What are 10 risk factors for rheumatoid arthritis?
Several issues can increase the chances of developing rheumatoid arthritis (RA). Some are unavoidable, but a person can take action to prevent others.
Having a healthful diet, avoiding smoking, looking after the teeth and gums, and taking probiotics may reduce the risk of developing RA.
In this article, learn more about the factors that can increase RA risk, and which lifestyle changes may help.
1. Genetic factors
RA causes pain and swelling in the joints and other symptoms.
If a close family member has RA, a person may have a higher risk of developing it themselves.
Genetic factors alone may not predict the disease.
However, they can make a person more likely to develop RA if other triggers, such as smoking or obesity, are present.
According to the Centers for Disease Control and Prevention (CDC), women are two or three times more likely to develop RA than men. Hormones may play a role, and research into this is ongoing.
Also, the CDC note that women who have never given birth may have a higher chance of developing the disease.
Some research points to a link between low testosterone levels and RA.
In 2018, researchers published results of a case study involving 59 people with RA and 61 people, matched for sex and age, without the condition. Those with RA were more likely to have abnormal testosterone levels.
Some participants with RA then received serum testosterone therapy, and the activity of RA reduced. The authors believe that hormone replacement may help treat symptoms of RA.
During and after menopause, females with RA often find it harder to function physically. Physical ability also seems to decline more quickly after menopause than before in females with the disease, according to results of a 2018 study.
These findings also suggest that hormones play a role in the progression of RA.
Anyone can develop RA, but the risk increases with age. It is most likely to start when a person is in their 60s, according to the CDC.
Smoking is a key risk factor for RA.
Regular smokers have a significantly higher risk of developing RA than nonsmokers, and the outlook is worse for those who continue to smoke.
Results of studies indicate that smoking may change the body's immune response, especially in people genetically predisposed to develop RA.
Smoking can cause oxidative stress and increase the frequency of the body's inflammatory response. It can also make some prescription RA medications less effective.
According to the authors of one study, "Smoking has been implicated as one of the most important extrinsic risk factors" for the development and severity of RA.
RA is an immunological disease, but some researchers suggest that it may also involve factors unrelated to the immune system. For example, the way the body reacts to stress may worsen symptoms.
People with rheumatic conditions often report that traumatic or stressful experiences occurred shortly before symptoms first appeared. Many people find that stress causes RA symptoms to flare up.
The CDC report a link between obesity and the risk of developing RA.
Researchers also associate obesity with several health issues, such as metabolic syndrome, that can exacerbate RA symptoms. For example, inflammation is a common feature of both obesity and metabolic syndrome.
7. Early life factors
Growing up with exposure to certain triggers, such as cigarette smoking, can increase a person's risk of developing RA later in life.
The CDC report that people from a low-income background appear to have a higher risk of developing the disease.
8. Previous infection
An infection's impact on the immune system may trigger RA.
In 2013, researchers suggested that infection may result in RA if:
- part of the immune system loses its ability to handle certain microbes (bacteria or viruses)
- the infection triggers the production of new antigens, causing the immune system to become overactive
- the immune system's response to the infection also attacks some of the body's functions, in a process called bystander activation
Infections that may contribute to RA
Also, some research indicates that the following infections may contribute to RA:
- a urinary tract infection with Proteus mirabilis bacteria
- the Epstein–Barr virus
- infection with bacteria in the Mycoplasma genus
- periodontal disease, which can result from infection with Porphyromonas gingivalis bacteria
- gastrointestinal or genitourinary infections with Chlamydia trachomatis bacteria, or with species of Salmonella, Shigella, Campylobacter, or Yersinia bacteria
Will gum disease or a tummy bug give me RA?
Periodontal disease: Gum disease is twice as common in people with RA than in those without the condition.
However, this does not necessarily mean that having periodontal disease increases the likelihood of developing RA. Other factors may need to be present to trigger the arthritis.
Genitourinary or gastrointestinal infection: Signs of some kinds of arthritis may appear within 4 weeks of infection.
Infections with a possible link
Other infections that can trigger arthritis or mimic RA include:
However, in some cases it is not clear whether the inflammation and other symptoms of infection are due to RA, or if the RA results from the infection.
9. Gut bacteria
Results of a 2013 study indicate that 75 percent of participants with new-onset, untreated RA had Prevotella copri (P. copri) bacteria in their intestines.
This type of bacteria was present in only 21 percent of participants in a control group, and only 12 percent of a group receiving treatment for chronic RA.
The researchers proposed that P. copri may play a role in inflammation, which can help trigger RA.
Authors of a 2016 study concluded that an abundance of certain microbes can characterize RA, and that finding indications of these microbes in the gut may predict the development of the disease.
Almost a year later, in an animal-based study, researchers found that altering the balance of microbes in the gut could prevent the onset of RA.
A diet that is rich in fresh vegetables and fruits offers antioxidant and anti-inflammatory benefits for people with RA.
A healthful diet can reduce the risk of many diseases, and it may play a role in RA management.
In addition, some researchers have suggested that certain substances in foods can trigger the onset of RA.
Authors of a study from January 2018 found that a type of bacteria in some milk and beef may trigger RA in people with genetic predispositions.
Anti-inflammatory foods may help with symptoms
The authors recommended, among other foods:
- raw or lightly cooked vegetables, especially legumes and green vegetables
- spices, such as turmeric and ginger
- seasonal fruits
- probiotic yogurt
They urged people to avoid:
- animal-based products
- foods that contain high amounts of salt and oil, including many processed products
The researchers did not suggest that dietary interventions could prevent the development of RA.
However, incorporating anti-inflammatory foods into the diet may help reduce symptoms in people with this type of arthritis.
It is not clear exactly what causes RA, but some factors can increase the risk of developing it.
Some factors are unavoidable, but quitting smoking, maintaining a suitable body weight, and eating a healthful diet with limited amounts of processed food may help some people to prevent the onset of this painful condition.