Everything about amino acids in skincare

Proteins are an important component of skin cells, with the two most prevalent ones being collagen and keratin. While collagen alone accounts for 75 percent of skin, keratin is mostly present in the epidermis and is the main component of hair and nails. Collagen and elastin, another protein, are mainly part of the dermis, where both proteins are in charge of maintaining adequate skin elasticity and support. It is within the dermis that wrinkles form.

Adequate supplementation of proteins, whether sourced from animals or vegetables, is essential for maintaining healthy skin and for allowing wounds to heal. Quality proteins and amino acids such as lysine, proline, arginine, and glycine are important for skin maintenance and collagen health and can be found in a variety of dietary sources, including peanuts, walnuts, flaxseeds, chickpeas, quinoa, dairy, egg whites, fish, and poultry.

It is also important to maintain sufficient levels of vitamin C, since it is a co-player involved in in-vivo amino acid production (hydroxyproline). Additionally, it is a valuable antioxidant that plays an important role in preserving collagen and preventing its breakdown.

UNSATURATED FATTY ACIDS

Unsaturated fatty acids are so-called because they possess one or more double bonds in their carbon main chain molecule. Monounsaturated fatty acids have a single double bond between the main chain carbon atoms; polyunsaturated fatty acids have multiple double bonds between the main chain carbon atoms. Polyunsaturated fatty acids (PUFA), or essential fatty acids, are of great importance to the skin. Vegetable oils are rich in essential fatty acids.

Essential fatty acids are acids that the human body needs but is unable to synthesize or produce such as linoleic acid (LA) and alpha linolenic acid (ALA). They are therefore necessary as part of the diet.

Polyunsaturated acids are divided into the following types:

1. Omega-3 polyunsaturated fatty acids: 

These are named as such because the first double bond occurs between the third and fourth carbon atom from the omega end of the chain. They are abundant in fish such as sardines, mackerel, salmon, scallops, and halibut, as well as in flaxseeds and walnuts. They are present to a lesser extent in many other sources, such as olive oil, beans, and tofu. Specific omega-3s of physiological importance to human beings are ALA (alpha linolenic acid), DHA (docosahexaenoic acid), and EPA (eicosapentaenoic acid). The human body can produce, to some extent, DHA and EPA from ALA, but not at the skin level, where the appropriate enzymes are absent. That is why they are considered essential fatty acids. Flaxseed oil (also known as linseed oil) and walnut oil are both high in ALA.

2. Omega-6 polyunsaturated acids: 

These are named as such because the first double bond occurs after the sixth carbon atom from the omega end of the chain. Omega-6s include GLA (gamma linolenic acid), DGLA (dihomo GLA), AA (arachidonic acid), and LA (linoleic acid). The human body can produce GLA and AA from LA, but, again, not at the skin level, where the appropriate enzymes are absent. Evening primrose and borage oils are high in GLA. Sunflower and safflower oils are rich in LA.

3. Omega-9 polyunsaturated acids: 

These are named as such because the first double bond occurs after the ninth carbon atom from the omega end of the main chain; examples include oleic acid, eicosenoic acid, and others.

4. There are also conjugated fatty acids and other polyunsaturates that are not considered essential fatty acids.

Omega-6 essential fatty acids are considered skin building blocks and are incorporated into ceramides, a type of lipid molecule; omega-3s are anti-inflammatory and protect skin from sun damage.

It is established now that essential fatty acids are important for many metabolic functions of the body. Individual levels of these, as well as their relative proportions, may have significant physiological impact. Research shows that western diets are often too elevated in omega-6 oils and relatively low in omega-3s, with unhealthy ratios, exceeding by multiple times the recommended omega-6 to omega-3 ratio of between 1:1 and 4:1.

VITAMINS AND MINERALS

Vitamins and minerals are valuable micronutrients, essential for optimal bodily functions. A number of those micronutrients are specifically important for skin cell maintenance.

Vitamin A

Vitamin A and its precursors, also known as retinoids, are vital for skin health. Animal sources (such as liver and eggs) provide retinol precursors. Retinol itself is then converted to retinoic acid, which contributes to rejuvenating skin by acting as a growth factor for epithelial cells.

Vegetable sources (such as carrots and spinach) provide another kind of pro-vitamin A, which are pigments known as carotenoids. In humans, four different types of carotenoids are able to exhibit vitamin A activity: alpha-carotene, beta-carotene, gamma-carotene, and beta-cryptoxanthin.

Vitamin A is essential for the adequate functioning of epithelial cells, and its deficiency can lead to the replacement of mucus-secreting cells by keratin-producing cells, which can result in severely dry skin (known as xerosis). Vitamin A is also an important antioxidant that plays an essential role in maintaining vision and eye health.

Retinyl palmitate, which is a vitamin A precursor, is widely used in topical creams. It is ultimately converted to retinoic acid, an active form of vitamin A. Tretinoin (also known as ATRA: all-trans retinoic acid) is used to treat skin conditions such as acne and follicular keratosis.

Isotretinoin is reserved for cystic acne, because it can effectively counteract sebaceous glands. Since it could cause fetal harm, its use has strict medical restrictions.

Excessive intake of vitamin A or its derivatives can result in toxicity, which is why it is advisable not to exceed the recommended daily dose. Also, pregnant women and women who intend to or might become pregnant should consult with their physician regarding vitamin A and carotenoid intake (including topical applications) due to the risk of fetal harm related to high vitamin A levels.

Vitamin E

Also known as tocopherol and tocotrienol, vitamin E plays various physiological roles and is particularly important for the skin. Because it is a natural antioxidant, it is capable of protecting skin cells from free radicals and preventing skin aging. It reduces sunspots and wrinkles and is also beneficial in cases of psoriasis and erythema.

Vitamin E is widely added to skin care formulations, including sun care products, since it helps improve the efficacy of sunscreens. It is also widely used as a preservative in food and skin care products, where it protects oils from oxidation and helps extend shelf life.

Vegetable oils and nuts are excellent dietary sources of vitamin E. Low-fat diets can result in a low intake of vitamin E unless fortified sources are included. However, excessive intake of vitamin E may increase the risk of bleeding; people with certain medical conditions should consult with their physician prior to supplementing with vitamin E.

Vitamin B5

Also known as pantothenic acid, vitamin B5 is part of the vitamin B complex. It acts as a skin moisturizer and hydrator and is capable of improving skin elasticity and softness. Studies have shown that it can help in skin regeneration. It can also counteract hair loss and is beneficial for hair and nail health.

Meat, vegetables, grains, legumes, eggs, and milk are good sources of vitamin B5.

Vitamin C

Sometimes known as ascorbic acid, Vitamin C is a powerful antioxidant. It is essential for skin because it plays a key role in collagen synthesis. Present in both the epidermis and the dermis, vitamin C acts against damaging free radicals and slows collagen breakdown, wrinkle formation, skin aging, age spots, and sun damage. It is also capable of recycling vitamin E by reversing its oxidation.

Foods rich in vitamin C include oranges, grapefruits, parsley, broccoli, strawberries, and potatoes.

Topically, vitamin C is used to reverse skin aging, improve the appearance of sunspots, and prevent wrinkle formation.

Copper

Copper is a valuable trace mineral that plays major important roles in the body. It is essential for the adequate activity of the antioxidant enzyme super oxide dismutase and regulates the activity of lysyl oxidase, an enzyme needed for collagen formation in bones, connective tissues, and skin. Copper is also essential for melanin production.

The best sources of copper are liver, oysters, tahini, sesame seeds, cashews and other nuts, squid, and lobster.

Manganese

Manganese is a heavy metal needed in trace amounts for multiple bodily functions. It plays a structural role in skin collagen synthesis. It also activates an enzyme called prolidase, which is responsible for providing proline, an amino acid that is incorporated into collagen during its synthesis.

Whole grains, nuts, and leafy vegetables are good food sources of manganese.

Silica

Silica plays a role in preserving skin elasticity.

The best food sources for silica include leeks, green beans, garbanzo beans, strawberries, cucumber, mango, celery, and asparagus.

Zinc

Zinc is an essential mineral that has antioxidant properties and plays key physiological roles. Zinc deficiency has been linked to acne, since zinc helps regulate sebum production and tame hormones associated with acne.

Oysters, pumpkin seeds and nuts, ginger, oats, and eggs are excellent sources of zinc.

Antioxidants

Antioxidants are essential in fighting harmful free radicals and protecting cellular DNA. They are abundant in fruits such as berries and apples, vegetables such as broccoli and tomatoes, nuts and seeds, and various spices.

Vitamins A, C, and E are known antioxidants. Oil-soluble vitamin E is present in many vegetable oils and protects the oils from rancidity and oxidation of double bonds.

Many vegetable oils are capable of providing a number of additional antioxidants that help protect skin from sun damage, premature aging, and collagen breakage. Antioxidants including beta-carotene, lycopene, lutein, xanthin, phytosterols, flavonoids, and polyphenols can be found in many vegetable oils, depending on the source of that oil.

Vegetable oils that are rich in antioxidants include blueberry seed oil, pomegranate seed oil, tomato seed oil, and walnut oil, among others.