Antioxidants inhibit our age-related immune system impairment

Even the earliest ageing processes are known to damage central parts of our immune system, leaving us more exposed to infection, inflammation, and cancer. However, new studies demonstrate that antioxidants such as vitamin C and selenium may repair the damage.

With an immune system that functions optimally, we are literally impervious to contamination. The immune system is also responsible for removing toxins from the bloodstream, destroying abnormal cells, and preventing cancer, and that is why it is vital to have a strong immune defense - throughout life.

Free radicals speed up the ageing process

A study carried out in Florida by scientists at the The Scripps Research Institute supports the theory that links free radicals to the ageing processes. First of all, free radicals are a by-product of our own energy metabolism, which becomes increasingly inadequate as we age, causing it to generate more and more free radicals. Secondly, the free radical impact is strongly increased by stress, infection/inflammation, smoking, environmental toxins, medicine, and radiation. Free radicals are highly aggressive molecules that attack cells and tissues. Over time, they accelerate our ageing process and tend to promote age-related disease.

New formation of white blood cells should adjust itself to loss and need

In the above mentioned study, the researchers focused on one of the most important glands of the immune system, the thymus gland, which is situated right behind the breastbone (sternum). The thymus is in charge of making a type of specialized white blood cells called T-cells that normally attack microorganisms and abnormal, potential cancer cells quickly and effectively. As T-cells have a limited lifespan, the thymus must be able to produce new T-cells in step with the actual loss of these cells and the body's need for them. However, according to Dr. Howard Petrie, the thymus begins to shrink in size in early adulthood, while losing more and more of its ability to function properly.

Lack of antioxidants may cause cellular damage to the thymus gland

The researchers looked at different types of cells from the thymus of mice and observed that lack of the antioxidant enzyme catalase resulted in free radical production, which increased cellular damage to the gland.
Afterwards, the researchers increased levels of catalase in the thymus glands of the mice and witnessed how this enabled the mice to maintain the size of their glands for longer time. The researchers were also able to maintain the size of the thymus by administering different dietary antioxidants to the mice - including vitamin C.

New theories: Why does the thymus shrink?

The big question remains: Why does the thymus shrink faster than other tissues in the body?
While other scientists have pointed to the relation to sex hormones, the new study reveals that the ageing process in the thymus is similar to that of any other tissue. However, the fact that the thymus ages that much faster may be explained by a deficiency of the antioxidant enzyme catalase, as the new study suggests. Levels of this enzyme happen to be higher in other tissues.
Other studies have demonstrated a relation between shrinking of the pineal gland in the brain and the thymus gland. The pineal gland is a superior gland that regulates numerous functions in the human body, including our circadian rhythm and fertility. The shrinking of the pineal gland is also of huge importance to our ageing process.

Low dietary selenium content harms the thymus gland and our T-cells

There are large concentrations of selenium in the thymus, the spleen, and in lymph nodes. Here, in these tissues, selenium promotes the formation and activity of T-cells and other types of white blood cells. Selenium is also a powerful antioxidant that protect the thymus and T-cells against free radicals. Nonetheless, studies of chickens have shown that low dietary selenium causes the thymus to shrink faster, while lowering the activity of T-cells in the blood.

Are you getting enough selenium?

The European agricultural soil generally contains very little selenium, which is why the selenium content in crops is low. A diet without organ meat, fish, and shellfish contributes to the low selenium status. The selenium intake of an average European is below the recommended daily allowance (RDA). Supplementation with organic selenium yeast is a way to compensate for this deficiency.

References:

James Mcintosh: Age-related immune system decline slowed by antioxidants. Medical News Today 2015

Scripps Research Institute. Study shows how aging cripples the immune system, suggesting benefits of antioxidants. Science Daily. 2015

X Peng et al. Low dietary selenium induce increased apoptotic thymic cells and alter peripheral blood T cell subsets in chicken. Biol Trace 2011

Danmarks Fødevare forskning: Selen og sundhed