Are True ‘Anti-Ageing’ Skin Products Just Around The Corner?

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Cosmetic skin products have a reputation for dubious claims concerning their effectiveness. This reputation is, in many cases, well founded. Most cosmetic products do not fall under the strict regulations for pharmaceutical drugs, in which new compounds must demonstrate safety and efficacy in rigorously controlled clinical trials before they make it onto the shelf. As a result, marketing phrases like ‘clinically proven’ are essentially meaningless in relation to cosmetic products without knowing what kind of studies were done.

Nevertheless, there is massive demand for products that reduce the appearance of skin ageing, and so the cosmetic industry has become very large, despite having relatively little substance. But this could all change as the techniques available to target the biology of skin ageing, rather than the appearance of ageing, improve. This isn’t a vanity project – the skin is the body’s largest organ and has many vital functions, providing a physical barrier against infection, regulating body temperature and allowing us to sense the outside world through touch. Just like all other organs, the skin becomes less able to fulfil these functions with age and grows thinner, more fragile and slower to heal. Slowing down skin ageing is therefore a valuable medical goal and one that could be within our grasp. In this review, researchers discuss the merits of targeting skin ageing and the emerging technologies that are being used to do so.

Why Target Skin Ageing?

While the impact of skin ageing on human health might not be as significant as ageing of some other organs like the heart or brain, focusing on skin ageing has some unique advantages. Firstly, we know that skin ageing is quite modifiable due to the observation of photoageing (the acceleration of skin ageing by exposure to ultraviolet radiation). It is well established that UV radiation causes various forms of damage (DNA damage, collagen and elastin breakdown and so on) that accelerate both the cosmetic and functional ageing of the skin. Therefore, there is reason to think that targeting these same forms of damage could stop or reverse skin ageing.

There is also another advantage in that the skin is a highly accessible organ – that is to say that it is much easier to deliver a treatment to the skin in a non-invasive way compared to most other organs. It also opens up the opportunity for forms of treatment that would be impractical to deliver to other organs, such as some forms of radiation that don’t penetrate deeper than the skin. The accessibility of the skin also makes it easier to monitor the biological effects of any treatment. This all makes the skin a attractive ‘testing ground’ to demonstrate that a treatment targeting the fundamental biology of ageing can be successful. So what are the treatments in question?

Partial Epigenetic Reprogramming

One strategy with the potential to rejuvenate ageing skin is partial epigenetic reprogramming. Epigenetics refers to how and which parts of the DNA in each cell are read, which is determined by how the DNA is packaged. For example, a skin cell contains the same DNA as a white blood cell, but looks and behaves very differently because not every gene is being expressed or ‘switched on’. With advancing age, damage to the DNA can cause genes that should be inactive to be switched on and vice-versa in a process called epigenetic modification. A skin cell might start over-producing or under-producing key proteins that are only supposed to be produced in another cell type, and over time, this degrades the function of the cell.

Partial epigenetic reprogramming is a technique that aims to reverse the epigenetic modifications associated with the ageing process, but not those that are important for maintaining a cell’s ‘identity’ (as a skin cell, for example), hence the ‘partial’ nature of the reprogramming. This is done by boosting the genetic expression of a group of proteins called reprogramming factors. This strategy is being trialled in humans for the first time this year for the treatment of specific age-related eye diseases. However, such a technique could be tested locally in the skin, for example by applying a topical treatment containing RNA that encodes reprogramming factors.

Energy-Based Devices

Energy-Based Devices (EBDs) are a collection of devices that use electromagnetic radiation (including visible light) to produce a biological response. Photobiomodulation is the application of visible light (usually near-infrared light) that has been shown to enhance the activity of enzymes involved in supplying cellular energy, suppress inflammation and activate genes involved in cellular repair. Research also suggests that lasers can, by delivering energy to specific layers of the skin, cause ‘microdamage’ that then activates beneficial cellular repair pathways, promotes blood vessel development and enhances collagen production. Some of these changes seem to be the result of epigenetic changes, so while it is currently uncertain whether EBDs are practical for delaying skin ageing in humans, this suggests that partial reprogramming may not be the only way to shift the skin’s epigenetic profile towards a more ‘youthful’ version.

Conventional Treatments

In addition to the more ‘outlandish’ strategies above, the more conventional approach of delivering bioactive molecules to the skin (topically, via injection, or orally) could still be valuable. These compounds are mostly aimed at stimulating fibroblasts (the cells responsible for laying down collagen and elastin), some by targeting the fibroblasts directly, others by targeting inflammation and oxidative stress (which, when chronic, leads to fibroblast dysfunction).

Some of these compounds like resveratrol (a plant-derived with antioxidant, anti-inflammatory and collagen production-stimulating properties) have already make their way into skin products – possibly a little prematurely, as the clinical evidence for their effectiveness is generally quite limited, with larger, longer-lasting trials necessary.

The Skin Microbiome and the Brain-Skin Axis

As you probably know, the skin, just like the gut, is home to many different species of bacteria, but their influence on skin health (and in turn, our ability to target skin bacteria in order to influence skin health) has been less well researched compared to that of the gut microbiome. Just like in the gut, bacteria on the skin produce short-chain fatty acids and other molecules with beneficial effects on skin function and repair, while reduced microbial diversity has been found to correlate with skin ageing. This means it may be possible to improve skin health by either modifying the bacteria on the skin, or by identifying and delivering the bacterial products that are identified as being beneficial.

Another similarity shared with the gut is that the central nervous system can directly affect skin health. Chronic stress is well known to contribute to skin conditions, and this happens not just via the release of stress hormones, but also due to the effects of nerve fibres that directly connect the brain to the skin. Together, these systems influence blood flow, inflammation, repair and other processes important for skin health. There is therefore another opportunity to target skin health by influencing this brain-skin axis.

Practical Implications

Though promising, most of the above strategies for skin rejuvenation are at best in the earlier stages of clinical testing. So, to answer the titular question: no, skin anti-ageing probably isn’t ‘just around the corner’, but there are multiple interesting paths forward. In the meantime, there are a few ways we may be able to apply this knowledge in everyday life to delay skin ageing and maintain skin health:

• Avoid skin exposure to sources of DNA damage. The most obvious and by far the most consequential of these is exposure to ultraviolet light, but pollutants and chemicals like those present in cigarette smoke are also worthy of consideration. Some practices such as calorie restriction (a sharp reduction in calorie intake without causing malnutrition) and consumption of ‘anti-inflammatory diets’ (such as the Mediterranean diet) may also reduce age-related epigenetic alterations.
• You may consider the use of commercially available energy-based devices. Be warned, however, that many such devices differ from those that have been used in scientific studies, often being less powerful or using different wavelengths of light. While unlikely to do any harm, these devices are still largely unproven, so make sure you understand this before parting with your money.
• Consume a diet rich in plants, as many of the compounds under investigation for their effects on skin health are obtainable from a plant-based diet.
• Look after the skin microbiome by avoiding harsh soaps, antibacterial and alcohol-based products. There is also some evidence that spending more time outdoors increases skin microbial diversity.
• Look after your neurological health by limiting exposure to stress, learning how to cope with stress and ensuring you get sufficient good quality sleep.