Introduction

Rheumatoid Arthritis (RA) is characterised as a chronic inflammatory disease. Over time, it can lead to cartilage and bone damage, significantly affecting mobility. It targets the joints but may develop and affect vasculature and metabolism.¹ It leads to a lot of pain, stiffness and swelling around these joints, which affects the person’s ability to complete basic tasks due to immobility. Sufferers will have an inflamed synovial membrane as well as cartilage destruction and bone erosion, which is extremely painful.² Over the years, significant research has been conducted that points to diet having a significant role in the risk and management of the disease. The most important effect of diet on RA is its ability to have anti-inflammatory results if the correct choices are made.³

Pro-inflammatory foods

Some foods, such as red meat, salt, and excessive calorie intake, are pro-inflammatory and can increase the rate of disease development; hence, they should be heavily avoided. Oil, fatty fish, fruit, and many others typically reduce inflammation. In this essay, I will explain the different types of diets and how they affect sufferers of RA. 

The western diet and its negative effects

The Western diet is typically inferior for managing disease risk and overall health in general. The excess intake of red meat, saturated and trans fats, the low intake of omega-3 and omega-6 fatty acids, and the extremely high intake of refined carbohydrates is extremely unhealthy for RA and general health as it promote inflammation. The diet increases inflammation and leads to resistance, resulting in higher obesity rates in individuals with this diet. The excess mass that comes along with being obese puts a lot of stress on the joints of the individual, which further hinders mobility significantly.³ Furthermore, the more fat tissue is present in the body, the more stimulation for releasing cytokines is increased. This then leads to substantially higher rates of inflammation in the body and leads to RA progression.⁴ Inflammation is dangerous as it leads to fluid buildup around the joints where the immune cells target the synovial joint, cartilage and bone, slowly eroding and weakening them.⁵ Research has shown that diet does have a significant effect on disease progression in RA. However, smoking has the absolute worst effect, with diet being second to that. 

RA, chronic diseases, and the role of diet

As rheumatoid arthritis is an inflammation-caused chronic disease, it shares a lot of similarities and markers with other chronic diseases and cardiovascular diseases, such as type 2 diabetes, Alzheimer's disease, etc. These diseases are heavily affected by diet and proper nutrient selection in decreasing inflammation and metabolism regulation. Most research has been conducted on carbohydrates and fats in relation to their effect on RA. The glycemic index of carbohydrates is more impactful than the quantity of carbohydrates. In terms of fats, it seems that trans-fats such as margarine, fried foods, crackers, etc, are all pro-inflammatory and worsen the disease as they lead to increased levels of TNF-α, IL-1, CRP and vascular endothelial dysfunction. The research points to consuming polyunsaturated fats omega-3, which are abundant in fish oils and have significant anti-inflammatory properties. 

The mediterranean diet and its benefits

The Mediterranean diet is opposite to the Western diet. It is mostly composed of vegetables, unrefined cereals, legumes, fish, fruit, extra-virgin olive oil, and decent levels of eggs, poultry, dairy, and low amounts of refined sugars and red meat. This is a much more anti-inflammatory diet and typically less caloric, which results in lower obesity rates. The diet has a relatively high intake of alfa-linolenic acid, specifically anti-inflammatory. The results of this diet are recognised by the reduction in total and cardiovascular mortality, cancer, Alzheimer's and Parkinson’s disease incidence. 

The role of tea and flavonoids in reducing inflammation

Black tea consumption has been highlighted as an anti-inflammatory effect due to its ability to decrease CRP levels, leukocyte and platelet aggregation and activation, which is key in reducing inflammatory and immune attacks. Studies point to flavonoids (plant compounds found naturally in fruits and vegetables) and carotenoids ( pigments in plants, algae and photosynthetic bacteria) as having properties that are very high in producing anti-inflammatory effects in the human body. As a result, people should be encouraged to consume many fruits and vegetables as these naturally occur in them. Specifically, flavonoids have a vital role in inhibiting the two isoforms of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2). These are heavily involved in the production of inflammatory mediators. However, they also downregulate adhesion molecules and increase antioxidant defences, further increasing anti-inflammatory effects. Tomatoes have lycopene, significantly affecting cardiovascular function, reducing LDL cholesterol, improving endothelial function, and decreasing inflammatory factors.³ 

Study on anti-inflammatory diets and DAS28-ESR levels

A study was conducted where they recorded the changes in DAS28-ESR levels in volunteers when they were given a diet that consisted of mostly anti-inflammatory foods. The DAS28-ESR levels act as an indicator of inflammatory levels in this study. The volunteers with RA had their diets drastically changed to consist of large quantities of dairy, granola, walnuts, fruits like blueberries, probiotic shots, large levels of salmon and cod, beans, chickpeas, lentils, potatoes and more. This diet is rich in antioxidants, flavonoids and carotenoids, essential for anti-inflammatory responses. The DAS28-ESR levels significantly dropped after the diet had been implemented for its control period, displaying that this change in diet led to substantially less inflammation in volunteers with RA.⁶

Importance of antioxidants in RA management

Overall, the data signifies a diet that follows roughly along these guidelines to help patients with RA and high levels of inflammation in general. Fish and berries are vital in relieving symptoms of RA due to the antioxidants in the berries and the omega fatty acids. Omega-3 fatty acids led to a reduction of 35% in the risk of RA in women and further the risk of progressive RA. This is due to their anti-inflammatory properties, which inhibit leukocyte chemotaxis, adhesion molecule expression, and production of pro-inflammatory leukotrienes. Fruits, vegetables, and olive oil can decrease RA's progressive risk as they provide many nutrients with antioxidant properties, such as tocopherols in olive oil, which are free radical scavengers.³ As you can see, antioxidant foods are essential in the diet for RA sufferers, as they have a massive impact on the expression of transcription factors in the immune system, specifically on the suppression and reduction of pro-inflammatory cytokines. It does this by interrupting the signal pathways and enzymes involved in this process.⁷ 

Uncertainties in certain foods and beverages

However, the data on certain foods, like potatoes, tomatoes, and eggplants, is still not fully collected, as some studies suggest they can lead to an increased RA risk. The reason is believed to be that solanine and glycoalkaloids are present, which can increase intestinal permeability and negatively affect RA progression. Some foods need to be more researched, and it has also been proven to be quite challenging to assess the performance of a single food on the inflammation effect, as the diets used in the studies are typically balanced. As a result, even if the survey results indicate lower inflammation, it could be due to the majority of the diet being anti-inflammatory. However, some foods may still be pro-inflammatory. In addition to this, drinks that are high in sugar were linked to RA development; the high fructose drinks lead to an excessive build-up of glycation products that support inflammation. The link between coffee and RA is not fully understood, with some studies suggesting that more than 4 cups of coffee a day can increase RA risk; however, the studies mentioned that many of these coffee drinkers would also smoke a cigarette with their coffee, which undoubtedly increases inflammation risks and is a key RA development factor.³         

Summary

Overall, it is important to understand that diet has a very significant role in determining the progression of RA. Whilst some food groups aren’t adequately researched, substantial data points towards foods that are antioxidants and anti-inflammatory as key for decreasing RA progression. These foods tend to be fruits and vegetables, and the omega fats from fatty fish are essential. Whole grains, nuts, and seeds are also recommended for RA sufferers. It is important for those with RA to maintain a diet rich in these foods and a lifestyle that incorporates regular exercise to improve blood circulation and reduce inflammation. It is also key to avoid ultra-refined sugars, processed foods, red meats, and some dairy products, but most importantly, no smoking. If RA sufferers focus on implementing these changes into their lifestyle, they may be able to reduce the progression of RA significantly.