Nutrition and the way the body utilizes nutrients obtained from food involve several biochemical processes and functions involving the status of the digestive system, cellular metabolism, and metabolic sequencing. Bioavailability is an essential transportation method for delivering nutrients. It includes the availability, absorption, retention, and utilization of nutrients consumed. Bioavailability relates to the proportion of a nutrient that is absorbed from the diet and how it is used for normal body functions. It is important to note that how those nutrients are delivered has consequential effects regarding the ability to provide nourishment to the skin. Just simply consuming “good food” does not necessarily assure that nutrients are being absorbed properly or being utilized to their best advantage – poor digestion, inadequate absorption, and assimilation may impede nutrient utilization.
Contribution by Dr. Erin Madigan-Fleck, N.M.D, CDT, LMC, LEI
Erin Madigan-Fleck, N.M.D, CDT, LMC, LEI, has decades of experience in the aesthetic and natural health industry. She is a master esthetician, licensed instructor, and naturopathic medical physician with a private practice, Naturophoria, in Atlanta. She is a member of the Association for Applied Corneotherapy and American Society for Nutrition. She is the owner and founder of DermaEducationTV Post Graduate Esthetic Training and the Scientific Esthetics Symposium. She can be reached at dermaeducationtv@gmail.com
Vitamins and minerals uniquely vary in size, quantity, and their specific function. Many nutrients and minerals have synergistic relationships with each other and utilize proportional absorption for optimum effectiveness. Nutrients feature active transports, or “viaducts,” that extrude the vitamin or mineral through the intestinal wall into the body where it may be directly released or connected to other molecules. Diffusion occurs throughout the body via the bloodstream, and, without it, cells are void of nutrients. As a nutrient encircles a cell, the nutrient remains inside a blood vessel, whereas the cell itself is positioned outside. Spaces surrounding the cell and blood vessel instigate a transfer to diffuse the nutrient through the blood vessel wall and allow it to pass into the cell. Perfusion refers to blood flow and the mechanism by which blood provides nutrients and removes cellular waste. Inadequate perfusion creates depleted oxygen, compromising the vitality of the tissue.
Nutrients can also be transported through the cell wall by pinocytosis or phagocytosis. Pinocytosis is an “engulfing” process where liquid substances are captured in a vesicle and pulled into the cell. Phagocytosis occurs when cells surround and “envelope” a nutrient particle and pull the material into the cell. These functions are responsible for absorbing nutrients into the cell and the ability to reduce cellular waste.
The rate of blood flow through the skin is influenced by body temperature and is based on internal metabolism and external temperature. The epidermis is dependent on nutrients, water, and oxygen transport via the dermis. If nutrients are lacking in the dermis, the skin cells will be undernourished. Additionally, the core organs of the body will “grab” and utilize nutrients before the skin, hair, and nails receive them – stressing the significance of individual nutritional status.
4 Nutrient Foundations For The Skin
1. Protein
Protein remains a critical component in skin health and represents the primary constituent in building cells for the entire body. Every cell in the body collects critical amino acids and then utilizes the required protein for bodily functions, including building the structure of organs, tissues, and the skin. The inclusion of protein consumed should be “complete” proteins in the diet and are to include all twenty of the amino acids combined with the eleven non-essential amino acids that are produced by the body as a result of protein consumption on a regular basis. Amino acids are important nutrients required for wound healing, the repair of damaged skin, the acid-base balance and water retention in cellular layers, protection against sun damage, and the maintenance of the skin microbiome.
Amino acids are essential for both dermal and epidermal structures and produce the extracellular proteins and enzymes needed for the synthesis of the epidermal barrier. By age 50, many women may lose up to half of the collagen from their skin, which may be compounded to a larger extent by not consuming enough protein for an extended period. Complete amino acid chains (typically 100 to 10,000 amino acids) are linked together to form structural units and fibrous proteins. Complete amino acid chains are not configured properly in the body by eating only a few of the amino acids obtained by limited protein sources. A variety and regular rotation of proteins should be consumed to build healthy cells, muscles, and skin. Protein deficiencies can lead to muscle wasting, poor wound healing, frequent infections, swelling under the eyes and ankles, splitting nails, hair breakage, and hair loss.
2. Vitamin C
Vitamin C is a normal skin constituent that is found in high levels of the dermis and the epidermis and is a critical co-factor required to stabilize the triple helical structure of collagen and its crosslink formation. Specific transport proteins for ascorbic acid are found on cells in all layers of the skin and keratinocytes, which have a high potential for transport. Nutritional intake of vitamin C is imperative since vitamin C is not naturally synthesized by the human body. Some nutrient-dense sources of vitamin C include citrus fruits, strawberries, kiwi, blackcurrant, rose hip, guava, broccoli, kale, Brussel sprouts, peppers, and parsley. Approximately 70-90% of vitamin C may be absorbed by the body with a conservatively moderate intake of 30-180 mg. per day.
Vitamin C and its interaction with copper ions at the tyrosinase active site may inhibit the action of the enzyme tyrosinase, thereby decreasing melanin formation. Vitamin C is an essential part of skin health as a small molecular weight antioxidant, it synergizes with other antioxidants in the formation of complex activities of enzymatic reactions against ROS free radicals. Ultraviolet light decreases the vitamin C content of the skin, which is influenced by the intensity and duration of exposure. The antioxidant activity of vitamin C helps to protect the skin from ultraviolet damage resulting from free radicals. Additionally, it may reduce ultraviolet-related DNA damage and lipid peroxidation, limit the release of pro-inflammatory cytokines, and protect against cell apoptosis.
3. Vitamin A
Dietary Vitamin A is presented in two forms: active vitamin A and beta carotene. Provitamin A is obtained from fruits and vegetables that contain carotenoids. Carotenoids are converted to retinol by the body after the food is ingested and are effective antioxidants. Beta carotene, which is found primarily in plants, is endorsed for its pro-vitamin activity and can act as a lipid radical scavenger and singlet oxygen quencher. Beta carotene metabolism takes place in several organs, including the skin. With dietary supplementation, beta carotene can be further enhanced in the skin and the bioavailability of provitamin A and retinol can be increased by essential fatty acid status. Dietary sources of vitamin A include apricot, beef, butter, broccoli, chicken, carrot, cheddar cheese, cod liver oil, eggs, fish liver, kale, milk, mangos, spinach, pork, peas, pumpkin, sweet potato, and turkey.
4. Essential Fatty Acids
Linoleic Acid (LA) – Omega 6 Fatty Acid (vegetable oils, safflower oil, meat, poultry, eggs)
Linolenic Acid (ALA) Omega 3 Fatty Acid (dark green leafy vegetables, flax, chia, walnut, fish, oily fish)
EFAs are functional components for both the dermis and epidermis and are a form of polyunsaturated fats that cannot be synthesized by the human body and must be obtained from various and specific foods. Essential fatty acids play a major role in skin functioning and health including intercellular cohesion, superficial lipid film, cell membrane fluidity, and precursors for eicosanoid anti-inflammatory mediators. An essential fatty acid deficiency can produce severe cutaneous abnormalities by affecting both function and appearance, including hyperproliferation of the epidermis, trans epidermal water loss, and dermatitis. Trans epidermal water loss is directly related to structural cell lipids and essential fatty acids – biochemical evidence of essential fatty acid deficiency can be determined from just a few days to weeks. Symptoms include dryness, scaling, flaking, itching, increased sensitivity, keratosis pilaris, and potential rashes.
