The Aging Process - Free Radicals and Antioxidants by Don Owen, Ph.D.

The Aging Process - Free Radicals and Antioxidants by Don Owen, Ph.D.

The aging process—free radicals and antioxidants

Life on earth took a big step when it began using oxygen for energy about 2.3 billion years ago—it allowed for the development of rapid movement (advanced life), complex chemical processes (such as color, vision) and ultimately the creative brainpower we possess.

However it came with a price. The Mitochondria in every cell, which are the energy producers that make Adenosine TriPhosphate (ATP transports energy in cells), also produce undesired free radicals.

Assault on healthy cells

Free radicals—unstable and highly reactive atoms with unpaired electrons (atoms are bonded by pairs of electrons)— in their quest for electrons, create a lot of damage to healthy cells. The destruction they bring when they react with important cellular components such as the DNA, not only can lead to cancer but its damage is also among the leading theories of aging—aging thus results from free radical damage in which critical systems are eventually eroded, leading to failure and death. Free radicals can be generated endogenously (at the intracellular level, thus as a “natural” consequence of body functions) or exogenously (chemicals, drugs, cigarette smoking, sun exposure, radiation…). As such some sources of free radicals can be controlled, others cannot. In skin cells, the damage causes the wrinkles characteristic of aging.

Preventing and delaying cell damage

To help prevent self-destruction of the cells within the body, cells must produce antioxidants at all times to handle generated free radicals. As their name indicate, antioxidants block the process of oxidation and neutralize free radicals. However as we age our organism slows down, thus reducing the release of critical hormones to fight off free radical formation and damage. Aging is controlled in the human body at the total organism level by the hypothalamus, which produces the Growth hormone releasing hormone (GHRH), or Somatoliberin. In turn, GHRG causes the release of human growth hormone (hGF) and its critical binding factors. Yet as we get older, the biological clock in the hypothalamus causes a significant reduction in hGF, which in turn causes the reduction of circulating insulin-like growth factor 1 (IGF-1). IGF-1 is the principal circulating growth factor necessary to maintain regional repair and produce the enzymes that control free radical formation and resulting damage repair.

The skin (epidermis and dermis) is composed of cells that generate free radicals because of normal metabolic activity, but must also take care of free radicals produced by the environment. Yet, as previously expounded, as we age, our body reduces its ability to produce proteins to respond to environmental insults and enzymes associated with free radical reduction (more below).

Just as we slowly stop repairing gravity damage (i.e. collagen, elastin, etc.) we also stop repairing solar damage and free radical formation damage. Skin care products can provide a source of antioxidants useful in supplementing nature’s repair.

Kinds of antioxidant

There are two basic categories of antioxidants: enzymes (produced by the body and living organisms) and small molecular types that are either actual antioxidants or induce antioxidant activity (vitamins, minerals, and other molecular types found in fruits, vegetables, herbs).

Enzymes controlling free radical formation:

Superoxide dismutase 1, 2 and 3 (SOD1, SOD2, SOD3). SOD is among the body’s most powerful natural antioxidant enzymes. SOD is naturally found in foods such as yeast and barley green. Zinc is an important component of SOD.

Catalase is another important enzyme found in all living organism. Foods high in catalase include wheat sprouts, collard greens and other cruciferous vegetables.

Glutathione peroxidase (GPx); its main role is to protect the organism from oxidative damage. Foods rich in glutathione precursors, thus that help raise glutathione levels naturally include spices (such as turmeric, cinnamon, cardamom), sulfur rich vegetables (onions, cabbage, broccoli, kale), avocados, aloe vera and brazil nuts among others.

Thioredoxin reductase—its level of activity is reduced by selenium deficiency.

Small molecular types can be further divided into numerous groups:

Vitamin C: ascorbic acid, magnesium ascorbic phosphate (water soluble derivative of vitamin C); ascorbyl palmitate (another form of vitamin C).

Phenolics: quercetin (a flavonoid found in red wine, berries, green tea); cathechin (a flavonoid found in tea, which includes epigallocatechin-3- gallate EGCG); resveratrol (red wine).

Carotenoids: beta-carotene, lycopene, lutein, vitamin A (retinoids).

Sulfur containing compounds: lipoic acid, N-acetyl cysteine (NAC, which comes from the amino acid L-cysteine, replenishes intracellular levels of the natural antioxidant glutathione).

Minerals: zinc, selenium, copper (all three needed for SOD enzymes).

Skin care formulations have for many years added both synthetic and plant derived small molecule antioxidants to improve the skin’s ability to handle the many sources of free radicals associated with being alive. Recently enzymes such as catalase and SOD, commercially available via isolation from plant sources and fermentation, have also been added to reduce free radical concentrations.

Retinoids have always been useful for anti-aging and fine line reduction, and newer derivatives are allowing ease of formulation. Retinyl olivate, retinyl safflowerate and retinyl phosphate, are only a few of the oil and water soluble derivatives that are certainly being introduced into new formulations.

Also receiving interest are agents that aid in increasing DNA/RNA (ribonucleic acid) single strand repair or double strand repair—unlike DNA, RNA is single-stranded.

Applied topically, certain antioxidants might not penetrate deeply into the intact stratum corneum (SC, the outermost layer of the epidermis)—depending of the circumstances compounds can exhibit pro- or antioxidant activity—however, they can indeed be effective at reducing free radical formation on the surface and immediate sub-surface of the SC. 

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