Antioxidants are compounds that neutralize free radicals, which are unstable molecules that can cause tissue destruction. Free radicals are produced normally during metabolism and are actually used to kill viruses and bacteria by our own immune cells. While our body is equipped to handle small quantities of free radicals, environmental agents, such as, cigarette smoke, radiation and pollution are sources of additional free radicals.

When the body natural defenses are exhausted, the unstable molecules become destructive. The damage accumulates with age and has been implicated in disease states ranging from Alzheimer’s disease to cancer. Antioxidants, however, are capable of defusing the free radicals, transforming them into inert stable compounds, which are harmless.

As we age, our immune system experiences a natural decline, but this is what makes us more susceptible to disease. Now, emerging research is showing the aging process and its damage to the immune system, while showing how antioxidants in the diet could slow the build-up of this damage. 

The study, published in Cell Reports, supports the free-radical theory of aging where reactive oxygen species such as hydrogen peroxide that are produced by normal metabolism causes damage to cells. This damage contributes to aging and age-related diseases. 

The study was conducted by researchers from The Scripps Research Institute (TSRI) who focused their attention on an organ called the thymus that is responsible for the production of T lymphocytes - also referred to as T cells.

T cells are white blood cells that control the body's immune response. These cells are continuously lost, and it is the job of the thymus - located between the lungs - to replenish them, enabling the body to respond to new infections. However, the thymus is unable to continuously produce high levels of T cells.

Antioxidants are substances that could prevent or delay damage to cells. Examples include beta-carotene, vitamin C and vitamin E. They can often be found in fruits and vegetables and are also available in the form of supplements.

The researchers set out to explore the mechanisms behind the connection by developing a computational approach they could use to assess gene activity in two types of thymus cell in mice - stromal cells and lymphoid cells.