A Scientific Look at Moisturizers Pt. 2

Emollients and Occlusives

Emollients

Emollients, which are mainly lipids and oils, hydrate and improve the appearance of the skin by contributing to skin softness, enhanced flexibility, and smoothness. The “skin slip” or lubricity of some moisturizers, contributes to consumer satisfaction and product preference.5 Consumers desire smooth skin following moisturizer application. Emollients serve to fill the cracks between clusters of desquamating corneocytes and are not usually occlusive unless applied heavily.

Long chain saturated fatty acids and fatty alcohols are commonly used in topical pharmaceuticals and cosmetic formulations. They exert their benefits through effects on the skin barrier, partially through improved repair, and on permeability. Examples include stearic, linoleic, linolenic, oleic, and lauric, which can be found in palm oil, coconut oil, and wool fat. A sterol-enriched fraction from canola oil reduced clinical signs of sodium lauryl sulphate (SLS)-induced irritation. Other lipids (e.g., fish oil, petrolatum, shea butter, and sunflower seed oil) had no effect on the degree of irritation. Loden and Andersson suggested that canola oil assisted the skin in supplying the damaged barrier with adequate lipids. Essential fatty acids (i.e., linoleic and alpha-linoleic acids) influence skin physiology and pathology via their effects on skin barrier functions, eicosanoid production, membrane fluidity, and cell signaling.

Occlusives

Occlusives reduce TEWL by creating a hydrophobic barrier over the skin and contributing to the matrix between corneocytes, and have the most pronounced effect when applied to slightly dampened skin. There is a wide range of agents with occlusive properties. Their main limitations include odor, potential allergenicity, and the greasy feel associated with most occlusives.

Astringent Emollients
Cyclomethicone, dimethicone, isopropyl myristate, octyl octanoate

Dry Emollients
Decyl oleate, isopropyl palmitate, isostearyl alcohol

Fatting Emollients
Castor oil, glyceryl stearate, jojoba oil, octyl stearate, propylene glycol

Protective Emollients
Diisopropyl dilinoleate, isopropyl isostearate

Protein Rejuvenators
Collagen, elastin, keratin

Common substances with emollient properties
Fatty Acids
Lanolin acid, stearic acid
Fatty Alcohols
Cetyl alcohol, lanolin alcohol, stearyl alcohol
Hydrocarbon Oils/ Waxes
Caprylic/capric triglyderide, mineral oil, paraffin, petrolatum, silicone derivatives (cyclomethicone, dimethicone), squalene

Common substances with occlusive properties

Petroleum jelly, in a minimum concentration of 5%, reduces TEWL by more than 98% and is the most effective occlusive, followed by lanolin, mineral oil, and silicones (e.g., dimethicone), which only reduce TEWL by 20%-30%. Occlusives are thought to diffuse into the intercellular lipid domains, thus contributing to their efficacy. Petrolatum is widely used as a classic moisturizer. Lanolin, a complex structure of esters, diesters, and hydroxyesters of high molecular weight, lanolin alcohols, and lanolin acids, is also widely used and quite effective.

Humectants

Humectants are able to attract water from two sources: they enhance water absorption from the dermis into the epidermis, and in humid conditions they also help the SC to absorb water from the external environment. Many humectants also have emollient properties. The most effective humectant is the trihydroxylated molecule, glycerol. Immature corneocytes are fragile but mature into more resilient and protective cells as they migrate through the SC. Glycerol hastens the maturity of corneocytes through the activation of residual transglutaminase activity in the SC.18 Also, by facilitating the digestion of desmosomes and subsequently enhancing desquamation, glycerol reduces the scaling associated with xerosis.

Gelatin
Glycerin
Honey
Hyaluronic acid
Panthenol
Propylene glycol
Sodium and ammonium lactate
Sodium pyrrolidine carboxylic acid
Sorbital
Urea

Common substances with humectant properties
Found in the NMF, pyrrolidine carboxylic acid hydrates the skin, and has been shown to improve xerosis.20 Urea is another important humectant. In double-blind studies moisturizers with urea have been shown to reduce TEWL in atopic and ichthyotic patients,21,22 and reduce SLS-induced skin irritation.

Alpha hydroxy acids (e.g., lactate) are effective agents for the treatment of dry skin; following treatment with lotions containing D-, L-lactic acid, the SC prevents xerosis more effectively. Lactic acid, particularly the L-isomer, stimulates ceramide biosynthesis leading to higher SC ceramide levels that result in a superior lipid barrier and more effective resistance against xerosis.

One major drawback of humectants is that some of them can increase TEWL3 by enhancing water absorption from the dermis into the epidermis where it can then be lost into the environment. For this reason, they are almost always combined with an occlusive agent. Occlusive and humectant ingredients work together to enhance epidermal hydration and barrier function.

A Scientific Look at Moisturizers (pt.1)

Moisturizers are widely used products that are important in many dermatologic and cosmetic skin therapies. They contain varying combinations of emollients, occlusives, and humectants to achieve their beneficial effects, and there is an overwhelming number of formulations available. To develop a rational approach for prescribing moisturizers, commercially available products can be categorized on the basis of application site.

There is a vast array of moisturizers available on the market today and consumer demand for these products is growing. These products range from value brands that provide basic moisturization to luxury therapeutics with claims of anti-aging benefits. A recent US study found that moisturizers are the third most commonly recommended OTC topical skin product (13.4%) behind hydrocortisone (27.6%) and anti-infectives (23.4%).

What Are Moisturizers?

The term moisturizer is a marketing term with little or no scientific meaning. Consumers see moisturizers as actively increasing the water content of the skin. Dermatologists see moisturizers as bland oleaginous substances that are applied to the skin by rubbing. The term “moisturizer” does not necessarily imply that moisture or water is being added to the skin. Moisturizers are a key component of basic skin care especially when there is alteration of the epidermal barrier and reduced water content in the epidermis.
They are used to restore the barrier function of the epidermis, to cover tiny fissures in the skin, provide a soothing protective film, and increase the water-content of the epidermis. They may, thus, slow evaporation of the skin’s moisture, thereby maintaining hydration and improving the appearance and tactile properties of dry and aging skin. Newer products claim to have other properties such as anti-aging, skin-firming, anticellulite, and sun-protectant effects.

How Do Moisturizers Work?

For many years, epidermal water content has been known to be crucial for skin plasticity and the prevention of “dry skin”. Traditionally, moisturization was believed to inhibit transepidermal water loss (TEWL) by occlusion. Water originates in the deeper epidermal layers and moves upward to hydrate cells in the stratum corneum (SC), eventually being lost to evaporation.

The SC architecture is the most important factor in water flux and retention in the skin, and in overall level of moisturization. The four key processes for the formation and functioning of the SC are the corneocyte process, SC lipid process, natural moisturizing factor (NMF) process, and desquamation process. Corneocytes are the physical barrier of the SC and, when hydrated, contribute to elasticity. The lipid bilayers of the SC function as a moisture barrier and although they prevent the entry of many chemicals, they are the means of entry for most topically applied substances. The NMF is found within corneocytes and is a mix of hygroscopic molecules that, by helping maintain hydration in the corneocyte, keep the SC hydrated. Half of the NMF is amino acids derived from the protein filaggrin in keratinocytes, and the other half is salts, including lactates, urea, and electrolytes. Production of NMF is directly related to external humidity. In desquamation, corneodesmosomes are degraded by water-dependent hydrolytic agents. When there is low moisture in the SC, these enzymes do not work efficiently. Corneocytes accumulate on the skin surface producing the signs of dry skin, e.g., when the moisture content is less than 10%, and when there is loss of continuity of the SC.

The moisturizing treatment involves repairing the skin barrier, retaining/increasing water content, reducing TEWL, restoring the lipid barriers’ ability to attract, hold and redistribute water, and maintaining skin integrity and appearance. Moisturizers perform these functions by acting as humectants, emollients, and occlusives. Moisturizers containing collagen and other proteins, i.e., keratin and elastin, claim to rejuvenate the skin by replenishing its essential proteins but whether or not they have any effect on skin hydration is questionable. Moisturizers also act to reduce skin friction and increase skin hydration by providing water directly to the skin from their water phase and by increasing occlusion, as measured as a decrease in TEWL. Loden suggests that skin care products not only form an inert, epicutaneous layer, but that they also penetrate and influence the structure and function of the skin.

Moisturizers have little effect on the mechanical properties (i.e., distensibility, hysteresis, and elasticity) of the skin but do increase skin hydration significantly, as shown by an increased skin capacitance.10 When moisturizers are used to improve skin plasticity it is suggested that lipid-rich formulations be used.

Emollients

Emollients, which are mainly lipids and oils, hydrate and improve the appearance of the skin by contributing to skin softness, enhanced flexibility, and smoothness. The “skin slip” or lubricity of some moisturizers, contributes to consumer satisfaction and product preference. Consumers desire smooth skin following moisturizer application. Emollients serve to fill the cracks between clusters of desquamating corneocytes and are not usually occlusive unless applied heavily.

Long chain saturated fatty acids and fatty alcohols are commonly used in topical pharmaceuticals and cosmetic formulations. They exert their benefits through effects on the skin barrier, partially through improved repair, and on permeability. Examples include stearic, linoleic, linolenic, oleic, and lauric, which can be found in palm oil, coconut oil, and wool fat. A sterol-enriched fraction from canola oil reduced clinical signs of sodium lauryl sulphate (SLS)-induced irritation. Other lipids (e.g., fish oil, petrolatum, shea butter, and sunflower seed oil) had no effect on the degree of irritation. Loden and Andersson suggested that canola oil assisted the skin in supplying the damaged barrier with adequate lipids. Essential fatty acids (i.e., linoleic and alpha-linoleic acids) influence skin physiology and pathology via their effects on skin barrier functions, eicosanoid production, membrane fluidity, and cell signaling.

Next article will focus on emollients, occlusives, and humectants and what an ideal moisturizer should be….

J. N. Kraft, BSc (Hons)1 and C. W. Lynde, MD, FRCPC2
1Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
2University Health Network (Western Division) and Department of Dermatology, University of Toronto, Toronto, Ontario, Canada

Skin Care Ingredients to Avoid

Many consumers are frustrated by skin care products that don’t do what they claim to. Worse still is investing in an expensive yet ineffective cream or treatment only to discover the cheapest drug-store brand would work just as well. In a world of hyper-consumerism, false advertising and a plethora of products from which to choose, how do you choose the good from the bad?

There are some great products on the market that can genuinely improve your skin’s appearance and help your skin look smoother, more radiant, and youthful. But, there are literally thousands of products to choose from and unless you spend hours a day researching beauty products, it’s difficult to find the one of the few that actually produces real results and eliminates years of aging from your face and body.

As the law of supply and demand proves, the higher the demand for youth and beauty, the more manufacturers will rush to provide the solution. Many times this rush results in the creation of an inferior product with little to no research and development to back it.

Caveat Emptor – or “let the buyer beware” - is the rule to live by. Do your homework. Know where you are “voting” your hard-earned money. If it is important to you, make sure you are investing in a quality, skincare ingredient backed by proven results. If the environment and being ‘green’ is important to you, then be aware of the manufacturing practices of the company and product you support with your purchase.

Ingredients to Avoid

Due to certain preservative requirements, many skin care products are unfortunately loaded with ingredients that actually harm your skin over time. Following are a few prominent ingredients widely used in skincare products to day and are to be avoided if you prefer you skincare to be more natural or organic.

•    Mineral Oil. This oil has been used in literally hundreds of products. Mineral oil may also go by the alternative names liquid paraffin, paraffin wax and petrolatum on the product label. Mineral oil is used pervasively in skin care products as a moisturizing agent due to its low cost.

Mineral oil, once applied, is meant to ‘trap’ moisture in the skin, but once applied, actually prevents the skin from “breathing.” As such, it clogs pores, interferes with your skin’s natural ability to eliminate toxins, and can lead to acne flare ups. Also, it is irritating to the skin and if used for any length of time, your skin can become dependent on it, causing chapping and dryness. Lastly, it can lead to premature aging of the skin.

•    Dioxane: (a synthetic derivative of coconut). This substance is widely used in skincare products. It often contains high concentrations of 1,4-dioxane, which is readily absorbed through the skin. In the State of  California, 1,4-dioxane has been reported as “known to cause cancer.”

•    Fragrances: No one wants to smell bad, but if you want to be on the safe side, you are better off choosing an organic essential oil or diluted cologne, hydrosol or even a bodyspray. Your skin care products typically contain chemically engineered fragrances to mask the unpleasant “chemical odor” of the foundational product itself. Many of these masking fragrances are produced from ingredients that are known to be toxic or carcinogenic.

Your skin is the largest organ of the body. Anything you put on it can be easily absorbed through the pores. When you use skin care products, they are typically applied all over the face, neck, and body. This covers a lot of surface area and, therefore, a great deal of chemical absorption occurs. However, with perfumes and colognes, you can achieve what you want by a small dab here and there, which will result in less chemical absorption overall. If you really want a beauty product to smell great without the harsh side effects, try buying a fragrance-free product and add your own essential oil blend. You can customize a whole line of products with you won signature scent!

•    Parabens: methyl, propyl, butyl, and ethyl paraben. Many skin care products (and moisturizing products) will use parabens as a preservative so their products have a long shelf life. The reason is purely economical. However, studies suggest that they may cause cancer and interfere with the body’s endocrine system, as well as causing allergic reactions and skin rashes.

•    Alcohols:  ethanol, ethyl alcohol, methanol, benzyl alcohol, isopropyl  alcohol and SD alcohol. Not all alcohols have the same properties, but these, which are commonly found in skin care products, are very drying and irritating for the skin. Alcohols such as these strip away the skin’s natural acid mantle, making you more vulnerable to bacteria, moulds and viruses.

Now that we’ve looked at some of the bad, let’s examine some of the good ingredients and some ingredients that sound good but in fact aren’t.

Skin Care - What is Skin Care?

Skin Care is the first step towards achieving a healthy body. Skin care is an essential part of most people’s daily routine. Skin care specialists say any imbalance in the protective barrier that envelops the human body provides a perfect breeding ground for bacteria, resulting in many types of skin irritations and accelerating the aging process.

Natural skin care is the care of the skin (the largest organ of the body) using naturally-derived ingredients (such as herbs, roots, essential oils and flowers) combined with naturally occurring carrier agents, preservatives, surfactants, humectants and emulsifiers (everything from natural soap to oils to pure water).

Skin care treatment is going green, but you still have to make sure you read the labels. Skin care treatment may be the least of your problems if you’re a middle-aged male, but many dry skin remedies will also raise testosterone levels. The latest craze in skin care is also the oldest: herbal products.

Natural skin care has its roots in the 4th millennium BC in China and the Middle East. Natural body lotion has become a big business in recent years as more and more consumers seek a gentler, healthier alternative for their skin care needs.

The best skin care beauty tips are not only the right products but also healthy diet. People who use natural skin care products are less concerned with artificial beauty enhancements, as they feel that natural beauty is healthy beauty.

Healthy skin care for skin problems is part of overall good health. Healthy Skincare store sells skin care products that are effective anti-aging treatments for aging skin.

Acne is a common skin care problem for many individuals of all ages and all skin types. Acne Skin Care, no matter what kind of acne treatment you select, an outbreak can still emerge even after all blemishes have vanished.

The skin on your face needs more attention than the rest of your body because it has more oil glands. It is important to not just put sunscreen on your face, but also on your body as well.

Some women are seen with bangs but these bangs look very natural with the face, not a blunt cut style look. Most skin is a combination of skin types, with different areas of the face having different conditions that fluctuate with factors such as weather, diet, stress, health, and travel.

Organic and natural ingredients are healthier and more effective then the harmful chemically based products on the market today. Skin care is becoming increasingly more high tech but at the same time there is growing popularity in natural and organic products.

The single most important breakthrough in skin care is understanding that the only Way to truly moisturize your skin is to get water into it. Proper skin care is important to maintaining health, and is an integral part of overall wound management.

While skin care products in the 1990s were almost exclusively focused on wellness and simple body care lotions, today, skin care is one of the most dynamic and technologically advanced segments of the beauty market.

Oil Production in the skin

The skin has many oil (sebaceous) glands, which secrete oil that contains wax esters, triglycerides, and squalene - a hydrocarbon that is an intermediate in the formation of cholesterol. These fats (or lipids) form a film that helps keep moisture in the skin. While increased sebum production results in oily skin, the opposite is not always the case, as dry skin can also arise from an impaired skin barrier. Oil production can be affected by diet, stress, and hormones-as well as genetics. In a study of twenty pairs each of identical and nonidentical same-sex twins, identical twins had virtually identical amounts of oil production, while the nonidentical twins had significantly different amounts.

No amount of blotting and scrubbing will “remove” the skin’s oil production, and many of us unknowingly destroy the natural beauty of the skin in pursuit of clarity. The skin’s own sebum mechanism is there to regulate own moisture. Drying your skin profusely with oil-stripping, foaming cleansers, detergents and de-greasers like soap and sulfates, or alcohol-based toners that leave the skin feeling tight (always a sign it’s been stripped), will only cause the skin to “rebound” with excess oiliness and destroy its protective and anti-bacterial “matrix,” leaving it sensitized. By stripping the natural acid mantle of the skin, these deep cleaning products actually make skin more vulnerable to bacteria and inflammation. Dabbing benzoyl peroxide often destroys the beauty of the skin by causing flaking, while more aggressive treatments, such as antibiotics or Accutane can cause a cascade of side-effects.