How does nutrition reduce inflammation and aid healing?

Nutrition and inflammation

Have you ever wondered if your diet has an impact on inflammation?

Inflammation shows up in our body as inflamed joints, fatigue, and achy muscles, it can also be silent, inflammation we can’t feel that slowly damages blood vessels leading to cardiovascular disease.

We now have evidence that what we eat has an impact on inflammation¹, and by changing the food you eat inflammation can be reduced.

What is the inflammatory process?

Inflammation is a normal defense response that is triggered by damage, either by injury, infection, or toxic compounds, and plays an important role in the healing process. It can be acute or chronic. In acute inflammation, infection or injury will trigger a fast onset of inflammation and once the threat is dealt with, inflammation reduces, and we heal up. Chronic inflammation persists indefinitely, like that in osteoarthritis (joints) or autoimmune disease (where the body attacks its own tissues).

The inflammatory response consists of two phases

The first phase – onset

When tissue is damaged or infected, the damaged cells send out signals which bring white blood cells (leukocytes) to the area. These send out pro-inflammatory cytokines, chemical messengers made from proteins, and inflammatory eicosanoids, signaling molecules made from fatty acids, which increase blood flow causing redness, swelling, heat, and fluid leaking into tissues, they also stimulate nerves causing pain. White blood cells fight the infection by devouring bacteria and virus-infected cells. The role of inflammation is to eliminate whatever is causing the damage, clear out damaged cells, and initiate tissue repair. This should be a natural and temporary response and an essential part of the healing process.

The second phase – resolution

The resolution phase is the cleaning up and healing phase. It begins once the stimulus causing the damage has been removed, for example, the immune system cells have killed the germs causing infection, the inflammatory signals reduce, and inflammation begins to cease. Inflammation must be actively stopped to reduce unnecessary damage to tissues. The macrophages (a type of white blood cell) change from being in a pro-inflammatory state to an anti-inflammatory state. The immune cells exit the scene.  Beneficial anti-inflammatory cytokines and eicosanoids are produced and released, these are small molecules that send messages to cells,  in this case sending a message to cells to decrease inflammation, and start repairing and rebuilding tissues².

Ideally, we need a short effective onset phase and then the strong anti-inflammatory resolution phase.

Chronic inflammation occurs when the trigger for inflammation continues. Certain white blood cells (macrophages) and pro-inflammatory chemicals continue to stay in an area and resolution does not occur. The tissue affected becomes thickened and scarred over time, for example, chronic liver inflammation from fatty liver causes liver sclerosis or scarring.

Common factors that promote chronic inflammation are:

• Ongoing mechanical stress, such as repetitive stress injuries, or an infection causing tissue damage
• A persistent irritant; diet or environmental, such as smoking, allergens, polluted air, or industrial chemicals
• An autoimmune disorder, like rheumatoid arthritis, where the immune system mistakenly attacks healthy tissue as though it were foreign
• A chronic infection like a virus that stays in the body

What role does diet play?

Food and nutrients counteract inflammation and facilitate healing in two different ways:

• Reduce chronic inflammation resulting from metabolic syndrome
• Supply the nutrients required for a healthy immune response and then switch off inflammation and promote healing.

Reduce chronic whole-body inflammation

Systemic inflammation is chronic inflammation that is generalised, inflammatory mediators or chemicals are increased throughout the body at a low level all the time. This alters our ability to turn off inflammation properly and heal when we are injured.

Metabolic syndrome is a state in which there is increased chronic inflammation. How do you know if you have metabolic syndrome? You will be suffering from high blood pressure, abnormal lipids (cholesterol), insulin resistance, high blood glucose (pre-diabetes and type 2 diabetes), and obesity, especially internal abdominal fat^3,4. Fat cells in visceral (internal fat) contain immune cells that secrete inflammatory cytokines, chemicals that increase inflammation^5,6. In diabetes or prediabetes blood glucose levels are higher than ideal all the time, and the glucose binds to proteins in the body. This changes the proteins’ structure and function. Inflammatory chemicals are increased as HbA1c (average blood glucose) levels increase⁷. You might have seen this on a blood test if you have been tested for diabetes. Over time high blood glucose damages small blood vessels that supply organs like the eyes, kidneys, and nerves. High blood glucose also increases the damage in osteoarthritis (inflamed joints)⁸.

Reducing body fat, and managing blood glucose will reduce chronic inflammation

Simple diet changes to lose weight, and manage your blood glucose

Fat and carbohydrates are the macronutrients that, when eaten in excess increase blood glucose and fat storage. This is exactly the combination of foods that has increased in the last 50 years of the obesity epidemic; highly refined starches and fats^9,10. Think about all the snack food and easy meals we grab; muffins, cake, cereal bars, savoury snacks, bakery products, pasta with creamy sauces, donuts, deep-fried foods, pizza, chocolate, and ice-cream. Fat in these foods is often invisible, for example, a donut can contain around 4 teaspoons of oil, a small packet of French fries 3 teaspoons of fat.

A simple switch to unprocessed whole-food carbohydrates primarily from colourful vegetables, fruit, and fibre-rich starches like root vegetables, true whole grains, and legumes will fill you up, digest slowly, thereby controlling blood glucose, as well as increase the nutrients in your diet. For some eating fewer carbohydrates overall is necessary to decrease blood glucose.

Dietary fat does not increase blood glucose, however, in excess, it gets tucked away in our fat cells. Fat eaten in whole food forms like nuts, seeds, egg yolks, and avocado are preferable as they are nutrient-rich and less easily overeaten.

To reduce hunger while cutting calories, protein is your friend. Protein increases satiety more than fat or carbohydrates, by sending chemical signals to your brain where appetite is regulated. Protein is difficult to turn into fat, as well it does not increase blood glucose. Eat a portion of protein at every meal, around a palm size; lean meat, poultry, fish, eggs, seafood, tofu, tempeh, are good choices¹¹.

Protein is also essential for the healing process as all the cells in our body, including those in your bones, joints, and muscles are made from amino acids, the building blocks of protein¹².

Nutrients that quell inflammation

The active process of switching off inflammation is done by anti-inflammatory mediators or signaling molecules; cytokines and eicosanoids. Anti-inflammatory eicosanoids are made from the long-chain omega 3 fatty acids EPA and DHA^13,14.  Long-chain Omega 3 is found mainly in seafood, particularly oily fish like salmon, sardines, mackerel, and tuna.

Australian studies show that 80% of us do not consume enough Omega 3 in our diet¹⁵. To make sure we get adequate omega 3 we need to eat oily fish at least 3 times a week or take Omega 3 supplements. If you do not eat seafood or animal products, there are algae-based Omega 3 supplements available. Quality is paramount when choosing an omega 3 supplement, as many off the shelf in New Zealand have high levels of oxidation and are poor quality¹⁶. For people with high levels of inflammation, a daily high dose supplement is recommended ¹⁷, the upper limit is 3000mg of EPA plus DHA.

You may be aware that some plant sources, like flax oil, contain omega 3. However, this is in a short-chain form and is not able to be used to make the anti-inflammatory mediators until our body converts it to the active long-chain forms of EPA and DHA. Humans do not convert this well, which is why it is best to use EPA and DHA forms.

Polyphenols and antioxidants

Polyphenols are found in abundance in plant foods, and a number have been studied for their anti-inflammatory properties. Polyphenols reduce proinflammatory mediators and oxidative stress, and slow joint damage in arthritis¹⁸. Increase the polyphenols in your diet by eating a rainbow of plant foods, all the different colours are associated with different polyphenols. Specific foods to include are turmeric, garlic, green tea, olive oil, cocoa, and berries¹⁹. Aim for at least 6 fists or cups of colourful fruit and vegetables per day.

Micronutrients

All micronutrients (vitamins and minerals) are important for health, and we cannot build and repair our body’s tissues without the entire range of building blocks. Nutrient deficiencies impair a proper immune response to infection and slow our ability to heal. For example, magnesium deficiency²⁰ is associated with chronic inflammation, and deficiencies of vitamin K and D are associated with more severe osteoarthritis ²¹. A poor diet is associated with greater inflammation in rheumatoid arthritis, an autoimmune disease²².

New Zealander’s diets are often deficient, with 25% of us deficient in zinc, 30% have insufficient vitamin D levels, and in those with darker skin, up to 60% have inadequate vitamin D. Over one-third of males and half of females are deficient in selenium, and for vitamin A, 23% of males and 12% of females are deficient ²³

How to increase nutrients in your diet

To get an entire spectrum of nutrients in your diet, ditch or decrease the highly processed foods (as these displace nutrient dense foods) and include:

Protein-rich foods; lean meats, poultry, eggs, and dairy, tofu, tempeh, plus a variety with seafood and shellfish at least 3 times a week. Aim for a palm-size or more at each meal. Bone broth or collagen hydrolysate is rich in certain amino acids that may help rebuild cartilage²⁴.

Eat a large range of fibre-rich plant foods; legumes, lentils, true whole grains, colourful fruit and vegetables, mushrooms, and seaweed. Aim for 6 fists or more of colour each day. Add plenty of herbs and spices, like ginger, garlic, and turmeric.

Whole food fats; seeds, nuts, avocado, virgin olive oil, fish oil and egg yolks. Eat 1 -2 small handfuls of fat rich food each day depending on your calorie needs.

Foods to ditch when fighting inflammation

Certain foods increase inflammation by either displacing nutrient-dense foods or supplying the building blocks of pro-inflammatory mediators.

As mentioned above – limit consumption of sugars and starches, you may need to be especially strict if you have prediabetes or diabetes. Think of removing white and beige foods – sugar, white grains, finely ground and processed flours, and foods made from these. Certain foods contribute to inflammation in autoimmune diseases for example gluten, nightshade fruit and vegetables, and dairy. (See previous articles on rheumatoid athritis and diet). In these cases, an elimination/reintroduction diet can pinpoint the problem foods.

Certain fats in excess increase inflammation.  Seed oils are high in the polyunsaturated fat Omega 6, which is the building block of pro-inflammatory eicosanoids. The current western diet includes large amounts of omega 6 rich fat, as it is used widely in the food industry and in margarine. Seed oils high in omega 6 are safflower, sunflower, and soybean oil. The imbalance of high omega 6 and low omega 3 tips our body towards inflammation. Using oils high in monounsaturated fats; olive oil, nuts and nut oils, avocado, and limiting processed foods will ensure you do not over-consume omega 6 ²⁵.

Fats used in deep frying vats, which are reheated many times, are especially damaging as they have high levels of oxidised and damaged fats, which increase inflammation ²⁶. Avoid deep-fried foods in general.

Meats that are charred produce chemicals that are inflammatory, slow-cooked, or low heat cooking is preferable²⁷.

Supplements that may help:

For those suffering from high levels of inflammation, supplementation can be useful adjunct to diet, for example certain plant extracts like curcumin reduce inflammation²⁸, as do higher levels of micronutrients like magnesium ²⁰.

If you would like more guidance on your diet and supplements to reduce inflammation contact me (Julianne) for an appointment

 Image credit

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