The link between food and inflammation you may not know about
If you're wanting to reduce inflammation, and are curious about whether food can help, this post is for you!!
Inflammation is not a new concept - it actually goes back to Roman times…
It’s defined as the reaction of the body to injury or infection, where certain processes are activated, to help the body fight off invaders, or heal from injury. Inflammation is a complex topic that involves many different pathways, but essentially in the right circumstances, short term inflammation helps our bodies heal and survive.
In contrast, the discovery of chronic low grade inflammation is a relatively new concept, and is the idea of inflammation not 'turning off' when it's meant to, and instead continuing at low levels.
The analogy of a fire is a useful one - instead of burning hot and bright for a short time to clear out waste, it keeps smouldering, and causes damage.
In 1993 a Turkish researcher discovered that overweight patients had low levels of chronic inflammation throughout the body
He theorised that it could be one of the main causes of heart attacks, strokes, and insulin resistance, as it appeared to be strongly linked to higher rates of these - he coined the term 'meta inflammation'
Since then a lot more research has been done in this area, and meta inflammation is now thought to be a potential cause of many diseases, including heart disease, dementia, depression, autoimmune diseases, lung disease, allergy, and even cancer
Its also one of the main drivers of severe covid infection, with the inflammatory response to the covid virus causing most of the damage - explaining part of why obesity, Western diet, metabolic syndrome and vitamin D deficiency have been associated with worse outcomes in the initial waves of covid, whereas plant based diets and other lifestyle factors were be protective
The theory behind food can cause inflammation follows on from this, and is intriguing.
We know that humans have an effective immune response to protect us from 'invaders' ie bacteria and viruses that could make us sick
As food is a foreign molecule (ie not part of our body), in order to tolerate it, our body has to recognise it as harmless, and not create an immune reaction against it
Prior to the industrial revolution, human diets were fairly stable for millenia - ie whole foods, mostly plants, with small amounts of wild game, free range eggs, and dairy (in some cultures), and with minimal processing (think stone ground flour, pressed oils etc). But since then, and particularly in the last 50 years, foods have changed dramatically and rapidly due to technology and new processing methods
This rapid rise in ultra processed food consumption has also correlated strongly with a rise in chronic disease.
Its thought that as processed foods are relatively 'new' to humans, our body sees them as invaders, and mounts an immune response when we eat them.
If eaten occasionally, and in the context of an overall whole food diet, our body can 'put out' the inflammation and cope with it.
But over time if these foods are eaten often, especially as we follow other lifestyle habits that can also cause an inflammatory response (high stress, lack of sleep, lack of exercise etc), our body can't keep up with' putting out the fires', and chronic inflammation can develops.
Again using the analogy of a fire - if there are occasional small fires popping up in our body, we can put them out. But if they're occurring all the time, our 'firefighting' processes just can't keep up, and the fire spreads.
Going back to food, there has been a huge amount of research in recent decades about the role of food in chronic inflammation.
As a result, some foods have been found to cause low levels of inflammation when eaten, which over time can lead to 'meta inflammation', whereas other foods reduce inflammation
Most of the studies in this area have been done with the dietary inflammatory index (DII) - a validated tool measuring levels of different markers in the blood after foods are eaten, to provide a measure of how 'inflammatory' a food is.
It uses micronutrients rather than whole foods, as this gives a more standardised form of measurement.
The DII was developed by looking at over 6000 studies from around the world, analysing the data available on inflammation and food. Since then its been used in over 200 studies and 12 metanalyses, looking at the role of dietary inflammation in conditions such as cancers, heart disease, diabetes, obesity, asthma, lung disease, mental health, arthritis, osteoporosis, and even child development
The DII research has consistently shown that higher intake of 'inflammatory' foods are linked with higher rates of these diseases - and often higher levels of inflammatory markers in the bloodstream.
The actual DII is below - the more negative the score, the more anti-inflammatory a nutrient is, whereas more positive scores are more inflammatory
Not surprisingly, the nutrients found to create the most inflammation when eaten were saturated fat and cholesterol , then refined carbohydrates, protein, total energy and trans fats
B12/iron were mildly inflammatory - these all the nutrients found in a meat heavy processed food diet ie the typical Western diet
In contrast the most anti-inflammatory compounds are all from plants, such as flavonoids and isoflavones, as well as most other vitamins and herbs/spices, green tea and caffeine.
This fits perfectly with other research, which shows that whole food plant focused diets low in saturated fat and refined carbohydrates (ie the Mediterranean diet) reduce the risk of all the diseases mentioned above, and can also be powerful in helping to improve disease that's already occurred.
Following on from the DII another great study was done to 'rate' foods based on their concentration of these micronutrients (2)
Again whole plant foods were all anti-inflammatory (esp tomatoes and brightly coloured fruits/veges), whereas processed meats, refined carbs, processed oils, and added sugars were highly inflammatory
Unprocessed red meat was midlly inflammatory, and chicken and fish were anti-inflammatory. Alcohol was dependent on amount - heavy intake was inflammatory (>2/day), but lighter intake was not
So how can you eat to reduce inflammation, reducing your risk of chronic disease, and improving health issues that have already occurred?
Eat whole foods, mostly plants, and eat a rainbow of different colours and flavours, to maximise your intake of anti inflammatory nutrients!
Swap saturated fat (from animal sources) for unsaturated fat (olive oil, nuts, and seeds) ; limit or avoid processed meat, red meat, added sugar and refined carbs; and seal out animal protein for plant protein (from legumes and whole grains)
Avoid trans fats and refined seed oils, and add herbs and spices to your diet
And don't overeat - excess calories are inflammatory too!!
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