Reducing Inflammation With Oranges

Introduction

What is inflammation? And why oranges?

Inflammation is our bodies' response to harmful or foreign stimuli in the body. We need this in order to heal from injury and fight off disease-causing pathogens. However, too much inflammation causes serious health problems. 

Here are just a few diseases thought to be caused by too much inflammation:

• Asthma
• Eczema
• Rheumatoid arthritis
• Crohn’s disease (inflammatory bowel disease)
• Heart disease

Oranges are one example of a food that helps the body deal with inflammation due to the micronutrients they contain, including Vitamin C. 100 g of orange contains between 51.8 and 65.6 mg of Vitamin C, more than the NHS minimum recommended daily intake of 40 mg, making them a particularly good option to add to your daily diet.

What’s in an orange?

Antioxidants

Imagine your body is a machine. When exposed to damp air, it gets rusty. Rust is damaging, sometimes causing parts to fail or break. Rust is “oxidation”, and oxidation happens in the cells of our bodies, where a group of atoms loses an electron or reacts with a “reactive oxygen species”. When this happens a lot, it is called “oxidative stress” and can lead to excessive cell growth (cancer) or cell death. Antioxidants are compounds that counteract this and, therefore, repair the damage caused by stress or oxidation.

Vitamin C (ascorbic acid)

Oranges are an excellent source of Vitamin C, a key antioxidant that reduces inflammation and boosts the immune system. 

Originally, Vitamin C was identified as the cure for scurvy, and it was noted in sailors with poor diets who experienced bleeding gums and fatigue. In 1747, James Lind experimented with different treatments and found oranges and lemons were the only options that led to scurvy recovery. Now, vitamin C is known to be an essential part of our diets, which helps the immune system recover from illnesses such as the common cold, reduces inflammation, and fights off scurvy.¹

Phytochemicals

Phytochemicals is an umbrella term for chemicals from the plant immune system, produced to fight off bacteria, viruses and fungi. Phytochemicals have antioxidant effects and have been suggested to help us resist cancers, heart disease and brain disorders including dementia.

Carotenoids

Carotenoids are a type of phytochemical that causes the bright orange pigment in the fruit. Many carotenoids can be converted into vitamin A in our bodies; this micronutrient is linked to immune health, eye health, and healthy skin.

One example is lycopene, a red-orange antioxidant which several studies have linked to reducing cancer risk. Lycopene’s chemical structure means that it easily removes or ‘quenches’ reactive oxygen and prevents oxidative damage in our bodies. Further research into lycopene has shown it is protective against cardiovascular problems and heart disease. Low lycopene correlates with a build-up of fat in arteries, which puts you at risk of stroke or heart attack.^{2, 3, 4} 

Another carotenoid is beta-cryptoxanthin, an antioxidant that, again, reduces inflammation and has been implicated in fighting several types of cancer due to its involvement in important chemical signalling pathways that affect cell growth and death. Beta-cryptoxanthin significantly reduces the risk of type 2 diabetes and non-alcoholic liver damage.^{5, 6}

Flavonoids

Orange juice contains more than 60 flavonoids, phytochemicals which are found to benefit our immune systems. These have a different chemical structure to carotenoids, but again they are anti-inflammatory and fight off infections due to their antibacterial and antiviral properties. 

One example is hesperidin, which was shown to reduce blood pressure and is also suggested to reduce risk of neurodegenerative disease and enhance brain cell growth.^{7, 8, 9}

Another flavonoid is naringenin, a flavonoid abundant in citrus fruits with a bitter flavour. Therefore, more bitter citrus fruits are higher in naringenin. Naringenin affects fat processing in the body in a positive way, reducing the risk of fatty liver disease. It also has a general anti-inflammatory effect, reducing the risk of cancer growth and helping us fight off pathogens. In vitro studies (using cells in lab dishes) have shown that naringenin reduces ageing processes.^{10, 11}

Flavonoids also have anti-wrinkle properties when used in skincare products, causing smoother and less dry skin.¹²

Other benefits of oranges

100g of oranges also contains, according to the USDA database:

• 166 mg of potassium, which may reduce blood pressure, protect against heart disease, and maintain kidney health
• 43 mg of calcium, important for body strength, bone health, and keeping the heart rhythm normal
• 23 mg phosphorus, important for cell growth and repair
• 11 mg magnesium, essential for healthy muscles, a healthy heart and a healthy brain
• 34 µg folate, also known as vitamin B9, is crucial for blood cell formation and healthy cell growth and key in reducing the risk of birth defects during pregnancy

What happens during inflammation?

The body gets 'inflamed' when injured, and this means white blood cells flood in, blood flow increases, the area gets warmer, and histamines are released causing redness and soreness.

There are several types of white blood cells, and B and T lymphocytes are particularly important in inflammation processes. B cells are white blood cells which produce antibodies, which help us fight off infections and develop immunity to familiar illnesses. T cells are more involved in fighting and killing the infection by releasing chemicals such as cytokines to cause inflammation. Cytokines are proteins which tend to trigger ‘cascades’ or ‘cytokine storms’ where they lead to the production of many other cytokines, causing the inflammatory effects which can become damaging. One example of cytokine is interleukin-6, a chemical found in our bodies which is linked to autoimmune diseases and cancers.¹³

What causes inflammation?

Inflammation after injury

Inflammation is a necessary response our bodies have following injury or damage by foreign pathogens (such as viruses and bacteria). When physically injured, our body activates white blood cells and produces inflammatory chemicals, causing the area to swell with fluid to help protect it. The increased flow of blood brings extra white blood cells that heal the injury as fast as they can. Oranges may be helpful to this process as its vitamin C increases the production and specialisation of the white blood cells required.¹⁴

Allergens

Inflammation occurs in response to exposure to allergens. For example, eczema and asthma occur via allergens causing inflamed skin or inflamed airways. In asthma, high levels of inflammatory cytokines are found in the airways. A flurry of cytokines causes excess white blood cells to be recruited as if to heal damage in the airways. This can cause protective processes like swelling and mucus production to happen when they shouldn’t, causing an asthma attack. Similarly, in eczema, excessive levels of cytokines are produced when the skin encounters an irritant, and the immune system responds with swelling, soreness and redness.¹⁵ 

Inflammation and cancer

Inflammation is a process involved in both fighting cancer and also causing cancer. Our body naturally has in-built inflammatory mechanisms to try and stop cancer from occurring and to cause these cells to die. However, high inflammation is also known to promote cancer progression.

The inflammatory chemical interleukin-6 is a cytokine strongly correlated with cancer. The increase in cytokines and inflammatory chemical pathways can cause cell damage in the form of DNA mutation, which can cause cells to divide excessively, forming a tumour. This is supported by the fact that tumours are found to contain high levels of many cytokines, including interleukin-6 and other interleukins. ^{13, 16}

How can antioxidants help?

Antioxidants such as vitamin C work to reduce oxidative damage in our bodies in several ways. For example, it removes reactive oxygen chemicals, which would damage DNA and damage cells. Vitamin C also inhibits cytokines, the chemicals released by T lymphocytes (white blood cells) that trigger inflammation. Vitamin C also assists and regenerates other antioxidants, such as vitamin E. 

Many antioxidants, such as vitamin C, boost the production of white blood cells, which are the cells that help us fight off colds and other viruses.¹⁴

What else can I do to reduce inflammation?

In addition to adding oranges to your diet regularly, you can adopt other lifestyle changes to reduce inflammation. Plenty of rest and sleep reduces inflammation - studies have shown that sleep deprivation increases cytokines and inflammatory effects in our bodies.¹⁷

Exercise reduces inflammatory chemicals and reduces the risk of inflammatory diseases such as cardiovascular disease, type 2 diabetes, and several cancers. However, intense exercise, e.g. taking part in elite sport, has been shown to be negative for immune defences against infections. So we should take part in regular, moderate exercise to optimise our health, but not aim for extreme fitness.¹⁸

Other anti-inflammatory foods

Several other foods high in antioxidants can reduce inflammation in our bodies:

• Berries such as blueberries, cranberries and strawberries
• Apples
• Stone fruits, e.g. peaches, plums, cherries and apricots
• Pomegranates
• Green and black teas

Inflammatory foods to avoid

• Red meat increases inflammation and may have a negative effect on the immune system ¹⁹
• Foods high in fat (e.g. fried foods) contribute to inflammation and may increase the risk of inflammatory bowel disease.²⁰

Summary

Oranges are an excellent anti-inflammatory food due to the micronutrients they contain. Not only vitamin C, but other hugely beneficial antioxidants such as flavonoids and carotenoids are abundant in citrus fruit. These antioxidants are not magic cures for illnesses such as cancer or arthritis, but they are known to directly reduce inflammation and reduce the risk for inflammatory disorders. The chemicals found in oranges are hugely beneficial for our heart health, gut health, and brain health.