Obesity a leading cause of knee osteoarthritis

A global study led by researchers at the University of Sydney has identified obesity, knee injury, and occupational risks such as shift work and heavy lifting as primary causes of knee osteoarthritis. The research also found that dietary habits, including following a Mediterranean diet and consuming green tea and dark bread, may lower the risk of developing the condition.

Published in the journal Osteoarthritis and Cartilage, the study was conducted by Associate Professor Christina Abdel Shaheed and Dr Vicky Duong from the Faculty of Medicine and Health’s Sydney Musculoskeletal Health, a collaborative initiative between the University of Sydney, Sydney Local Health District, and Northern Sydney Local Health District.

The researchers reviewed data from 131 studies published between 1988 and 2024, examining over 150 risk factors among adults aged 20 to 80 years. Their analysis focused on identifying environmental and lifestyle contributors to knee osteoarthritis, a condition that currently affects over 500 million people worldwide.

“Knee osteoarthritis is a debilitating condition that affects over 500 million people around the world and is a leading cause of disability. Our research found that while factors such as eating ultra-processed foods and being overweight increase the risk, addressing lifestyle factors – such as losing weight or adopting a better diet – could significantly improve people’s health,” said Associate Professor Abdel Shaheed.

Professor David Hunter, co-author of the study, researcher at the Kolling Institute and Professor of Medicine at the University of Sydney, added, “Women were twice as likely to develop the condition than men, and older age was only mildly associated with increased risk.”

The study also explored potential strategies to reduce the risk of developing the condition. Dr Vicky Duong, lead author and post-doctoral researcher at the Kolling Institute, said, “Eliminating obesity and knee injuries combined could potentially reduce the risk of developing knee osteoarthritis by 14 percent across the population.

“We urge governments and the healthcare sector to take this seriously and to implement policy reforms that address occupational risks, subsidise knee injury prevention programs, and promote healthy eating and physical activity to reduce obesity,” she added.

The findings are expected to inform future health policy and prevention strategies targeting one of the most common forms of musculoskeletal disease.