According to Susan C. Taylor, board-certified dermatologist and author of Rx for Brown Skin, there are four basic mechanisms of skin aging:
1.) genetic factors;
2.) telomere shortening and chromosomal alterations;
3.) free radical generation (in excess of free radicals necessary for normal metabolism);
4.) UV light-induced skin damage.
Each of these are discussed in more detail below.
Genetic factors that contribute to skin aging
Skin aging is the result of genetic, as well as environmental, factors. In several lower species, genes that contribute to aging have been identified, and it is believed that corresponding genes may play a role in aging of humans. For instance, studies in mice have shown that caloric restriction increases the life of the mice and the expression of sirt1 genes, which code for sirtuins that may be responsible for prolonging the life of cells by turning off unnecessary gene expression. For human skin, caloric restriction has also been proposed to decrease contact dermatitis, decrease free radical formation, and potentially preserving the softened, youthful state of collagen by decreasing the formation of advanced glycation endproduct glucosepane. More on caloric restriction and human skin is available here.
Telomere shortening and chromosomal alterations
Telomeres are repeated patterns of DNA sequences (TTAGGG) found at the end of chromosomes. With each round of DNA replication, telomeres shorten. Older adults have shorter telomeres compared with younger adults and children; when telomeres reach a certain shortened length, the cell is no longer able to divide, and cell death occurs. In fact, according to this study, the size of telomeres found in adrenal (kidney) chromosomes shortens by about 0.24% per year of human life. The telomere theory of aging is also supported by patients with Werner’s Syndrome, a rare disease in which aging is accelerated. Although an enzyme, telomerase, is able to make telomeric sequences to replace shortened sequences, and the introduction of telomerase into retinal epithelial cells and fibroblasts has been shown in this 1994 study by Bodnar et. al. to regenerate telomeres, telomerase is also reactivated in cancer cells, and so the introduction of telomerase into normal human cells to fight aging is not in fact a sound therapy at all.
Other chromosomal alterations reported by Dr. Susan C. Taylor in Cosmetic Dermatology include a defective DNA helicase, which is the enzyme used to uncoil DNA prior to each round of replication. It has been found that a mutation in DNA helicase is responsible for Werner’s Syndrome and the premature aging symptoms that result. In another disease resulting in accelerated aging, progeria, a misregulation of mitosis has been identified as the major cause.
Free radical generation
The free radical theory of aging has existed since the 1950’s by Denham Harman. The theory essentially states that free radical processes cumulatively lead you to age. Free radical generating processes include UV exposure, environmental pollutants, and smoking, and also mandatory processes, like respiration and metabolism. As respiration and metabolism are necessary for life to continue, it is impossible to eradicate free radical production in the body completely. For this reason, it has been proposed by deGrey in Ending Aging (amongst others) that free radicals are a natural byproduct of life that should not necessarily be neutralized with antioxidants. According to Dr. Jeannette Graf in Cosmetic Dermatology, newfound technologies like “spin traps” have been developed to eradicate only the rare free radicals that are created when an aberrant electron “spins” out of its orbit. (Spin traps, being developoed by Dr. J. Carney and his associates, are not yet available in skin care products.)
Despite this, most experts emphatically recommend the use of topical antioxidants, with support from numerous nutritional studies that demonstrate eating antioxidant-rich fruits and vegetables helps to prevent aging and certain diseases. As topical application of an ingredient results in a maximal absorption of about 33% of the ingredient, according to this 2002 study by Briggs et. al., so applying topical antioxidants and consuming them through the diet should have synonymous effects. In addition, while studies at MIT have suggested that oxygen free radicals do not contribute to a shortened lifespan, another study has demonstrated that oxygen free radicals can damage the DNA of cultured skin cells. As such, free radical-induced aging seems to be one of the only causes we can treat: eat a diet rich in antioxidants and apply a multitude of topical antioxidants to eradicate free radical production.
To eat as many antioxidant-rich vegetables as possible, according to this 2006 study by the American Botanical Council, vegetables were found to retain 80% of their raw antioxidant capacity when steamed, but just 30% when boiled. Also, of 27 vegetables, those with the highest antioxidant capacity were artichokes, beetroot, cabbage, broccoli, red chicory, red chili, and yellow pepper, so eat up!
To maximize the benefit of topically applied antioxidants, use products with network antioxidants (vitamin C, vitamin E, lipoic acid, coenzyme Q10 and glutathione), and/or strong antioxidants, such as coffeeberry, idebenone, vitamin E and kinetin.
UV Radiation
UV radiation generates free radicals, which turn on matrix metalloproteinases (enzymes). In a 1996 study by Fisher et al., it was found that UV exposure increase MMPs (and hence collagen production) in three steps, as mentioned in Dr. Leslie Baumann’s Cosmetic Dermatology. One, UV exposure increases the production of the transcription factor c-jun. Two, the “extra” c-jun combines with another transcription factor already present in high concentration, c-fos, to produce activator protein, AP-1. Three, AP-1 activates the MMP genes, which produce collagenase, gelatinase, and stromelysin-1. It may further be noted that there are twenty-three human MMPs, and MMP-1 has been found in studies to be the MMP responsible for collagen degradation. And, similar to how natural antioxidants keep free radicals in check, the body naturally produces Tissue Inhibitors (TMPs) to keep levels of MMPs down. Unfortunately, however, as people age, MMP activity increases, while levels of Tissue Inhibitors (TMPs) decrease.
Matrix metalloproteinase activity can be stopped in two ways. The first is to prevent their production. This is best done with a sunscreen with high UVB protection (UVB has been directly liked to MMP production by Fisher et al.) Fortunately, the best UVB protection is easy to find: look for the sunscreen with the highest sun protection factor (SPF), a direct measure of UVB protection. The second method is to stop the degrading activities of the MMPs. According to Dr. Wexler, there are several substances that act as MMP inhibitors (MMPis): epigallocatechin-3-gallate (a derivative of green tea), retinoic acid, eicosapentaenoic acid (an omega-3 fatty acid), beta-carotene, DHEA (though this is controversial), polysaccharides, vitamin E, and vitamin C, and flavonoids. Research has shown all of these inhibit MMPs and increase TIMPs. Patricia Wexler’s MMPi Skin Regeneration Serum, available at Bath and Body Works stores, uses MMPis to inhibit MMP activity in skin cells by more than 80% (statistic from drpatriciawexlermd.com).
In short, what should I do to prevent skin aging?
First and foremost, wear a broad-spectrum (UVA/UVB) sunscreen and avoid the sun with protective hats, clothing, and sunglasses, particularly when the sun’s rays are the strongest, between 9 AM and 4 PM. However, according to a 2007 study from the University of Pittsburgh, there is a nationwide vitamin D deficiency, so make sure that you get 10-15 minutes of sunscreen-free exposure per week between hours of 9 AM and 4 PM to areas like your face, hands, back, and feet.
Second, try to eat a diet filled with steamed (not boiled) antioxidant-rich vegetables like artichokes, beetroot, cabbage, broccoli, red chicory, red chili, and yellow pepper. Use topical antioxidants with documented independent research behind them as well, particularly vitamin C, vitamin E, lipoic acid, coenzyme Q10, glutathione, idebenone, coffeeberry and kinetin (of course you don’t have to use them all!).
Lastly, be healthy. The skin is often an early indicator of disease, so what’s good for your body is ultimately good for your skin. Take care of yourself! 
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December 29th, 2007
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futurederm |
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Recently, a reader asked me to research and review Remergent High Intensity DNA Repair SPF 30 ($94.95, SkincareRx.com). The company’s “super concentrated” product claims to “protect your skin from the sun as well as help to regenerate your skin and heal the damage that has already been done.” But does the product live up to the hype?
Not “super” concentrated, after all
Based on the ingredients list provided by SkincareRx.com, the product is a physical sunscreen with 5.1% Titanium Dioxide and 0.97% Zinc Oxide. Unfortunately, many products, like Blue Lizard Australian Suncream for Sensitive Skin ($13.19 for two, Amazon.com) provide more sun protection, with 5.0% Titanium Dioxide and over ten times the Zinc Oxide, with a full 10% Zinc Oxide. It may also be noted that microfine zinc oxide absorbs appreciably more UV light in the long-wave UVA spectrum from 340 to 380 nm, according to Dr. Leslie Baumann’s Cosmetic Dermatology textbook. As a result, Remergent High Intensity DNA Repair SPF 30 does not provide more concentrated zinc oxide than other cheaper competitors.
Two network antioxidants, vitamin C and vitamin E, are included in the product as tetrahexyldecyl ascorbate and tocopheryl acetate, respectively. The combination of vitamin C and vitamin E synergistically enhance the power of one another, and have been reported by Djerassi et. al. to prevent the formation of carcinogenic nitrosamines (although in different forms of C and E). Vitamin C and vitamin E have also been shown in this 1996 study, amongst others, to enhance the photoprotective effects of sunscreen. Unfortunately, vitamin C and vitamin E are in low concentration in this product, as they are both amongst the bottom three ingredients on the list.
Extremely hydrating
The product contains cetearyl alcohol (which is one of the hydrating alcohols), glycerin, arachidyl alcohol, arachidyl glucoside, and several other ingredients as emollients. Unfortunately, this gives the product a very thick texture that is unappealing to some users.
Overall?
I do not like this product. It contains little vitamin C and vitamin E for the money, and its sun protection can be beaten for a fraction of the cost. Save your money! Or, if you are going to spend this much on antioxidant vitamins C and E and sunscreen, try one of my favorite products, Skinceuticals C E Ferulic ($95.99, Amazon.com), which contains a full 15% vitamin C as L-ascorbic acid, vitamin E as tocopherol acetate, and ferulic acid as a stabilizer, with a potent broad spectrum (UVA/UVB) sunscreen layered over top, like Neutrogena Dry Touch Ultra Sheer Sunblock SPF 70 ($18.49 for two, Amazon.com), . Overall rating of Remergent High Intensity DNA Repair SPF 30: 2/10 (expensive, good antioxidants but very low concentration of them, decent sun protection but not for the cost!)
Ingredients
Active Ingredients: Titanium Dioxide 5.1%, Octinoxate 5%, Oxybenzone 3%, Zinc Oxide 0.97%. Other Ingredients: Water, C12-15 Alkyl Benzoate, Cetearyl Alcohol, Glycerin, Phenoxyethanol, Arachidyl Alcohol, Alumina, Arachidyl Glucoside, Behenyl Alcohol, Caprylyl Glycol, Cetearyl Glucoside, Disodium EDTA, Ethylhexylglycerin, Hexylene Glycol, Isopropyl Titanium Triisostearate/Triethoxycarpylylsilane, Crosspolymer, Lecithin, Micrococus Lysate, Plankton Extract, Polyhydroxystearic Acid, Sodium Dehydroacetate, Steareth-2, Steareth-21, Triethoxycaprylylsilane, Tocopheryl Acetate, Tetrahexyldecyl Ascorbate, Xanthan Gum
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December 28th, 2007
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Sunblocks, Worst Products |
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In the harsh winter months, many women suffer from dry lips. When the lips crack at the corners of the mouth, it is a condition known as chelitis, in which moisture accumulates in the area. According to New York City dermatologist Patricia Wexler in the January 2008 Allure magazine, to get rid of cracks at the corner of the lips:
“The best way to heal them is with a rich emollient, such as Aquaphor ($27.25 for two, Amazon.com) which contains petrolatum to seal in moisture [and prevent excess moisture from accumulating in the area]. Apply a pea-size amount to the cracks a few times a day, then rub an oil-free moisturizer [like Neutrogena Oil-Free Moisturizer ($19.53 for two, Amazon.com) on the surrounding areas (this provides hydration without causing breakouts.”
How do you avoid getting dry lips in the future?
According to Wexler: “Avoid waxing, chemical peels, exfoliating scrubs, or glycolic-acid treatments…The area can also be irritated by retinoids or even toothpaste.” As such, use these items with care around the lip area to avoid cracking at the corners of the mouth, particularly during the harsh winter months.
What if my lips are severely cracked?
If your lips are severely cracked at steep angles going down from your lips, you may have angular chelitis. According to Dr. Michael Fisher, M.D. Ph.D., angular chelitis is generally seen in adults with ill-fitting dentures, and in children with overbite, overlapping teeth, braces, poor closure of the mouth and even drooling at night. According to Dr. Fisher, either petrolatum or corticosteroid ointments applied two or three times a day to the corners of the mouth, the avoidance of the habit of lip-licking, and the application of topical antibiotics and anticandidal agents when Candida bacteria is involved may alleviate the severe situations. As always, see your dermatologist with your concerns before you self-diagnose!
One last note…
Thank you for all of your questions over the holidays. December has been a very busy month for me (this is my first year being married during the holidays!), and I appreciate your patience as I research all of your questions. Thank you, and happy continued reading! Please check back; hopefully the answer to your question will be here soon.
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December 27th, 2007
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Dry Skin Treatments, How to Get Rid of... |
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Selenium is a nonmetal that has been said to exhibit anticancer properties in numerous studies, including this 1997 study in the journal Nutrition and Cancer. However, do products containing selenium help the skin?
Selenium as an antioxidant and anti-inflammatory ingredient
According to Dr. Jeannette Graf in Cheryl M. Burgess’ Cosmetic Dermatology textbook, “Selenium’s protective ability lies in its essential role as a cofactor in the formation of the important protective enzyme glutathione peroxidase.” Selenium is also anti-inflammatory, as has been demonstrated from its ability to inhibit skin-damaging UV-induced inflammatory cytokines in this 2002 study by Greul et. al.
Selenium does not prevent skin cancer, but does help prevent lung, colorectal, and prostate cancers
A Nutritional Prevention of Cancer trial conducted among individuals at a high risk of nonmelanoma skin cancer reported in Cheryl M. Burgess’ Cosmetic Dermatology textbook demonstrated that selenium supplementation is ineffective at preventing skin cancer and basal cell carcinoma, and probably increases the risk of squamous cell carcinoma and total nonmelanoma skin cancer. However, the dosages taken by these individuals was not reported in the textbook.
On the contrary, the NIH reports here that, while selenium supplementation with 200 micrograms per day does not decrease the risk of skin cancer, it does decrease the risk of other cancers, including lung, colorectal, and prostate cancers.
Is selenium effective in skin care products?
According to Dr. Jeannette Graf, selenium applied topically does not penetrate the skin well, so the beneficial antioxidant and anti-inflammatory properties would not be exhibited if selenium is incorporated into skin care products. However, selenium in selenomethionine form penetrates the skin and is therefore bioavailable. Selenomethionine is available in the Murad APS Youth Builder Supplement.
Recommended daily allowance of selenium
The recommended daily allowance for selenium for men and women is 55 micrograms/day, and the upper limit is 400 micrograms per day. Sources of selenium include nuts, meat, oatmeal, and pasta. To estimate daily selenium intake from food and supplementation, an excellent table from the NIH is available here.
Overall…
For the average adult, selenium intake of 55 micrograms per day is recommended, 200 micrograms has been shown to prevent lung, colorectal, and prostate cancers, and 400 micrograms is the upper limit not to be exceeded. Although selenium does not prevent skin cancer and may increase the risk of squamous cell carcinoma and total nonmelanoma skin cancer, according to the NIH, selenium is still beneficial, as selenium exhibits potent antioxidant and anti-inflammatory properties. When included in topicals, selenium should be in selenomethionine form to be bioavailable. Overall, a good ingredient, just keep daily allowances within FDA bounds until further research following up the disturbing Nutritional Prevention of Cancer study becomes available.
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December 26th, 2007
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Antioxidant Treatments, Spotlight On... |
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Johnson’s 24 Hour Moisturizer contains a high concentration of mineral oil. $4.99,
Drugstore.comVisit your local drugstore, and you are bound to find a plethora of lotions with mineral oil as one of the main ingredients. Hailed for its emollient properties, but believed by many women to clog pores, is this inexpensive ingredient good or bad for your skin?
What is mineral oil?
Mineral oil is a colorless, odorless substance that is derived from petrolatum. It is widely used in cosmetics because it rarely causes allergic reactions and provides a barrier of moisture on the skin and promotes wound healing.
What are some benefits of mineral oil?
According to Cosmetics Cop Paula Begoun, “Cosmetics-grade mineral oil is [among those] considered the safest, most nonirritating, and effective moisturizing ingredients ever found.” In fact, this 1989 study in the journal Dermatitis found that mineral oil was more effective in preventing water loss from the skin than a solution with 15% linoleic acid, a fatty acid. Mineral oil has also been shown to be effective in wound healing, according to Begoun.
Is mineral oil really comedogenic or pore-clogging?
According to Rebecca James Gadberry, chairman and co-CEO of YG Laboratories, mineral oil is not as offensive as many women believe. On a rating of zero-to-five, with five being highly pore-clogging, Gadberry says that tests of the cosmetic grade of mineral oil usually grant a one or two rating, depending upon the methodology of the test.
Further, mineral oil is an occlusive agent, which, according to the textbook Cosmetic Dermatology “functions by filling the spaces between desquamating corneocytes to create a smooth surface.” When filling those spaces, unfortunately, mineral oil traps other ingredients into the skin. If the other ingredients are comedogenic (pore-clogging), mineral oil can exacerbate their negative effect, as Gadberry notes, “Caution should be used when mineral oil is included in leave-on products containing pore-clogging ingredients — at least when these products are applied to clog-prone skin.” A list of comedogenic ingredients may be found here, from Natural Beauty Care.
Why does mineral oil have such a bad reputation?
Mineral oil is derived from petroleum. However, as Gadberry notes, many people do not realize “more than 50% of the ingredients used in cosmetics are.” In addition, mineral oil comes in different grades, ranging from technical grade mineral oil, used to lubricate engines and equipment, to cosmetics grade mineral oil, which has undergone purification. Contaminants that are not removed in the purification of mineral oil have been shown to clog pores; however, Gadberry notes that most manufacturers of cosmetics purify their mineral oil. Further, if patients use leave-in products containing mineral oil and comedogenic ingredients, the occlusive mineral oil would trap the comedogenic ingredients in the skin, resulting in more rapidly clogged pores.
As a result, should I use products containing mineral oil?
In a moisturizer, mineral oil appears to have high moisturizing ability combined with low irritation rates and a low price tag. However, care needs to be taken not to use a mineral oil-based moisturizer in conjunction with any products containing comedogenic (pore-clogging) ingredients, as the mineral oil would tend to trap the pore-clogging ingredients into the skin. For this reason, mineral oil should also not be used in leave-on treatments containing comedogenic (pore-clogging) ingredients. However, as long as care is taken to exclude comedogenic (pore-clogging) ingredients from the skin care regime, based on the science, mineral oil makes an inexpensive moisturizer that will hydrate your skin. Don’t expect the results of niacinamide; just expect hydration from mineral oil. (For this reason, rating for Johnson’s 24 Hour Moisturizer: 6/10, will hydrate your skin, but don’t expect anything else!)
All in all, a solid hydrating ingredient (much better than I previously thought!), just don’t expect anything but hydration, and be careful of what you use in conjunction with it.
Ingredients in Johnson’s 24 Hour Moisturizer
Water, Mineral Oil, Glycerin, Carbomer, Phenoxyethanol, Ceteareth 6, Methylparaben, Sodium Citrate, Fragrance, Stearyl Alcohol, Sodium Hydroxide, Citric Acid, Ethylparaben, Propylparaben, Glyceryl Oleate, Squalane
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December 21st, 2007
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Commentary, Quick Questions, Spotlight On... |
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According to Dr. Kenneth Beer, a dermatologist in Palm Beach, FL, for the December 2007 Glamour: “The complete benefit of skin creams won’t be visible until after a full cycle of skin-cell turnover to take place, at least a month.” He adds that sun and smoke interferes with the results you get, so avoid the sun and cigarette smoking (bad for the skin, even in moderation) at all costs.
With that said, give your next skin care cream a full month before you decide it is (or isn’t) working!
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December 20th, 2007
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In a since-revised October 28, 2007 blog post, I erroneously attacked the form of vitamin C known as ascorbyl glucoside, due to the fact that there was little established research on the ingredient. However, luckily for me, I was recently contacted by the North American Cosmetic Ingredient Sales and Technical Support Representative for Hayashibara International, the manufacturer of ascorbyl glucoside since 1990, who provided me with a plethora of the company’s research on the ingredient. Again, my apologies to the company. It may also be noted that all of the research cited below is from Hayashibara International, unless cited otherwise.
What is ascorbyl glucoside?
Ascorbyl glucoside has a structure in which the C2-hydroxyl group of L-ascorbic acid is masked with glucose. Once selectively permeated through the skin, ascorbyl glucoside is broken down into L-ascorbic acid and glucose by the enzyme alpha-glucosidase. Because ascorbyl glucoside is broken down into L-ascorbic acid, it has the same functions as L-ascorbic acid: exhibiting high antioxidant activity, acting as a coenzyme for enzymes involved in collagen synthesis (namely prolyl and lysyl hydroxylase), and inhibiting the synthesis of melanin. Although Hayashibara International maintains that this breakdown process leaves a high concentration of vitamin C in the skin, a competitor maintains that ascorbyl glucoside use maintains vitamin C at only a low level. Clearly, more independent, non-company affiliated research involving ascorbyl glucoside needs to be done!
So what are the benefits of using products with ascorbyl glucoside as opposed to the usual vitamin C found in skin care formulations (L-ascorbic acid)?
Ascorbyl glucoside has greater stability than L-ascorbic acid, which tends to break down in heat, light, in the presence of oxygen, and in certain pH levels (hence why your vitamin C cream turns dark yellow or brown after a few uses). According to the research by Hayashibara International, ascorbyl glucoside has excellent stability in heat, light, and in the presence of oxygen and metal ions when compared to other forms of vitamin C. This means, according to Hayashibara International researchers, that ascorbyl glucoside lasts over twice as long as other forms of vitamin C, and thereby delivers the effects of vitamin C to the skin for a longer period of time.
In what products is ascorbyl glucoside found?
Ascorbyl glucoside is found in a multitude of products, including:
*Clarins Intensive Age Control Brightening Program (pictured above; $145.00, Amazon.com). Features ascorbyl glucoside in a fairly high concentration (based on the ingredients list) to brighten the skin, reduce the appearance of dark spots (probably not as well as hydroquinone, but still…), and to provide antioxidant protection.
*Garnier Nutritioniste Skin Renew Daily Regenerating Serum ($12.63, Amazon.com). Features ascorbyl glucoside, magnesium, and lycopene. The lycopene is the reason I do not like this product; for more information, please visit my review of this product.
*Neutrogena Moisture Shine SPF 20 ($7.29, Walgreens.com). A moisturizing lip balm featuring ascorbyl glucoside as a form of vitamin C together with vitamin E and SPF — I love it!
Are there any possible detriments to ascorbyl glucoside?
One foreseeable detriment is the presence of additional glucose in the skin. After alpha-glucosidase breaks ascorbyl glucoside into L-ascorbic acid and glucose, does the glucose contribute to the formation of advanced glycation endproducts (which can age/harden collagen) via the Maillard pathway? Or does something else happen to the glucose entirely? Based on current research, it is impossible to tell if ascorbyl glucoside contributes to the overall concentration of sugars that feed into the Maillard pathway in the skin.
The other foreseeable detriment is that ascorbyl glucoside’s concentration is not listed on the product, unlike some products with L-ascorbic acid, which state that they are 5%, 10%, or 15% L-ascorbic acid. One may argue that ascorbyl glucoside is more stable than L-ascorbic acid, so a higher concentration of L-ascorbic acid does not dictate higher potency than a lower concentration of ascorbyl glucoside. Still, there is hope for labeling with concentrations of ascorbyl glucoside in the future, with this study by Lin et. al. suggesting that high-performance liquid chromatography with on-line microdialysis sampling can be used to determine the concentration of ascorbyl glucoside in skin care formulations.
So, overall, is ascorbyl glucoside a beneficial skin care ingredient?
Based on current research by the manufacturer of ascorbyl glucoside, yes, ascorbyl glucoside does seem beneficial, due to the fact that it provides the benefits of vitamin C to the skin in a more stable (and hence longer-lasting) formulation. In the meantime, it would be interesting if researchers investigate the effects of additional glucose from ascorbyl glucoside in the skin, as it could possibly be detrimental. However, based on what is currently known, ascorbyl glucoside seems like an excellent way to get the benefits of vitamin C without having to worry as much about your product breaking down in the air, heat, or light. I will give more information if and when it surfaces on this exciting ingredient!
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December 19th, 2007
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Antioxidant Treatments, Spotlight On... |
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Although you may not be thinking of sunscreen in the winter months, think again: damaging UV rays can bounce off of the opaque snow, right onto your face. Furthermore, about fifty percent of UV rays penetrate through car and home windows, contributing to the majority of cumulative sun damage year-round. With that said, you really do need to be wearing sunscreen every single day, even in the winter. Is L’Oréal Revitalift UV with Mexoryl SX SPF 15 ($18.85, SaleAwaySavings.com) worth your money? Or are there other sunscreens on the market that provide better UVA and/or UVB protection?
What is Mexoryl?
Mexoryl (ecamsule) is an ingredient in chemical sunscreens that has been available in Europe for many years, and which came to the U.S. only this year. Mexoryl, available as SX (water soluble) and XL (lipid soluble), is very effective for two reasons: one, it is very stable [as a benzylidene camphor derivative], and two, because it absorbs light at a broader range of UVA wavelengths than many other sunscreens. After absorbing light from this broad spectrum, ecamsule undergoes photoisomerization, followed by photoexcitation, which means that it causes for UV light to be released as thermal energy rather than allowing for UV light to be absorbed into the skin and cause damage, as most chemical sunscreens do. Additionally, Mexoryl SX and Mexoryl XL are even more stable than each alone; however, Mexoryl XL is often too oily for some with sensitive skin, and so only Mexoryl SX is featured in L’Oréal products sold in the U.S.
Until FDA approval in 2006, Mexoryl was not available in the U.S., and many who knew of their high PD and PPD ratings from Europe ordered products (like LaRoche Posay Anthelios SX, $29.00, Dermstore.com) with Mexoryl SX and/or Mexoryl XL online. However, the coveted ingredient is today available in the U.S. in sunscreens by L’Oreal, such as L’Oréal Revitalift UV with Mexoryl SX SPF 15.
Does Mexoryl feature the best UVA protection on the market at this time?
At this time, products in the U.S. do not quantify the amount of UVA protection in a product, so this is hard to determine from published data. However, products in the U.S. must feature UVA protection on a 1-to-4-star scale by 2009. Already in Europe, the IPD (immediate pigment darkening assay) and the PFA or PPD (persistent pigment darkening assay) are used to assess UVA protection.
In a 2004 study by Moyal, it was demonstrated that products containing Mexoryl (chemical name Ecamsule) had higher UVA protection than sunscreens without Mexoryl. However, these Mexoryl-containing sunscreens were not compared to Neutrogena sunscreens with Helioplex. Helioplex is a stabilized, patented combination of oxybenzone and avobenzone that has been demonstrated in clinical tests to provide longer-lasting UVA protection than most other sunscreens. In comparing mexoryl and Helioplex, Neutrogena Ultra Sheer SPF 70 has been reported to have a PFA value of 23.3 or 26.5, interestingly higher than the reported PFA value of 10 for Mexoryl SX and XL in combination. Based on the current reported PFA data, it seems that Neutrogena Ultra Sheer SPF 70 provides better UVA protection than Mexoryl; however, these numbers are only speculative, as they have not been directly compared in any known independent published study.
Is SPF 15 enough UVB protection?
A 1997 study by Stokes et al. cited by Baumann in Cosmetic Dermatology, it was found that most users achieve a mean SPF of between 20 and 50 percent of that expected from the product label, because they do not apply the sunscreen as thickly as in laboratory conditions (2 mg/square centimeter of skin, or 30 mL of sunscreen over the average human body). Baumann instructs patients to estimate their UVB protection by multiplying the SPF by one-third; therefore, the L’Oréal product contains only an SPF of about 5 for the average user.
One caveat about sunscreen…
Most dermatologists recommend stimulating synthesis of adequate levels of vitamin D with ten to fifteen minutes of sunscreen-free sun exposure at least two times per week to the face, arms, hands, or back without sunscreen, and taking vitamin D supplements, particularly in the winter months in colder areas. Vitamin D is important for promoting calcium absorption, and works in concert with a number of other vitamins, minerals, and hormones to promote bone mineralization. Insufficient levels of vitamin D have been associated with rickets in children and osteomalacia in adults. As such, wear sunscreen daily, but sneak in 10-15 minutes of sunscreen-free exposure between 9 AM and 4 PM at least twice a week. More is available about sunscreens in this article from October, 2007.
Two of my favorite sunscreens are:
1. La Roche-Posay Anthelios Fluide Extreme ($45.00, Skincarelab.com), which contains both Mexoryl SX and Mexoryl XL for extra-stable UVA protection and an SPF of 50+ for ultra UVB protection (50+ is the highest SPF rating in European countries!). Unfortunately, Mexoryl XL is not good for those with oily skin, so beware.
2. Neutrogena Ultra Sheer Dry Touch Sunblock SPF 70 ($18.49 for two, Amazon.com), which contains Helioplex, i.e., a stabilized combination of avobenzone and oxybenzone for excellent UVA protection, and an SPF of 70 for excellent UVB protection. It is also quite a bit cheaper than the La Roche-Posay Anthelios Fluide Extreme product.
As such, don’t forget to wear your sunscreen every day, even during the holiday season (!). Furthermore, consider a product with Mexoryl SX and XL first if you do not have oily skin (it is more stable), or a product with Mexoryl SX and a higher SPF (for added UVB protection). Happy holidays!
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December 18th, 2007
Posted by
futurederm |
Sunblocks, Worst Products |
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Neutrogena Anti Oxidant Age Reverse Eye Cream ($16.95, Amazon.com) claims to neutralize skin-damaging free radicals, crow’s feet, puffiness, and dark circles. Yet how effective do the ingredients indicate the eye cream really is in treating these signs of aging?
What are the antioxidant sources in this product?
Neutrogena Anti Oxidant Age Reverse Eye Cream contains three antioxidant sources: Soybean Extract, Feverfew Extract (Chrysantemum Parthenium), and Vitamin E (in the form of alpha-tocopherol). Interestingly enough, Johnson and Johnson manufactures this product and has the rights to “active soy” (soy without estrogenic compounds) and feverfew extract without parthenolide (an irritant). As such, it is an excellent source of safe forms of soybean extract and feverfew extract. Furthermore, vitamin E as alpha tocopherol has been shown to have an environmental protection factor (EPF) of 80 on a scale of up to 100, and as such is considered to be a potent antioxidant.
In comparison to other skin care formulations, how potent are the antioxidants in this product?
In comparison to other antioxidant formulations, unfortunately, the product does not contain two or more “network antioxidants,” which synergistically enhance the power of one another (source: Dr. Leslie Baumann). These “network antioxidants” are vitamins C and E, glutathione, lipoic acid, and coenzyme Q10. (One source containing two or more “network antioxidants” is Skinceuticals C E Ferulic serum.) In addition, no single antioxidant on the market has the antioxidant potency of CoffeeBerry (which is not found in this product) as measured by Oxygen Radical Absorbance Capacity Score (ORAC) — a method developed by the U.S. Department of Agriculture as the standard to measure the antioxidant capacity of natural substances.
However, despite the lack of “network antioxidants” or coffee berry, Neutrogena Anti-Oxidant Age Reverse has been found in studies by Johnson & Johnson to neutralize 99% of free radicals in the skin. This is highly impressive, as an established, more expensive product like Esteé Lauder Advanced Night Repair claims to neutralize only “up to 90% of free radicals” in studies released by Esteé Lauder Companies. Therefore, Neutrogena Anti-Oxidant Age Reverse seems to be highly effective in neutralizing free radicals. Hopefully, studies in the future will compare the efficacy of this product directly to those containing synergistic network antioxidants and supreme antioxidants like coffee berry.
Can the product improve my crow’s feet like products with retinoids or glycolic acid?
Antioxidants protect against future damage by neutralizing free radicals within the skin that can damage DNA. However, of soybean extract, feverfew extract and vitamin E, soybean extract has been noted in this study in the British Journal of Dermatology (amongst others) to stimulate the production of collagen and hyaluronic acid in human fibroblasts. Over time, this will increase the firmness, elasticity, and suppleness of skin.
However, no independent scientific research has demonstrated that topical application of the ingredients in Neutrogena Anti Oxidant Age Reverse Eye Cream can significantly improve crow’s feet. This is unlike retinoids and L-ascorbic acid (vitamin C), which have been reported in this 2003 study in the Journal of Plastic and Reconstructive Surgery to improve the appearance of crow’s feet. (One eye cream with retinol is RoC Retinol Correxion Eye Cream.) Use of glycolic acid has also been shown in this 2007 study in the Journal of Plastic and Reconstructive Surgery to improve the appearance of crow’s feet over vitamin-based formulas or placebo, although both retinoids and glycolic acid tend to make the skin photosensitive, so a broad-based sunscreen must be used everyday with either ingredient.
The dearth of research on soybean and feverfew extract and crow’s feet may be due to the fact that they are relatively new to skin care formulations; if information surfaces to indicate they are as effective in treating existing wrinkles as retinoids, vitamin C (L-ascorbic acid) or glycolic acid, I will certainly report it and correct this article!
Can this product really help puffy eyes?
Puffy eyes are normally caused by fluid retention, stress, allergies, and/or hormonal changes. Skin care formulations that claim to take care of puffy eyes often include caffeine to shrink the blood vessels, reducing the amount of fluid in the area. However, based on the ingredients list, Neutrogena Anti Oxidant Age Reverse Eye Cream does not contain caffeine, so puffy eyes caused by fluid retention would not be helped by this product. [A complete article on puffy eyes is available here.]
On the other hand, if puffy eyes are the result of stress and/or certain hormonal changes, the product contains many soothing and anti-irritating ingredients (shea butter, dimethicone, feverfew extract without parthenolide), that calm the skin. Puffiness may therefore be reduced.
Can this product improve the appearance of dark circles?
It depends on the cause of dark circles. According to Dr. Leslie Baumann in her text Cosmetic Dermatology, the complete origin of dark circles is not entirely known, but it may be related to vasodilation of the blood vessels, making them appear more visible through the skin, or excess melanin production. If dark circles are caused by hyperpigmentation, it has been reported in this 2000 study in the journal Dermatology that products containing soybean extract have been shown to lighten hyperpigmentation after twice-daily application for two weeks. If dark circles are caused by vasodilation, applying cool, moistened tea bags under the eyes for ten minutes should ease their appearance.
Cosmetically, the product contains mica and silica to reflect the light away from dark circles. However, these ingredients do nothing to actually treat dark circles.
How does this product compare to Neutrogena Anti Oxidant Age Reverse Facial Moisturizer?
Based on ingredients alone, the products are similar; a review about the facial moisturizer is available here from November 30, 2007. However, unfortunately, unlike the daily facial cream, the eye cream does not contain a sunscreen. Although care needs to be taken when applying sunscreen in the area, the undereye area is thin and delicate and needs to be protected from the sun. One eye cream with SPF and vitamin C (an antioxidant) is Murad Essential C Eye Cream SPF 15 ($65.00, Sephora.com).
Overall opinions?
Based on research of the ingredients, the product would be excellent at soothing/calming the skin and moisturizing the skin. I would say the eye cream is also excellent at preventing future damage (with antioxidants soybean extract, feverfew extract, and vitamin E), but it does not contain a broad-spectrum UVA/UVB sunscreen, which is instrumental in preventing future damage.
Depending on the source of puffy eyes and dark circles, the product may help (with soybean extract). However, based on the published research that is available, the ingredients in this product are not heavy-hitters against existing wrinkles in comparison to reigning champions like retinoids, vitamin C and glycolic acid. As such, a great eye cream, but wear a sunscreen over it, and don’t expect it to get rid of your existing wrinkles anytime soon. Overall rating: 7.5/10 (like the day lotion, but -1 for no sunscreen)
Ingredients (courtesy Amazon.com):
Water, Glycerin, Butyrospermum Parkii (Shea Butter), Soybean (Glycine Soja) Seed Extract, Dimethicone, Phenyl Trimethicone, Cetearyl Alcohol, Cetearyl Glucoside, Xylitylglucoside, Anhydroxylitol, Xylitol, Feverfew (Chrysanthemum Parthenium) Extract, Silica, Tocopherol, Dipotassium Glycyrrhizate, 1,2 Hexanediol, Caprylyl Glycol, Methylisothiazolinone, Arachidyl Alcohol, Behenyl Alcohol, Arachidyl Glucoside, Steareth-2, Steareth-21, Ethylene Acrylic Acid Copolymer, Titanium Dioxide, Mica, Polymethyl Methacrylate, Aluminum Starch Octenylsuccinate, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Acrylamide/Ammonium Acrylate Copolymer, Polyisobutene, Polysorbate 20, Methylparaben, Propylparaben, Triethanolamine, Fragrance.
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December 16th, 2007
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Antioxidant Treatments, Best Products |
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Soy extract first became popular in skin care in 2004, when Johnson and Johnson purchased rights to the ingredient from the AMBI brand. Since that time, many companies have jumped on the soy extract bandwagon, adding the ingredient to their formulations. However, is the ingredient safe and effective?
What are some benefits to using skin care products with soy extract?
According to Johnson & Johnson, soy contains small proteins, soybean trypsin inhibitor (STI), Bowman-Birk inhibitor (BBI), amino acids, essential fatty acids, isoflavones, lecithins, mono- and polyunsaturated fatty acids, saponins, phytosterols, phytic acid, minerals and vitamins. According to Paula Begoun, author of Don’t Go to the Cosmetics Counter Without Me, one isoflavone contained in soy is genistein, which has been shown in independent research studies to exhibit both anti-inflammatory and antioxidant properties, and to stimulate the production of collagen and hyaluronic acid in human fibroblasts cultured in vitro, which together increase the firmness, elasticity, and suppleness of skin. These findings have been affirmed in this 2005 study in the journal of Photochemistry and Photobiology, which further reported that use of soy extract twice daily for two weeks reduced the number of hair follicles (dermal papillae) on the skin. Finally, it has been reported in this 2000 study in the journal Dermatology that human trials demonstrate lightening of hyperpigmentation after use of soybean extract for two weeks.
Are there any problems with using soy extract in skin care products?
Many women experience a darkening of the skin during pregnancy (”the mask of pregnancy”) that is caused by overactive melanin production. According to BabyCenter.com, some soy-containing products have estrogenic effects, which can make this form of melasma (darkening of the skin) worse. However, products by Johnson & Johnson brands (i.e., Neutrogena, Aveeno, amongst others) contain a form of soy known as “active soy,” in which the estrogenic compounds have been extracted, so these should not exacerbate melasma like other products.
Does soy in food help improve the skin?
Although the research is limited, this 2004 study from the Journal of the American College of Nutrition demonstrates that mice who were fed soy extract containing isoflavones and subjected to UV light had increased collagen production and decreased matrix metalloproteinase formation (i.e., collagen-digesting enzyme formation) than mice who were not fed soy extract and subjected to UV light. This indicates that soy may have protective anti-aging effects.
Soy is found in foods like (surprise!) soy milk, soy flour, soy sauce and tofu. However, estrogenic compounds have not been extracted from soy. For instance, it was reported in this 2002 study in Nutrition and Cancer that male rats consuming soy isoflavones had lowered testosterone levels. Soy is often considered to be a health food because anti-carcinogenic and cholesterol-lowering effects have been speculated. However, several reports speculate that soy consumption may also lead to disrupted thyroid function. On the contrary, this study in the Journal of Endocrinology and Metabolism reported that the changes in hormonal levels, including thyroid hormone, from soy consumption are modest at best.
Overall, how does soy measure up against other skin care ingredients?
Soy extract with isoflavones acts as an antioxidant that fights hyperpigmentation, decreases hair production, increases collagen and hyaluronic acid production, and has low rates of contact dermal sensitization (irritation) in comparison with 0.15% retinol formulations.
In comparison with retinoids, which do all of the above except decreasing hair production, soy extract has less substantiative research backing its effects, and cannot erase wrinkles and fine lines like retinoids. However, if skin sensitivity or hair production on the face is a problem, soy extract may be desired anyway.
In comparison with niacinamide, which has been found to reduce fine lines and wrinkles, hyperpigmented spots, red blotchiness, and skin sallowness (yellowing), and to increase skin’s elasticity, soy extract again does not erase fine lines and wrinkles like niacinamide can. However, if hair production on the face is a problem, soy extract may be desired instead anyway.
As a result, soy extract overall is an excellent ingredient, particularly if you want to reduce the number of hair follicles on your face. However, due to the estrogenic compounds found in many forms of soy extract, the “active soy” found in Johnson and Johnson products (like Aveeno Active Naturals Ultra Calming Lotion with SPF 15, $17.99, Amazon.com) is probably your best bet. Happy shopping!
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December 15th, 2007
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futurederm |
Antioxidant Treatments, Hyperpigmentation Treatments, Spotlight On... |
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