Dear reader,

This week we want to offer you information and tips to care for and protect your skin from aggressive external agents in these approaching summer dates.

To do this, we will first talk about the skin as an organ and its functioning, and then how to prevent the diseases that affect it at this time of the year from a natural perspective.

The skin

The cutaneous structure is the largest organ of the human body, since it covers it externally, separating it from the external environment. It is more than two meters long and weighs between 4.5 and 5 kilograms.

It is a heterogeneous structure consisting of three overlapping layers: the epidermis, the dermis and the hypodermis.

- The epidermis is the outermost and thinnest layer. It is subdivided into the layers: basal or germinative, stratum spinosum or mucous body of Malpighi, stratum granulosum or granular layer and stratum corneum or horny layer.

It is mainly made up of living cells, the keratinocytes, which are progressively transformed in the process of keratinization to form the different layers, each with its specific characteristics.

These living cells, in the course of keratinization, flatten and lose their nuclei, becoming corneocytes, the cells that form the stratum corneum or horny layer of the skin, the outermost and most desquamative layer.

The epidermis forms a barrier against heat, light and pathogens in its outermost layer, whose "dead" cells contain a number of enzymes involved in metabolic processes and are rich in water-binding substances (maintaining hydration).

More internally, the epidermis produces melanocytes, cells responsible for skin pigmentation that form melanin, which gives color to the skin and constitutes a mechanism of natural protection against ultraviolet radiation from the sun.

In addition, we also find in the epidermis the Langerhans cells, which are part of the immune system, in charge of capturing allergens and presenting them to the T lymphocytes. They ensure the immune defense of the skin by triggering a cellular immune response (type IV contact allergy or delayed hypersensitivity).

Merkel cells are the sensitive receptors of our sense of touch. They are more numerous in the lips, palms of the hands and extremities of the fingers, and capture vibratory stimuli, transmitting them to the nerve endings with which they are connected.

Thus, the epidermis has the main function of protection, although it is also important from an aesthetic point of view, since it is the visible part.

- The dermis is thicker than the epidermis and is composed mainly of connective tissue made up of collagen and elastic fibers.

It is the middle layer of the skin and at its junction with the epidermis (dermoepidermal junction) there are substances such as glycoproteins, type IV collagen and fibronectin. This junction between the basal layer of the epidermis and the dermis has a wavy structure in young skin, while it flattens and distends as the skin ages (loses tone).

The dermis is made up of proteins such as collagen (which gives strength to the skin) and elastin (responsible for skin elasticity).

Oxytalanic fibers and reticulin fibers (elastin and collagen fibers, respectively) are very fine fibers that are the first to disappear during aging.

Other substances found in the dermis are: proteoglycan gel where the above fibers are located, composed of hyaluronic acid, chondroitin sulfate and dermatan sulfate (in this gel water molecules are captured, constituting a water reservoir for the skin); and cells such as fibrocytes and fibroblasts, macrophages, lymphocytes and eosinophilic granulocytes.

In this layer of the skin there is a small amount of adipose tissue, as well as the skin appendages: hair follicles, sebaceous glands and sweat gland ducts.

The dermis gives the skin its elasticity and strength.

- The hypodermis is the innermost layer and is composed of connective tissue (mainly collagen and proteoglycan gel) and adipose tissue.

Fat cells or adipocytes store triglycerides, giving the skin its insulating power and constituting an energy reserve.

En esta capa encontramos todo el sistema de vascularización, linfática y arteriovenosa, así como la inervación, que afecta tanto a la dermis como a la epidermis (ésta última sólo recibe terminaciones nerviosas).

Blood circulation ensures oxygenation and nutrition of the different layers of skin cells, plays an essential role in thermoregulation and maintains the balance of blood pressure. It is also involved in transcutaneous absorption processes.

pH of the skin

The skin has a pH close to 7 in the dermis layer, while it becomes an acid pH in the outermost layer. This acid pH close to 5, variable according to individuals and body zones is generally between 4 and 7, on average it is 5.5.

The pH is regulated by the secretion of sweat from the eccrine glands, which secrete lactic acid, among other substances. This acid secretion constitutes a defense mechanism for the skin against attack by microorganisms.

Thus, it is necessary to keep the skin clean and healthy, with washing products that maintain this pH (avoid alkaline preparations), taking into account that the pH increases with age and is more alkaline in women.

Cutaneous flora

It is important to know that there are a number of colonies microorganisms that live on the skin: bacteria, fungi, yeasts, whose amount and nature vary with age.

The areas of the skin rich in microorganisms are the hands, scalp, underarms, forehead, the members and the back.

These microorganisms are involved in the defense of the skin against massive invasions of other microorganisms, so it should not be deleted.

You can only be considered dangerous, a proliferation exaggerated of these germs, either by a modification of the pH, moisture, due to lack of hygiene or by an alteration in the epithelium.

Maintaining a proper hygiene and a few basic care we can keep the balance of this medium and avoid infections that are unwanted.

Functions of the skin

With what we have discussed above, we can summarize the functions of the skin:

– Protective function: Protects the internal organs buffering the external aggressions. Prevents the penetration of liquids, but is permeable to different substances such as oils. It constitutes a barrier against aggression bacterial, dehydration and ultraviolet radiation.

– Secretory function and cleansing: Through the sweat excreted by the sweat glands eliminate waste products of cellular metabolism. The elimination of the sweat will depend on the outside temperature, the physical exercise, the stress at which a person is subject to, and the amount of liquid ingested.

Through the sebaceous glands can remove the products of fermentation, gut from the digestion of the liver, and the sebum secreted has a function impermeabilizadora of the skin, and provides flexibility to the same.

– Function reserve: In the skin occurs a storage of fat-soluble substances (mainly ceramides) and water.

The water content determined by the state of hydration of the skin: if the proportion of water is less than 10%, the skin gets dry, rough, scaly, whitish, chapped, uncomfortable, and a little aesthetic. If the skin, on the contrary, is too hydrated (above 13%), its cells appear plump, dull and dehydrated at a great speed.

– Sensory function touch: The sense of touch allows us to capture impressions that come from the outside. Our skin is a great surface deployed endings sensitive to interact and engage with the world around us.

– Immune function: In addition to acting as a natural barrier against aggression, the skin has cells components of the immune system, as we have already commented.

– Function synthesis- Specifically, the skin is able to synthesize vitamin D from substances in the diet and by the action of ultraviolet light on it. It is, therefore, essential for life to take the sun and you receive your solar energy to prevent disease or injury due to a lack or deficit of vitamin D (that enables the absorption and fixation of calcium in bones and teeth and the maintenance of the proper functioning of the nervous system). Obviously, the sun exposure should be controlled, not excessive, and provided with adequate protection to prevent skin injuries such as burns or skin cancer.

How to care for and protect the skin from the inside

– Hydration:

The skin, as the largest organ and the largest of our body, whose primary tissue is connective, rich gel and collagen and elastin fibers, needs a major hydration.

As a general rule, for the health of the whole organism, it is recommended not to drink less than 1.5 liters of water a day, ideally about 2 litres.

The hydration also benefits from the intake of food rich in water such as fruits and vegetables.

– Healthy diet:

Healthy foods that will have a positive impact on the state of our skin are mainly of plant origin, such as fruits and vegetables, thanks to their contribution in water and in vitamins, minerals, and phytonutrients.

The fruits and vegetables promote the removal of toxins via the kidney in the urine (they are diuretic and detoxifying). The fruits of yellow and orange are good sources of vitamin A (carotenoids, antioxidants).

The wheat germ, nuts, and avocado are good sources of vitamin E, also an antioxidant (to great effect anti-aging or “anti-aging” premature).

Vegetables such as cucumber, which contains sulfur, can improve processes such as acne with very positive results. It can be consumed in juices and shakes, but also applied locally on the skin. It is a great moisturizer and cleanser.

The lettuce and celery, in addition to being a diuretic and rich in minerals and vitamins, are advised, for example, in psoriasis.

Foods rich in omega-3 fatty acids, such as soybean, the blue fish, algae (also detoxifying and cleansing), the nuts and the chia seeds, have an antioxidant action and anti-inflammatory on the skin.

– Damaging foods:

The sugar (especially refined), milk and dairy foods, salt, saturated fats and alcohol are the foods that can affect our general health and our skin in particular, especially in some specific pathologies.

The sugars in excess is transformed into fat deposits, which together with an excess of saturated fats, salt and alcohol may favor the appearance of cellulite.

Milk and dairy products of cow's favour certain inflammatory processes, as well as the retention of liquids, also at subcutaneous level, perpetuating the poor microcirculation, lymphatic and cellulite.

The excessive consumption of salt favors dermatitis and the inflammation of the sebaceous glands, in addition to causing the well-known fluid retention or edema.

The saturated fat exacerbate certain diseases and promote inflammatory processes.

The alcohol can aggravate the symptoms of itching and redness of processes such as the psoriasis, eczema, acne and other inflammatory diseases of the skin, due to vasodilation that occurs at the dermal level.

In the next post we will continue by explaining the nutrients to contribute to maintaining the health of the skin, as well as the natural therapies more beneficial to achieve a healthy and beautiful skin, and prevent and treat issues dermatological more frequent.

Happy week!

Sara Gómez Marquina

Specialist in Alternative Therapies, Naturopathy and Nutrition. Physical therapist

Collaborator of Ecolife Food and Club Manager AV Natural Cantabria