Medical Nutrition Therapy For Inflammatory Conditions

Introduction

Inflammation occurs when the body’s immune system responds to harmful stimuli. There are two types of inflammation: acute and chronic. Acute inflammation is short-lived and resolves when the healing process finishes, whereas chronic inflammation persists long-term.

Acute inflammatory responses are an important self-defence mechanism, however, uncontrolled acute inflammation may become chronic, leading to chronic inflammatory conditions. Inflammatory conditions are difficult to live with and can significantly lower an individual’s quality of life.¹

Fortunately, a range of treatments are available including pharmacological options like anti-inflammatory drugs, and non-pharmacological options like medical nutrition therapy (MNT). MNT is defined as nutrition-based advice and treatment regimes provided by a registered nutritionist to manage health conditions. Dietary intervention can be used to reduce inflammation by altering the gut microbiome.²

Understanding inflammatory conditions

Inflammation is normal in an individual and a useful mechanism in adaptive immune responses. It is a natural and essential response of the body to infection or injury. However, problems arise when adaptive immune responses are ongoing and cause chronic inflammation. This leads to a range of inflammatory conditions. There are many different forms of inflammatory conditions; the most common are rheumatoid arthritis, inflammatory bowel disease, and chronic inflammation.³

Rheumatoid arthritis 

Rheumatoid arthritis is a chronic inflammatory autoimmune disorder affecting an estimated 1% of the world population. It is an extremely debilitating disorder affecting joints in the body, particularly in the hands and feet. Symptoms of rheumatoid arthritis can vary in different individuals and change over time, it includes stiffness, pain, and swelling; all of which are characteristics of inflammation.

Rheumatoid arthritis is an autoimmune disease; when the immune system targets the body’s tissue surrounding the joints- the synovium. Inflammatory agents in the joints can cause it to lose its shape and misalign if it goes untreated over time. The cause of rheumatoid arthritis is still currently unknown, speculated risk factors include genetic and environmental factors.⁴ 

Inflammatory bowel disease

Inflammatory bowel disease (IBD) is an autoimmune disease where the digestive system is attacked by its immune cells, characterised by chronic inflammation of the gastrointestinal (GI) tract. There are 2 main types of IBD: Crohn’s disease and ulcerative colitis. Crohn’s disease affects anywhere along the GI tract, but mostly the small intestines, with inflammation localised to the walls of the GI tract. Whereas, ulcerative colitis affects the large intestines (colon) and the rectum, with inflammation localised to the innermost layer of the colon.

Symptoms include persistent diarrhoea, abdominal pain, bloody stools, and fatigue. The cause of IBD is still undetermined, however, it is clear that genetic mutations and predispositions play a role. Genetic risk factors and exposure to bacteria and viruses weaken the immune system, increasing the chance of inflammation in the GI tract.⁵

Chronic inflammation 

Chronic inflammation refers to persistent and long-term inflammation. There are many possible causes of chronic inflammation:

1. Failure to treat acute inflammation, for example, infection or injury
2. An autoimmune disorder, for example rheumatoid arthritis
3. Recurring acute inflammation 
4. Auto-inflammatory disorders 
5. Long-term exposure to inflammatory inducers, for example, industrial chemicals or polluted air

It is important to note that some cases of chronic inflammation don't have clear underlying causes. Symptoms of acute inflammation include pain, redness, and swelling, symptoms of chronic inflammation encompass this and additional symptoms of gastrointestinal complications and changes in weight. 

Inflammation-related diseases significantly impact global health; chronic inflammatory conditions are the leading causes of death. Persistent inflammation can alter your body’s natural immune responses, leading to autoimmune diseases. Chronic inflammation is also linked to many other diseases like cardiovascular disease, diabetes, cancer, and asthma.⁶

The role of nutrition in managing inflammation

Altering your diet and opting for more anti-inflammatory foods can help manage inflammatory conditions. This consists of eating various fruits and vegetables, unsaturated fats, oily fish, refined whole grains, herbs and spices, nuts, and seeds.

Patients may opt for a Mediterranean diet or the DASH diet as it encompasses many of anti-inflammatory foods. Eating anti-inflammatory foods provides the nutritional components for inflammation management, which synergize to strengthen immunity. These foods provide antioxidants, omega-3 fatty acids, and fiber which promote a healthy gut microbiome. 

Antioxidants

A vegan diet consisting of only fruit and vegetables has been reported to reduce immune responses to certain food antigens and influence inflammatory responses. Consumption of fruits and vegetables provides rich dietary sources of important antioxidants; vitamins C and, E, and minerals like selenium and zinc. These nutritional components can reduce proinflammatory mediators and stimulate immune cell proliferation.⁷

Antioxidants can suppress the transcription of proinflammatory mediators and inhibit signalling pathways involved in autoimmunity, for example, vitamin C reduces the expression of proinflammatory cytokine IL-6 and C reactive proteins (CRP).⁸

Omega-3 fatty acids

Omega-3 fatty acids exert anti-inflammatory effects on the body by reducing inflammatory biomarkers. They produce metabolites; resolvins- D, -E and protectins which act as anti-inflammatory agents.⁹ Omega-3 intake can be increased by eating more fatty fish (mackerel, salmon, tuna) or by taking supplements like fish oil (cod liver oil), however, the dose of omega-3 fatty acids needed to produce an anti-inflammatory effect is unknown.

Studies have suggested that an intake of over 2 g of EPA+DHA (2 types of omega-3 fatty acids) will produce anti-inflammatory effects in healthy volunteers. Patients with rheumatoid arthritis need on average, over 3.5g of EPA+DHA per day, over a long period (3-12 months) to produce anti-inflammatory effects.¹⁰

Fibre 

Dietary fibre is an important component of a healthy diet due to its impact on the gut microbiome, high fibre intake can reduce inflammation by altering the pH level and the permeability of the gut. This reduces and expells proinflammatory biomarkers; studies have shown that people with high-fibre diets have lower amounts of CRP in their blood.¹¹

Fiber-rich foods also provide nutrients for beneficial gut bacteria, ensuring good gut health. The gastrointestinal tract is home to many immune cells, gut microorganisms regulate the permeability of the intestines and release cytokines and other mediators to combat inflammation. Foods that are high in fibre include fruits, vegetables, beans, and grains.¹² 

Foods to avoid

An elimination diet whereby the pro-inflammatory foods are avoided can help manage inflammation. Limit the intake of processed foods, saturated and trans fats, refined sugars, meat, and excess alcohol. These foods can impact the release of inflammatory mediators into the blood and promote bad bacterial growth in the gut. 

Important considerations

Professional guidance 

It is important to consult with a healthcare professional before altering your diet for medical purposes, they can provide individualised dietary recommendations to help manage inflammatory conditions. A nutritionist can also help support those who are not used to sticking to meal plans, as well as providing support for those at risk of disordered eating.

MNT is flexible and does not include strict meal plans, a patient can occasionally indulge in their favourite pro-inflammatory foods. When undertaking an anti-inflammatory diet, it is important to monitor calories and portion sizes, it minimises the risk of weight gain and the development of other health disorders. 

Combination therapy for inflammation 

There are many different methods of treating inflammation; combined pharmacological treatment, medical nutritional therapy, and lifestyle changes can work synergistically to induce the remission of inflammation diseases. Lifestyle changes include partaking in regular exercise, limiting smoking, getting adequate sleep every night, and reducing stress.

MNT is currently underutilised for conditions like IBD, with doctors opting for drugs like NSAIDs to treat inflammation. Dietary and lifestyle changes can help in the remission of inflammatory conditions, under pharmacological intervention.¹³ 

Future perspectives

The literature shows enough evidence in favour of MNT, as an effective therapy for inflammation-related diseases as well as a multitude of other health disorders. The future of MNT involves integrating emerging technology like artificial intelligence (AI). AI can help healthcare professionals monitor patient conditions and personalise nutritional intervention by analysing the association between diet and disease outcomes.¹⁴

Summary

Inflammatory conditions are common and have devastating effects on global health. A useful, yet underutilised management option is medical nutritional therapy (MNT). Increasing intakes of anti-inflammatory food and limiting pro-inflammatory foods are effective ways to manage and treat inflammation.

Not limited to inflammatory conditions, nutritional therapy should be utilised when managing any health condition as it promotes healthy eating and lifestyle. MNT can empower individuals and help them cope with managing health conditions. Patients often feel like they have control over their condition, and seek to optimise nutrition, enhance well-being and achieve long-term goals. Doctors should refer patients to registered nutritionists as part of treatment plans when making dietary changes, it is important to consult a professional as there are many challenges and considerations.

However, MNT alone is not a viable treatment option for inflammatory conditions. It cannot cure chronic and autoimmune disorders but should be used in addition to other established therapies. For many health conditions, often the best treatment combines lots of different therapies. Diet and nutrients are integral for the growth, development, and maintenance of the human body, therefore medical nutritional therapy should always be considered and utilised.