Hot Topics: Inflammation and Diet

by Stephanie Liang, APD

If you’ve ever cut your finger, bruised your knee, or had a pimple, you’ve experienced inflammation. This kind of acute inflammation is our body’s normal immune response to protect our body against infection and injury,[i] and results in increased blood flow, redness, swelling, as well as the release of hormones and proteins called cytokines that work to reverse the damage.[ii] But what happens when inflammation sticks around? Read on for a summary on how inflammation and diet overlap.

How does inflammation relate to health and disease?

A prolonged state of inflammation, known as chronic low-grade inflammation, involves an increased level of pro-inflammatory cytokines compared to anti-inflammatory cytokines in our body. Chronic low-grade inflammation is a risk factor for chronic diseases such as cardiovascular disease, type 2 diabetes, cancer and age-related neurodegenerative conditions including Alzheimer’s disease and dementia.^3-6 People carrying extra weight are more likely to have inflammation, as fat tissue is known to release hormones and pro-inflammatory cytokines that initiate chronic inflammation.²

High levels of specific inflammatory markers in our blood might mean we are suffering chronic low-grade inflammation, which can be checked by a blood test. One part of preventing this is by following a healthy diet and lifestyle, which can play a hand in protecting our health in the long-term.²

A prolonged state of inflammation, known as chronic low-grade inflammation, involves an increased level of pro-inflammatory cytokines compared to anti-inflammatory cytokines in our body.

How does our diet relate to inflammation?

Research has shown diet plays a role in the development of chronic diseases and inflammation, and there is promising research that shows specific dietary patterns can be particularly effective in protecting against inflammation and chronic disease.⁴  

Dietary patterns and inflammation

The general consensus is that typical Western-style diets are linked to low-grade inflammation. These diets are generally high in red and processed meats like salami and bacon, refined grain foods like white bread and pasta, discretionary foods like desserts, soft drinks and fried foods, and research shows they are more likely to lead to higher levels of pro-inflammatory markers in the blood.^7,8

Conversely, Mediterranean-style diets, rich in antioxidants, fibre and healthy fats, are known to provide numerous health benefits including weight management and promoting heart health, and further research has found they can also help to reduce inflammation.^10-12 Mediterranean diets are predominantly plant-based, featuring plenty of olive oil, fruit, vegetables, legumes, grains and nuts, and moderate amounts of fish, seafood, poultry and dairy foods. Alcohol in the form of red wine is often enjoyed with meals – a common, but non-essential part of the eating pattern, and we suggest sticking to the Australian Dietary Guidelines recommendation of limiting alcohol to no more than two standard drinks per day.⁹

Following a Mediterranean dietary pattern may help protect against inflammation by lowering pro-inflammatory markers in the blood, but also by protecting against other conditions that encourage inflammation, like high cholesterol, type 2 diabetes, hypertension, and cardiovascular disease.^10-12

Mediterranean-style diets, rich in antioxidants, fibre and healthy fats, are known to provide numerous health benefits including weight management and promoting heart health, and further research has found they can also help to reduce inflammation.^10-12

What about grains and legumes?

As major components of Mediterranean-style diets, it’s no surprise that diets high in grains and legumes are generally linked with lower inflammation.

Whole grains in particular show protective properties, with observational studies linking them to lower levels of inflammatory markers.² In a ten year study of dietary patterns, whole grain consumption had the strongest anti-inflammatory effect of the 37 food groups studied, with a lower whole grain intake linked to elevated levels of IL-6, a pro-inflammatory marker.¹³ Higher whole grain intakes have also been linked to a significant reduction in CRP,^2,14 another pro-inflammatory marker, with every serve of whole grain food estimated to reduce CRP concentrations by 7%.¹⁵

Similarly, there is good evidence for legumes and lower inflammatory markers in the blood.¹⁶ One study found replacing two serves of red meat with legumes three days each week reduced inflammatory markers in patients with diabetes, regardless of whether they lost weight.¹⁷

Interestingly, one research study found peas and legumes were associated with higher rates of inflammation. However, it is assumed that legume intake included consumption of baked beans which were often consumed with pro-inflammatory foods including processed meats such as bacon and other fried foods.¹³ So there’s no need to ditch the baked beans, just enjoy with whole grain bread!

Whole grains in particular show protective properties, with observational studies linking them to lower levels of inflammatory markers².

Gut health and inflammation

There is emerging evidence on our diet and gut microbiome, and its role in inflammation as well as health and disease. In particular, prebiotics such as soluble fibre from plant foods and whole grains, and resistant starch are known to feed the good bacteria in our gut, by resisting digestion in the stomach and small intestine, and traveling to the large intestine where they become fermented by our gut microbiota.¹⁸ Fermentation of these non-digestible fibres causes the production of short-chain fatty acids such as butyrate and acetate, which can work to reduce inflammation.¹⁹  Read more about gut health in this recent hot topic on the microbiome by APD Nicole Dynan.

So what’s the bottom line?

Diet and inflammation is complex and a number of factors can promote inflammation in our body. By choosing a diet high in fruit, vegetables, whole grains, legumes, nuts and seeds, and including more fish, seafood, poultry, dairy and unsaturated fats (such as olive oil) in your diet, you’ll be reducing the risk of inflammation, the development of chronic diseases and improving your overall health and wellbeing.

For personalised nutrition advice, we recommend seeking support from an Accredited Practising Dietitian (APD) who will tailor their advice to you based on the most up-to-date evidence. Find an APD near you by heading to daa.asn.au and ‘Find an APD.’

Stephanie Liang is a Sydney-based Accredited Practising Dietitian (APD) who is dedicated to teaching individuals about the importance of nutrition and health, and strives to help others lead healthier lives by providing simple and practical advice.

You can follow Stephanie on Instagram @thenutritiouspalate.

 

References

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