Although there’s no single ‘anti-inflammatory diet’, it’s usually described as a pattern of eating which emphasises foods with anti-inflammatory benefits (like olive oil, oily fish and nuts) and limits foods thought to have pro-inflammatory effects, such as refined carbohydrates and some types of dietary fat1.
What do we know about anti-inflammatory diets and psoriasis?
For thousands of years, inflammation has been characterised by four signs – redness, swelling, heat and pain2. Although a certain amount of inflammation is a completely normal and essential part of the body’s immune response (for example when you develop an infection or break a bone), research shows that long term inflammation plays a role in the development of many diseases, including cancer, heart disease and psoriasis3 4.
In psoriasis, an overactive immune response triggers abnormally high levels of inflammation5. Some studies show that psoriasis activity (measured by the Psoriasis Area and Severity Index or PASI score6) is linked to levels of inflammation 7 8 so as inflammation increases, so does redness, scaling, and the amount of skin involved.
Because of the connection between inflammation and psoriasis, it’s possible that an anti-inflammatory diet may help to reduce psoriasis severity. For example, fish oil can lower levels of pro-inflammatory hormones in a similar way to anti-inflammatory drugs9 10 11. Other foods including olive oil and nuts have been shown to lower inflammatory markers and suppress the messenger cells thought to trigger overgrowth of skin cells in psoriasis 12 13 14.
What does the science say?
To date, no scientific studies have looked at the effects of a specific ‘anti-inflammatory diet’ in psoriasis, although some have included elements of anti-inflammatory eating (for example increasing intake of fish and nuts) as part of a treatment plan.
In one case-study of five patients with chronic plaque psoriasis, a 6-month dietary programme emphasising fish, fruit and vegetables, olive oil and limiting red meat, processed food reduced psoriasis severity (PASI) scores from an average of 18.2 to 8.715.
Other studies have looked at the effects of anti-inflammatory nutrients in psoriasis, with omega-3, oily fish, and curcumin (part of the turmeric spice) found to have positive effects on psoriasis severity either as a single therapy, or in combination with other treatments 16 17 18 19.
Outside of psoriasis, red wine, oily fish, olive oil, nuts, fruits, vegetables, tea, herbs and spices have been shown to exert anti-inflammatory effects 20 21 22. In one study looking at the fruit and vegetable intake of over 1000 men and women, those who ate the most fruit and vegetables had the lowest levels of inflammatory markers, even after adjusting for other habits including smoking and exercise23.
If we look at inflammatory diseases, there is evidence to support the benefits of an anti-inflammatory diet. In a recent study of patients with Crohn’s disease (a chronic inflammatory condition), an anti-inflammatory diet emphasising lean meat, poultry, fish, fruits, vegetables, spices and probiotic foods improved self-reported symptoms in 60 per cent of patients24.
How do we know if a diet is anti-inflammatory?
In recent years scientists have developed a ‘dietary inflammatory index’ 25, to help categorise people’s diets on a scale from pro-inflammatory to anti-inflammatory. The index is based on 45 different foods and nutrients (including alcohol, meat, omega-3, spices and tea) and their ability to increase, decrease or have a neutral effect on inflammatory markers in the body.
Nutrients with anti-inflammatory effects include turmeric, tea, fibre, vitamin A, beta-carotene, omega-3, quercetin and magnesium. Scientists use the index together with dietary questionnaires to assess how many of these anti-inflammatory nutrients people consume to arrive at an overall diet score.
By using the ‘inflammatory index’ to score people’s diets, scientists have been able to accurately predict changes in CRP (C-reactive protein), a marker of inflammation in the body26. They have also been able to show that pro-inflammatory diets (as measured by the index) are associated with higher risk of inflammatory diseases including asthma and metabolic syndrome 27 28.
Until research determines the ideal anti inflammatory diet, scientists agree that a Mediterranean style diet is the most likely to offer similar anti inflammatory benefits.
- An anti-inflammatory diet emphasises foods with proven anti-inflammatory effects including oily fish, spices and tea. It’s possible this style of eating may benefit psoriasis by reducing inflammation in the body.
- No studies have evaluated the effects of a single anti-inflammatory diet in psoriasis, but research shows individual elements such as omega-3, oily fish and curcumin can benefit psoriasis severity
- A Mediterranean style diet is close to an anti-inflammatory diet, with recent research showing this pattern of eating may benefit psoriasis severity.
What the dietician says
We know that psoriasis is an inflammatory disease and that diet plays a big role in either aggravating or lowering inflammation, so it seems logical that eating more anti-inflammatory foods will be helpful.
The problem is, dietary studies in psoriasis are very limited. However, plenty of research supports the idea that we eat can alter levels of inflammation in the body through diet. For example, a western style diet high in saturated fat and refined (processed, low fibre) carbohydrates has been linked with pro-inflammatory effects, where as a Mediterranean style diet (which is perhaps the closest style of eating to an ‘anti-inflammatory diet’) has been linked with reduced inflammation in both groups of healthy adults, and those with disease 29 30 31.
There’s also evidence that oily fish, fruits, vegetables and spices can have anti-inflammatory effects in psoriasis. In a recent study, fish intake was correlated with lower psoriasis severity, so people consuming the most fish tended to have the lowest psoriasis severity scores, as measured by the PASI index.
Even though the effects of an anti-inflammatory diet in psoriasis aren’t certain, this style of eating protects against heart disease (which is higher in people with psoriasis) so including more anti-inflammatory foods stands to benefit your health in a number of ways. Try these simple changes to benefit from more anti inflammatory nutrients.
- Replace some of your red meat meals with oily fish, aiming for 2-4 servings of oily fish per week.
- Switch to using olive oil to dress vegetables, salad and drizzle over bread instead of butter or margarine.
- Eat a diet rich in fruits and vegetables, aiming for 2-3 portions at each meal.
- Switch from white bread, white pasta and white flour to high fibre carbohydrates like brown rice, wholegrain bread and pasta.
- Swap higher sugar snacks for nuts.
- Use herbs and spices in cooking – turmeric, ginger, and garlic are particularly beneficial.