A Nutritious Diet and Exercise Can Prevent Osteoarthritis
by Lynn Hetzler
A nutritious diet and regular exercise can prevent a number of diseases, such as diabetes and cancer. A well-balanced diet and moving around can even reduce the symptoms of certain conditions. In fact, the Arthritis Foundation calls physical activity “the best non-drug treatment for improving pain and function” in those with osteoarthritis. Now, a new literature review shows eating well and engaging in physical activity can actually prevent osteoarthritis by reducing adiposity that causes metabolic changes within joints.
Researchers from the University of Surrey performed an expert review that included important information from 134 sources, revealing a crucial link between metabolism and osteoarthritis. They found that poor diet and a sedentary lifestyle could trigger metabolic changes in joints and body cells that could lead to the development of osteoarthritis.
Studies like that that identify metabolic changes in cells may someday help practitioners control or slow the progression of symptoms of osteoarthritis, thereby alleviating the suffering of millions.
Osteoarthritis is the most common joint disorder in the United States, according to the Centers for Disease Control and Prevention (CDC), with the disease affecting more than 30 people in the nation. Sometimes called ‘degenerative joint disease’ or ‘wear and tear disease’ because of the way it breaks down cartilage between bones, osteoarthritis most frequently occurs in the hands, hips and knees. Because degeneration usually occurs slowly and worsens with time, many people assume osteoarthritis is a normal part of aging.
“For too long, osteoarthritis has been known as the ‘wear and tear disease’ and it has been assumed that it is part and parcel of getting older. However, this is not the case and what we have learnt is that we can control and prevent the onset of this painful condition,” said lead author Professor Ali Mobasheri, Professor of Musculoskeletal Physiology at the University of Surrey in a press release.
“It is important never to underestimate the significance of a healthy diet and lifestyle as not only does it impact upon our general wellbeing but can alter the metabolic behavior of our cells, tissues and organs leading to serious illnesses.”
There is no cure for osteoarthritis, but a combination of therapies may alleviate pain and improve function. These therapies include:
- Physical activity
- Prescription and non-prescription analgesics
- Physical therapy featuring muscle strengthening exercises
- Weight loss
- Use of crutches, canes, or other supportive devices
- Surgery when other treatment options are ineffective
Risk factors associated with osteoarthritis include:
- Older age
- Gender, as adult females are more likely to develop osteoarthritis
- Joint injuries, even those that occur much earlier in life
- Certain occupations, particularly those that place repetitive stress on one particular joint
- Bone deformities or defective cartilage
Obesity, together with aging and injury, is a primary risk factor for osteoarthritis. Every pound of body weight places an additional three pounds of stress on the knees and six pounds of pressure on the hips. Carrying excess weight over the course of many years causes cartilage to erode.
Obesity-related osteoarthritis affects weight-bearing joints but also the hands, which suggests osteoarthritis has a systemic metabolic component. Adipose tissue releases adipokines, which play an important role in bone and cartilage homeostasis. Recent research shows adipokines are important factors linking obesity and inflammation in osteoarthritis. The review contributes more information that further strengthens the body of evidence supporting the link between diet, exercise, metabolism and the pathogenesis of osteoarthritis.
The role of metabolism in the pathogenesis of osteoarthritis
Metabolism has a key role in the physiological turnover of synovial joint tissues, including the smooth, white articular cartilage covering the ends of bones. In people with osteoarthritis, chondrocytes responsible for the production and maintenance of cartilage and cells in non-cartilage joint tissues undergo metabolic alterations, shifting from a resting regulatory state to a highly metabolically active state. This shift also increases metabolic intermediates for the biosynthesis of inflammatory and degradative proteins that can then activate key transcription factors and inflammatory signaling pathways that affect the catabolic process and drive pathogenesis.
In the results of their review, printed in Nature, the researchers found that inflammatory mediators, metabolic intermediates and immune cells influence cellular responses in other ways that contribute to the development of osteoarthritis.
Increased adiposity and dysfunction of white adipose tissue is closely associated with the chronic low-grade inflammatory status that is common to both obesity and osteoarthritis. White adipose tissue produces adipokines that promote inflammation and cartilage degradation. Affecting the microenvironment of joints can also alter the activity of immune cells in patients with osteoarthritis.
The infrapatellar fat pad may be another potential source of pro-inflammatory adipokines in the joint. Other types of cells in the fat pad, such as chondrocytes, synoviocytes, adipocytes and macrophages, may collectively contribute to the production of pro-inflammatory cytokines and chemokines.
Additionally, the metabolic changes brought about by poor diet and lack of exercise can affect the cells’ ability to produce energy necessary for cell function, thereby forcing cells to generate alternative sources of energy. The generation of alternative energy sources is taxing on cells, and the stress can stimulate the overproduction of glucose. The body transforms leftover glucose into lactic acid, which is difficult to eliminate. High levels of lactic acid cause inflammation of cartilage in joints; this inflammation impedes movement and causes pain.
Because of this strong connection between metabolism and osteoarthritis, lifestyle changes may be a realistic and attainable approach for preventing osteoarthritis and alleviating the disease’s burden on society. To reduce the effect this disease has on society, however, a greater understanding of how diet and exercise, along with biomechanical factors and joint injury, play a role in the pathogenesis of osteoarthritis is necessary. Future therapies for osteoarthritis may target key metabolic pathways and mediators.