11 Risk Factors for Rheumatoid Arthritis and What You Can Do about Them
You can take measures to help prevent this autoimmune disease. Here’s what you need to know.
By Linda Rath | Dec. 14, 2022
If a parent or close relative has rheumatoid arthritis (RA) — a potentially disabling autoimmune disease — you may wonder if you will develop it, too. The answer is probably not. You can inherit a susceptibility to RA, but not the disease itself. According to the American College of Rheumatology (ACR), relatives of people with RA have a 0.8% risk of developing it compared to 0.5% for people with no family history.
You may have heard that heritability of RA is around 60%; that doesn’t mean the ACR statistics are wrong. Heritability is an estimate of the degree to which genes explain the risk of disease in a population. Sixty percent heritability doesn’t mean that 60% of RA cases are inherited; it means that genes account for more than half of the susceptibility to RA found in northern Europeans, who dominate most genetics studies. It’s also becoming clearer that genetic risk for RA varies among races and ethnicities.
Most scientists think that RA, although not well understood, usually results from the interplay of genetic susceptibility and environmental and lifestyle factors. An increasingly important school of thought also focuses on epigenetics. This refers to the way that factors like diet or exercise change the way genes work. Although epigenetic changes don’t alter DNA, they can be passed on to future generations. There are certain rheumatoid arthritis risk factors that you can’t change, but others that you may be able to control.
RA Risk Factors You Can’t Control
You may not always be able to avoid environmental risk factors such as infections and toxins, but it’s important to know they may trigger RA, especially in genetically susceptible people.
A healthy lifestyle can help prevent RA, no matter what your genetic risk. Some rheumatologists say the new paradigm for RA is to treat it as a preventable condition, much like heart disease, in part because it’s possible to control some common risk factors, including:
If a parent or close relative has rheumatoid arthritis (RA) — a potentially disabling autoimmune disease — you may wonder if you will develop it, too. The answer is probably not. You can inherit a susceptibility to RA, but not the disease itself. According to the American College of Rheumatology (ACR), relatives of people with RA have a 0.8% risk of developing it compared to 0.5% for people with no family history.
You may have heard that heritability of RA is around 60%; that doesn’t mean the ACR statistics are wrong. Heritability is an estimate of the degree to which genes explain the risk of disease in a population. Sixty percent heritability doesn’t mean that 60% of RA cases are inherited; it means that genes account for more than half of the susceptibility to RA found in northern Europeans, who dominate most genetics studies. It’s also becoming clearer that genetic risk for RA varies among races and ethnicities.
Most scientists think that RA, although not well understood, usually results from the interplay of genetic susceptibility and environmental and lifestyle factors. An increasingly important school of thought also focuses on epigenetics. This refers to the way that factors like diet or exercise change the way genes work. Although epigenetic changes don’t alter DNA, they can be passed on to future generations. There are certain rheumatoid arthritis risk factors that you can’t change, but others that you may be able to control.
RA Risk Factors You Can’t Control
- Age. Conventional wisdom has it that the chance of RA increases with age. But experts say RA that develops after age 60 — called late-onset RA — is different from RA in younger people. Also, the risk as you get older may not be as great as originally thought; current research shows that RA antibodies develop many years before symptoms appear.
- Biological sex. RA is far more common in people born female than those born male. The disparity is often blamed on hormones, mainly because RA can get better or worse as hormones shift. Yet studies about the relationship between RA and sex hormones show mixed results. Newer theories focus on women’s more robust immune response to infections, which generates more antibodies, and on differences in the innate immune system.
- Your genes. Hundreds of gene variants, especially a genetic marker called the shared epitope, are associated with RA, but their exact role isn’t clear. Many people who have these gene variants never develop RA, while others who don’t have them get arthritis or other autoimmune diseases. Genes may influence the progression of RA or response to treatment, but by themselves aren’t enough to cause disease.
You may not always be able to avoid environmental risk factors such as infections and toxins, but it’s important to know they may trigger RA, especially in genetically susceptible people.
- Infections. Epstein-Barr virus, Escherichia coli (E. coli) and hepatitis C have been suggested as possible causes of autoimmunity and RA. One theory is that the immune system overreacts to infections, creating chronic inflammation and ultimately autoimmune arthritis. Some scientists also think there may be cross-reactivity between certain antibodies and healthy cells. Normally, antibodies only attack a single antigen, but antibodies produced against Epstein-Barr, for example, might also target normal tissue.
- Toxins. Lots of different toxins, pollutants and chemicals have been linked to RA, but not all are proven. Those that have a clear association include second-hand smoke, asbestos, silica dust and pesticides. Chronic lung inflammation is known to lead to the formation of autoantibodies, and scientists speculate these may travel from the lungs to distant sites, including the joints. It’s likely many more toxins are implicated in RA, but more research is needed to find the worst offenders.
- Childhood trauma. Violence, abuse and neglect in childhood are increasingly linked to RA in adults. Emotional distress is known to trigger an immune response that can lead to autoimmune disease. It is also one of the factors that affect arthritis pain and other symptoms. In one study, adults with RA and a history of childhood trauma were found to have significantly more pain than similar patients without traumatic backgrounds.
A healthy lifestyle can help prevent RA, no matter what your genetic risk. Some rheumatologists say the new paradigm for RA is to treat it as a preventable condition, much like heart disease, in part because it’s possible to control some common risk factors, including:
- Smoking. Tobacco smoke is a known risk factor for RA as well as heart disease and a host of other chronic conditions. It’s involved in the transition from pre-clinical RA, when you have autoantibodies but no symptoms, to full-blown disease. It may even trigger RA in someone who is not genetically susceptible, especially in those who smoke at least a pack a day for 20 years or more. If you already have RA, smoking can make your treatment less effective and your symptoms more severe.
- Obesity. Excess weight can trigger systemic inflammation because fat cells release inflammatory proteins called cytokines, which play a fundamental role in the destruction of joint tissue. The more fat cells you have, the more cytokines your body produces. Being overweight or obese also makes you less likely to respond adequately to arthritis medications or achieve disease remission.
- Gum disease. It’s now well established that gum disease is a factor in causing RA as well as lung disease, heart disease and Alzheimer’s. Your mouth has more than 700 species of bacteria. Most of the microbes are beneficial and help keep harmful bacteria in check. When harmful bacteria over-ride these defenses, you can develop gingivitis and oral cancer. You can also aspirate bacteria into your lungs, where they cause massive inflammation. The inflammation can then spread to other parts of your body, including your joints.
- Food. Although there is no specific arthritis diet, the type of food you eat affects every aspect of your health. Avoiding some foods, such as red meat, dairy products, sugar and high-fructose syrup, and emphasizing fish, vegetables and olive oil, may make a difference in whether you develop arthritis as well as improve existing symptoms.
- Changes in the microbiome. In the last 20 years, the microbiome — the vast communities of beneficial microorganisms living on and in the body — has been recognized as a critical determinant of health and disease. This is especially true for autoimmune diseases like RA because the microbiome regulates and is regulated by the immune system. Although every nook and cranny in the body has a microbiome, those in your mouth and gut are the most extensive and have the greatest impact on your health. Ideally, the trillions of microorganisms in these communities work in harmony to maintain a state of balance that helps prevent illness. When that balance is disrupted, some beneficial species of microbes lose their dominance and others that may be harmful or found in smaller numbers take over. When this happens, you’re more likely to develop chronic conditions like diabetes, metabolic syndrome or RA. The makeup of your gut microbiome can vary, depending on your age (the microbiome changes as you get older), diet, race, ethnicity and where you live. It’s not clear what a normal microbiome looks like. It is clear, however, that people with RA and other autoimmune diseases have different proportions of gut microbes compared to healthy people. They also have less — sometimes far less — microbial diversity. The loss of certain microorganisms means there is less protection against inflammation and autoimmunity. Leaky gut, another risk, occurs when inflammation and changes in the composition of the microbiome make the intestinal wall more permeable and allow bacteria to escape into the rest of the body. This produces even more inflammation and may eventually lead to RA. Lots of things can upset the balance of the microbiome, with antibiotics topping the list. But certain foods, especially red and processed meat, sugar and dairy products, as well as stress, lack of exercise, trauma and drinking alcohol also contribute. Scientists think that we shape the microbiome almost as much as it shapes us.
Given that these and other risk factors for RA are within your control, you have every reason to feel positive about your ability to help you and your family stay healthy.