The smallest act of kindness is worth more than the grandest intention. 

                                                              --Oscar Wilde

SATURDAY, Nov. 5 (HealthDay News) -- Arthritis of the knee is striking Americans at younger ages, new research has found, but shedding a few pounds if you're overweight may reduce your risk.

The studies were to be presented Saturday at the American College of Rheumatology annual meeting, in Chicago.

Nearly 6.5 million Americans between the ages of 35 and 84 will receive a diagnosis of knee osteoarthritis in the next decade, according to these new projections.

"The diagnosis of knee osteoarthritis is occurring much earlier," said study author Dr. Elena Losina, co-director of the Orthopedics and Arthritis Center for Outcomes Research at Brigham and Women's Hospital in Boston.

When she compared the age at diagnosis in the 1990s to ages in the 2010s, "the average age at diagnosis has moved from 69 to 56," she said.

It strikes some earlier than the average age, of course. Losina found that adults aged 45 to 54 will account for nearly 5 percent of all knee osteoarthritis (OA) cases in the 2010s, while they represented only 1.5 percent of the knee OA patients in the 1990s.

Losina suspects that obesity and knee injuries, both of which have become more common in the past decade, may be helping to drive the increase in knee OA among younger people.

Injuries to the knee have been linked with an increased risk of knee arthritis. And certain sports are riskier than others, said another researcher, Dr. Jeffrey Driban, an assistant professor of rheumatology at Tufts Medical Center in Boston. He reviewed studies that looked at a link between sports participation and knee OA. He focused on 16 studies, and then honed in on 10 that looked at athletes and nonathletes.

While there were not great differences later in the amount of knee OA for former sports players and nonathletes, he did find a risk linked with the type of sport and level of participation.

Soccer players, whether elite level or not, had a greater risk of knee OA, he found. So did elite long-distance runners, competitive weight lifters and wrestlers.

The increased risk of arthritis in these participants varied from about threefold to more than sixfold compared to nonathletes, he said.

For those who already have knee OA, the best medicine may be weight loss if they are overweight, and exercise.

In another study, Dr. Stephen Messier of Wake Forest University found that a program of diet and exercise reduced pain and improved mobility by as much as 50 percent in those with knee arthritis.

He assigned adults with knee OA and pain to one of three groups for the 18-month program. One group dieted only, one group exercised only and one group did both.

In all, 399 overweight or obese men and women, average age 66, completed the study. The diet and exercise group lost the most weight, averaging 11.4 percent of their body weight. The diet-only group lost 9.5 percent; the exercise-only group lost 2.2 percent.

When they compared pain and mobility, the diet and exercise group reported much less pain and had greater walking speed than the other groups.

Driban suggested that those who want to minimize the risk of knee OA later should consider sports with a lower knee injury risk, such as swimming and cycling.

However, a sports medicine specialist took issue with that suggestion. "There is no evidence that impact sports like running causes arthritis in a healthy knee," said Dr. Stephen Nicholas, director of the Nicholas Institute of Sports Medicine and Athletic Trauma at Lenox Hill Hospital, in New York City.

Like other experts, he does agree that once a knee injury occurs, a person is at higher risk for knee arthritis.

However, if someone has a healthy knee, Nicholas said he would tell them to pick the sport they enjoy.

Losina's research was funded by the U.S. National Institutes of Health's National Institute of Arthritis and Musculoskeletal and Skin Diseases. All three studies should be viewed as preliminary, as they were presented at a medical meeting and not yet peer-reviewed.

More information

To learn more about osteoarthritis, visit the American College of Rheumatology  .

MONDAY, Oct. 31 (HealthDay News) -- Another study finds that yoga classes can improve back function among people with chronic or recurrent lower back pain.

While the British researchers found that yoga could help people move about and perform tasks, the ancient practice did not appear to reduce back pain itself.

The finding comes on the heels of similar results from a U.S. investigation published last week by University of Washington researchers in the Archives of Internal Medicine. That study found that sufferers of chronic lower back pain could get pain relief by participating in either instructor-led yoga classes or stretching classes.

Although last week's study focused on the relief of back pain, as opposed to the improvement of back function, both of the new studies found yoga classes worked better compared to people simply trying to help themselves with a self-help book on easing back pain.

"Our results showed that yoga can provide both short- and long-term benefits to those suffering from chronic or recurrent back pain, without any serious side effects," said study lead author Helen E. Tilbrook, of the University of York's department of health sciences in Heslington, England.

Tilbrook and her team published their findings in the Nov. 1 issue of the Annals of Internal Medicine.

The researchers noted that chronic or recurrent back pain is one of the most common ailments driving people to seek health care.

To assess what role yoga might play in alleviating back pain, between 2007 and 2010 the team focused on the experience of just over 300 British back pain patients, most of whom were middle-aged women.

By the time of the study launch, the participants had endured an average 10 years of back pain, the authors noted.

Throughout the study all the participants continued their previous back pain standard of care (which can include medication, massage therapy and chiropractic treatment), supplemented by the distribution of a back pain education booklet.

However, roughly half the participants were also offered a three-month, 12-session yoga course led by experienced teachers.

No more than 15 students were enrolled in any one class, which were based on the "asana" and "pranayama" forms of yoga, and included a range of relaxation and mental focus techniques.

The result: disability and pain questionnaires completed at the end of the yoga program, as well as three and six months thereafter, revealed that those who had taken yoga classes reported better back function at every juncture, compared with the non-yoga group.

The biggest boost in back function among the yoga group was observed immediately following the conclusion of classes.

Back pain and general health, however, was no better among the yoga group than the non-yoga group, the team observed. That said, yoga participants expressed a greater confidence than those in the non-yoga group in their ability to perform normal activities both at the conclusion of yoga classes and three months after.

Tilbrook's team concluded that yoga appeared to offer back pain patients a better shot at improving back function than the usual course of back pain treatment.

Karen Sherman, the lead author of the back pain study published last week, believes the two new studies provide "better evidence that yoga is worth trying for patients with non-specific low back pain."

"Persons with 'non-specific' chronic low back pain don't have a lot of conventional medical options that have been shown to be helpful," noted Sherman, who is associate professor in the department of epidemiology at the University of Washington, Seattle. "So, they commonly turn to various alternative therapies for relief," she explained.

"Prior to the publication of our recent study and the U.K. trial, there were less than 10 smallish studies suggesting that yoga might be a viable treatment option for persons with chronic low back pain," Sherman continued. "Our studies are larger and more robust than previous studies."

And while Sherman pointed to some differences in the way the two investigations were designed, both came to the same conclusion: "That yoga improves function among back pain patients," she said.

"So, I think the bottom line is that yoga is a viable treatment option," said Sherman, "and one that physicians and other clinicians should feel comfortable recommending to patients, especially if they have more mild or moderate back pain that limits their abilities to perform various activities that are a normal part of life for them."

More information

There's more on back pain at the U.S. National Institute of Neurological Disorders and Stroke.