Oxidative stress: the silent wear and tear inside your body

Every day, your body is hard at work producing energy, fighting infections and repairing itself. But these normal processes also generate unstable molecules known as free radicals.

When too many free radicals build up, and overwhelm the body’s natural antioxidant defences, the result is oxidative stress – an imbalance that can gradually damage cells and contribute to the development of disease.

According to pharmacist Benjamin Lim, the body contains free radicals, which can damage cells when in excess, as well as antioxidants, natural substances that help protect cells from that very damage.

“In the past, we used to think having a lot of free radicals was bad, and we needed as many antioxidants as possible to deal with them. But now we know we need more of a balance between the two,” Lim told FMT Lifestyle.

“If you have zero free radicals, that’s not a good thing either. They have important functions, such as helping your immune system fight germs and clearing damaged cells and debris.”

Lim said problems arise when the body consistently produces too many free radicals without enough antioxidants to keep them in balance. Over time, this can lead to oxidative stress that damages cells and tissues.

“Think of them as heat. Heat is useful. It is a necessity. But when it gets out of control, it causes damage. And antioxidants are like a cooling system to balance them out,” said Lim.

He explained that many free radicals and other reactive oxygen species (ROS) are produced in the mitochondria, the cell’s energy-producing structures. Over time, without antioxidants to counter their effects, excess ROS can damage mitochondria themselves.

This damage, in turn, would lead to the creation of more free radicals, further impairing mitochondrial function, reducing energy production and causing inflammation.

In severe or chronic cases, persistent oxidative damage may contribute to tissue dysfunction and the development or progression of diseases.

Lim added that oxidative stress could contribute to “brain fog”, a common term used to describe a temporary feeling of mental sluggishness.

As the brain consumes large amounts of energy, its cells naturally produce high levels of ROS during metabolism, making them particularly vulnerable to oxidative stress.

He added that modern lifestyle habits – unhealthy diets, insufficient sleep, smoking, alcohol consumption, and high stress – could lead to the build-up of oxidative stress.

University of Malaya Professor of Geriatric Medicine Dr Tan Maw Pin added that oxidative stress also occurs during exercise, making it important to avoid overexertion or placing the body under excessive stress too suddenly.

“Exercise places the body under mild stress, which causes a certain degree of cellular damage. But the body is able to repair this damage. It is this cycle of stress and repair that helps renew the body and may slow some of the processes associated with ageing,” Tan told FMT Lifestyle.

“So oxidative stress is not all bad. A small amount is actually beneficial. It’s the cumulative effects of excessive oxidative stress over a long period that become harmful.”

Signs of excessive oxidative stress include fatigue, declining energy levels, premature ageing, slower mental processing and slower wound healing.

Lim added that long-term oxidative stress is linked to a range of chronic health conditions, including high cholesterol, diabetes, immune system deterioration and impaired liver function.

To counter these effects, a healthy supply of antioxidants produced naturally in the body is needed. One of the body’s main antioxidant-producing organs is the liver, which produces glutathione.

Cells also produce superoxide dismutase (SOD), an enzyme that converts harmful free radicals into less harmful molecules.

Besides a healthy diet, Lim said antioxidant intake could also be increased through certain supplements, such as ginkgo biloba.

He explained that the herbal supplement contains flavonoids, which are plant compounds with antioxidant properties, that may help protect cells from oxidative damage.

Lim added that nitric oxide, a molecule essential for maintaining healthy blood vessels, could be depleted by oxidative stress.

According to him, the antioxidant properties of ginkgo biloba may help preserve nitric oxide activity, thereby supporting vascular health and brain function.

“Eat a balanced diet. Avoid ultra-processed foods, and eat more fruits and vegetables. Eat the rainbow – include a wide variety of colourful foods in your diet as they provide flavonoids and other beneficial plant compounds,” Lim said.

“Get consistent amounts of exercise, and manage your stress well. Spend time with friends and family, and make sure to always take time for yourself.”

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