Why have I got arthritis?
As the answer is not always readily available, a collection of myths or half-truths have evolved around the topic.
This article looks at why certain types of arthritis occur and examines the facts behind some of the common myths concerning arthritis.
To paraphrase Somerset Maugham, just because "everyone" says so, does not mean it is true.
For the inflammatory arthritides such as rheumatoid arthritis (RA), the cause of the disease is not known.
It is thought that RA occurs when a susceptible individual becomes exposed to factors that start the autoimmune inflammatory process.
Susceptibility factors are those that determine the risk of developing a disease.
In the case of RA, gender and genes are susceptibility factors. Females are three times more likely than males to develop RA.
People with specific variants of the Human Leucocyte Antigen (HLA) gene are more likely to develop RA.
But not everyone with these genes will develop RA, so there must be additional initiating factors.
For example, in identical twins, who share exactly the same genes, the risk of the second twin developing RA, once the first twin has RA, is approximately 15 per cent.
This is much higher than the prevalence of RA in the population, which is around 1 per cent, but not 100 per cent as it should be if the development of RA was purely due to genes.
Some initiating factors that have been postulated to trigger RA include cigarette smoking and stress (patients with RA have reported stressful events more frequently in the six months prior to RA diagnosis compared to the general population).
Although infection as a trigger for RA has been studied intensively, there is no evidence at this point in time linking it to the onset of RA.
Thus, though we may know who are at risk of developing RA, we do not know why the disease starts only in certain individuals.
Regardless of why it starts, it is important that RA is recognised, diagnosed and treated early, as untreated RA leads to progressive joint damage, causing joint deformity, and consequently, disability.
Osteoarthritis (OA) occurs as a result of various factors acting collectively, resulting in cartilage loss and associated bony changes.
As mentioned in the previous article, age is a major risk factor for OA, with an increasing incidence in older, compared to younger, persons.
However, there are genetic influences as well, as females are twice more likely to get OA compared to males.
Other factors that contribute to OA risk are obesity and previous injuries to the joint.
Thus, there are some obvious reasons as to why OA can develop.
But as with RA, it is not known why some will develop the disease and others are spared.
In contrast to RA, the natural history of OA is less aggressive, and the rate of progression is very much slower.
In spite of this, patients with suspected OA should still be assessed to make a definite diagnosis and to exclude other causes of joint pain.
Gout is a painful arthritis that occurs in some people with a high urate, or uric acid, level.
Not everyone with high blood uric acid levels (called hyperuricaemia) develops gout; up to two-thirds of individuals with hyperuricaemia never develop symptoms and it is unclear why some people with hyperuricaemia develop gout while others do not.
A typical attack of gouty arthritis starts in one joint, which becomes very painful, swollen, warm and tender over a few hours, followed by gradual resolution over a few days.
Rarely, a few joints can be involved simultaneously.
Joint pain without swelling or redness, even in the presence of hyperuricaemia, cannot be automatically labelled as gout.
Why is there uric acid in the body?
Uric acid is the end product when purine compounds are completely broken down.
Purines are natural substances found in all of the body's cells, and in virtually all foods, as they provide part of the chemical structure of our genes and the genes of plants and animals.
Some foods contain more purine than others; some examples of high-purine foods are organ meats like kidney, fish like mackerel, sardines and mussels, and also yeast.
When cells die and get recycled, the purines in their genetic material get broken down and uric acid is formed.
Thus, it is normal for uric acid to be present in our blood.
In addition, uric acid is thought to have beneficial antioxidant properties.
However, at higher levels, uric acid crystals can deposit in the joints, soft tissues and kidneys, and can cause disease.
A high intake of dietary purine as well as fructose (and table sugar which is roughly 50% fructose) can cause increased levels of uric acid.
Reassuringly, moderate intake of purine-rich vegetables has not been shown to be associated with an increased risk of gout.
It can be seen from the above that not all arthritis is the same, and it is not possible to make general statements about arthritis that are applicable to all.
The following are some of the common (mis)conceptions about arthritis:
1. Arthritis is part of growing old
This depends on what type of arthritis is under discussion.
OA can be regarded as part of growing old. But it is definitely not true of RA; the peak onset of RA is in people between 30 and 55 years old.
As RA can potentially cause irreversible joint damage.
It is important that people with unexplained joint pain and/or swelling, especially in the "younger" age groups, see a specialist to get a full assessment and appropriate treatment.
2. Arthritis is not treatable
This is not true; there are many medications available to treat and control RA so that progressive joint damage does not happen and quality of life is maintained.
For gout, treatments are available to relieve the acute attack and prevent future attacks.
In OA, supplementation with glucosamine and/or chondroitin can reduce further cartilage loss and interventions such as exercise, physiotherapy and/or injections have been shown to improve the quality of life in OA patients.
3. Arthritis does not happen in children
This is not true, as the inflammatory arthritides can happen in children.
Approximately one in 10,000 children (under 16 years old) develop juvenile idiopathic arthritis (JIA), which includes childhood RA.
Similar to adults, children should be assessed by a specialist when they have persistent joint pain and/or swelling for more than six weeks.
In some cases, the child can present with unexplained fever, rashes, eye symptoms or limping.
4. A wrong diet has caused my rheumatoid arthritis
RA is an autoimmune disease, due to the overproduction of abnormal antibodies by the immune system, leading to inflammation, all of which is unrelated to diet.
The only arthritis where diet may play a role is gout, as discussed above and in the next paragraph.
5. I need to go on a restricted diet for my arthritis
As explained above, gout is the only arthritis that has a relationship to food. But even in gout, it is not only the diet that leads to a high uric acid level.
Approximately 70% of the body's uric acid is produced from the breakdown of the body's own cells, and only 30% comes from the diet.
The vast majority of patients with gout do not get rid of the uric acid effectively through the kidneys and others over-produce uric acid.
So, although a restricted diet may be helpful in gout patients, the reduction in uric acid level with diet alone would be modest, around 20% at most.
In contrast, there is no evidence that dietary restrictions can treat RA as the body's immune system function is unaffected by diet.
6. Arthritis is a mild disease and will eventually go away on its own
There is no cure for arthritis, which means that it will not "go away on its own".
In fact, if untreated, over 90% of RA patients will have progressive disease.
It is therefore vitally important that patients with suspected RA are seen and assessed early for appropriate treatment, rather than to hope that it will "go away on its own".
OA is also progressive, albeit at a much slower rate.
Gout sufferers can have episodes where they are asymptomatic, but if uric acid levels are persistently high, uric acid crystals can form and deposit in joints and other organs, causing damage.
7. Alternative/traditional medicine can "cure" arthritis
For the inflammatory arthritides such as RA, there is no cure, in the sense of the disease going away forever.
The aim of treatment is to fully settle the joint pain and swelling, ie to control the disease.
With the conventional medications that are currently available, good control of RA is definitely achievable.
In contrast, there is no scientific evidence at present that alternative/traditional medicine (TM) can control the inflammation in RA.
In OA and gout, there is also no evidence that TM can cure the arthritis.
TM modalities such as acupuncture can help in relieving pain, but it does not alter the underlying pathology, so can be regarded as useful for symptomatic relief only.
8. I have a high uric acid level, I must have gout.
As described above, gout is a type of arthritis where the affected joint gets swollen, warm and painful.
Joint pain without swelling, even in the presence of a high uric acid level, is not automatically considered as gout.
1. Choi HK, Atkinson K, Karlson EW, Willett W and Curhan G. Purine-rich foods, dairy and protein intake, and the risk of gout in men. N Engl J Med 2004; 350: 1093-1103
This article is a collaborative effort by Dr Yeap Swan Sim together with MSD and is supported by the Arthritis Foundation of Malaysia. This article is for educational purposes only.