants and animals. These short sequences can be quickly analyzed — much like the bar codes on the items at a supermarket — and compared with others in an electronic database. An electronic reference library at Guelph, called the International Barcode of Life Project, contains over 2.6 million bar code records for almost 200,000 species of plants and animals.

The testing technique is not foolproof. It can identify the substances in a supplement, but it cannot determine their potency. And because the technology relies on the detection of DNA, it may not be able to identify concentrated chemical extracts that do not contain genetic material, or products in which the material has been destroyed by heat and processing.

But Dr. Newmaster emphasized that only powders and pills were used in the new research, not extracts. In addition, the DNA testing nearly always detected some plant material in the samples — just not always the plant or herb named on the label.

Some of the adulteration problems may be inadvertent. Cross-contamination can occur in fields where different plants are grown side by side and picked at the same time, or in factories where the herbs are packaged. Dr. Gafner of the American Botanical Council said that rice, starch and other compounds were sometimes added during processing to keep powdered herbs from clumping, just as kernels of rice are added to salt shakers.

But that does not explain many of the DNA results. For instance, the study found that one product advertised as black cohosh — a North American plant and popular remedy for hot flashes and other menopause symptoms — actually contained a related Asian plant, Actaea asiatica, that can be toxic to humans.

Those findings mirror a similar study of black cohosh supplements conducted at Stony Brook University medical center last year. Dr. David A. Baker, a professor of obstetrics, gynecology and reproductive medicine, bought 36 black cohosh supplements from online and chain stores. Bar coding tests showed that a quarter of them were not black cohosh, but instead contained an ornamental plant from China.

Dr. Baker called the state of supplement regulation “the Wild West,” and said most consumers had no idea how few safeguards were in place. “If you had a child who was sick and three out of 10 penicillin pills were fake, everybody would be up in arms,” Dr. Baker said. “But it’s O.K. to buy a supplement where three out of 10 pills are fake. I don’t understand it. Why does this industry get away with that?”

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