Introduction
The word inflammation is commonly used, however there is often some confusion as to what it actually means and whether it is positive or negative. The process of inflammation is the body’s defence mechanism to protect itself against any form of stress or harm. Therefore, we need inflammation as it is a way to protect the body. However, too much inflammation can also be detrimental.
One way we can reduce harmful inflammation in the body is through our diet. There are many foods which can cause inflammation and also foods that reduce inflammation. Continue reading to find out more about what inflammation means, the foods we should avoid eating and those we should try and incorporate into our diet to minimise inflammation.
What is inflammation?
As mentioned earlier, inflammation is the body’s response to anything it deems harmful to the body. The stressors can vary widely; ranging from a germ causing an infection, an allergen (such as nuts) or a foreign object such as a splinter in your finger. Inflammation is hence your body’s way of fighting these irritants. This process usually involves four key signs and symptoms- heat, pain, redness and swelling. These signs and symptoms may lead to a temporary loss of function, depending on where in the body the irritant is affecting. Examples of loss of function include not being able to move a joint properly, or finding it more difficult to breathe if you have a chest infection.
Your body’s immune system cells are involved in inflammation. In response to a stressor, these cells release various chemical substances that have knock-on effects. The effects of these substances include causing blood vessels to widen in order to allow more blood flow to reach the injured or affected area to deliver cells that can help fight and heal. This causes the area to turn red and hot. These chemicals also irritate nerves which causes pain signals to be sent to the brain. This acts as a protective function that lets you know that you are injured and need to be protected. Immune system cells also cause more fluid to enter the affected area which causes swelling.
It is easier to imagine these processes when you have an external stress, such as when you fall and twist your ankle. Your ankle quickly becomes swollen, red, hot and painful. Another example would be how after an intense workout session, your muscles feel sore. This is also a type of inflammatory response since your body is trying to repair the overused muscle fibres from the workout.
Acute vs Chronic Inflammation
Internally, when your body encounters a germ, or you ingest an allergen or a toxic substance, your body’s immune system recognises it as foreign and therefore initiates an immune response to help combat it. This inflammation may manifest in your body as a fever, cough or body aches such as when you have the flu. This type of inflammation is known as acute inflammation and is essential in keeping us healthy and safe.
When inflammation persists for a long time and is to a high level, this is known as chronic inflammation, and this can cause damage to us. Your body acts like it is under constant attack and therefore the immune system continuously fights. There are many causes of chronic inflammation. Examples include the body reacting to toxins from cigarette smoke, infections that have not been cleared, or if you are overweight. When you have more fat cells, they surround your organs and the immune system sees this as a threat and therefore initiates an immune response.
Chronic inflammation is often more difficult to spot than acute inflammation, as we cannot externally see the physical signs such as redness. However, chronic inflammation can manifest in various ways in the body. Studies have shown that chronic inflammation is associated with many diseases such as diabetes, arthritis, heart disease, cancer, and bowel diseases such as ulcerative colitis and Crohn’s disease. Unfortunately, worldwide, 3 out of 5 people die due to chronic inflammatory diseases. Therefore, it is necessary to control chronic inflammation. One of the ways we can do this is by managing our diet effectively.1
Important Nutrients to Decrease Inflammation
Omega-3 fatty acids
Omega-3 and 6 are types of fatty acid molecules that are essential to health. They play a role in developing the brain and eyes and improving the function of blood vessels. These molecules can’t be made by the body and therefore must be obtained from the diet. In the West, in general, we consume much more omega-6 in our diet than omega-3. The reason for this is likely the large amount of seed and vegetable oils used when cooking fast food, as well as the high intake of meat products. Although we do need some omega-6, too much of it promotes inflammation in the body.
Hence, a good balance of omega-3 and omega-6 fatty acids are needed for optimal health and to reduce inflammation in the body. Studies have found that dietary omega-3 fatty acids are associated with lower levels of inflammation.2 Omega-3 fatty acids are converted into molecules which signal the resolution of inflammation. This reduction in inflammation may be particularly beneficial in preventing heart diseases including reducing the risk of blood clots and lowering blood pressure. More research is being carried out on how omega-3 can benefit other inflammatory diseases such as rheumatoid arthritis.
Omega-6 fatty acids are found in foods including: seed and vegetable oils, meat, dairy and eggs. Whereas sources of omega-3 include: flaxseeds, hemp seeds, walnuts, chia seeds and cold water oily fish such as salmon, sardines and herrings. It is important to bear in mind that the non-fish sources of omega-3 do contain a less active form than what is found in fish. For vegetarians and vegans, a more efficient source of omega-3 is algal oil as it contains the most active form of omega-3, similarly to fish.
Antioxidants
Free radicals are molecules in the body that are a natural byproduct of cell reactions and as a result of exercise. They are also produced by the body in response to external factors such as air pollution or tobacco smoke. Some free radicals are necessary, however, they can also cause inflammation and damage to cells by a process known as oxidative stress. The body does have its own way of dealing with free radicals, however, the system can become overwhelmed if there are too many free radicals present. Antioxidants are molecules that counteract free radicals and so help protect tissues from damage caused by oxidative stress and therefore prevent inflammation. Your body produces some antioxidants but we can further increase our antioxidant levels by the food we eat.
Many chemicals which are found in plants work as antioxidants. Therefore, by consuming a wide range of fruits and vegetables we also increase the amount of antioxidants we are consuming. For example, vitamin C is a great antioxidant which is found not only in citrus fruits but also in bell peppers, strawberries, tomatoes, broccoli, brussel sprouts and even potatoes. Leafy green vegetables (e.g. kale), cocoa, blueberries, apples, onions, pomegranate, green tea and many other foods contain a wide range of beneficial antioxidants. In general, it is best to consume a well-rounded diet, rich in fruits and vegetables to make sure you consume a wide range of antioxidants.
Studies have found that olive oil has anti-inflammatory effects, even when only a small amount is consumed. The main reason for this is because of the antioxidant that it contains, which research suggests has a similar effect to the medicine ibuprofen.3
It is important to make sure you buy extra virgin cold-pressed olive oil, as the way it is processed ensures that it retains its great nutrients.
Curcumin (turmeric)
Curcumin is the yellow pigment that gives turmeric its colour. It has been used for centuries in Ayurvedic and Chinese medicine as a way to reduce inflammation. Studies have suggested that turmeric may reduce inflammation, however, it is not well absorbed by the body.4,5
You may benefit from adding turmeric when cooking your foods or using it in some tea. To increase the amount of curcumin that is absorbed, try combining it with black pepper. Black pepper helps your body absorb the beneficial compounds in turmeric. Turmeric tablets are also available, however, always speak to medical professionals before starting any supplements because too much curcumin may not always be beneficial.
Fibre
Fibre is found in foods such as fruits, vegetables, beans, nuts, oats and whole grains. Fibre has many benefits, one of which includes lowering the inflammatory molecules in the body. According to The British Dietetic Association, most adults only consume 60% of the recommended daily intake of fibre. Studies have found that people who eat more fibre have lower levels of CRP in their blood, which is a marker of inflammation and is associated with diseases such as rheumatoid arthritis and other inflammatory conditions.
Foods that are high in fibre feed the ‘good’ bacteria that live in the gut, which produce substances that help lower inflammation in the body. Try increasing your fibre intake by consuming whole-wheat pasta and rice, oats and lots of fruits and vegetables. You may experience some symptoms such as gas and bloating as your body gets used to the higher intake of fibre. It is also important to stay hydrated when eating a high-fibre diet.
Foods that increase inflammation
Foods to limit or avoid as much as possible include:
- Processed foods- such as sausages and burgers
- Refined carbohydrates- white bread, white rice and white potatoes
- Sugar- cakes, pastries, sweets and chocolates
- Saturated fats- pizza, cheese, red meat and full-fat dairy
- Trans fats- fried foods, processed snacks, cookies, doughnuts and margarine
- Omega-6 fatty acids- vegetable and seed oils, peanuts, mayonnaise and salad dressings
- Monosodium Glutamate (MSG)- an additive most commonly found in Asian foods to enhance the flavour
- Gluten- some people are more sensitive to foods that contain gluten, including wheat, barley and rye
- Aspartame- an artificial sweetener found in many products such as fizzy drinks, fruit yoghurts and protein shakes
- Alcohol
Summary
In summary, we can reduce inflammation by following a diet rich in anti-inflammatory foods and by avoiding those foods that can increase inflammation. It is important to recognise that all of our bodies are unique and react differently to foods, therefore what works for some may not work for others. In general, it is important to eat a varied diet, rich in fruits, vegetables, seeds, nuts and whole-grain foods, and to avoid foods that are unhealthy such as red meats, processed foods, and foods high in saturated fats, trans fats and sugar. The Mediterranean diet encompasses these factors, and studies have found that people who regularly follow the diet have lower levels of inflammation. Take a look here for more information on the Mediterranean diet. Remember to speak to a healthcare professional before making any drastic changes to your diet.
References
- Pahwa R, Goyal A, Jialal I. Chronic inflammation. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Nov 23]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK493173/
- Rangel-Huerta OD, Aguilera CM, Mesa MD, Gil A. Omega-3 long-chain polyunsaturated fatty acids supplementation on inflammatory biomakers: a systematic review of randomised clinical trials. British Journal of Nutrition [Internet]. 2012 Jun [cited 2023 Nov 23];107(S2):S159–70. Available from: https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/omega3-longchain-polyunsaturated-fatty-acids-supplementation-on-inflammatory-biomakers-a-systematic-review-of-randomised-clinical-trials/ACC3D69BCC45AFFCCFF12E2426C83068
- Lucas L, Russell A, Keast R. Molecular mechanisms of inflammation. Anti-inflammatory benefits of virgin olive oil and the phenolic compound oleocanthal. Curr Pharm Des. 2011;17(8):754–68.
- Hay E, Lucariello A, Contieri M, Esposito T, De Luca A, Guerra G, et al. Therapeutic effects of turmeric in several diseases: An overview. Chemico-Biological Interactions [Internet]. 2019 Sep 1 [cited 2023 Nov 23];310:108729. Available from: https://www.sciencedirect.com/science/article/pii/S0009279719308610
- Peng Y, Ao M, Dong B, Jiang Y, Yu L, Chen Z, et al. Anti-inflammatory effects of curcumin in the inflammatory diseases: status, limitations and countermeasures. Drug Des Devel Ther [Internet]. 2021 Nov 2 [cited 2023 Nov 23];15:4503–25. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8572027/