01.04.09
Why Lipids and Sunscreen Are Your Best Protection Against Dehydration, Aging and Breakouts
It is a truism in natural circles that your body does its best job fighting off disease and healing itself when it has the nutritional wherewithal to do so. This notion has even more applicability when it comes to treating your skin. Here are some ideas about how to give your skin, regardless of what skin type you are, the building blocks it needs to heal and repair itself. First let’s look at the all-important role played by lipids.
Oily Skin and Lipids
If you look at the structure of skin, you will see that surrounding every skin cell is a layer of fat-like substances. These substances are termed ‘lipids,’ of which there are many types. Lipids form the epidermal water barrier and, in the stratum corneum (the uppermost layer of skin) this barrier is called the ‘lipid barrier’.
The two sources of lipids in the skin are:
• Sebaceous lipids (Sebum)
• Epidermal lipids
Sebaceous Lipids
If you are a teenager plagued by breakouts that seem to be the result of suddenly oilier skin the culprit may indeed be sebaceous lipids, known collectively as sebum. Sebum is excreted by the sebaceous gland, and includes major classes of lipids like triglycerides, wax esters and squalene. (1) Children produce very little or no sebum, and now some skin experts are saying that sebum no longer plays an important role in the human body since we have very little hair to lubricate. (2) Sebaceous glands may be like the appendix or the muscles governing ear-wiggling; whatever their original purpose, these days we seem to manage quite well without them. Some of you would probably be just as happy to see your sebaceous glands go the way of the mastodon.
In defense of sebum, sebaceous lipids are supposed to keep the skin supple and pliable as well as provide mild anti-microbial activity. When all is working as it should this is probably what happens, because during the passage through the sebaceous duct of the sebaceous lipids the triglycerides are enzymatically transformed into free fatty acids which are then incorporated into the lipid barrier of the stratum corneum. In their free fatty acid form lipids assist in reducing trans-epidermal water loss (TEWL) or the evaporative loss of water from skin.
Though fatty acid deficiencies in skin have long been implicated in causing dry skin and more severe skin conditions, not much attention has been paid to how these same deficiencies also contribute to breakouts. Yet it’s a simple story–instead of a smooth passage from sebaceous duct to stratum corneum the thick, waxy sebum hardens in the sebaceous duct, where it collects bacteria and becomes inflamed. Topical applications of fatty acids help alleviate breakouts in two ways: first, by restabilizing the lipid barrier, thus restoring anti-microbial activity on the skin’s surface, and second, by breaking up congestion at the source, because lipids dissolve lipids.
Treating oily skin with oils may seem counter-intuitive to you at first, and may even go against everything you have been taught, but the methodology bears some thinking about. Scrubs, harsh soaps and other drastic treatments that strip off your topmost lipid barrier do a number of things that may actually aggravate breakout problems: 1) stripping away your protective barrier makes your skin more vulnerable to P. acneens, the common bacteria which causes acne vulgaris, 2) squeezing, picking and too-vigorous scrubbing may drive the infection deeper, or spread the bacteria to new sites, 3) oil-stripping prompts your skin to produce more oil, but it may be producing more of the sebaceous lipids you are trying to bring under control, resulting in more clogged pores and an aggravation of the problem.
Dry Skin and Lipids
When the lipid barrier is compromised moisture loss increases (increase of trans-epidermal water loss, or TEWL) which leads to dry, scaly or even cracked skin. Further damage occurs by moisture loss from the skin cells in the lower layers of the epidermis, which affects the health of these cells. Dehydrated cells function poorly and the immune system of the skin becomes weakened. Exposure to UV and harsh climates in addition to the use of soaps and detergents leads to pronounced loss of lipids from the skin. This damage occurs on a daily basis, requiring a continuous input of lipids to the skin to maintain an effective lipid barrier.
All of this suggests to us that the solution for both too-dry and too-oily skin types may be to apply topical oils that will replenish the top layer of skin to optimize barrier function. Latest research studies indicate that this is not such a bad supposition.
Epidermal Lipids
One researcher has demonstrated that a mixture of three lipids (cholesterol, palmitic acid and ceramide) repaired the lipid barrier in skin where lipids were intentionally removed by the use of acetone. The symptoms were relieved with linoleic acid (an Omega-6 fatty acid) applied topically. Indications are that topical application may be beneficial to people with essential fatty acid deficiency syndrome (EFAD).
If applying the correct lipids assists in maintaining the structure of the lipid barrier and improving the health and beauty of the skin, the obvious question becomes:which lipids are critical to barrier function and should be part of a “lipid mix”?
Lipid research in the cosmetic field is very new, how ever, we do know this:
1) The composition of lipids compromising the extracellular matrix are 50% ceramides, 25% cholesterol and 15% free fatty acids.
2) Essential fatty acid deficiencies have been identified as resulting in abnormalities in stratum corneum function.
Essential fatty acids in the form of parent Omega 3’s and 6s can be found in a number of wonderful oils. The following oils are high in a-linolenic acid (Omega 3 fatty acid):
• Kiwi seed
• Flax seed
• Sea buckthorn
These oils are high in a-linoleic acid (Omega-6 fatty acid)
• Sunflower oil
• Hemp seed oil
• Coconut oil
• Rice bran oil
• Sesame oil
Certain oils contain a wonderfully healing and nourishing blend of Omega 3, 6 and 9 essential fatty acids:
• Emu oil
• Krill oil
• Red raspberry seed
• Cranberry seed
Conclusion: Topical applications of oil blends containing a judicious mix of EFA-rich oils is the best way to hydrate and moisturize dry skin and keep oily skin balanced and blemish-free.
Sun Protection
There are numerous discussions on my blog about the role UVA exposure plays in accelerating aging of the skin. There is yet one more reason why applying a sunblock containing zinc oxide over an oil-blend layer in the morning is your best bet if you want to moisturize and protect your skin while delaying the aging process, and it is this: lipids are not immune to the environment. When in contact with sunlight (specifically UV light) or air, lipids will undergo what is known as peroxidation. These peroxidized lipids lose their barrier ability and gaps occur in the lipid matrix. Applications of sunblock keep the lipid barrier intact by limiting UV exposure, which in turn prevents peroxidation.
A Skin Protection Routine
The following morning routine ensures that you are protecting your skin using advanced state-of-the art solutions in combination with a healthy dose of just plain common sense.
1) Cleanse (but not too much): Studies show that people who wash their faces with soaps in the morning are about 50% less protected when they go out in the sun (strips the lipid barrier). Dry skin–wash with tepid water only. Oily skin-if your skin is very oily or you have an excess of sebum, wash with a mild cleanser. Avoid detergent or oil-stripping type cleansers.
2) Huydrate: Dry skin–Apply an oil blend that contains a balanced mix of linoleic and linolenic acids (the Omega-3 and 6 fatty acids). Oily skin—Lavender essential oil makes a good addition to an oil blend containing a balanced mix of linoleic and linolenic acids (the Omega-3 and 6 fatty acids). Lavender essential oil cleans out hair follicles.
3) Protect: Dry skin–Apply a nanoparticle-free sunblock containing zinc oxide over the oil layer to block UV/UVB rays and guard against lipid peroxidation. Oily skin–Look for a sunblock that uses zinc oxide as its active ingredient and contains no nanoparticles. In addition to effectively blocking UV rays, zinc oxide is an excellent anti-inflammatory that helps to control breakouts. Wax-free sunscreens containing zinc oxide are the best bet for the blemish-prone.
To determine which sunscreen might work for you, a place to start may be with our Sunscreen Specs table on the Marie Veronique website.
1) N. Nicolaides, Lipids, membranes and the Human Epidermis. The Epidermis, W. Montagna and W. C. Lobitz, Jr., New York: Academic Press p. 511 (1964).
2) A.M. Kligman, The Uses of Sebum, Brit. J. Dematol., 75: 307-319 (1963)
prune said,
May 13, 2009 at 12:56 am
Thanks for a very informative article. I came here after trying to do research on whether wax that I keep seeing in skin care products is bad for the skin. I’ve been slowly developing a skincare regimen to try to resolve problems with raw patchy itchy skin.
I’ve recently adopted a skincare progam of water with a bit of borax for cleansing, and a light dab of zinc oxide cream over the raw parts…which is helping it to heal quite a bit. Now I am trying to figure out what to use to moisturize my skin and protect it from the sun. I live in South america, so I’m looking to formulate my own products rather than try to navigate the products available to me here.