Natural ageing of the joints
As we get older, cartilage gradually loses some of its ability to repair itself. It becomes thinner and less flexible, making it less effective at cushioning the joints during movement. This helps explain why osteoarthritis is more common after the age of 55, although it is not an inevitable part of ageing.
Repeated strain and joint injuries
Some joints are put under repeated strain throughout our lives, particularly through work, sport or repetitive movements. Joint injuries, such as fractures or severe sprains, can also have lasting effects on how a joint functions and increase the risk of developing osteoarthritis years later.
Being overweight or obese
Excess weight puts additional strain on weight-bearing joints, particularly the knees, hips and ankles. Fat tissue also releases molecules involved in low-grade inflammation, which may contribute to the progression of osteoarthritis.
Genetic factors
Osteoarthritis can run in families, particularly when it affects the hands. Genetic variations can influence the structure of the joints and the quality of cartilage, making some people more susceptible to the condition.
Joint abnormalities and certain diseases
Joint deformities, misalignment of the limbs and certain joint conditions can speed up cartilage wear. These factors can cause pressure to be distributed unevenly across a joint, leading to more rapid deterioration.
Diet
Diet does not directly cause osteoarthritis, but it can influence some of the factors involved in its development and progression. An unbalanced diet can contribute to weight gain, putting extra strain on the joints, particularly the knees and hips. Diets high in ultra-processed foods, added sugars and saturated fats have also been linked to low-grade inflammation, which may contribute to the gradual breakdown of joint tissue.
A varied, balanced diet, on the other hand, can help support overall health. Fruit, vegetables, pulses, wholegrains, oily fish, nuts and seeds provide a range of important nutrients. Antioxidants, omega-3 fatty acids, vitamins and minerals help protect cells from oxidative stress, a process involved in tissue ageing, including changes to cartilage.