Written by: Ana Vrbanović, MD
Our skin is a mirror that reflects our inner health and age. The link between nutrition and skin has always been the subject of many research studies. Vitamins (such as C, E and D), carotenes, flavonoids and various plant extracts possess many anti-oxidative properties and are widely used in the skincare industry as anti-aging ingredients. They are both applied topically and taken orally as food supplements. The skin ages in two ways. The first is intrinsic (endogenous) aging which follows the same mechanism as all internal organs. The second is extrinsic (exogenous) aging caused by external factors such as UV radiation, smoking, poor nutrition, pollution, etc. Prevention is the most effective way to avoid exogenous effects on the skin. The best prevention is restriction of caloric intake, exercise and food rich in anti-oxidants.
Vitamin C, L-ascorbic acid, is water soluble, photosensitive and one of the most important antioxidants for human beings. It is not synthesised naturally in the human body but must be ingested through food or supplements. Citruses present a rich source of natural vitamins. Vitamin C is used both orally and topically to improve skin health. Its effect is that it serves as a cofactor to certain substrates that stabilise collagen. A deficiency in that vitamin leads to a disruption in collagen synthesis. Often as one of the first signs of the deficiency keratosis appears in the area of hair follicles. Keratin accumulates, blocks the hair follicle and so creates small rough feeling bumps, most often on the upper arms (https://www.mayoclinic.org/diseases-conditions/keratosis-pilaris/symptoms-causes/syc-20351149). In addition, since collagen synthesis is disrupted, weakness and breaking of skin starts to occur as well as healing of wounds begins to slow down. As a result, skin looks visibly older. Vitamin C is used in various cosmetic products for local application. It is considered that its antioxidative effect protects the skin by reacting to harmful external factors on its surface.
Vitamin E, tocopherols, is a group of 8 anti-oxidants which are fat soluble. Sources of the natural vitamin may be found in different oils like sunflower oil and various seeds. It is considered that its effect is to help bind collagen which helps against skin aging.
Polyphenols are anti-oxidants that in the recent decades have been attracting the attention of many scientists. Studies have shown that oral intake plays a role in preventing various diseases related to oxidative stress such as cancer, cardiovascular and neurodegenerative diseases. They are present in different fruits, tea, coffee, red wine and chocolate. More and more often mentioned within the group of polyphenols are flavonoids due to the fact that on today’s market (including Croatia) there are supplements with natural flavonoids which have a positive effect on skin health and also on the health of the cardiovascular system, endothelium function and on the possible alleviation of symptoms of Alzheimer disease. Research shows that intake of polyphenols along with the use of sunscreen protects the skin against UV radiation and reduces the risk of cancer.
It is considered that caloric restriction, without malnutrition, slows down aging and prolongs life. There is still no scientific explanation for this mechanism but experiments have shown that restriction of calories leads to increase of collagen, elastin and fibroblasts in the skin and dermal depth increases. A promising strategy for maintaining skin health is the intake of anti-oxidants with ingredients normally present in the skin. At the same time, one must avoid intake of anti-oxidants only through supplements. The healthiest and safest diet is one rich in fruits and vegetables.