Free radicals: what they are, effects and how to fight them

Free radicals are unstable molecules or atoms that have at least one unpaired electron. They occur naturally in the body, for example as a result of metabolic processes, but also due to external factors such as environmental pollution, UV radiation or excessive stress.

Due to their instability, they are highly reactive and try to ‘steal’ electrons from other molecules, which can lead to a chain reaction of cell damage. This process is called oxidative stress and is associated with premature skin aging, inflammation and various chronic diseases.

Free radicals can be formed in the body in a number of different ways. A distinction is made here between endogenous (produced by the body itself) and exogenous (external) factors.

Internal processes:

• Cell breathing: During the production of energy in the mitochondria, free radicals are produced as by-products.

• Immune reactions: Immune cells use free radicals to fight bacteria or viruses as part of the defence against pathogens. However, the quantities produced in this process are very small and do not contribute to the load.

External influences:

• Environmental factors: air pollution, UV radiation and cigarette smoke increase free radical exposure.

• Diet: A diet low in vital substances (e.g. industrially processed foods), alcohol and an unhealthy lifestyle in general can contribute to the development of oxidative stress.

• Stress: Chronic stress increases the release of stress hormones, which weaken the body's antioxidant defences.

• Lack of sleep: Not getting enough sleep affects the body's regeneration processes and can promote the development of oxidative stress. It also makes it more difficult to neutralise free radicals.

• Medication: certain drugs, such as chemotherapy drugs or some painkillers, can promote the formation of free radicals.

Free radicals are produced naturally during our metabolic processes. However, these unstable molecules can cause considerable damage if they become excessive and the body is no longer able to neutralise them sufficiently. Here are a few examples of how they can affect the body:

Damage to cells and tissues: They attack cell membranes and proteins, which can lead to a loss of function or even cell death.

DNA damage: Free radicals can alter the DNA in cell nuclei, which affects the entire cellular metabolism and, in the long term, increases the risk of cancer.

Diseases: Oxidative stress is linked to conditions such as diabetes, cardiovascular disease and neurodegenerative diseases (e.g. Alzheimer’s).

Skin damage: Free radicals attack collagen and elastin fibres. As a result, the skin loses its elasticity, wrinkles form more quickly and the complexion appears duller. Pigmentation disorders and an increased risk of skin cancer are also closely linked to oxidative stress.

Ageing processes: Cell damage caused by free radicals accelerates both visible and internal ageing processes.

Ageing is a natural biological process – however, excessive oxidative stress can significantly accelerate it. If free radicals are produced in excessive quantities and are not adequately neutralised, they attack essential cellular structures – including the lipids in cell membranes, the mitochondria (the cell’s energy centres) and the DNA in the cell nucleus.

As a result, cells lose structural stability, their ability to produce energy and their capacity for regeneration. Tissues with high metabolic activity – including the skin, heart and brain – are particularly vulnerable, as they are continuously exposed to increased oxidative stress.

At the cellular level, oxidative damage also contributes to so-called ‘inflammaging’ processes. The term combines ‘inflammation’ and ‘ageing’ and describes a chronic, low-grade inflammatory response that increases over the course of a person’s life. Free radicals can activate inflammatory signalling pathways and further exacerbate these underlying processes. In the long term, this places additional strain on cells and tissues, accelerates functional decline and increases the risk of age-related diseases.

A balanced ratio between free radicals and antioxidants is therefore crucial for regulating oxidative stress, maintaining a balance in inflammatory processes and supporting long-term cell health.

Antioxidants are the natural antagonists of free radicals. They have the ability to neutralise the unstable molecules by providing them with an electron without becoming unstable themselves. In doing so, they interrupt the chain reaction of cell damage and help to protect against oxidative stress. This is why antioxidants are also referred to as radical scavengers.

The most important antioxidants include:

• Vitamins: Vitamin C and vitamin E

• Minerals and trace elements: selenium, zinc, copper and manganese

• Phytochemicals: polyphenols, flavonoids and carotenoids, which are found in fruit and vegetables.

• Enzymes: superoxide dismutase (SOD), catalase and glutathione peroxidase, which occur naturally in the body.

A healthy lifestyle is the key to maintaining a balance between free radicals and antioxidants. Here are some helpful tips:

• Reduce stress: relaxation techniques such as yoga, meditation or walks in the fresh air can help.

• Live smoke-free: give up cigarettes, as smoking massively increases free radical exposure.

• Use sunscreen: protect your skin from UV rays with sunscreen and clothing. In addition, some antioxidants, such as astaxanthin, also provide protection from within.

• Regular exercise: Moderate exercise supports the body's antioxidant capacity, while excessive exercise can increase oxidative stress.

• Healthy diet: A varied, plant-based diet with foods rich in antioxidants is a suitable supportive measure.

Eating the right foods is a key part of the fight against free radicals. It is especially important to eat foods that are rich in antioxidants.