Inflammation can be a good thing. It is a natural process that helps your body heal and defend itself from harm. However, chronic inflammation is also one of the root causes of many diseases. It may drive obesity, type 2 diabetes, heart disease, and depression and contribute to all sorts of serious health problems from osteoarthritis and rheumatoid arthritis to some cancers. In this article, we introduce the science and research behind the role of nutrition in the cause, prevention and treatment of inflammatory disease.
Everyone has experienced the remarkable phenomenon of acute inflammation – a sprained ankle, splinter, or cut – and as a result have witnessed the affected area turn red, puffy and hot as your immune system rushes to your aid to assess the injury and fight any pathogen that might have entered your body.
A normal, healthy inflammatory response should flare up and die down again a short time later, as the healing process resolves the inflammation, the injury heals and homeostasis returns. Pain and inflammation should not be long term; they should go away – but sometimes inflammation runs wild, becomes chronic and last for a long time. Constant inflammation may damage tissue, affect organ function and lead to a dysregulated immune system and serious health conditions.
The inflammation process in brief (warning abit technical so you may wish to skip this bit)
Say you cut a finger, then bacteria enters the body and causes tissue and cellular damage. This foreign body triggers mast cells to release inflammatory mediators such as histamine and cytokines leading to the classic signs of inflammation – redness, heat, swelling and pain.
Next, the release of these mediators triggers inflammatory cells, such as white blood cells neutrophils and lymphocytes, to move to the injury, release other substances and start the immune response.
As inflammation continues, cells called macrophages remove damaged cells or tissue and if the injury in eliminated the next phase is tissue repair.
Resolution is the solution.
The death of neutrophils is the hallmark of the move to the resolution phase of inflammation. Resolution is triggered when neutrophils and macrophages secrete chemical messengers known as specialised pro-resolving mediators (SPMs). These SPMs are derived from polyunsaturated fatty acids (PUFA’s), including the essential omega-3 and -6 fatty acids. One group of SPM’s, lipoxins, is derived from Omega -6 arachidonic acid, while the SPM groups, resolvins, protectins and maresins, from Omega -3 EPA or DHA.
The interesting thing is that evidence suggests people eating a Westernised diet are getting adequate arachidonic acid for lipoxin synthesis but insufficient intake EPA/DHA for resolvin, protectin and maresin synthesis. Hence omega-3 fatty acids such as those found in oily fish are vital to resolving inflammation.
What drive’s inflammation?
Certain lifestyle factors can promote inflammation, especially when they occur on a regular basis, such as:
- Obesity leading to metabolic syndrome
- Unrepaired tissue damage including periodontal disease.
- Oxidative stress from smoking, medications, food additives, physical and emotional stress including sleep disorders.
- Persistent pathogens
- Persistent allergens
- Gut dysbiosis or microbial overgrowth.
- Essential fatty acid deficiency
- Low sex hormones
- Poor diet
These drivers lead to five key biochemical inducers of inflammation including
- Mitochondria dysfunction due to environmental toxins, ageing and by-products of free radical damage.
- Advanced glycation end products (AGEs) where excess sugars in the blood stream, come into contact with proteins and lipids, to form AGEs.
- Uric acid Most often due to obesity, purine-rich foods, diabetes, alcohol and diuretics.
- Oxidised lipoproteins, which may contribute to atherosclerotic plaques. This occurs due to poor diet and lifestyle factors.
- High homocysteine levels caused by poor diet and lifestyle factors.
How can we reduce inflammation through diet?
- Reducing calories. Fat around the abdomen is biologically active and increases proinflammatory cytokines, cholesterol and triglycerides, and unregulated glucose.Research has shown us that there are four key areas of nutrition that significantly influence inflammation;
- Increased Omega 6 and reducing Omega 3 essential fatty acids. Increasing Omega 3 consumption inhibits the production of proinflammatory cytokines and acts as precursors of the SPM groups, resolvins, protectins and maresins, needed to trigger inflammation resolution.
- Increasing polyphenol-rich foods. Fruits, vegetables, grains, spices and herbs are the richest source of dietary polyphenols. They act as both antioxidants and anti-inflammatories and as such interact and neutralise reactive oxygen species (ROS) in the cell, downregulate the expression of proinflammatory markers, and boost beneficial gut bacteria.
4. A high fibre diet. Dietary fibre that has prebiotic activity supports healthy gut bacteria, contributes to a healthy immune response and reduces inflammation. Fibre also ensures food passes more quickly through the gut and reduces gut irritation.
The Mediterranean diet and inflammation
Research findings indicate that eating a diet focused on anti-inflammatory principles such as The Mediterranean Diet, not only helps protect against certain diseases, but also slows the ageing process by stabilising blood sugar and increasing metabolism.
Traditional diet in olive-growing areas of Crete, Greece and southern Italy in the late 1950s and early 1960s showed positive effects on inflammation and disease such as CVD.
Major characteristics are;
- high consumption of non-reﬁned grains, legumes, nuts, fruits and vegetables (lots of colours);
- relatively high-fat consumption (even greater than 40% of total energy intake) mostly from monounsaturated fatty acids (MUFA), which accounts for 20% or more of the total energy intake;
- olive oil as the principal source of fat;
- moderate to high consumption of ﬁsh;
- low to moderate consumption of poultry and dairy products (usually as yoghurt or cheese);
- low consumption of red meats, processed meats or meat products; and
- moderate alcohol intake, usually in the form of red wine consumed with meals.
Although this article has only touched the surface on the role diet and nutrition play in the cause, prevention and treatment of inflammatory diseases, it is clear that;
- Diet and exercise are major determinants of disease susceptibility and ageing.
- A healthy diet avoids genetic predispositions to disease, and a ‘bad’ diet displays those genetic defects.
- Many diseases are initiated and exacerbated by diet-based inflammation and may be ameliorated by appropriate diet, alongside other lifestyle changes such as stress management, reduction in alcohol, smoking and regular physical activity.
Sheena Hendon (Nutritionist, Naturopath, Health and nutrition writer)
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