Inflammation 101: What is it and can it be caused by what you eat?

June 12, 2020

‘Inflammation’ is often blamed as the cause behind a multitude of health concerns, from allergies to exhaustion, with anti-inflammatory diets frequently touted as the answer to all your problems.

Gut problems? Inflammation. Allergies? Must be inflammation. Fatigue? You guessed it, inflammation again. 

But what is this mysterious health condition that you can’t see or feel? And, more importantly, what can you do to reduce it?

In this post we take a closer look at what inflammation is and how it affects your body. We also explore how what you eat influences inflammation in your body.

The low-down on inflammation

  • Acute inflammation is part of a healthy immune response to infections and illness.
  • Sometimes inflammation can become chronic and threaten our health.
  • Unhealthy responses to food can increase inflammation.
  • What you eat can increase or decrease inflammation in your body
  • Picking the right foods can help to control inflammation and maintain your health

What is inflammation?

Inflammation is the body’s immune response to an irritant and a way of protecting itself against injury and disease. These irritants can be anything from germs to foreign objects, chemicals, toxins, and even parts of your own body. 

If you are sick or you injure yourself, and your white blood cells encounter a foreign substance such as a germ, or even a thorn in your finger, they release chemicals to protect you. These chemicals increase blood flow to the area, bringing more immune cells to fight the invader. 

There are two types of inflammation: acute and chronic.

Acute inflammation is a localized response to injury or infection, resulting in part of the body becoming reddened, swollen, hot, and often painful. It’s something you’ll probably have experienced around a small cut or insect sting, for example, and is an important part of the healing process.

The increased blood flow causes the tell-tale signs of acute inflammation, including redness and warmth. The chemicals can also cause your tissues to swell and stimulate your nerves, causing pain. Once you are healed or no longer sick, this kind of acute inflammation subsides - usually within a few hours or days - and things go back to normal.

Chronic inflammation is a longer-lasting immune response that persists over months or even years. Sometimes this may be caused by an illness or infection, long-term exposure to harmful chemicals, or and underlying auto-immune condition. But in other cases there is no known cause. 

Chronic inflammation is harmful to your health

Acute inflammation is an important part of the body’s response to infection and disease. But when inflammation continues for a long time, it can do more harm than good. 

Scientists have linked chronic inflammation to conditions such as diabetes, cancer, Alzheimer’s, heart problems, stroke, kidney problems, joint diseases, and allergies.

A large study also showed that people with markers of chronic inflammation in their blood were more likely to die sooner, even after taking other diseases and lifestyle into account. 

Unfortunately, it’s much harder to detect chronic inflammation inside the body, compared with the redness and swelling of acute inflammation. 

Chronic inflammation often happens silently, with symptoms that are easy to dismiss, including body pain, fatigue, insomnia, depression, anxiety, digestive problems, weight gain, and frequent infections. 

Although these symptoms can be challenging to monitor, doctors can measure the levels of inflammation using substances in your blood called biomarkers. For example, we use a biomarker called GlycA to measure the levels of inflammation in our PREDICT study participants.

There are several medical approaches for reducing chronic inflammation, including anti-inflammatory drugs such as NSAIDs and corticosteroids. But although these treatments can be effective, they aren’t suitable for everyone and can cause side effects, especially when used for a long time.

The good news is that you can help to reduce chronic inflammation by altering your diet, alongside seeking appropriate medical care. 

What is dietary inflammation?

Research has shown that the foods we eat can increase or decrease inflammation within the body. Let’s start with how your food can increase inflammation

When you eat, sugar and fat make their way into your bloodstream. In response, your body takes action to bring your blood sugar and fat levels back to normal in a controlled way. If these nutritional responses don’t work properly, blood sugar or fat levels remain high for a long time, leaving your body in a stressed state that can lead to inflammation. On the other hand, there are some foods actively combat inflammation

We use the term "dietary inflammation" to capture all of the unhealthy metabolic effects that can be triggered after we eat. Repeated, excessive blood sugar and fat rises can lead to long-term inflammation, weight gain and chronic diseases such as diabetes and heart disease. Many different mechanisms are involved, from increased calorie consumption as a result of regular blood sugar crashes, to oxidative stress and altered blood fat metabolism.

Research has consistently shown that foods containing polyphenols reduce inflammation through a range of mechanisms, including reducing cell damage, boosting sensitivity to insulin (the hormone that helps to move sugar from your bloodstream into your cells), and shutting down genes that cause inflammation.

Our inflammation abstract published for Nutrition Live Online is available here.

You can reduce chronic inflammation by changing your diet

Carbohydrates (carbs) are often portrayed as an inflammatory villain that should be avoided on anti-inflammatory diets, because they can cause unhealthy blood sugar spikes. 

However, our PREDICT study showed that unhealthy fat responses after eating are actually more strongly associated with inflammation than blood sugar responses. 

People don't all have the same responses either. Our large-scale PREDICT studies not only show that we all have different sugar and fat responses after eating - even identical twins, who share all their genes - everyone’s inflammatory responses to food are personal too. So a food that causes an unhealthy blood sugar or fat response in one individual might not in another.  

To maintain healthy blood sugar and fat responses and reduce chronic inflammation, you need to know how you respond to foods and choose the ones that suit you best. Increasing the amount of polyphenols in your diet can also help to combat inflammation. 

Fruit and vegetables are excellent sources of polyphenols, and studies have shown that eating lots of different fruit and veg can reduce your inflammation levels. And researchers have found that a glass of mixed fruit juice, orange juice or even a glass of red wine can help to counteract the metabolic effects of an unhealthy meal.

Sign up for early access to our home test kit to be one of the first to discover your individual responses to food.

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