菊粉补充剂或有助缓解膝骨关节炎疼痛，117人临床试验报告小幅改善

• New research suggests that taking a fiber supplement could ease knee pain.
• The benefits are slight, but noticeable.
• Fiber shouldn’t replace existing treatments, doctors say.

Knee osteoarthritis can be a debilitating condition due to the joint pain, stiffness, and swelling it causes. Unfortunately, it's a reality for an estimated 14 million Americans. There are a range of potential treatment options that can help, including cortisone shots and GLP-1s, but a new study suggests a more accessible option may also help: taking a fiber supplement.

Research from a recent clinical trial published in the journal Nutrients suggests that adding a daily fiber supplement could ease pain from knee osteoarthritis, strengthen your muscles, and maybe even make you feel pain less intensely.

The Academy of Nutrition and Dietetics recommends having 14 grams of fiber for every 1,000 calories you consume, which means most women should aim for 25 grams of fiber daily, while men should strive for 38 grams each day. But the average American only eats around 17 grams of fiber per day, suggesting that many of us consistently fall short on this important nutrient.

Experts aren’t saying that you should take a fiber supplement instead of physical therapy or seeing a specialist for knee pain. But if you're doing everything else right, adding a fiber supplement to your routine might be worth trying out. Here's why.

Meet the experts: Afroditi Kouraki, lead study author and researcher in the School of Medicine at the University of Nottingham; Will Harvey, MD, rheumatologist at Tufts Medical Center and president of the American College of Rheumatology; Timothy Gibson, MD, orthopedic surgeon and medical director of the MemorialCare Joint Replacement Center at Orange Coast Medical Center in Fountain Valley, California

What did the study find?

For the study, researchers recruited 117 adults with knee osteoarthritis and split them into four groups. One group took a 20-gram daily inulin supplement (inulin is a naturally occurring fiber that's considered a prebiotic—it’s also commonly found in healthier soda alternatives), another did digitally supported physical therapy exercises (PSE), the third group did a combination of inulin and physical therapy, and the final group took a placebo.

Researchers discovered that people in the inulin and PT groups had less knee pain, and that people who took inulin had other perks that didn't surface in the physical therapy group, like better grip strength and less pain sensitivity. Also worth noting: Those who took inulin were more likely to stick with their prescribed treatment compared to the 21 percent of people in the PT-only group who dropped out.

“Earlier studies had linked certain gut bacteria, such as Streptococcus, to worse knee pain,” says Afroditi Kouraki, lead study author and researcher at the School of Medicine at the University of Nottingham. That, plus feedback from people suffering from knee arthritis who said they wanted diet-based ways to manage their pain, led Kouraki and her team to study inulin.

Why might fiber help with knee pain?

The researchers didn't study the why behind this association, but experts have a few theories. "Good gut bacteria feed on fiber like inulin and, in doing so, they produce substances that calm inflammation and help keep the gut lining healthy," Kouraki says. Your gut "talks" to your brain and nerves, and it can influence how sensitive you are to pain, she explains.

Kouraki points out that people in the study who took inulin also had higher levels of the gut hormone GLP-1 (yep, that GLP-1), which is also tied to pain regulation, and that those with bigger rises in GLP-1 tended to have a stronger grip. "These clues are early, and we need more research to understand exactly what’s going on," she says.

But it's important to put the findings into context. "Exercise still did more to improve walking and chair-rise ability, which matters for patients," says Timothy Gibson, MD, orthopedic surgeon and medical director of the MemorialCare Joint Replacement Center at Orange Coast Medical Center in Fountain Valley, California.

And while the findings suggested perks with taking an inulin supplement, they weren't huge differences, points out Will Harvey, MD, rheumatologist at Tufts Medical Center and president of the American College of Rheumatology. "At best, further study is warranted," he says.

Is this better than other joint-supporting supplements?

People concerned about their joints will often take collagen, glucosamine and/or chondroitin. But "there is no strong evidence to support the use of dietary supplements," Dr. Harvey says.

Kouraki also points out that collagen and glucosamine are aimed at the joint itself, while inulin works indirectly through the gut bacteria and the body’s immune and hormone systems. "It’s a different approach, using diet and the gut to help manage symptoms,” she says.

What's the takeaway?

Knee pain is complicated, and it's a stretch to say that taking a fiber supplement will make everything better. "This doesn’t replace proven treatments like exercise and physiotherapy, which also worked well in our study," Kouraki says. "But it suggests diet could be a useful extra tool."

If you're struggling with knee pain, Dr. Gibson recommends doing the following:

• Don't ignore proven care. While fiber is an "interesting add-on," it should be used with exercise, physical therapy, and your doctor's care plan—and not as an intervention on its own, he says.
• Change up your diet and exercise plan. "A balanced high-fiber diet, healthy weight, and regular leg-strengthening exercise remain the proven base for knee arthritis," Dr. Gibson says.
• Look for new developments. A growing body of research suggests that arthritis is a whole-body inflammation problem with ties to gut health, Dr. Gibson says. "Fiber and GLP-1 are exciting new angles, but we need longer studies to know if the pain benefit lasts and protects the joint," he says.

And, of course, if you're in pain and it's not getting better, talk to your doctor. They should be able to suggest alternative strategies to make you more comfortable.

Carina Hsieh, MPH, is the deputy features editor of Women’s Health. She has more than a decade’s worth of experience working in media and has covered everything from beauty, fashion, travel, lifestyle, pets, to health.

She began her career as an intern in the fashion closet at Cosmopolitan where she worked her way up to Senior Sex & Relationships Editor. While covering women’s health there, she discovered her passion for health service journalism and took a break to get her Masters in Public Health. Post-grad school, she worked as a freelance writer and as The Daily Beast’s first Beauty, Health, and Wellness Reporter.

Carina is an alum of the Fashion Institute of Technology and the Yale School of Public Health. She and her French Bulldog, Bao Bao, split their time between Brooklyn and Connecticut. She enjoys reformer Pilates, (slow) running, and smelling the fancy toiletries in boutique fitness class locker rooms.