Introduction

Antioxidants are molecules that are able to fight off harmful free radicals within the body. Free radicals are highly reactive, unstable species which damage the nucleus and cell membranes of biological molecules such as DNA, proteins, carbohydrates and lipids.

The body produces its own antioxidants (endogenous antioxidants) for protection, however, the consumption of raspberries can also provide a great defence against harmful free radicals within the body. There are many different types of raspberries, including purple, black and golden, but the red raspberry (Rubus idaeus) is the most common and has great health benefits within the body.¹

Composition of red raspberries 

Red raspberries are typically harvested in the summer and autumn months and they are native to Europe and Northern Asia. They contain high amounts of polyphenols and antioxidants. Red raspberries have a relatively unique phytochemical profile that is rich in ellagitannins and anthocyanins, which differs from other fruits and berries.¹ While raspberries are low in calories, they are nutrient dense and a great source of vitamins and minerals, including:^2,3

• Fibre: These fruits pack 6 grams of fibre into a 1 cup (140 g) serving, which is 24% of the recommended daily intake for women, and 16% of the recommended daily fibre intake for men
• Vitamin C: Also known as ascorbic acid. One cup of raspberries contains more than half of the recommended daily intake of vitamin C for both men and women
• Vitamin A: Contains trace amounts of vitamin A which is important for reproduction and growth
• Vitamin B6: Raspberries contain small amounts of vitamin B6. It is important for normal brain development and the nervous system
• Calcium: Raspberries contain 43 mg of calcium in one cup serving. It is vital in building and maintaining strong bones
• Zinc: Zinc is important in the creation of DNA and healing damaged tissues. One cup of raspberries contains 0.7 mg of zinc

Antioxidant compounds

Phytochemicals are plant-based bioactive compounds that are produced by the plant for their protection. They are not essential, however, they can be very beneficial to our health. Phytochemicals are able to protect our cells from damage caused by environmental toxins and chemicals, such as free radicals, which are produced in the body’s natural metabolic processes.⁴

• Ellagitannins are bioactive polyphenols, known for their ability to induce cell cycle arrest of cancer cells, prevent cardiovascular disease and scavenge for oxidative free radicals. This makes them a great addition to your diet
• Anthocyanins are the coloured, water-soluble pigments within raspberries that give them their signature colour. Much like ellagitannins, they belong to the phenolic group and possess antidiabetic, anticancer and anti-inflammatory properties, as well as aiding in the prevention of cardiovascular disease
• Vitamin C (ascorbic acid) is a type of phytochemical. It helps to protect cells, maintain a healthy skin barrier and protect blood vessels and bones from damage. Vitamin C is also used by the immune system as it is vital in the body’s healing process
• Flavonoids are another form of phytochemical which were once known as vitamin P. They are a large class of plant compounds that are found in deeply coloured fruits such as raspberries. They also have antioxidant effects, helping to protect the body from damaging free radicals

Oxidative stress

Free radicals are unstable molecules that are continuously formed in the body through either normal cell metabolism or from external sources such as pollution, radiation and cigarette smoke. Due to an uneven number of electrons, free radicals react easily with other molecules. This causes a large chain chemical reactions within the body, resulting in damage to the cells and tissues. These reactions are referred to as oxidation. 

Despite this, our immune system utilises free radicals when fighting off infection, and for this reason they also serve important functions in our bodies. Therefore, there should be a healthy balance between free radicals and antioxidants within the body. 

Oxidative stress is the term used to describe an imbalance between the production of free radicals and the body’s antioxidant capacity. This results in damage to fatty tissues, DNA and proteins within the body. Chronic oxidative stress can lead to a range of diseases, such as diabetes, atherosclerosis, heart disease, Alzheimer’s and cancer. However, during oxidative balance, molecularly stable antioxidants are able to protect the body by donating an electron to a dangerous free radical. This neutralises the free radical, reducing its capacity to cause damage within the body. Therefore, to reduce oxidative stress and maintain optimal health, it is vital to ensure that your body receives a sufficient amount of antioxidants. 

Health benefits of raspberry antioxidants

The antioxidant properties of raspberries can provide a variety of health benefits, in particular the reduction of cellular damage, inflammation, and the risk of many chronic and neurodegenerative diseases.

Cardiovascular diseases

A vast range of research has shown that antioxidants are beneficial in improving heart health and can even help to prevent diseases such as coronary heart disease (CHD). Oxidative stress has been linked to atherosclerosis and coronary artery disease.⁵ In the cardiovascular system, cells continuously generate reactive oxygen species (free radicals) to use them as signalling molecules. When the level of reactive oxygen species exceeds the cellular antioxidant level, lipids and proteins may be damaged, having a detrimental impact on vascular function and structure. 

Similarly, oxidative stress may damage the artery endothelium and damage vascular relaxation, causing increased vascular contractile activity, resulting in hypertension or high blood pressure. However, the consumption of antioxidant rich foods, such as raspberries, results in a higher antioxidant capacity in the body.¹ This diminishes the damaging effect that free radicals can have on the vascular system, over time preventing cardiovascular diseases. Because of this, antioxidants are vital in the reduction of cardiovascular diseases. 

Inflammatory diseases

Furthermore, free radicals can trigger the inflammatory response of the immune system, over time this can have a detrimental effect on the body. Chronic diseases such as rheumatoid arthritis and Crohn’s disease are examples of serious inflammatory responses that can affect the quality of a person’s life. The removal of free radicals by antioxidants found in raspberries reduces the free radical attack therefore decreasing physiological inflammation. It is possible that increasing the body’s antioxidant levels by adding more raspberries to our diets could reduce these inflammatory effects, helping those with chronic inflammatory diseases live more comfortable lives.⁶

Neurodegenerative diseases

There is evidence to suggest that neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease could be treated with raspberry antioxidants.⁷ Free radicals are involved in neurotransmission, and therefore they are particularly active in the brain and neuronal tissue. However, an excessive production of free radicals can attack glial cells and neurons, leading to neuronal damage and cell death. Neutralisation of these free radicals by antioxidants could prevent the damage of neural tissue and slow down the effects of neurodegenerative diseases. For this reason, increased raspberry consumption may help to delay or prevent the development of neurodegenerative diseases. 

Therefore, the rich antioxidant nature of raspberries play an important role in the promotion of overall health, wellbeing and longevity by contributing to the reduction of certain diseases. 

Allergies and portions 

It is important to note that some individuals may be allergic to fruits such as raspberries, so you should always try one or two at a time if you have never eaten a raspberry before. Allergic reactions to raspberries are usually associated with oral allergy syndrome (OAS) or pollen-food allergy, caused by cross-reacting allergens that are found in pollen and raw fruits. The immune system recognises the pollen and certain fruit proteins as an invader and begins an allergy response to protect the body from the supposed attack. Symptoms of this can include itching and swelling of the lips, mouth and tongue, medical professionals should be consulted if these symptoms persist. 

It is recommended that adults should consume around at least five portions of a variety of fruits and vegetables daily, with one portion being 80 grams. It is important to not eat too many raspberries in one day as they are high in oxalic acid, which can cause stone formation in the urinary tract if in high quantities.

How to eat raspberries

Raspberries can be incorporated into your diet in a range of ways: 

• Eating fresh raspberries as a snack is arguably the easiest way to incorporate the fruit into your diet, these can be added to cereal, pancakes or granola. They can also be added whole to porridge
• A berry salad, including raspberries, blueberries, strawberries and blackberries is a great way to ensure you are consuming a high level of antioxidants and important vitamins
• Fresh or frozen raspberries can be added to a smoothie so that you can consume your antioxidants on the go
• Raspberries can be dipped in dark chocolate if you are craving something sweet. Making jam, jelly or puree from your raspberries are also popular ways to consume the fruit. It is recommended to steam the fruit rather than boil, as steaming ensures that none of the good nutrients and antioxidants are lost

 Summary

• Free radicals are unstable species that attack biological molecules within the body such as proteins, lipids and carbohydrates 
• Antioxidants are able to neutralise these free radicals by donating an electron to them 
• Our bodies produce endogenous antioxidants, however, we can gain many of our antioxidants from foods such as raspberries 
• Raspberries contain bioactive polyphenols that are known for their ability to prevent cancer cells from forming, prevent cardiovascular disease and scavenge for oxidative free radicals 
• Raspberries also contain a range of vitamins and minerals that are important in growth, reproduction and general organ health
• It is recommended that adults should consume around 20 raspberries per day and children should consume around 10 
• These raspberries can be eaten in a range of ways, from on their own to mixed in a smoothie and dipped in dark chocolate 
• The benefits of raspberries for your body are great, making them a vital part of everyone’s diets