A single course of low-dose radiation therapy may provide a safe and effective alternative treatment option for people with painful knee osteoarthritis, according to a new randomized, placebo-controlled clinical trial. The study showed patients with mild to moderate knee osteoarthritis reported significant reductions in pain and improved physical function in the four months after receiving the low dose of radiation (just a small fraction of what’s used to treat cancer). The study included a control group with simulated treatment so the researchers could distinguish the therapy’s effects from placebo responses.
“People with painful knee osteoarthritis often face a difficult choice between the risks of side effects from pain medications and the risks of joint replacement surgery,” said principal investigator Dr. Byoung Hyuck Kim, who is an assistant professor of radiation oncology at Seoul National University College of Medicine in Korea. “There’s a clinical need for moderate interventions between weak pain medications and aggressive surgery. We think radiation may be a suitable option for those patients especially when drugs and injections are poorly tolerated.”
Osteoarthritis is the most common type of arthritis and affects an estimated 32.5 million U.S. adults. It occurs when the cartilage that cushions the ends of bones wears down over time. Symptoms often involve the knees and hips and can substantially limit daily activities and quality of life. Initial treatment typically involves pain medications and lifestyle measures, with surgery considered when symptoms worsen.
Low-dose radiation is regularly used for joint pain in European countries such as Germany and Spain where it is widely accepted. However, high-quality, randomized evidence has been limited before this trial. In this study, the doses were less than 5% of those typically used for cancer treatments. No radiation-related side effects were observed.
In this multicenter trial, researchers enrolled 114 patients with moderate-to-mild knee osteoarthritis across three academic centers in Korea. Participants were randomly assigned to receive one of two radiation regimens (a very low dose (0.3 Gy) or a low dose (3 Gy)) or a control group that underwent simulated (sham) radiation. In the placebo group, patients went through the same setup for radiation therapy, but the treatment machine did not deliver any radiation. All participants received six sessions and did not know which group they were in.
After four months, 70% of patients in the 3 Gy group met responder criteria, compared to 42% in the placebo group. Meaningful improvements in the composite score of pain, stiffness and physical function were reported more often in the 3 Gy group (56.8%) than in the placebo group (30.6%).
Dr. Kim emphasized that low-dose radiation should be considered as part of shared decision-making alongside standard measures such as weight loss, exercise, and medications. “In clinical practice, responses could be even stronger when radiation is properly combined with other treatments, and patient satisfaction may be higher than with current options alone,” said Dr. Kim.
Changing your exercise routine and diet may boost memory
Lifestyle changes have proven effective for reducing risks of cardiovascular and other major diseases. Now, it turns out certain lifestyle changes may also help reduce cognitive decline. Dr. Charles Hennekens, who is with Florida Atlantic University, said deaths from cardiovascular disease have declined since 2000. Conversely, deaths from Alzheimer’s disease have surged by more than 140%. “At the same time, it is estimated that up to 45% of dementia risk could be attributed to modifiable lifestyle and environmental factors,” said Dr. Hennekens.
Lifestyle risk factors such as physical inactivity, poor diet, obesity, alcohol use can lead to cognitive decline. Social or intellectual isolation is also believed to contribute to cognitive decline. The recently published results from the POINTER study underscore the importance of lifestyle choices. The POINTER study is the first large-scale U.S-based randomized trial to test whether intensive lifestyle changes can improve cognitive outcomes in older adults at high risk of decline.
In this trial, participants were assigned at random to a structured, team-based lifestyle intervention. The brain benefits were especially notable in executive functions such as memory, attention, planning and decision-making. The intervention emphasized regular physical activity,
a combination of Mediterranean and DASH-style diets, cognitive stimulation, and social engagement. These findings are similar to an earlier Finnish trial. In the FINGER trial, participants with elevated cardiovascular risk scores were assigned at random to a multidomain lifestyle approach. It was shown to be highly effective at improving cognitive function.
Physical activity increases brain-derived neurotrophic factor, which supports hippocampal growth, while also improving blood flow and reducing inflammation. Healthy dietary patterns (Mediterranean and DASH diets) can lower oxidative stress and improve insulin sensitivity as well as risks of cardiovascular disease. Quitting smoking may help preserve brain structure and white matter integrity. Regular social and cognitive engagement promotes neuroplasticity and mental resilience.
Beyond the health care system, the societal costs of dementia are staggering. In 2024, nearly 12 million family members and unpaid caregivers provided an estimated 19.2 billion hours of care to individuals living with dementia. This led to a societal cost of more than $413 billion.
Caregiving also takes an emotional toll, often resulting in mental health challenges and caregiver burnout. The researchers emphasize that these realities underscore the need for practical, community-based solutions that support both patients and caregivers and reduce the long-term burden on families and the economy. “While more research is needed, the current totality of evidence supports a clear path forward: Invest in lifestyle-based strategies to protect brain health,” said Dr. Hennekens.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at medicalminutes@gmail.com.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.
