How does our skin age and how effective are anti-aging products? Does the advertising live up to its promise? Tatjana Pavicic, MD, an expert in this field, provides information and an overview of the evidence base in this interview.
Dr. Pavicic, which intrinsic and extrinsic factors and processes are responsible for skin aging? In which areas is it thus possible to influence by lifestyle alone, and in which is it not?
Dr. Pavicic:
As the term implies, the intrinsic or genetic aging process is hard to influence and difficult to observe on its own, since most parts of our skin are exposed to environmental factors. A good 90% of our visible skin aging is therefore due to extrinsic factors. In some cases, “purely” intrinsic skin aging can probably still be observed most readily on the buttocks (lack of sun exposure), which is why corresponding studies are then often limited to this.
Since the intrinsic skin aging process is thus superimposed on extrinsic skin aging to varying degrees in different parts of the body and the processes run in parallel, the two must be considered together. The focus is on the so-called free oxygen radicals, which drive the aging process of the skin (but of course also of other organs and ultimately of the entire organism). They lead to an increase in matrix metalloproteinases (especially MMP1 and 2) and thus to increased degradation and decreased build-up of collagen and elastic fibers. Environmental and lifestyle-related, i.e. extrinsic, factors that contribute to a specific extent are UV exposure (especially UV-B) and smoking. In addition, there are environmental toxins such as air pollution as well as alcohol consumption, certain sleeping and eating habits, and stress. The result of a complex interplay between proinflammatory genetic, environmental, and lifestyle factors is now also described by the concept of “inflammaging.”
What are the clinical characteristics of aged skin (volume, elasticity, tone, moisture, pigmentation, wrinkling, etc.)?
Of course, the texture of the skin differs depending on the localization and intrinsic and extrinsic skin aging overlap, as mentioned. In simpler terms, intrinsic skin aging causes the skin to become thinner, cigarette paper-like, whitish with fine wrinkles and even pigmentation (no large pigment spots). It is not rough, but rather fine or fragile. Extrinsic skin aging, on the other hand, tends to cause coarse wrinkles and strong pigment differences (age spots, melasma). The skin is rough, the stratum corneum is thickened, histologically the retele ridges are no longer nicely formed. The skin is more vulnerable and heals worse. As the network of collagen and elastic fibers wears down and the hyaluronic acid content in the skin also decreases, it is more difficult to store moisture. The skin loses elasticity and is less plump. In addition, in both cases there is reduced sebaceous and sweat gland activity, which can further dry out the skin.
How to clean and care for such skin?
Although I also have older patients whose skin is still relatively oily (so this needs to be clarified beforehand with a dermatologist or expert pharmacist), aging skin normally needs more moisture and lipids. Therefore, rich, i.e. lipid-rich emulsions with the addition of water-binding components such as glycerin, urea, etc. are usually recommended for skin care. In general, gentle products should be used when cleansing and caring for aging skin (mild surfactants, etc.) because, as mentioned, aging skin is more vulnerable and heals less quickly. Preservatives and fragrances should be avoided.
Depending on the region of the body, the cleansing and care process is somewhat different: the face is usually more exposed to UV radiation, which promotes solar elastosis. Older people with a thickened stratum corneum (a real “armor” on the cheeks, etc.) primarily often do not benefit at all from lipid-rich creams, because the product does not penetrate properly. Accordingly, for typical sun-aged rough skin on the face, cleansing in the sense of exfoliation with fruit acid, lactic acid, salicylic acid (or a mixture of these components in low concentration, depending on the skin type) or a cleansing mask/gel may also be included. The dead skin cells are thus first removed so that anything at all can penetrate. For very dry or sensitive skin, where exfoliation is not indicated, rather mild cleansing milk or lotion is used. The residues of the cleaning agents must be removed afterwards. the natural pH of the skin must be restored. Only then do you add care products with water-binding components, lipids, etc., according to the skin type.
Cleansing of the rest of the body with atrophic, dry skin takes place in the form of mild moisturizing shower/bath oils (and then not every day). Normal soaps should be avoided. As mentioned above, moisturizing emulsions with glycerin, urea, phytosterols, panthenol, jojoba, etc. are used for aftercare.
In addition to cosmetics, which are limited to the area of cleansing and care, there is the broad field of anti-aging products: The industry is quick to come up with catchy phrases and products in the field of antioxidants, which are supposed to protect the body from free radicals that cause oxidative stress. Terms such as “oxidative stress”, “antioxidants”, “free radicals” have thus entered common parlance. They are expert in assessing the evidence of dermocosmetics and have participated in the preparation of various guidelines.
What do you think, how (and how well) do so-called anti-aging products, i.e. antioxidants/cell regulators like retinol, vitamin C/E, peptides etc. work?
For some agents, there are placebo-controlled, double-blind in vivo studies in sufficiently large study populations – the gold standard of evidence. This is the only way to ensure that the effects, e.g. on wrinkle formation, are really due to the test substances and not just from the above-mentioned moisturizing care with glycerin, etc. These category IA active ingredients include antioxidants (radical scavengers) such as vitamin C or alpha lipoic acid, but also cell regulators such as the “classic” vitamin A (retinol) and peptides (hexapeptides, pentapeptides, tetrapeptides, tripeptides, dipeptides). There are a lot of studies on the latter two, they are among the most potent anti-aging agents. Retinol is especially recommended for skin that is not too dry. If this is the case, peptides are a viable alternative; they have good penetration potential but hardly any irritation potential.
In everyday life, even with these well-studied anti-aging dermocosmetics, the problem arises that, according to INCI nomenclature, the composition of the contents of such products must be stated in descending order of quantity, but without exact concentration values. So we don’t always know whether the products we buy actually contain the amounts of the active ingredient that have been successfully tested in studies. In the case of vitamin A, the legal maximum amount in over-the-counter dermocosmetics also varies greatly from country to country. This reveals a fundamental dilemma for the cosmetics industry: although an anti-aging product is intended to smooth wrinkles, it must not – if it is to be classified as over-the-counter and not subjected to the complex approval procedure for pharmaceuticals – contain active ingredients that are too potent, i.e. it must be largely “harmless”. In addition, stability is also a potential pitfall in everyday practice: for example, vitamin C, as the most widely used and best-tested antioxidant, is (naturally) easily oxidized. If it stands around in the bathroom for too long or is not stabilized in appropriate bases, after three weeks there will hardly be any positive effect, and possibly even an irritating effect due to the degradation products.
For vitamin E and niacinamide (vitamin B3), although there are no studies with a placebo-controlled, double-blind design, there is evidence of efficacy in in vivo studies with objectifiable methods, which corresponds to category IB according to our guideline. The combination of antioxidant vitamins E and C in dermocosmetics is useful. Vitamin B3 is believed to be effective not only against wrinkles, but also against unwanted pigmentation.
Coenzyme Q10 also has antioxidant potential. The problem at the moment is that when applied externally, it arrives in the skin in insufficient concentration. Currently, it is listed under category II (in vitro studies).
Low-molecular hyaluronic acid should preferably be combined with high-molecular hyaluronic acid in dermocosmetics – the former goes a little deeper and has an actual anti-aging effect (category IA), the latter causes a moisturizing film on top of the skin (due to its ability to bind large amounts of water).
How recommendable are herbal products (phytotherapy in connection with aging skin)?
With age, women experience changes in skin physiology due to estrogen deficiency (lowered hormone levels during menopause lead to dry skin). In postmenopausal women, therefore, one likes to use the so-called phytohormones (e.g. isoflavones such as genestein and daidzein), for which there are in vivo studies (category IB). They are of plant origin, but have a chemical structural similarity to “real” hormones. However, it must be honestly said that most patients have already damaged their skin before menopause due to the other external influencing factors mentioned above to such an extent that the effect of the menopause is probably no longer too significant. Direct efficacy comparisons with retinol do not exist.
In addition to phytohormones, antioxidant plant polyphenols (category II) such as epicatechin, which is found in green tea extracts, and numerous others are used in anti-aging creams.
Let’s leave the topical approaches and come to the topic of nutrition and skin aging. To what extent does nutrition exert an influence on skin (aging) and what do you think of dietary supplements, i.e. systemic anti-aging approaches?
As we have seen, topical anti-aging approaches with dermocosmetics can be quite effective and useful. Their use is usually gradual, i.e. first add antioxidants from the mid-20s/early 30s, then from around 40 years of age or earlier depending on skin type, and sun protection consistently since childhood. By the way, when it comes to sun protection, it’s not just the SPF, UVB and UVA filters, etc. that count – the skin type should also be factored into the product choice (for example, someone with oily skin won’t take a cream consistently, but will need a gel-based sunscreen).
With systemic anti-aging, on the other hand, I am more cautious and tend to rely on natural approaches, i.e. taking enough vitamins from natural sources such as fruits and vegetables, cooking fresh and varied meals, ensuring sufficient water intake etc. Food supplements are not really necessary in such a lifestyle. If the body absorbs substances poorly, e.g. in the case of intestinal diseases, etc., one can of course think about a substitution.
Which skin diseases and problems actually occur more frequently in old age?
On the body, in fact, dryness eczema (exsiccation eczema) is the most common. Dry skin and poorer healing ability are often accompanied by vein problems and thus open legs and ulcers. With urea, phytosterol, panthenol, etc., a great deal can be achieved here. When inflammation occurs, it is important for patients to seek medical attention quickly. The inflammatory process and thus the vicious circle of itching, scratching, further introduction of bacteria, superinfections, etc. must be interrupted early. Then, when eczema has healed, patients must continue to take good care of themselves and apply cream daily.
On the face, and especially on the “sun terraces” such as the forehead/ bald head or nose, one observes the cumulative damage done over a lifetime by external factors such as UV radiation – actinic keratosis, but also a wide variety of pigmentations, including. Lentigo maligna etc.
Interview: Andreas Grossmann
DERMATOLOGIE PRAXIS 2018; 28(4): 8-10
